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SubjectRe: [PATCH v2 2/3] Added Xilinx XDMA IP core driver
From
Hi Martin,

Glad to know that you are using XDMA IP in your product. And AMD/Xilinx
is actually working on adding XDMA support to linux kernel.  The other
kernel driver may use dmaengine APIs to transfer data through XDMA.

Please see the V3 patch series:

https://lore.kernel.org/lkml/1663631039-49732-1-git-send-email-lizhi.hou@amd.com/


Here is an example for using this V3 XDMA driver with Alveo accelerator
PCIe device driver:

https://github.com/houlz0507/XRT-1/blob/qdma-v1/src/runtime_src/core/pcie/driver/linux/xocl/subdev/xdma.c#L338


Currently, the V3 patch series does not support register user logic
interrupt yet. And you may refer this patch for it:

https://github.com/houlz0507/linux-xoclv2/commit/4f24f17862dbf527b7a32edf89559b7c732f1833


Could you convert your driver to use this?


Thanks,

Lizhi

On 9/19/22 11:55, tumic@gpxsee.org wrote:
> From: Martin Tůma <martin.tuma@digiteqautomotive.com>
>
> Added support for the Xilinx XDMA PCIe DMA IP core. The XDMA IP core is used in
> many FPGA PCIe card designs for DMA transfers between the PCIe card and the host
> system. This driver can be incorporated into any PCIe card (that contains
> the XDMA IP core) driver to initialize the XDMA HW and process DMA transfers.
>
> The driver is originally based on the code provided by Xilinx at
> https://github.com/Xilinx/dma_ip_drivers
>
> Signed-off-by: Martin Tůma <martin.tuma@digiteqautomotive.com>
> ---
> drivers/dma/Kconfig | 7 +
> drivers/dma/xilinx/Makefile | 1 +
> drivers/dma/xilinx/xilinx_xdma.c | 2042 ++++++++++++++++++++++++++++++
> include/linux/dma/xilinx_xdma.h | 44 +
> 4 files changed, 2094 insertions(+)
> create mode 100644 drivers/dma/xilinx/xilinx_xdma.c
> create mode 100644 include/linux/dma/xilinx_xdma.h
>
> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> index a06d2a7627aa..932086cd5962 100644
> --- a/drivers/dma/Kconfig
> +++ b/drivers/dma/Kconfig
> @@ -804,4 +804,11 @@ config DMATEST
> config DMA_ENGINE_RAID
> bool
>
> +config XILINX_XDMA
> + tristate "Xilinx XDMA Engine"
> + depends on PCI
> + select DMA_ENGINE
> + help
> + Enable support for Xilinx XDMA IP controller.
> +
> endif
> diff --git a/drivers/dma/xilinx/Makefile b/drivers/dma/xilinx/Makefile
> index 767bb45f641f..55e97686f8ea 100644
> --- a/drivers/dma/xilinx/Makefile
> +++ b/drivers/dma/xilinx/Makefile
> @@ -2,3 +2,4 @@
> obj-$(CONFIG_XILINX_DMA) += xilinx_dma.o
> obj-$(CONFIG_XILINX_ZYNQMP_DMA) += zynqmp_dma.o
> obj-$(CONFIG_XILINX_ZYNQMP_DPDMA) += xilinx_dpdma.o
> +obj-$(CONFIG_XILINX_XDMA) += xilinx_xdma.o
> diff --git a/drivers/dma/xilinx/xilinx_xdma.c b/drivers/dma/xilinx/xilinx_xdma.c
> new file mode 100644
> index 000000000000..9db637c25045
> --- /dev/null
> +++ b/drivers/dma/xilinx/xilinx_xdma.c
> @@ -0,0 +1,2042 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * This file is part of the Xilinx DMA IP Core driver for Linux
> + *
> + * Copyright (c) 2016-2021, Xilinx, Inc.
> + * Copyright (c) 2022, Digiteq Automotive s.r.o.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/string.h>
> +#include <linux/mm.h>
> +#include <linux/errno.h>
> +#include <linux/sched.h>
> +#include <linux/vmalloc.h>
> +#include <linux/pci.h>
> +#include <linux/dma/xilinx_xdma.h>
> +
> +
> +static unsigned int enable_credit_mp = 1;
> +module_param(enable_credit_mp, uint, 0644);
> +MODULE_PARM_DESC(enable_credit_mp,
> + "Set 0 to disable credit feature, default is 1 (enabled)");
> +
> +#define XDMA_BAR_SIZE 0x8000UL
> +
> +#define XDMA_CHANNEL_NUM_MAX 4
> +#define XDMA_ENG_IRQ_NUM 1
> +#define XDMA_MAX_ADJ_BLOCK_SIZE 0x40
> +#define XDMA_PAGE_SIZE 0x1000
> +#define RX_STATUS_EOP 1
> +
> +#define XDMA_OFS_INT_CTRL 0x2000UL
> +#define XDMA_OFS_CONFIG 0x3000UL
> +
> +#define XDMA_TRANSFER_MAX_DESC 2048
> +
> +#define XDMA_DESC_BLEN_BITS 28
> +#define XDMA_DESC_BLEN_MAX ((1 << (XDMA_DESC_BLEN_BITS)) - 1)
> +
> +/* bits of the SG DMA control register */
> +#define XDMA_CTRL_RUN_STOP (1UL << 0)
> +#define XDMA_CTRL_IE_DESC_STOPPED (1UL << 1)
> +#define XDMA_CTRL_IE_DESC_COMPLETED (1UL << 2)
> +#define XDMA_CTRL_IE_DESC_ALIGN_MISMATCH (1UL << 3)
> +#define XDMA_CTRL_IE_MAGIC_STOPPED (1UL << 4)
> +#define XDMA_CTRL_IE_IDLE_STOPPED (1UL << 6)
> +#define XDMA_CTRL_IE_READ_ERROR (0x1FUL << 9)
> +#define XDMA_CTRL_IE_DESC_ERROR (0x1FUL << 19)
> +#define XDMA_CTRL_NON_INCR_ADDR (1UL << 25)
> +#define XDMA_CTRL_POLL_MODE_WB (1UL << 26)
> +#define XDMA_CTRL_STM_MODE_WB (1UL << 27)
> +
> +/* bits of the SG DMA status register */
> +#define XDMA_STAT_BUSY (1UL << 0)
> +#define XDMA_STAT_DESC_STOPPED (1UL << 1)
> +#define XDMA_STAT_DESC_COMPLETED (1UL << 2)
> +#define XDMA_STAT_ALIGN_MISMATCH (1UL << 3)
> +#define XDMA_STAT_MAGIC_STOPPED (1UL << 4)
> +#define XDMA_STAT_INVALID_LEN (1UL << 5)
> +#define XDMA_STAT_IDLE_STOPPED (1UL << 6)
> +
> +#define XDMA_STAT_COMMON_ERR_MASK \
> + (XDMA_STAT_ALIGN_MISMATCH | XDMA_STAT_MAGIC_STOPPED | \
> + XDMA_STAT_INVALID_LEN)
> +
> +/* desc_error, C2H & H2C */
> +#define XDMA_STAT_DESC_UNSUPP_REQ (1UL << 19)
> +#define XDMA_STAT_DESC_COMPL_ABORT (1UL << 20)
> +#define XDMA_STAT_DESC_PARITY_ERR (1UL << 21)
> +#define XDMA_STAT_DESC_HEADER_EP (1UL << 22)
> +#define XDMA_STAT_DESC_UNEXP_COMPL (1UL << 23)
> +
> +#define XDMA_STAT_DESC_ERR_MASK \
> + (XDMA_STAT_DESC_UNSUPP_REQ | XDMA_STAT_DESC_COMPL_ABORT | \
> + XDMA_STAT_DESC_PARITY_ERR | XDMA_STAT_DESC_HEADER_EP | \
> + XDMA_STAT_DESC_UNEXP_COMPL)
> +
> +/* read error: H2C */
> +#define XDMA_STAT_H2C_R_UNSUPP_REQ (1UL << 9)
> +#define XDMA_STAT_H2C_R_COMPL_ABORT (1UL << 10)
> +#define XDMA_STAT_H2C_R_PARITY_ERR (1UL << 11)
> +#define XDMA_STAT_H2C_R_HEADER_EP (1UL << 12)
> +#define XDMA_STAT_H2C_R_UNEXP_COMPL (1UL << 13)
> +
> +#define XDMA_STAT_H2C_R_ERR_MASK \
> + (XDMA_STAT_H2C_R_UNSUPP_REQ | XDMA_STAT_H2C_R_COMPL_ABORT | \
> + XDMA_STAT_H2C_R_PARITY_ERR | XDMA_STAT_H2C_R_HEADER_EP | \
> + XDMA_STAT_H2C_R_UNEXP_COMPL)
> +
> +/* write error, H2C only */
> +#define XDMA_STAT_H2C_W_DECODE_ERR (1UL << 14)
> +#define XDMA_STAT_H2C_W_SLAVE_ERR (1UL << 15)
> +
> +#define XDMA_STAT_H2C_W_ERR_MASK \
> + (XDMA_STAT_H2C_W_DECODE_ERR | XDMA_STAT_H2C_W_SLAVE_ERR)
> +
> +/* read error: C2H */
> +#define XDMA_STAT_C2H_R_DECODE_ERR (1UL << 9)
> +#define XDMA_STAT_C2H_R_SLAVE_ERR (1UL << 10)
> +
> +#define XDMA_STAT_C2H_R_ERR_MASK \
> + (XDMA_STAT_C2H_R_DECODE_ERR | XDMA_STAT_C2H_R_SLAVE_ERR)
> +
> +/* all combined */
> +#define XDMA_STAT_H2C_ERR_MASK \
> + (XDMA_STAT_COMMON_ERR_MASK | XDMA_STAT_DESC_ERR_MASK | \
> + XDMA_STAT_H2C_R_ERR_MASK | XDMA_STAT_H2C_W_ERR_MASK)
> +
> +#define XDMA_STAT_C2H_ERR_MASK \
> + (XDMA_STAT_COMMON_ERR_MASK | XDMA_STAT_DESC_ERR_MASK | \
> + XDMA_STAT_C2H_R_ERR_MASK)
> +
> +/* bits of the SGDMA descriptor control field */
> +#define XDMA_DESC_STOPPED (1UL << 0)
> +#define XDMA_DESC_COMPLETED (1UL << 1)
> +#define XDMA_DESC_EOP (1UL << 4)
> +
> +/* upper 16-bits of engine identifier register */
> +#define XDMA_ID_H2C 0x1fc0U
> +#define XDMA_ID_C2H 0x1fc1U
> +
> +#define LS_BYTE_MASK 0x000000FFUL
> +
> +#define BLOCK_ID_MASK 0xFFF00000
> +#define BLOCK_ID_HEAD 0x1FC00000
> +
> +#define IRQ_BLOCK_ID 0x1fc20000UL
> +#define CONFIG_BLOCK_ID 0x1fc30000UL
> +
> +#define WB_COUNT_MASK 0x00ffffffUL
> +#define WB_ERR_MASK (1UL << 31)
> +
> +#define MAX_USER_IRQ 16
> +
> +#define DESC_MAGIC 0xAD4B0000UL
> +
> +#define C2H_WB 0x52B4UL
> +
> +#define H2C_CHANNEL_OFFSET 0x1000
> +#define SGDMA_OFFSET_FROM_CHANNEL 0x4000
> +#define CHANNEL_SPACING 0x100
> +#define TARGET_SPACING 0x1000
> +
> +/* obtain the 32 most significant (high) bits of a 32-bit or 64-bit address */
> +#define PCI_DMA_H(addr) ((addr >> 16) >> 16)
> +/* obtain the 32 least significant (low) bits of a 32-bit or 64-bit address */
> +#define PCI_DMA_L(addr) (addr & 0xffffffffUL)
