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SubjectRe: [PATCH v2 2/6] hwtracing: Add trace function support for HiSilicon PCIe Tune and Trace device
Hi Yicong,

On Tue, Nov 16, 2021 at 05:06:21PM +0800, Yicong Yang wrote:
> HiSilicon PCIe tune and trace device(PTT) is a PCIe Root Complex
> integrated Endpoint(RCiEP) device, providing the capability
> to dynamically monitor and tune the PCIe traffic(tune),
> and trace the TLP headers(trace).
>

Is there a reason to put "tune" and "trace" are whithin parentheses?

> Add the driver for the device to enable the trace function. The driver
> will create PMU device for each PTT device, and users can start trace
> through perf command.
>
> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
> ---
> drivers/Makefile | 1 +
> drivers/hwtracing/Kconfig | 2 +
> drivers/hwtracing/hisilicon/Kconfig | 8 +
> drivers/hwtracing/hisilicon/Makefile | 2 +
> drivers/hwtracing/hisilicon/hisi_ptt.c | 1146 ++++++++++++++++++++++++

Not sure about the "hisilicon" directory. Right now we have "coresight",
"intel_th" and "stm" - they concentrate on the technology rather than the
vendor. I think "ptt" would be just fine:

drivers/hwtracing/ptt/Kconfig
drivers/hwtracing/ptt/Makefile
drivers/hwtracing/ptt/hisi_ptt.c

That way if other vendors want to introduce support for the same kind of
technology we can simply put them under "drivers/hwtracing/ptt/" and things are
still accurate.


> 5 files changed, 1159 insertions(+)
> create mode 100644 drivers/hwtracing/hisilicon/Kconfig
> create mode 100644 drivers/hwtracing/hisilicon/Makefile
> create mode 100644 drivers/hwtracing/hisilicon/hisi_ptt.c
>
> diff --git a/drivers/Makefile b/drivers/Makefile
> index be5d40ae1488..bb0dc9b55ea2 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -176,6 +176,7 @@ obj-$(CONFIG_USB4) += thunderbolt/
> obj-$(CONFIG_CORESIGHT) += hwtracing/coresight/
> obj-y += hwtracing/intel_th/
> obj-$(CONFIG_STM) += hwtracing/stm/
> +obj-$(CONFIG_HISI_PTT) += hwtracing/hisilicon/
> obj-$(CONFIG_ANDROID) += android/
> obj-$(CONFIG_NVMEM) += nvmem/
> obj-$(CONFIG_FPGA) += fpga/
> diff --git a/drivers/hwtracing/Kconfig b/drivers/hwtracing/Kconfig
> index 13085835a636..e3796b17541a 100644
> --- a/drivers/hwtracing/Kconfig
> +++ b/drivers/hwtracing/Kconfig
> @@ -5,4 +5,6 @@ source "drivers/hwtracing/stm/Kconfig"
>
> source "drivers/hwtracing/intel_th/Kconfig"
>
> +source "drivers/hwtracing/hisilicon/Kconfig"
> +
> endmenu
> diff --git a/drivers/hwtracing/hisilicon/Kconfig b/drivers/hwtracing/hisilicon/Kconfig
> new file mode 100644
> index 000000000000..9c3ab80d99fe
> --- /dev/null
> +++ b/drivers/hwtracing/hisilicon/Kconfig
> @@ -0,0 +1,8 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +config HISI_PTT
> + tristate "HiSilicon PCIe Tune and Trace Device"
> + depends on PCI && HAS_DMA && HAS_IOMEM

What Arm architecture are you aiming this for? Can it be found on both armv7
and armv8?

> + help
> + HiSilicon PCIe Tune and Trace Device exist as a PCIe RCiEP
> + device, provides support for PCIe traffic tuning and
> + tracing TLP headers to the memory.

Please indicate what the name of the driver will be when compiled as a module.