> +
> +
> +enum transfer_state {
> + TRANSFER_STATE_NEW = 0,
> + TRANSFER_STATE_SUBMITTED,
> + TRANSFER_STATE_COMPLETED,
> + TRANSFER_STATE_FAILED,
> + TRANSFER_STATE_ABORTED
> +};
> +
> +enum shutdown_state {
> + ENGINE_SHUTDOWN_NONE = 0, /* No shutdown in progress */
> + ENGINE_SHUTDOWN_REQUEST = 1, /* engine requested to shutdown */
> + ENGINE_SHUTDOWN_IDLE = 2 /* engine has shutdown and is idle */
> +};
> +
> +struct config_regs {
> + u32 identifier;
> + u32 reserved_1[4];
> + u32 msi_enable;
> +};
> +
> +struct engine_regs {
> + u32 identifier;
> + u32 control;
> + u32 control_w1s;
> + u32 control_w1c;
> + u32 reserved_1[12]; /* padding */
> +
> + u32 status;
> + u32 status_rc;
> + u32 completed_desc_count;
> + u32 alignments;
> + u32 reserved_2[14]; /* padding */
> +
> + u32 poll_mode_wb_lo;
> + u32 poll_mode_wb_hi;
> + u32 interrupt_enable_mask;
> + u32 interrupt_enable_mask_w1s;
> + u32 interrupt_enable_mask_w1c;
> + u32 reserved_3[9]; /* padding */
> +
> + u32 perf_ctrl;
> + u32 perf_cyc_lo;
> + u32 perf_cyc_hi;
> + u32 perf_dat_lo;
> + u32 perf_dat_hi;
> + u32 perf_pnd_lo;
> + u32 perf_pnd_hi;
> +} __packed;
> +
> +struct engine_sgdma_regs {
> + u32 identifier;
> + u32 reserved_1[31]; /* padding */
> +
> + /* bus address to first descriptor in Root Complex Memory */
> + u32 first_desc_lo;
> + u32 first_desc_hi;
> + /* number of adjacent descriptors at first_desc */
> + u32 first_desc_adjacent;
> + u32 credits;
> +} __packed;
> +
> +struct interrupt_regs {
> + u32 identifier;
> + u32 user_int_enable;
> + u32 user_int_enable_w1s;
> + u32 user_int_enable_w1c;
> + u32 channel_int_enable;
> + u32 channel_int_enable_w1s;
> + u32 channel_int_enable_w1c;
> + u32 reserved_1[9]; /* padding */
> +
> + u32 user_int_request;
> + u32 channel_int_request;
> + u32 user_int_pending;
> + u32 channel_int_pending;
> + u32 reserved_2[12]; /* padding */
> +
> + u32 user_msi_vector[8];
> + u32 channel_msi_vector[8];
> +} __packed;
> +
> +struct sgdma_common_regs {
> + u32 padding[8];
> + u32 credit_mode_enable;
> + u32 credit_mode_enable_w1s;
> + u32 credit_mode_enable_w1c;
> +} __packed;
> +
> +
> +/*
> + * Descriptor for a single contiguous memory block transfer.
> + *
> + * Multiple descriptors are linked by means of the next pointer. An additional
> + * extra adjacent number gives the amount of extra contiguous descriptors.
> + *
> + * The descriptors are in root complex memory, and the bytes in the 32-bit
> + * words must be in little-endian byte ordering.
> + */
> +struct xdma_desc {
> + u32 control;
> + u32 bytes; /* transfer length in bytes */
> + u32 src_addr_lo; /* source address (low 32-bit) */
> + u32 src_addr_hi; /* source address (high 32-bit) */
> + u32 dst_addr_lo; /* destination address (low 32-bit) */
> + u32 dst_addr_hi; /* destination address (high 32-bit) */
> + /*
> + * next descriptor in the single-linked list of descriptors;
> + * this is the PCIe (bus) address of the next descriptor in the
> + * root complex memory
> + */
> + u32 next_lo; /* next desc address (low 32-bit) */
> + u32 next_hi; /* next desc address (high 32-bit) */
> +} __packed;
> +
> +/* 32 bytes (four 32-bit words) or 64 bytes (eight 32-bit words) */
> +struct xdma_result {
> + u32 status;
> + u32 length;
> + u32 reserved_1[6]; /* padding */
> +} __packed;
> +
> +struct sw_desc {
> + dma_addr_t addr;
> + unsigned int len;
> +};
> +
> +/* Describes a (SG DMA) single transfer for the engine */
> +#define XFER_FLAG_NEED_UNMAP 0x1
> +#define XFER_FLAG_ST_C2H_EOP_RCVED 0x2 /* ST c2h only */
> +struct xdma_transfer {
> + struct list_head entry; /* queue of non-completed transfers */
> + struct xdma_desc *desc_virt; /* virt addr of the 1st descriptor */
> + struct xdma_result *res_virt; /* virt addr of result, c2h streaming */
> + dma_addr_t res_bus; /* bus addr for result descriptors */
> + dma_addr_t desc_bus; /* bus addr of the first descriptor */
> + int desc_adjacent; /* adjacent descriptors at desc_bus */
> + int desc_num; /* number of descriptors in transfer */
> + int desc_index; /* index for 1st desc. in transfer */
> + int desc_cmpl; /* completed descriptors */
> + int desc_cmpl_th; /* completed descriptor threshold */
> + enum dma_data_direction dir;
> + struct swait_queue_head wq; /* wait queue for transfer completion */
> +
> + enum transfer_state state; /* state of the transfer */
> + unsigned int flags;
> + int cyclic; /* flag if transfer is cyclic */
> + int last_in_request; /* flag if last within request */
> + unsigned int len;
> + struct sg_table *sgt;
> +};
> +
> +struct xdma_request_cb {
> + struct sg_table *sgt;
> + unsigned int total_len;
> + u64 ep_addr;
> +
> + struct xdma_transfer tfer;
> +
> + unsigned int sw_desc_idx;
> + unsigned int sw_desc_cnt;
> + struct sw_desc sdesc[0];
> +};
> +
> +struct xdma_engine {
> + struct xdma_dev *xdev; /* parent device */
> + char name[16]; /* name of this engine */
> +
> + /* HW register address offsets */
> + struct engine_regs *regs; /* Control reg BAR offset */
> + struct engine_sgdma_regs *sgdma_regs; /* SGDAM reg BAR offset */
> +
> + /* Engine state, configuration and flags */
> + enum shutdown_state shutdown; /* engine shutdown mode */
> + enum dma_data_direction dir;
> + u8 addr_align; /* source/dest alignment in bytes */
> + u8 len_granularity; /* transfer length multiple */
> + u8 addr_bits; /* HW datapath address width */
> + u8 channel:2; /* engine indices */
> + u8 streaming:1;
> + u8 device_open:1; /* flag if engine node open, ST mode only */
> + u8 running:1; /* flag if the driver started engine */
> + u8 non_incr_addr:1; /* flag if non-incremental addressing used */
> + u8 eop_flush:1; /* st c2h only, flush up the data with eop */
> + u8 filler:1;
> +
> + int max_extra_adj; /* descriptor prefetch capability */
> + int desc_dequeued; /* num descriptors of completed transfers */
> + u32 status; /* last known status of device */
> + u32 interrupt_enable_mask_value; /* per-engine interrupt mask value */
> +
> + /* Transfer list management */
> + struct list_head transfer_list; /* queue of transfers */
> +
> + /* Members applicable to AXI-ST C2H (cyclic) transfers */
> + struct xdma_result *cyclic_result;
> + dma_addr_t cyclic_result_bus; /* bus addr for transfer */
> +
> + /* Members associated with interrupt mode support */
> + struct swait_queue_head shutdown_wq;
> + spinlock_t lock; /* protects concurrent access */
> + int prev_cpu; /* remember CPU# of (last) locker */
> + int irq_line; /* IRQ vector for this engine */
> + u32 irq_bitmask; /* IRQ bit mask for this engine */
> + struct work_struct work; /* Work queue for interrupt handling */
> +
> + struct mutex desc_lock; /* protects concurrent access */
> + dma_addr_t desc_bus;
> + struct xdma_desc *desc;
> + int desc_idx; /* current descriptor index */
> + int desc_used; /* total descriptors used */
> +};
> +
> +struct xdma_dev {
> + struct pci_dev *pdev;
> + void __iomem *config_bar;
> + unsigned int mask_irq_user;
> + int engines_num;
> + struct xdma_engine engine_h2c[XDMA_CHANNEL_NUM_MAX];
> + struct xdma_engine engine_c2h[XDMA_CHANNEL_NUM_MAX];
> +};
> +
> +
> +static void channel_interrupts_enable(struct xdma_dev *xdev, u32 mask)
> +{
> + struct interrupt_regs *reg =
> + (struct interrupt_regs *)(xdev->config_bar + XDMA_OFS_INT_CTRL);
> +
> + iowrite32(mask, &reg->channel_int_enable_w1s);
> +}
> +
> +static void channel_interrupts_disable(struct xdma_dev *xdev, u32 mask)
> +{
> + struct interrupt_regs *reg =
> + (struct interrupt_regs *)(xdev->config_bar + XDMA_OFS_INT_CTRL);
> +
> + iowrite32(mask, &reg->channel_int_enable_w1c);
> +}
> +
> +static void user_interrupts_enable(struct xdma_dev *xdev, u32 mask)
> +{
> + struct interrupt_regs *reg =
> + (struct interrupt_regs *)(xdev->config_bar + XDMA_OFS_INT_CTRL);
> +
> + iowrite32(mask, &reg->user_int_enable_w1s);
> +}
> +
> +static void user_interrupts_disable(struct xdma_dev *xdev, u32 mask)
> +{
> + struct interrupt_regs *reg =
> + (struct interrupt_regs *)(xdev->config_bar + XDMA_OFS_INT_CTRL);
> +
> + iowrite32(mask, &reg->user_int_enable_w1c);
> +}
> +
> +static void read_interrupts(struct xdma_dev *xdev)
> +{
> + struct interrupt_regs *reg =
> + (struct interrupt_regs *)(xdev->config_bar + XDMA_OFS_INT_CTRL);
> + u32 lo, hi;
> +
> + hi = ioread32(&reg->user_int_request);
> + lo = ioread32(&reg->channel_int_request);
> +}
> +
> +static void engine_reg_dump(struct xdma_engine *engine)
> +{
> + u32 w;
> +
> + w = ioread32(&engine->regs->identifier);
> + if ((w & BLOCK_ID_MASK) != BLOCK_ID_HEAD) {
> + pr_warn("XDMA: %s: 0x%08x: invalid engine id\n",
> + engine->name, w);
> + return;
> + }
> +
> + pr_info("XDMA: %s: ENGINE REGISTER DUMP\n", engine->name);
> + pr_info("%s: ioread32(0x%p) = 0x%08x (id).\n",
> + engine->name, &engine->regs->identifier, w);
> + w = ioread32(&engine->regs->status);
> + pr_info("%s: ioread32(0x%p) = 0x%08x (status).\n",
> + engine->name, &engine->regs->status, w);
> + w = ioread32(&engine->regs->control);
> + pr_info("%s: ioread32(0x%p) = 0x%08x (control)\n",
> + engine->name, &engine->regs->control, w);
> + w = ioread32(&engine->sgdma_regs->first_desc_lo);
> + pr_info("%s: ioread32(0x%p) = 0x%08x (first_desc_lo)\n",
> + engine->name, &engine->sgdma_regs->first_desc_lo, w);
> + w = ioread32(&engine->sgdma_regs->first_desc_hi);
> + pr_info("%s: ioread32(0x%p) = 0x%08x (first_desc_hi)\n",
> + engine->name, &engine->sgdma_regs->first_desc_hi, w);
> + w = ioread32(&engine->sgdma_regs->first_desc_adjacent);
> + pr_info("%s: ioread32(0x%p) = 0x%08x (first_desc_adjacent).\n",
> + engine->name, &engine->sgdma_regs->first_desc_adjacent, w);
> + w = ioread32(&engine->regs->completed_desc_count);
> + pr_info("%s: ioread32(0x%p) = 0x%08x (completed_desc_count).\n",
> + engine->name, &engine->regs->completed_desc_count, w);
> + w = ioread32(&engine->regs->interrupt_enable_mask);
> + pr_info("%s: ioread32(0x%p) = 0x%08x (interrupt_enable_mask)\n",
> + engine->name, &engine->regs->interrupt_enable_mask, w);
> +}
> +
> +static void engine_status_dump(struct xdma_engine *engine)
> +{
> + u32 v = engine->status;
> + char buffer[256];
> + char *buf = buffer;
> + int len = 0;
> +
> + len = sprintf(buf, "XDMA: %s: status: 0x%08x: ", engine->name, v);
> +
> + if ((v & XDMA_STAT_BUSY))
> + len += sprintf(buf + len, "BUSY,");
> + if ((v & XDMA_STAT_DESC_STOPPED))
> + len += sprintf(buf + len, "DESC_STOPPED,");
> + if ((v & XDMA_STAT_DESC_COMPLETED))
> + len += sprintf(buf + len, "DESC_COMPL,");
> +
> + /* common H2C & C2H */
> + if ((v & XDMA_STAT_COMMON_ERR_MASK)) {
> + if ((v & XDMA_STAT_ALIGN_MISMATCH))
> + len += sprintf(buf + len, "ALIGN_MISMATCH ");
> + if ((v & XDMA_STAT_MAGIC_STOPPED))
> + len += sprintf(buf + len, "MAGIC_STOPPED ");
> + if ((v & XDMA_STAT_INVALID_LEN))
> + len += sprintf(buf + len, "INVLIAD_LEN ");
> + if ((v & XDMA_STAT_IDLE_STOPPED))
> + len += sprintf(buf + len, "IDLE_STOPPED ");
> + buf[len - 1] = ',';
> + }
> +
> + if (engine->dir == DMA_TO_DEVICE) {
> + /* H2C only */
> + if ((v & XDMA_STAT_H2C_R_ERR_MASK)) {
> + len += sprintf(buf + len, "R:");
> + if ((v & XDMA_STAT_H2C_R_UNSUPP_REQ))
> + len += sprintf(buf + len, "UNSUPP_REQ ");
> + if ((v & XDMA_STAT_H2C_R_COMPL_ABORT))
> + len += sprintf(buf + len, "COMPL_ABORT ");
> + if ((v & XDMA_STAT_H2C_R_PARITY_ERR))
> + len += sprintf(buf + len, "PARITY ");
> + if ((v & XDMA_STAT_H2C_R_HEADER_EP))
> + len += sprintf(buf + len, "HEADER_EP ");
> + if ((v & XDMA_STAT_H2C_R_UNEXP_COMPL))
> + len += sprintf(buf + len, "UNEXP_COMPL ");
> + buf[len - 1] = ',';
> + }
> +
> + if ((v & XDMA_STAT_H2C_W_ERR_MASK)) {
> + len += sprintf(buf + len, "W:");
> + if ((v & XDMA_STAT_H2C_W_DECODE_ERR))
> + len += sprintf(buf + len, "DECODE_ERR ");
> + if ((v & XDMA_STAT_H2C_W_SLAVE_ERR))
> + len += sprintf(buf + len, "SLAVE_ERR ");
> + buf[len - 1] = ',';
> + }
> +
> + } else {
> + /* C2H only */
> + if ((v & XDMA_STAT_C2H_R_ERR_MASK)) {
> + len += sprintf(buf + len, "R:");
> + if ((v & XDMA_STAT_C2H_R_DECODE_ERR))
> + len += sprintf(buf + len, "DECODE_ERR ");
> + if ((v & XDMA_STAT_C2H_R_SLAVE_ERR))
> + len += sprintf(buf + len, "SLAVE_ERR ");
> + buf[len - 1] = ',';
> + }
> + }
> +
> + /* common H2C & C2H */
> + if ((v & XDMA_STAT_DESC_ERR_MASK)) {
> + len += sprintf(buf + len, "DESC_ERR:");
> + if ((v & XDMA_STAT_DESC_UNSUPP_REQ))
> + len += sprintf(buf + len, "UNSUPP_REQ ");
> + if ((v & XDMA_STAT_DESC_COMPL_ABORT))
> + len += sprintf(buf + len, "COMPL_ABORT ");
> + if ((v & XDMA_STAT_DESC_PARITY_ERR))
> + len += sprintf(buf + len, "PARITY ");
> + if ((v & XDMA_STAT_DESC_HEADER_EP))
> + len += sprintf(buf + len, "HEADER_EP ");
> + if ((v & XDMA_STAT_DESC_UNEXP_COMPL))
> + len += sprintf(buf + len, "UNEXP_COMPL ");
> + buf[len - 1] = ',';
> + }
> +
> + buf[len - 1] = '\0';
> + pr_info("%s\n", buffer);
> +}
> +
> +static void engine_status_read(struct xdma_engine *engine, bool clear, bool dump)
> +{
> + if (dump)
> + engine_reg_dump(engine);
> +
> + if (clear)
> + engine->status = ioread32(&engine->regs->status_rc);
> + else
> + engine->status = ioread32(&engine->regs->status);
> +
> + if (dump)
> + engine_status_dump(engine);
> +}
> +
> +static void engine_stop(struct xdma_engine *engine)
> +{
> + u32 w;
> +
> + if (enable_credit_mp && engine->streaming &&
> + engine->dir == DMA_FROM_DEVICE)
> + iowrite32(0, &engine->sgdma_regs->credits);
> +
> + w = 0;
> + w |= (u32)XDMA_CTRL_IE_DESC_ALIGN_MISMATCH;
> + w |= (u32)XDMA_CTRL_IE_MAGIC_STOPPED;
> + w |= (u32)XDMA_CTRL_IE_READ_ERROR;
> + w |= (u32)XDMA_CTRL_IE_DESC_ERROR;
> +
> + w |= (u32)XDMA_CTRL_IE_DESC_STOPPED;
> + w |= (u32)XDMA_CTRL_IE_DESC_COMPLETED;
> +
> + iowrite32(w, &engine->regs->control);
> +
> + engine->running = 0;
> +}
> +
> +static int engine_start_mode_config(struct xdma_engine *engine)
> +{
> + u32 w;
> +
> + /* write control register of SG DMA engine */
> + w = (u32)XDMA_CTRL_RUN_STOP;
> + w |= (u32)XDMA_CTRL_IE_READ_ERROR;
> + w |= (u32)XDMA_CTRL_IE_DESC_ERROR;
> + w |= (u32)XDMA_CTRL_IE_DESC_ALIGN_MISMATCH;
> + w |= (u32)XDMA_CTRL_IE_MAGIC_STOPPED;
> +
> + w |= (u32)XDMA_CTRL_IE_DESC_STOPPED;
> + w |= (u32)XDMA_CTRL_IE_DESC_COMPLETED;
> +
> + /* set non-incremental addressing mode */
> + if (engine->non_incr_addr)
> + w |= (u32)XDMA_CTRL_NON_INCR_ADDR;
> +
> + /* start the engine */
> + iowrite32(w, &engine->regs->control);
> + /* dummy read of status register to flush all previous writes */
> + w = ioread32(&engine->regs->status);
> +
> + return 0;
> +}
> +
> +/*
> + * Get the number for adjacent descriptors to set in a descriptor, based on the
> + * remaining number of descriptors and the lower bits of the address of the
> + * next descriptor.
> + * Since the number of descriptors in a page (XDMA_PAGE_SIZE) is 128 and the
> + * maximum size of a block of adjacent descriptors is 64 (63 max adjacent
> + * descriptors for any descriptor), align the blocks of adjacent descriptors
> + * to the block size.
> + */
> +static u32 xdma_get_next_adj(unsigned int remaining, u32 next_lo)
> +{
> + unsigned int next_index;
> +
> + if (remaining <= 1)
> + return 0;
> +
> + /* shift right 5 times corresponds to a division by
> + * sizeof(xdma_desc) = 32
> + */
> + next_index = ((next_lo & (XDMA_PAGE_SIZE - 1)) >> 5) %
> + XDMA_MAX_ADJ_BLOCK_SIZE;
> + return min(XDMA_MAX_ADJ_BLOCK_SIZE - next_index - 1, remaining - 1);
> +}
> +
> +/*
> + * start an idle engine with its first transfer on queue
> + *
> + * The engine will run and process all transfers that are queued using
> + * transfer_queue() and thus have their descriptor lists chained.
> + *
> + * During the run, new transfers will be processed if transfer_queue() has
> + * chained the descriptors before the hardware fetches the last descriptor.