> diff --git a/drivers/hwtracing/hisilicon/Makefile b/drivers/hwtracing/hisilicon/Makefile
> new file mode 100644
> index 000000000000..908c09a98161
> --- /dev/null
> +++ b/drivers/hwtracing/hisilicon/Makefile
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0
> +obj-$(CONFIG_HISI_PTT) += hisi_ptt.o
> diff --git a/drivers/hwtracing/hisilicon/hisi_ptt.c b/drivers/hwtracing/hisilicon/hisi_ptt.c
> new file mode 100644
> index 000000000000..e11e9b6cc2a8
> --- /dev/null
> +++ b/drivers/hwtracing/hisilicon/hisi_ptt.c
> @@ -0,0 +1,1146 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Driver for HiSilicon PCIe tune and trace device
> + *
> + * Copyright (c) 2021 HiSilicon Limited.
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/bitops.h>
> +#include <linux/delay.h>
> +#include <linux/dma-iommu.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/iommu.h>
> +#include <linux/iopoll.h>
> +#include <linux/kfifo.h>
> +#include <linux/module.h>
> +#include <linux/notifier.h>
> +#include <linux/pci.h>
> +#include <linux/perf_event.h>
> +#include <linux/sizes.h>
> +#include <linux/sysfs.h>
> +#include <linux/vmalloc.h>
> +#include <linux/workqueue.h>
> +
> +#define HISI_PTT_TRACE_ADDR_SIZE 0x0800
> +#define HISI_PTT_TRACE_ADDR_BASE_LO_0 0x0810
> +#define HISI_PTT_TRACE_ADDR_BASE_HI_0 0x0814
> +#define HISI_PTT_TRACE_ADDR_STRIDE 0x8
> +#define HISI_PTT_TRACE_CTRL 0x0850
> +#define HISI_PTT_TRACE_CTRL_EN BIT(0)
> +#define HISI_PTT_TRACE_CTRL_RST BIT(1)
> +#define HISI_PTT_TRACE_CTRL_RXTX_SEL GENMASK(3, 2)
> +#define HISI_PTT_TRACE_CTRL_TYPE_SEL GENMASK(7, 4)
> +#define HISI_PTT_TRACE_CTRL_DATA_FORMAT BIT(14)
> +#define HISI_PTT_TRACE_CTRL_FILTER_MODE BIT(15)
> +#define HISI_PTT_TRACE_CTRL_TARGET_SEL GENMASK(31, 16)
> +#define HISI_PTT_TRACE_INT_STAT 0x0890
> +#define HISI_PTT_TRACE_INT_STAT_MASK GENMASK(3, 0)
> +#define HISI_PTT_TRACE_INT_MASK 0x0894
> +#define HISI_PTT_TRACE_WR_STS 0x08a0
> +#define HISI_PTT_TRACE_WR_STS_WRITE GENMASK(27, 0)
> +#define HISI_PTT_TRACE_WR_STS_BUFFER GENMASK(29, 28)
> +#define HISI_PTT_TRACE_STS 0x08b0
> +#define HISI_PTT_TRACE_IDLE BIT(0)
> +#define HISI_PTT_DEVICE_RANGE 0x0fe0
> +#define HISI_PTT_LOCATION 0x0fe8
> +#define HISI_PTT_CORE_ID GENMASK(15, 0)
> +#define HISI_PTT_SICL_ID GENMASK(31, 16)

Extra spaces between #define and the literals. Please align the values with
that of HISI_PTT_TRACE_DMA_IRQ below.

> +
> +#define HISI_PTT_TRACE_DMA_IRQ 0
> +#define HISI_PTT_TRACE_BUFLETS_CNT 4
> +#define HISI_PTT_TRACE_BUFLET_SIZE SZ_4M
> +#define HISI_PTT_TRACE_BUFFER_SIZE (HISI_PTT_TRACE_BUFLET_SIZE * \
> + HISI_PTT_TRACE_BUFLETS_CNT)
> +#define HISI_PTT_FILTER_UPDATE_FIFO_SIZE 16
> +
> +/* Delay time for filter updating work */
> +#define HISI_PTT_WORK_DELAY_MS 100UL
> +/* Wait time for DMA hardware to reset */
> +#define HISI_PTT_RESET_WAIT_MS 1000UL
> +/* Poll timeout and interval for waiting hardware work to finish */
> +#define HISI_PTT_WAIT_TIMEOUT_US 1000000UL
> +#define HISI_PTT_WAIT_POLL_INTERVAL_US 100UL
> +
> +#define HISI_PCIE_CORE_PORT_ID(devfn) (PCI_FUNC(devfn) << 1)
> +
> +enum hisi_ptt_trace_status {
> + HISI_PTT_TRACE_STATUS_OFF = 0,
> + HISI_PTT_TRACE_STATUS_ON,
> +};
> +
> +struct hisi_ptt_dma_buflet {

I'm not sure what a "buflet" is... Probably best to just call this
hisi_ptt_dma_buffer" if it pertains to a buffer. On that note it is hard to
know due to the lack of proper structure documentation. Please have a look at
how "coresight_device" is documented. The same applies to the rest of the
structures declared below.

> + struct list_head list;
> + unsigned int size;
> + dma_addr_t dma;
> +
> + /*
> + * The address of the buflet holding the trace data.
> + * See Documentation/trace/hisi-ptt.rst for the details

As of this writing, hisi-ptt.rst doesn't exist.