> + * A transfer that was chained too late will invoke a new run of the engine
> + * initiated from the engine_service() routine.
> + *
> + * The engine must be idle and at least one transfer must be queued.
> + */
> +static int engine_start(struct xdma_engine *engine)
> +{
> + struct xdma_transfer *transfer;
> + u32 w, next_adj;
> + int rv;
> +
> + /* engine transfer queue must not be empty */
> + if (list_empty(&engine->transfer_list)) {
> + pr_warn("XDMA: %s: transfer queue must not be empty\n",
> + engine->name);
> + return -EIO;
> + }
> + /* inspect first transfer queued on the engine */
> + transfer = list_entry(engine->transfer_list.next, struct xdma_transfer,
> + entry);
> + if (!transfer) {
> + pr_warn("XDMA: %s: queued transfer must not be empty\n",
> + engine->name);
> + return -EIO;
> + }
> +
> + /* engine is no longer shutdown */
> + engine->shutdown = ENGINE_SHUTDOWN_NONE;
> +
> + /* Add credits for Streaming mode C2H */
> + if (enable_credit_mp && engine->streaming &&
> + engine->dir == DMA_FROM_DEVICE)
> + iowrite32(engine->desc_used, &engine->sgdma_regs->credits);
> +
> + /* initialize number of descriptors of dequeued transfers */
> + engine->desc_dequeued = 0;
> +
> + /* write lower 32-bit of bus address of transfer first descriptor */
> + w = cpu_to_le32(PCI_DMA_L(transfer->desc_bus));
> + iowrite32(w, &engine->sgdma_regs->first_desc_lo);
> + /* write upper 32-bit of bus address of transfer first descriptor */
> + w = cpu_to_le32(PCI_DMA_H(transfer->desc_bus));
> + iowrite32(w, &engine->sgdma_regs->first_desc_hi);
> +
> + next_adj = xdma_get_next_adj(transfer->desc_adjacent,
> + cpu_to_le32(PCI_DMA_L(transfer->desc_bus)));
> + iowrite32(next_adj, &engine->sgdma_regs->first_desc_adjacent);
> +
> + rv = engine_start_mode_config(engine);
> + if (rv < 0)
> + return rv;
> + engine_status_read(engine, 0, 0);
> +
> + engine->running = 1;
> +
> + return 0;
> +}
> +
> +static void engine_service_shutdown(struct xdma_engine *engine)
> +{
> + engine_stop(engine);
> + /* awake task on engine's shutdown wait queue */
> + swake_up_one(&engine->shutdown_wq);
> +}
> +
> +static struct xdma_transfer *engine_transfer_completion(
> + struct xdma_engine *engine,
> + struct xdma_transfer *transfer)
> +{
> + if (unlikely(!transfer)) {
> + pr_warn("XDMA: %s empty xfer\n", engine->name);
> + return NULL;
> + }
> +
> + /* synchronous I/O? */
> + /* awake task on transfer's wait queue */
> + swake_up_one(&transfer->wq);
> +
> + return transfer;
> +}
> +
> +static struct xdma_transfer *engine_service_transfer_list(
> + struct xdma_engine *engine,
> + struct xdma_transfer *transfer,
> + u32 *pdesc_completed)
> +{
> + if (unlikely(!transfer)) {
> + pr_warn("XDMA: %s empty xfer\n", engine->name);
> + return NULL;
> + }
> +
> + /*
> + * iterate over all the transfers completed by the engine,
> + * except for the last
> + */
> + while (transfer && (!transfer->cyclic) &&
> + (*pdesc_completed > transfer->desc_num)) {
> + /* remove this transfer from pdesc_completed */
> + *pdesc_completed -= transfer->desc_num;
> +
> + /* remove completed transfer from list */
> + list_del(engine->transfer_list.next);
> + /* add to dequeued number of descriptors during this run */
> + engine->desc_dequeued += transfer->desc_num;
> + /* mark transfer as successfully completed */
> + transfer->state = TRANSFER_STATE_COMPLETED;
> +
> + /*
> + * Complete transfer - sets transfer to NULL if an async
> + * transfer has completed
> + */
> + transfer = engine_transfer_completion(engine, transfer);
> +
> + /* if exists, get the next transfer on the list */
> + if (!list_empty(&engine->transfer_list)) {
> + transfer = list_entry(engine->transfer_list.next,
> + struct xdma_transfer, entry);
> + } else {
> + /* no further transfers? */
> + transfer = NULL;
> + }
> + }
> +
> + return transfer;
> +}
> +
> +static void engine_err_handle(struct xdma_engine *engine,
> + struct xdma_transfer *transfer)
> +{
> + u32 value;
> +
> + /*
> + * The BUSY bit is expected to be clear now but older HW has a race
> + * condition which could cause it to be still set. If it's set, re-read
> + * and check again. If it's still set, log the issue.
> + */
> + if (engine->status & XDMA_STAT_BUSY) {
> + value = ioread32(&engine->regs->status);
> + if ((value & XDMA_STAT_BUSY))
> + pr_warn("XDMA: %s has errors but is still BUSY\n",
> + engine->name);
> + }
> +
> + /* mark transfer as failed */
> + transfer->state = TRANSFER_STATE_FAILED;
> + engine_stop(engine);
> +}
> +
> +static struct xdma_transfer *
> +engine_service_final_transfer(struct xdma_engine *engine,
> + struct xdma_transfer *transfer,
> + u32 *pdesc_completed)
> +{
> + /* inspect the current transfer */
> + if (unlikely(!transfer)) {
> + pr_warn("XDMA: %s: empty xfer\n", engine->name);
> + return NULL;
> + }
> +
> + if (((engine->dir == DMA_FROM_DEVICE) &&
> + (engine->status & XDMA_STAT_C2H_ERR_MASK)) ||
> + ((engine->dir == DMA_TO_DEVICE) &&
> + (engine->status & XDMA_STAT_H2C_ERR_MASK))) {
> + pr_warn("XDMA: %s: status error 0x%x.\n", engine->name,
> + engine->status);
> + engine_status_dump(engine);
> + engine_err_handle(engine, transfer);
> + goto transfer_del;
> + }
> +
> + if (engine->status & XDMA_STAT_BUSY)
> + pr_info("XDMA: %s: engine unexpectedly busy, ignoring\n",
> + engine->name);
> +
> + /* the engine stopped on current transfer? */
> + if (*pdesc_completed < transfer->desc_num) {
> + if (engine->eop_flush) {
> + /* check if eop received */
> + struct xdma_result *result = transfer->res_virt;
> + int i;
> + int max = *pdesc_completed;
> +
> + for (i = 0; i < max; i++) {
> + if ((result[i].status & RX_STATUS_EOP) != 0) {
> + transfer->flags |=
> + XFER_FLAG_ST_C2H_EOP_RCVED;
> + break;
> + }
> + }
> +
> + transfer->desc_cmpl += *pdesc_completed;
> + if (!(transfer->flags & XFER_FLAG_ST_C2H_EOP_RCVED))
> + return NULL;
> +
> + /* mark transfer as successfully completed */
> + engine_service_shutdown(engine);
> + transfer->state = TRANSFER_STATE_COMPLETED;
> + engine->desc_dequeued += transfer->desc_cmpl;
> + } else {
> + transfer->state = TRANSFER_STATE_FAILED;
> + pr_warn("XDMA: %s: xfer stopped half-way\n",
> + engine->name);
> +
> + /* add dequeued number of descriptors during this run */
> + engine->desc_dequeued += transfer->desc_num;
> + transfer->desc_cmpl = *pdesc_completed;
> + }
> + } else {
> + if (!transfer->cyclic) {
> + /*
> + * if the engine stopped on this transfer,
> + * it should be the last
> + */
> + WARN_ON(*pdesc_completed > transfer->desc_num);
> + }
> + /* mark transfer as successfully completed */
> + transfer->state = TRANSFER_STATE_COMPLETED;
> + transfer->desc_cmpl = transfer->desc_num;
> + /* add dequeued number of descriptors during this run */
> + engine->desc_dequeued += transfer->desc_num;
> + }
> +
> +transfer_del:
> + /* remove completed transfer from list */
> + list_del(engine->transfer_list.next);
> +
> + /*
> + * Complete transfer - sets transfer to NULL if an asynchronous
> + * transfer has completed
> + */
> + transfer = engine_transfer_completion(engine, transfer);
> +
> + return transfer;
> +}
> +
> +static int engine_service_resume(struct xdma_engine *engine)
> +{
> + int rv;
> +
> + if (!engine->running) {
> + /* in the case of shutdown, let it finish what's in the Q */
> + if (!list_empty(&engine->transfer_list)) {
> + /* (re)start engine */
> + rv = engine_start(engine);
> + if (rv)
> + return rv;
> + /* engine was requested to be shutdown? */
> + } else if (engine->shutdown & ENGINE_SHUTDOWN_REQUEST) {
> + engine->shutdown |= ENGINE_SHUTDOWN_IDLE;
> + /* awake task on engine's shutdown wait queue */
> + swake_up_one(&engine->shutdown_wq);
> + }
> + } else if (list_empty(&engine->transfer_list)) {
> + engine_service_shutdown(engine);
> + }
> +
> + return 0;
> +}
> +
> +static int engine_service(struct xdma_engine *engine, int desc_writeback)
> +{
> + struct xdma_transfer *transfer = NULL;
> + u32 desc_count = desc_writeback & WB_COUNT_MASK;
> + u32 err_flag = desc_writeback & WB_ERR_MASK;
> + int rv;
> +
> + if (!engine->running) {
> + engine_status_read(engine, 1, 0);
> + return 0;
> + }
> +
> + /*
> + * If called by the ISR detected an error, read and clear
> + * engine status.
> + */
> + if ((desc_count == 0) || (err_flag != 0))
> + engine_status_read(engine, 1, 0);
> +
> + /*
> + * engine was running but is no longer busy, or writeback occurred,
> + * shut down
> + */
> + if ((engine->running && !(engine->status & XDMA_STAT_BUSY)) ||
> + (!engine->eop_flush && desc_count != 0))
> + engine_service_shutdown(engine);
> +
> + /*
> + * If called from the ISR, or if an error occurred, the descriptor
> + * count will be zero. In this scenario, read the descriptor count
> + * from HW.
> + */
> + if (!desc_count)
> + desc_count = ioread32(&engine->regs->completed_desc_count);
> + if (!desc_count)
> + goto done;
> +
> + /* transfers on queue? */
> + if (!list_empty(&engine->transfer_list)) {
> + /* pick first transfer on queue (was submitted to the engine) */
> + transfer = list_entry(engine->transfer_list.next,
> + struct xdma_transfer, entry);
> + }
> +
> + /* account for already dequeued transfers during this engine run */
> + desc_count -= engine->desc_dequeued;
> +
> + /* Process all but the last transfer */
> + transfer = engine_service_transfer_list(engine, transfer, &desc_count);
> +
> + /*
> + * Process final transfer - includes checks of number of descriptors to
> + * detect faulty completion
> + */
> + transfer = engine_service_final_transfer(engine, transfer, &desc_count);
> +
> + /* Restart the engine following the servicing */
> + if (!engine->eop_flush) {
> + rv = engine_service_resume(engine);
> + if (rv)
> + return rv;
> + }
> +
> +done:
> + return err_flag ? -1 : 0;
> +}
> +
> +static void engine_service_work(struct work_struct *work)
> +{
> + struct xdma_engine *engine;
> + unsigned long flags;
> + int rv;
> +
> + engine = container_of(work, struct xdma_engine, work);
> +
> + spin_lock_irqsave(&engine->lock, flags);
> +
> + rv = engine_service(engine, 0);
> + if (rv < 0)
> + goto unlock;
> +
> + /* re-enable interrupts for this engine */
> + iowrite32(engine->interrupt_enable_mask_value,
> + &engine->regs->interrupt_enable_mask_w1s);
> +
> +unlock:
> + spin_unlock_irqrestore(&engine->lock, flags);
> +}
> +
> +static irqreturn_t xdma_isr(int irq, void *dev_id)
> +{
> + struct xdma_dev *xdev;
> + struct xdma_engine *engine;
> + struct interrupt_regs *irq_regs;
> +
> + engine = (struct xdma_engine *)dev_id;
> + xdev = engine->xdev;
> +
> + irq_regs = (struct interrupt_regs *)(xdev->config_bar + XDMA_OFS_INT_CTRL);
> +
> + /* Disable the interrupt for this engine */
> + iowrite32(engine->interrupt_enable_mask_value,
> + &engine->regs->interrupt_enable_mask_w1c);
> + /* Dummy read to flush the above write */
> + ioread32(&irq_regs->channel_int_pending);
> + schedule_work(&engine->work);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int is_config_bar(void *bar)
> +{
> + u32 irq_id = 0;
> + u32 cfg_id = 0;
> + u32 mask = 0xffff0000; /* Compare only XDMA ID's not Version number */
> + struct interrupt_regs *irq_regs =
> + (struct interrupt_regs *)(bar + XDMA_OFS_INT_CTRL);
> + struct config_regs *cfg_regs =
> + (struct config_regs *)(bar + XDMA_OFS_CONFIG);
> +
> + irq_id = ioread32(&irq_regs->identifier);
> + cfg_id = ioread32(&cfg_regs->identifier);
> +
> + if (((irq_id & mask) == IRQ_BLOCK_ID)
> + && ((cfg_id & mask) == CONFIG_BLOCK_ID))
> + return 1;
> +
> + return 0;
> +}
> +
> +static void unmap_config_bar(struct xdma_dev *xdev, int config_bar_id)
> +{
> + pci_iounmap(xdev->pdev, xdev->config_bar);
> + pci_release_selected_regions(xdev->pdev, 1U<<config_bar_id);
> +}
> +
> +static int map_config_bar(struct xdma_dev *xdev, int config_bar_id)
> +{
> + int rv, bar_len;
> +
> + bar_len = pci_resource_len(xdev->pdev, config_bar_id);
> + if (bar_len < XDMA_BAR_SIZE) {
> + pr_err("XDMA: %d: Not a config BAR\n", config_bar_id);
> + return -EINVAL;
> + }
> + rv = pci_request_selected_regions(xdev->pdev, 1U<<config_bar_id,
> + "xdma");
> + if (rv) {
> + pr_err("XDMA: Failed to request config BAR memory\n");
> + return rv;
> + }
> + xdev->config_bar = pci_iomap(xdev->pdev, config_bar_id, bar_len);
> + if (!xdev->config_bar) {
> + pr_err("XDMA: Failed to map config BAR memory\n");
> + rv = -ENOMEM;
> + goto err_map;
> + }
> + if (!is_config_bar(xdev->config_bar)) {
> + pr_err("XDMA: %d: Not a config BAR\n", config_bar_id);
> + rv = -EINVAL;
> + goto err_bar;
> + }
> +
> + pr_debug("XDMA: Config BAR %d mapped at %p\n",
> + config_bar_id, xdev->config_bar);
> +
> + return 0;
> +
> +err_bar:
> + pci_iounmap(xdev->pdev, xdev->config_bar);
> +err_map:
> + pci_release_selected_regions(xdev->pdev, 1U<<config_bar_id);
> +
> + return rv;
> +}
> +
> +static void prog_irq_user(struct xdma_dev *xdev, int num_channel, int num_irq,
> + bool clear)
> +{
> + struct interrupt_regs *int_regs =
> + (struct interrupt_regs *)(xdev->config_bar + XDMA_OFS_INT_CTRL);
> + int i = num_channel;
> + int max = i + num_irq;
> + int j;
> +
> + for (j = 0; i < max; j++) {
> + u32 val = 0;
> + int k, shift = 0;
> +
> + if (clear)
> + i += 4;
> + else
> + for (k = 0; k < 4 && i < max; i++, k++, shift += 8)
> + val |= (i & 0x1f) << shift;
> +
> + iowrite32(val, &int_regs->user_msi_vector[j]);
> + }
> +}
> +
> +static void prog_irq_channel(struct xdma_dev *xdev, int num_channel, bool clear)
> +{
> + struct interrupt_regs *int_regs =
> + (struct interrupt_regs *)(xdev->config_bar + XDMA_OFS_INT_CTRL);
> + int i, j;
> +
> + for (i = 0, j = 0; i < num_channel; j++) {
> + u32 val = 0;
> + int k, shift = 0;
> +
> + if (clear)
> + i += 4;
> + else
> + for (k = 0; k < 4 && i < num_channel; i++, k++, shift += 8)
> + val |= (i & 0x1f) << shift;
> +
> + iowrite32(val, &int_regs->channel_msi_vector[j]);
> + }
> +}
> +
> +static void irq_channel_teardown(struct xdma_dev *xdev, int h2c_channel_max,
> + int c2h_channel_max)
> +{
> + struct xdma_engine *engine;
> + int i = 0, j = 0;
> +
> + engine = xdev->engine_h2c;
> + for (i = 0; i < h2c_channel_max; i++, j++, engine++) {
> + if (!engine->irq_line)
> + break;
> + free_irq(engine->irq_line, engine);
> + }
> +
> + engine = xdev->engine_c2h;
> + for (i = 0; i < c2h_channel_max; i++, j++, engine++) {
> + if (!engine->irq_line)
> + break;
> + free_irq(engine->irq_line, engine);
> + }
> +}
> +
> +static int irq_channel_setup(struct xdma_dev *xdev, int h2c_channel_max,
> + int c2h_channel_max)
> +{
> + int i, j, rv;
> + u32 vector;
> + struct xdma_engine *engine;
> +
> + j = h2c_channel_max;
> + engine = xdev->engine_h2c;
> + for (i = 0; i < h2c_channel_max; i++, engine++) {
> + vector = pci_irq_vector(xdev->pdev, i);
> + rv = request_irq(vector, xdma_isr, 0, engine->name, engine);
> + if (rv) {
> + pr_err("XDMA: %s: error requesting irq#%d\n",
> + engine->name, vector);
> + return rv;
> + }
> + pr_info("XDMA: %s: irq#%d\n", engine->name, vector);
> + engine->irq_line = vector;
> + }
> +
> + engine = xdev->engine_c2h;
> + for (i = 0; i < c2h_channel_max; i++, j++, engine++) {
> + vector = pci_irq_vector(xdev->pdev, j);
> + rv = request_irq(vector, xdma_isr, 0, engine->name, engine);
> + if (rv) {
> + pr_err("XDMA: %s: error requesting irq#%d\n",
> + engine->name, vector);
> + return rv;
> + }
> + pr_info("XDMA: %s: irq#%d\n", engine->name, vector);
> + engine->irq_line = vector;
> + }
> +
> + return 0;
> +}
> +
> +static void irq_teardown(struct xdma_dev *xdev, int h2c_channel_max,
> + int c2h_channel_max, int user_irq_max)
> +{
> + int num_channel = h2c_channel_max + c2h_channel_max;
> +
> + prog_irq_user(xdev, num_channel, user_irq_max, 1);
> + prog_irq_channel(xdev, num_channel, 1);
> +
> + irq_channel_teardown(xdev, h2c_channel_max, c2h_channel_max);
> +}
> +
> +static int irq_setup(struct xdma_dev *xdev, int h2c_channel_max,
> + int c2h_channel_max, int user_irq_max)
> +{
> + int rv;
> + int num_channel = h2c_channel_max + c2h_channel_max;
> +
> + rv = irq_channel_setup(xdev, h2c_channel_max, c2h_channel_max);
> + if (rv)
> + return rv;
> +
> + prog_irq_channel(xdev, num_channel, 0);
> + prog_irq_user(xdev, num_channel, user_irq_max, 0);
> +
> + return 0;
> +}
> +
> +/* Chains the descriptors as a singly-linked list
> + *
> + * Each descriptor's next pointer specifies the bus address of the next
> + * descriptor.
> + * Terminates the last descriptor to form a singly-linked list.
> + */
> +static void transfer_desc_init(struct xdma_transfer *transfer, int count)
> +{
> + struct xdma_desc *desc_virt = transfer->desc_virt;
> + dma_addr_t desc_bus = transfer->desc_bus;
> + int i;
> +
> + BUG_ON(count > XDMA_TRANSFER_MAX_DESC);
> +
> + /* create singly-linked list for SG DMA controller */
> + for (i = 0; i < count - 1; i++) {
> + /* increment bus address to next in array */
> + desc_bus += sizeof(struct xdma_desc);
> +
> + /* singly-linked list uses bus addresses */
> + desc_virt[i].next_lo = cpu_to_le32(PCI_DMA_L(desc_bus));
> + desc_virt[i].next_hi = cpu_to_le32(PCI_DMA_H(desc_bus));
> + desc_virt[i].bytes = cpu_to_le32(0);
> +
> + desc_virt[i].control = cpu_to_le32(DESC_MAGIC);
> + }
> +
> + /* zero the last descriptor next pointer */
> + desc_virt[i].next_lo = cpu_to_le32(0);
> + desc_virt[i].next_hi = cpu_to_le32(0);
> + desc_virt[i].bytes = cpu_to_le32(0);
> + desc_virt[i].control = cpu_to_le32(DESC_MAGIC);
> +}
> +
> +/* Set how many descriptors are adjacent to this one */
> +static void xdma_desc_adjacent(struct xdma_desc *desc, u32 next_adjacent)
> +{
> + /* remember reserved and control bits */
> + u32 control = le32_to_cpu(desc->control) & 0x0000f0ffUL;
> + /* merge adjacent and control field */
> + control |= 0xAD4B0000UL | (next_adjacent << 8);
> + /* write control and next_adjacent */
> + desc->control = cpu_to_le32(control);
> +}
> +
> +/* Set complete control field of a descriptor */
> +static void xdma_desc_control_set(struct xdma_desc *first, u32 control_field)
> +{
> + /* remember magic and adjacent number */
> + u32 control = le32_to_cpu(first->control) & ~(LS_BYTE_MASK);
> +
> + /* merge adjacent and control field */
> + control |= control_field;
> + /* write control and next_adjacent */
> + first->control = cpu_to_le32(control);
> +}
> +
> +static inline void xdma_desc_done(struct xdma_desc *desc_virt, int count)
> +{
> + memset(desc_virt, 0, count * sizeof(struct xdma_desc));
> +}
> +
> +/* Fill a descriptor with the transfer details */
> +static void xdma_desc_set(struct xdma_desc *desc, dma_addr_t rc_bus_addr,
> + u64 ep_addr, int len, int dir)
> +{
> + /* transfer length */
> + desc->bytes = cpu_to_le32(len);
> + if (dir == DMA_TO_DEVICE) {
> + /* read from root complex memory (source address) */
> + desc->src_addr_lo = cpu_to_le32(PCI_DMA_L(rc_bus_addr));
> + desc->src_addr_hi = cpu_to_le32(PCI_DMA_H(rc_bus_addr));
> + /* write to end point address (destination address) */
> + desc->dst_addr_lo = cpu_to_le32(PCI_DMA_L(ep_addr));
> + desc->dst_addr_hi = cpu_to_le32(PCI_DMA_H(ep_addr));
> + } else {
> + /* read from end point address (source address) */
> + desc->src_addr_lo = cpu_to_le32(PCI_DMA_L(ep_addr));
> + desc->src_addr_hi = cpu_to_le32(PCI_DMA_H(ep_addr));
> + /* write to root complex memory (destination address) */
> + desc->dst_addr_lo = cpu_to_le32(PCI_DMA_L(rc_bus_addr));
> + desc->dst_addr_hi = cpu_to_le32(PCI_DMA_H(rc_bus_addr));
> + }
> +}
> +
> +static void transfer_abort(struct xdma_engine *engine,
> + struct xdma_transfer *transfer)
> +{
> + struct xdma_transfer *head;
> +
> + head = list_entry(engine->transfer_list.next, struct xdma_transfer,
> + entry);
> + if (head == transfer)
> + list_del(engine->transfer_list.next);
> + else
> + pr_warn("XDMA: %s: transfer for abort NOT found\n",
> + engine->name);
> +
> + if (transfer->state == TRANSFER_STATE_SUBMITTED)
> + transfer->state = TRANSFER_STATE_ABORTED;
> +}
> +
> +static int transfer_queue(struct xdma_engine *engine,
> + struct xdma_transfer *transfer)
> +{
> + int rv = 0;
> + unsigned long flags;
> +
> + /* lock the engine state */
> + spin_lock_irqsave(&engine->lock, flags);
> +
> + engine->prev_cpu = get_cpu();
> + put_cpu();
> +
> + /* engine is being shutdown; do not accept new transfers */
> + if (engine->shutdown & ENGINE_SHUTDOWN_REQUEST) {
> + pr_info("XDMA: %s: engine offline, transfer not queued\n",
> + engine->name);
> + rv = -EBUSY;
> + goto shutdown;
> + }
> +
> + /* mark the transfer as submitted */
> + transfer->state = TRANSFER_STATE_SUBMITTED;
> + /* add transfer to the tail of the engine transfer queue */
> + list_add_tail(&transfer->entry, &engine->transfer_list);
> +
> + if (!engine->running)
> + rv = engine_start(engine);
> +
> +shutdown:
> + spin_unlock_irqrestore(&engine->lock, flags);
> +
> + return rv;
> +}
> +
> +static void engine_alignments(struct xdma_engine *engine)
> +{
> + u32 w = ioread32(&engine->regs->alignments);
> +
> + if (w) {
> + engine->addr_align = (w & 0x00ff0000U) >> 16;
> + engine->len_granularity = (w & 0x0000ff00U) >> 8;
> + engine->addr_bits = (w & 0x000000ffU);
> + } else {
> + /* Some default values if alignments are unspecified */
> + engine->addr_align = 1;
> + engine->len_granularity = 1;
> + engine->addr_bits = 64;
> + }
> +}
> +
> +static void engine_free_resource(struct xdma_engine *engine)
> +{
> + struct xdma_dev *xdev = engine->xdev;
> +
> + if (engine->desc) {
> + dma_free_coherent(&xdev->pdev->dev,
> + XDMA_TRANSFER_MAX_DESC *
> + sizeof(struct xdma_desc),
> + engine->desc, engine->desc_bus);
> + engine->desc = NULL;
> + }
> +
> + if (engine->cyclic_result) {
> + dma_free_coherent(
> + &xdev->pdev->dev,
> + XDMA_TRANSFER_MAX_DESC * sizeof(struct xdma_result),
> + engine->cyclic_result, engine->cyclic_result_bus);
> + engine->cyclic_result = NULL;
> + }
> +}
> +
> +static void engine_destroy(struct xdma_dev *xdev, struct xdma_engine *engine)
> +{
> + /* Disable interrupts to stop processing new events during shutdown */
> + iowrite32(0x0, &engine->regs->interrupt_enable_mask);
> +
> + if (enable_credit_mp && engine->streaming &&
> + engine->dir == DMA_FROM_DEVICE) {
> + u32 reg_value = (0x1 << engine->channel) << 16;
> + struct sgdma_common_regs *reg =
> + (struct sgdma_common_regs *)
> + (xdev->config_bar + (0x6 * TARGET_SPACING));
> + iowrite32(reg_value, &reg->credit_mode_enable_w1c);
> + }
> +
> + /* Release memory use for descriptor writebacks */
> + engine_free_resource(engine);
> +
> + memset(engine, 0, sizeof(struct xdma_engine));
> + /* Decrement the number of engines available */
> + xdev->engines_num--;
> +}
> +
> +static void engine_init_regs(struct xdma_engine *engine)
> +{
> + u32 reg_value;
> +
> + iowrite32(XDMA_CTRL_NON_INCR_ADDR, &engine->regs->control_w1c);
> +
> + engine_alignments(engine);
> +
> + /* Configure error interrupts by default */
> + reg_value = XDMA_CTRL_IE_DESC_ALIGN_MISMATCH;
> + reg_value |= XDMA_CTRL_IE_MAGIC_STOPPED;
> + reg_value |= XDMA_CTRL_IE_MAGIC_STOPPED;
> + reg_value |= XDMA_CTRL_IE_READ_ERROR;
> + reg_value |= XDMA_CTRL_IE_DESC_ERROR;
> +
> + /* enable the relevant completion interrupts */
> + reg_value |= XDMA_CTRL_IE_DESC_STOPPED;
> + reg_value |= XDMA_CTRL_IE_DESC_COMPLETED;
> +
> + /* Apply engine configurations */
> + iowrite32(reg_value, &engine->regs->interrupt_enable_mask);
> +
> + engine->interrupt_enable_mask_value = reg_value;
> +
> + /* only enable credit mode for AXI-ST C2H */
> + if (enable_credit_mp && engine->streaming &&
> + engine->dir == DMA_FROM_DEVICE) {
> + struct xdma_dev *xdev = engine->xdev;
> + u32 reg_value = (0x1 << engine->channel) << 16;
> + struct sgdma_common_regs *reg =
> + (struct sgdma_common_regs *)
> + (xdev->config_bar + (0x6 * TARGET_SPACING));
> +
> + iowrite32(reg_value, &reg->credit_mode_enable_w1s);
> + }
> +}
> +
> +static int engine_alloc_resource(struct xdma_engine *engine)
> +{
> + struct xdma_dev *xdev = engine->xdev;
> +
> + engine->desc = dma_alloc_coherent(&xdev->pdev->dev,
> + XDMA_TRANSFER_MAX_DESC *
> + sizeof(struct xdma_desc),
> + &engine->desc_bus, GFP_KERNEL);
> + if (!engine->desc)
> + goto err_out;
> +
> + if (engine->streaming && engine->dir == DMA_FROM_DEVICE) {
> + engine->cyclic_result = dma_alloc_coherent(
> + &xdev->pdev->dev,
> + XDMA_TRANSFER_MAX_DESC * sizeof(struct xdma_result),
> + &engine->cyclic_result_bus, GFP_KERNEL);
> +
> + if (!engine->cyclic_result)
> + goto err_out;
> + }
> +
> + return 0;
> +
> +err_out:
> + engine_free_resource(engine);
> + return -ENOMEM;
> +}
> +
> +static int engine_init(struct xdma_engine *engine, struct xdma_dev *xdev,
> + int offset, enum dma_data_direction dir, int channel)
> +{
> + int rv;
> + u32 val;
> +
> + engine->channel = channel;
> + engine->xdev = xdev;
> +
> + /* engine interrupt request bit */
> + engine->irq_bitmask = (1 << XDMA_ENG_IRQ_NUM) - 1;
> + engine->irq_bitmask <<= (xdev->engines_num * XDMA_ENG_IRQ_NUM);
> +
> + /* register address */
> + engine->regs = xdev->config_bar + offset;
> + engine->sgdma_regs = xdev->config_bar + offset +
> + SGDMA_OFFSET_FROM_CHANNEL;
> + val = ioread32(&engine->regs->identifier);
> + if (val & 0x8000U)
> + engine->streaming = 1;
> +
> + /* remember SG DMA direction */
> + engine->dir = dir;
> + sprintf(engine->name, "xdma-%s%d%s", (dir == DMA_TO_DEVICE) ? "H2C" : "C2H",
> + channel, engine->streaming ? "ST" : "MM");
> +
> + /* initialize the deferred work for transfer completion */
> + INIT_WORK(&engine->work, engine_service_work);
> +
> + xdev->engines_num++;
> +
> + rv = engine_alloc_resource(engine);
> + if (rv)
> + return rv;
> + engine_init_regs(engine);
> +
> + return 0;
> +}
> +
> +static void transfer_destroy(struct xdma_dev *xdev, struct xdma_transfer *xfer)
> +{
> + xdma_desc_done(xfer->desc_virt, xfer->desc_num);
> +
> + if (xfer->last_in_request && (xfer->flags & XFER_FLAG_NEED_UNMAP)) {
> + struct sg_table *sgt = xfer->sgt;
> +
> + if (sgt->nents) {
> + dma_unmap_sg(&xdev->pdev->dev, sgt->sgl, sgt->nents,
> + xfer->dir);
> + sgt->nents = 0;
> + }
> + }
> +}
> +
> +static void transfer_build(struct xdma_engine *engine,
> + struct xdma_request_cb *req, struct xdma_transfer *xfer,
> + unsigned int desc_max)
> +{
> + struct sw_desc *sdesc = &(req->sdesc[req->sw_desc_idx]);
> + int i, j;
> + dma_addr_t bus = xfer->res_bus;
> +
> + for (i = 0, j = 0; i < desc_max; i++, j++, sdesc++) {
> + /* fill in descriptor entry j with transfer details */
> + xdma_desc_set(xfer->desc_virt + j, sdesc->addr, req->ep_addr,
> + sdesc->len, xfer->dir);
> + xfer->len += sdesc->len;
> +
> + /* for non-inc-add mode don't increment ep_addr */
> + if (!engine->non_incr_addr)
> + req->ep_addr += sdesc->len;
> +
> + if (engine->streaming && engine->dir == DMA_FROM_DEVICE) {
> + memset(xfer->res_virt + j, 0,
> + sizeof(struct xdma_result));
> + xfer->desc_virt[j].src_addr_lo =
> + cpu_to_le32(PCI_DMA_L(bus));
> + xfer->desc_virt[j].src_addr_hi =
> + cpu_to_le32(PCI_DMA_H(bus));
> + bus += sizeof(struct xdma_result);
> + }
> +
> + }
> +
> + req->sw_desc_idx += desc_max;
> +}
> +
> +static void transfer_init(struct xdma_engine *engine,
> + struct xdma_request_cb *req, struct xdma_transfer *xfer)
> +{
> + unsigned int desc_max = min_t(unsigned int,
> + req->sw_desc_cnt - req->sw_desc_idx,
> + XDMA_TRANSFER_MAX_DESC);
> + int i, last;
> + u32 control;
> + unsigned long flags;
> +
> + memset(xfer, 0, sizeof(*xfer));
> +
> + spin_lock_irqsave(&engine->lock, flags);
> + init_swait_queue_head(&xfer->wq);
> +
> + /* remember direction of transfer */
> + xfer->dir = engine->dir;
> + xfer->desc_virt = engine->desc + engine->desc_idx;
> + xfer->res_virt = engine->cyclic_result + engine->desc_idx;
> + xfer->desc_bus = engine->desc_bus +
> + (sizeof(struct xdma_desc) * engine->desc_idx);
> + xfer->res_bus = engine->cyclic_result_bus +
> + (sizeof(struct xdma_result) * engine->desc_idx);
> + xfer->desc_index = engine->desc_idx;
> +
> + if ((engine->desc_idx + desc_max) >= XDMA_TRANSFER_MAX_DESC)
> + desc_max = XDMA_TRANSFER_MAX_DESC - engine->desc_idx;
> +
> + transfer_desc_init(xfer, desc_max);
> + transfer_build(engine, req, xfer, desc_max);
> +
> + xfer->desc_adjacent = desc_max;
> +
> + /* terminate last descriptor */
> + last = desc_max - 1;
> + /* stop engine, EOP for AXI ST, req IRQ on last descriptor */
> + control = XDMA_DESC_STOPPED;
> + control |= XDMA_DESC_EOP;
> + control |= XDMA_DESC_COMPLETED;
> + xdma_desc_control_set(xfer->desc_virt + last, control);
> +
> + if (engine->eop_flush) {
> + for (i = 0; i < last; i++)
> + xdma_desc_control_set(xfer->desc_virt + i,
> + XDMA_DESC_COMPLETED);
> + xfer->desc_cmpl_th = 1;
> + } else
> + xfer->desc_cmpl_th = desc_max;
> +
> + xfer->desc_num = desc_max;
> + engine->desc_idx = (engine->desc_idx + desc_max) % XDMA_TRANSFER_MAX_DESC;
> + engine->desc_used += desc_max;
> +
> + /* fill in adjacent numbers */
> + for (i = 0; i < xfer->desc_num; i++) {
> + u32 next_adj = xdma_get_next_adj(xfer->desc_num - i - 1,
> + (xfer->desc_virt + i)->next_lo);
> + xdma_desc_adjacent(xfer->desc_virt + i, next_adj);
> + }
> +
> + spin_unlock_irqrestore(&engine->lock, flags);
> +}
> +
> +static void xdma_request_free(struct xdma_request_cb *req)
> +{
> + kvfree(req);
> +}
> +
> +static struct xdma_request_cb *xdma_request_alloc(struct xdma_dev *xdev,
> + unsigned int sdesc_nr)
> +{
> + unsigned int size = sizeof(struct xdma_request_cb) +
> + sdesc_nr * sizeof(struct sw_desc);
> +
> + return kvzalloc(size, GFP_KERNEL);
> +}
> +
> +static struct xdma_request_cb *xdma_init_request(struct xdma_dev *xdev,
> + struct sg_table *sgt,
> + u64 ep_addr)
> +{
> + struct xdma_request_cb *req;
> + struct scatterlist *sg = sgt->sgl;
> + int max = sgt->nents;
> + int extra = 0;
> + int i, j = 0;
> +
> + for (i = 0; i < max; i++, sg = sg_next(sg)) {
> + unsigned int len = sg_dma_len(sg);
> +
> + if (unlikely(len > XDMA_DESC_BLEN_MAX))
> + extra += (len + XDMA_DESC_BLEN_MAX - 1) / XDMA_DESC_BLEN_MAX;
> + }
> +
> + max += extra;
> + req = xdma_request_alloc(xdev, max);
> + if (!req)
> + return NULL;
> +
> + req->sgt = sgt;
> + req->ep_addr = ep_addr;
> +
> + for (i = 0, sg = sgt->sgl; i < sgt->nents; i++, sg = sg_next(sg)) {
> + unsigned int tlen = sg_dma_len(sg);
> + dma_addr_t addr = sg_dma_address(sg);
> +
> + req->total_len += tlen;
> + while (tlen) {
> + req->sdesc[j].addr = addr;
> + if (tlen > XDMA_DESC_BLEN_MAX) {
> + req->sdesc[j].len = XDMA_DESC_BLEN_MAX;
> + addr += XDMA_DESC_BLEN_MAX;
> + tlen -= XDMA_DESC_BLEN_MAX;
> + } else {
> + req->sdesc[j].len = tlen;
> + tlen = 0;
> + }
> + j++;
> + }
> + }
> +
> + if (j > max) {
> + pr_err("XDMA: Max. transfer length (%d) exceeded",
> + XDMA_DESC_BLEN_MAX);
> + xdma_request_free(req);
> + return NULL;
> + }
> + req->sw_desc_cnt = j;
> +
> + return req;
> +}
> +
> +static struct xdma_engine *channel_engine(struct xdma_core *xdma, int channel,
> + bool write)
> +{
> + if (write) {
> + if (channel >= xdma->h2c_channel_max) {
> + pr_err("XDMA: %d: invalid H2C channel\n", channel);
> + return NULL;
> + } else
> + return &xdma->xdev->engine_h2c[channel];
> + } else {
> + if (channel >= xdma->c2h_channel_max) {
> + pr_err("XDMA: %d: invalid C2H channel\n", channel);
> + return NULL;
> + } else
> + return &xdma->xdev->engine_c2h[channel];
> + }
> +}
> +
> +static struct xdma_dev *alloc_dev(struct pci_dev *pdev)
> +{
> + int i;
> + struct xdma_dev *xdev;
> + struct xdma_engine *engine;
> +
> + xdev = kzalloc(sizeof(struct xdma_dev), GFP_KERNEL);
> + if (!xdev)
> + return NULL;
> +
> + xdev->pdev = pdev;
> +
> + engine = xdev->engine_h2c;
> + for (i = 0; i < XDMA_CHANNEL_NUM_MAX; i++, engine++) {
> + spin_lock_init(&engine->lock);
> + mutex_init(&engine->desc_lock);
> + INIT_LIST_HEAD(&engine->transfer_list);
> + init_swait_queue_head(&engine->shutdown_wq);
> + }
> +
> + engine = xdev->engine_c2h;
> + for (i = 0; i < XDMA_CHANNEL_NUM_MAX; i++, engine++) {
> + spin_lock_init(&engine->lock);
> + mutex_init(&engine->desc_lock);
> + INIT_LIST_HEAD(&engine->transfer_list);
> + init_swait_queue_head(&engine->shutdown_wq);
> + }
> +
> + return xdev;
> +}
> +
> +static int set_dma_mask(struct xdma_dev *xdev)
> +{
> + if (!dma_set_mask(&xdev->pdev->dev, DMA_BIT_MASK(64))) {
> + pr_devel("XDMA: Using a 64-bit DMA mask\n");
> + /* use 32-bit DMA for descriptors */
> + dma_set_coherent_mask(&xdev->pdev->dev, DMA_BIT_MASK(32));
> + } else if (!dma_set_mask(&xdev->pdev->dev, DMA_BIT_MASK(32))) {
> + pr_devel("XDMA: Using a 32-bit DMA mask\n");
> + dma_set_coherent_mask(&xdev->pdev->dev, DMA_BIT_MASK(32));
> + } else {
> + pr_err("XDMA: No suitable DMA possible.\n");
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static int get_engine_channel_id(struct engine_regs *regs)
> +{
> + int value = ioread32(&regs->identifier);
> +
> + return (value & 0x00000f00U) >> 8;
> +}
> +
> +static int get_engine_id(struct engine_regs *regs)
> +{
> + int value = ioread32(&regs->identifier);
> +
> + return (value & 0xffff0000U) >> 16;
> +}
> +
> +static void remove_engines(struct xdma_dev *xdev, int h2c_channel_max,
> + int c2h_channel_max)
> +{
> + int i;
> +
> + for (i = 0; i < h2c_channel_max; i++)
> + engine_destroy(xdev, &xdev->engine_h2c[i]);
> +
> + for (i = 0; i < c2h_channel_max; i++)
> + engine_destroy(xdev, &xdev->engine_c2h[i]);
> +}
> +
> +static int probe_for_engine(struct xdma_dev *xdev, enum dma_data_direction dir,
> + int channel)
> +{
> + struct engine_regs *regs;
> + int offset = channel * CHANNEL_SPACING;
> + u32 engine_id;
> + u32 engine_id_expected;
> + u32 channel_id;
> + struct xdma_engine *engine;
> +
> + if (dir == DMA_TO_DEVICE) {
> + engine_id_expected = XDMA_ID_H2C;
> + engine = &xdev->engine_h2c[channel];
> + } else {
> + offset += H2C_CHANNEL_OFFSET;
> + engine_id_expected = XDMA_ID_C2H;
> + engine = &xdev->engine_c2h[channel];
> + }
> +
> + regs = xdev->config_bar + offset;
> + engine_id = get_engine_id(regs);
> + channel_id = get_engine_channel_id(regs);
> +
> + if ((engine_id != engine_id_expected) || (channel_id != channel)) {
> + pr_err("XDMA: %s engine #%d not found\n",
> + dir == DMA_TO_DEVICE ? "H2C" : "C2H", channel);
> + return -EINVAL;
> + }
> +
> + engine_init(engine, xdev, offset, dir, channel);
> +
> + return 0;
> +}
> +
> +static int probe_engines(struct xdma_dev *xdev, int h2c_channel_max,
> + int c2h_channel_max)
> +{
> + int i, rv;
> +
> + for (i = 0; i < h2c_channel_max; i++) {
> + rv = probe_for_engine(xdev, DMA_TO_DEVICE, i);
> + if (rv)
> + return rv;
> + }
> +
> + for (i = 0; i < c2h_channel_max; i++) {
> + rv = probe_for_engine(xdev, DMA_FROM_DEVICE, i);
> + if (rv)
> + return rv;
> + }
> +
> + return 0;
> +}
> +
> +
> +int xdma_probe(struct xdma_core *xdma)
> +{
> + int rv;
> +
> + if (xdma->user_irq_max > MAX_USER_IRQ) {
> + pr_err("XDMA: %d: Invalid number of user IRQs\n",
> + xdma->user_irq_max);
> + return -EINVAL;
> + }
> + if (xdma->h2c_channel_max > XDMA_CHANNEL_NUM_MAX) {
> + pr_err("XDMA: %d: Invalid number of H2C channels\n",
> + xdma->h2c_channel_max);
> + return -EINVAL;
> + }
> + if (xdma->c2h_channel_max > XDMA_CHANNEL_NUM_MAX) {
> + pr_err("XDMA: %d: Invalid number of C2H channels\n",
> + xdma->c2h_channel_max);
> + return -EINVAL;
> + }
> +
> + xdma->xdev = alloc_dev(xdma->pdev);
> + if (!xdma->xdev)
> + return -ENOMEM;
> +
> + rv = map_config_bar(xdma->xdev, xdma->config_bar_id);
> + if (rv)
> + goto err_map;
> +
> + rv = set_dma_mask(xdma->xdev);
> + if (rv)
> + goto err_mask;
> +
> + channel_interrupts_disable(xdma->xdev, ~0);
> + user_interrupts_disable(xdma->xdev, ~0);
> + /* Flush writes */
> + read_interrupts(xdma->xdev);
> +
> + rv = probe_engines(xdma->xdev, xdma->h2c_channel_max, xdma->c2h_channel_max);
> + if (rv)
> + goto err_engines;
> +
> + rv = irq_setup(xdma->xdev, xdma->h2c_channel_max, xdma->c2h_channel_max,
> + xdma->user_irq_max);
> + if (rv < 0)
> + goto err_interrupts;
> + channel_interrupts_enable(xdma->xdev, ~0);
> + /* Flush writes */
> + read_interrupts(xdma->xdev);
> +
> + return 0;
> +
> +err_interrupts:
> + irq_teardown(xdma->xdev, xdma->h2c_channel_max, xdma->c2h_channel_max,
> + xdma->user_irq_max);
> +err_engines:
> + remove_engines(xdma->xdev, xdma->h2c_channel_max, xdma->c2h_channel_max);
> +err_mask:
> + unmap_config_bar(xdma->xdev, xdma->config_bar_id);
> +err_map:
> + kfree(xdma->xdev);
> +
> + return rv;
> +}
> +EXPORT_SYMBOL_GPL(xdma_probe);
> +
> +void xdma_remove(struct xdma_core *xdma)
> +{
> + channel_interrupts_disable(xdma->xdev, ~0);
> + user_interrupts_disable(xdma->xdev, ~0);
> + /* Flush writes */
> + read_interrupts(xdma->xdev);
> +
> + irq_teardown(xdma->xdev, xdma->h2c_channel_max, xdma->c2h_channel_max,
> + xdma->user_irq_max);
> +
> + remove_engines(xdma->xdev, xdma->h2c_channel_max, xdma->c2h_channel_max);
> + unmap_config_bar(xdma->xdev, xdma->config_bar_id);
> +
> + kfree(xdma->xdev);
> +}
> +EXPORT_SYMBOL_GPL(xdma_remove);
> +
> +/**
> + * xdma_irq_enable - enable XDMA user interrupt(s)
> + * @xdma: XDMA device handle
> + * @mask: bitmask of user interrupts (0 ~ 15) to be registered
> + */
> +void xdma_irq_enable(struct xdma_core *xdma, unsigned int mask)
> +{
> + xdma->xdev->mask_irq_user |= mask;
> + user_interrupts_enable(xdma->xdev, mask);
> + /* Flush writes */
> + read_interrupts(xdma->xdev);
> +}
> +EXPORT_SYMBOL_GPL(xdma_irq_enable);
> +
> +/**
> + * xdma_irq_disable - disable XDMA user interrupt(s)
> + * @xdma: XDMA device handle
> + * @mask: bitmask of user interrupts (0 ~ 15) to be unregistered
> + */
> +void xdma_irq_disable(struct xdma_core *xdma, unsigned int mask)
> +{
> + xdma->xdev->mask_irq_user &= ~mask;
> + user_interrupts_disable(xdma->xdev, mask);
> + /* Flush writes */
> + read_interrupts(xdma->xdev);
> +}
> +EXPORT_SYMBOL_GPL(xdma_irq_disable);
> +
> +/**
> + * xdma_transfer - do a DMA transfer
> + * @xdma: XDMA device handle
> + * @channel: channel number
> + * @write: slecets read/write operation
> + * @ep_addr: offset into the DDR/BRAM (card) memory to read from or write to
> + * @sg_table: the scatter-gather list of data buffers
> + * @timeout_ms: timeout in mili-seconds
> + *
> + * Returns # of bytes transferred on success, negative on failure
> + */
> +ssize_t xdma_transfer(struct xdma_core *xdma, int channel, bool write,
> + u64 ep_addr, struct sg_table *sgt, int timeout_ms)
> +{
> + struct xdma_engine *engine;
> + int rv = 0, i, nents;
> + ssize_t done = 0;
> + struct xdma_request_cb *req = NULL;
> +
> +
> + engine = channel_engine(xdma, channel, write);
> + if (!engine)
> + return -EINVAL;
> +
> + req = xdma_init_request(xdma->xdev, sgt, ep_addr);
> + if (!req)
> + return -ENOMEM;
> +
> + nents = req->sw_desc_cnt;
> + mutex_lock(&engine->desc_lock);
> +
> + while (nents) {
> + unsigned long flags;
> + struct xdma_transfer *xfer;
> +
> + /* build transfer */
> + transfer_init(engine, req, &req->tfer);
> + xfer = &req->tfer;
> +
> + /* last transfer for the given request? */
> + nents -= xfer->desc_num;
> + if (!nents) {
> + xfer->last_in_request = 1;
> + xfer->sgt = sgt;
> + }
> +
> + rv = transfer_queue(engine, xfer);
> + if (rv < 0)
> + break;
> +
> + if (timeout_ms > 0)
> + swait_event_interruptible_timeout_exclusive(xfer->wq,
> + (xfer->state != TRANSFER_STATE_SUBMITTED),
> + msecs_to_jiffies(timeout_ms));
> + else
> + swait_event_interruptible_exclusive(xfer->wq,
> + (xfer->state != TRANSFER_STATE_SUBMITTED));
> +
> + spin_lock_irqsave(&engine->lock, flags);
> +
> + switch (xfer->state) {
> + case TRANSFER_STATE_COMPLETED:
> + spin_unlock_irqrestore(&engine->lock, flags);
> + /* For C2H streaming use writeback results */
> + if (engine->streaming &&
> + engine->dir == DMA_FROM_DEVICE) {
> + struct xdma_result *result = xfer->res_virt;
> +
> + for (i = 0; i < xfer->desc_cmpl; i++)
> + done += result[i].length;
> +
> + /* finish the whole request */
> + if (engine->eop_flush)
> + nents = 0;
> + } else
> + done += xfer->len;
> + rv = 0;
> + break;
> + case TRANSFER_STATE_FAILED:
> + pr_warn("XDMA: transfer failed\n");
> + spin_unlock_irqrestore(&engine->lock, flags);
> + rv = -EIO;
> + break;
> + default:
> + /* transfer can still be in-flight */
> + pr_warn("XDMA: transfer timed out\n");
> + engine_status_read(engine, 0, 1);
> + transfer_abort(engine, xfer);
> + engine_stop(engine);
> + spin_unlock_irqrestore(&engine->lock, flags);
> + rv = -ERESTARTSYS;
> + break;
> + }
> +
> + engine->desc_used -= xfer->desc_num;
> + transfer_destroy(xdma->xdev, xfer);
> +
> + if (rv < 0)
> + break;
> + }
> +
> + mutex_unlock(&engine->desc_lock);
> + xdma_request_free(req);
> +
> + return rv ? rv : done;
> +}
> +EXPORT_SYMBOL_GPL(xdma_transfer);
> +
> +MODULE_AUTHOR("Digiteq Automotive s.r.o.");
> +MODULE_DESCRIPTION("Xilinx XDMA Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/dma/xilinx_xdma.h b/include/linux/dma/xilinx_xdma.h
> new file mode 100644
> index 000000000000..c63dc7768e66
> --- /dev/null
> +++ b/include/linux/dma/xilinx_xdma.h
> @@ -0,0 +1,44 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * This file is part of the Xilinx DMA IP Core driver for Linux
> + *
> + * Copyright (c) 2016-2021, Xilinx, Inc.
> + * Copyright (c) 2020-2022, Digiteq Automotive s.r.o.
> + */
> +
> +#ifndef XILINX_XDMA_H
> +#define XILINX_XDMA_H
> +
> +#include <linux/pci.h>
> +#include <linux/scatterlist.h>
> +
> +struct xdma_dev;
> +
> +/**
> + * struct xdma_core - representation of XDMA hardware
> + * @pdev: The parent PCIe device which contains the XDMA core
> + * @config_bar_id: PCI BAR id where XDMA config regs are located
> + * @user_irq_max: number of user IRQs
> + * @c2h_channel_max: number of C2H DMA channels
> + * @h2c_channel_max: number of H2C DMA channels
> + * @xdev: struct xdma_dev that is filed by ->probe()
> + */
> +struct xdma_core {
> + struct pci_dev *pdev;
> + int config_bar_id;
> + unsigned int user_irq_max;
> + unsigned int c2h_channel_max;
> + unsigned int h2c_channel_max;
> + struct xdma_dev *xdev;
> +};
> +
> +int xdma_probe(struct xdma_core *xdma);
> +void xdma_remove(struct xdma_core *xdma);
> +
> +void xdma_irq_enable(struct xdma_core *xdma, unsigned int mask);
> +void xdma_irq_disable(struct xdma_core *xdma, unsigned int mask);
> +
> +ssize_t xdma_transfer(struct xdma_core *xdma, int channel, bool write,
> + u64 ep_addr, struct sg_table *sgt, int timeout_ms);
> +
> +#endif /* XILINX_XDMA_H */

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