> + * of the data format.
> + */
> + void *addr;
> + int index;
> +};
> +
> +struct hisi_ptt_trace_ctrl {
> + enum hisi_ptt_trace_status status;
> + struct perf_output_handle handle;
> + struct list_head trace_buf;
> + /*
> + * The index of the buffer which trace data
> + * currently is writing to.
> + */
> + u32 buf_index;
> +
> + int default_cpu;
> + u32 buflet_size;
> + bool is_port;
> + u32 format:1; /* Format of the traced TLP headers */
> + u32 type:4; /* Type of the TLP headers to trace */
> + u32 direction:2; /* Direction of the TLP headers to trace */
> + u32 filter:16; /* Root port or Requester to filter the TLP headers */
> +
> + phys_addr_t rmr_addr;
> + size_t rmr_length;
> + bool has_rmr;
> +};
> +
> +struct hisi_ptt_filter_desc {
> + struct list_head list;
> + struct pci_dev *pdev;
> + u16 val;
> +};
> +
> +struct hisi_ptt_pmu_buf {
> + size_t length;
> + int nr_pages;
> + void *base;
> + long pos;
> +};
> +
> +/* Structure containing the information for filter updating */
> +struct hisi_ptt_filter_update_info {
> + struct pci_dev *pdev;
> + u32 port_devid;
> + bool is_port;
> + bool is_add;
> + u16 val;
> +};
> +
> +struct hisi_ptt {
> + struct hisi_ptt_trace_ctrl trace_ctrl;
> + struct notifier_block hisi_ptt_nb;
> + struct pmu hisi_ptt_pmu;
> + void __iomem *iobase;
> + struct pci_dev *pdev;
> + /*
> + * Use the mutex to protect the filter list and
> + * serialize the perf process.
> + */
> + struct mutex mutex;
> + const char *name;
> + u16 core_id;
> + u16 sicl_id;
> + /* PCI device range managed by the PTT device */
> + u32 upper;
> + u32 lower;
> + u8 busnr;
> +
> + /*
> + * The trace TLP headers can either be filtered by certain
> + * root port, or by the requester ID. Organize the filters
> + * by @port_filters and @req_filters here. The mask of all
> + * the valid ports is also cached for doing sanity check
> + * of user input.
> + */
> + struct list_head port_filters;
> + struct list_head req_filters;
> + u16 port_mask;
> +
> + /*
> + * We use a delayed work here to avoid indefinitely waiting for
> + * the hisi_ptt->mutex which protecting the filter list. The
> + * work will be delayed only if the mutex can not be held,
> + * otherwise no delay will be applied.
> + */
> + struct delayed_work work;
> + spinlock_t filter_update_lock;
> + DECLARE_KFIFO(filter_update_kfifo, struct hisi_ptt_filter_update_info,
> + HISI_PTT_FILTER_UPDATE_FIFO_SIZE);
> +};

It might be a good idea to spinoff a hisi_ptt.h for the above declarations.

> +
> +static inline struct hisi_ptt *to_hisi_ptt(struct pmu *pmu)
> +{
> + return container_of(pmu, struct hisi_ptt, hisi_ptt_pmu);
> +}

I'm not sure there is any value to this inline function. I suggest to simply
call container_of() whenever it is needed.

> +
> +static u16 hisi_ptt_get_filter_val(struct pci_dev *pdev)
> +{
> + if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT)
> + return BIT(HISI_PCIE_CORE_PORT_ID(PCI_SLOT(pdev->devfn)));
> +
> + return PCI_DEVID(pdev->bus->number, pdev->devfn);
> +}
> +
> +static int hisi_ptt_wait_trace_hw_idle(struct hisi_ptt *hisi_ptt)
> +{
> + u32 val;
> +
> + return readl_poll_timeout(hisi_ptt->iobase + HISI_PTT_TRACE_STS, val,
> + val & HISI_PTT_TRACE_IDLE,
> + HISI_PTT_WAIT_POLL_INTERVAL_US,
> + HISI_PTT_WAIT_TIMEOUT_US);
> +}
> +
> +static void hisi_ptt_free_trace_buf(struct hisi_ptt *hisi_ptt)
> +{
> + struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
> + struct device *dev = &hisi_ptt->pdev->dev;
> + struct hisi_ptt_dma_buflet *buflet, *tbuflet;
> +
> + list_for_each_entry_safe(buflet, tbuflet, &ctrl->trace_buf, list) {
> + list_del(&buflet->list);
> +
> + if (ctrl->has_rmr)
> + memunmap(buflet->addr);
> + else
> + dma_free_coherent(dev, buflet->size, buflet->addr,
> + buflet->dma);
> +
> + kfree(buflet);
> + }
> +}
> +
> +static int hisi_ptt_alloc_trace_buf(struct hisi_ptt *hisi_ptt)
> +{
> + struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
> + struct device *dev = &hisi_ptt->pdev->dev;
> + struct hisi_ptt_dma_buflet *buflet;
> + int i, ret;
> +
> + hisi_ptt->trace_ctrl.buf_index = 0;
> +
> + /* Make sure the trace buffer is empty before allocating */
> + if (!list_empty(&ctrl->trace_buf)) {
> + list_for_each_entry(buflet, &ctrl->trace_buf, list)
> + memset(buflet->addr, 0, buflet->size);
> + return 0;
> + }
> +
> + for (i = 0; i < HISI_PTT_TRACE_BUFLETS_CNT; ++i) {
> + buflet = kzalloc(sizeof(*buflet), GFP_KERNEL);
> + if (!buflet) {
> + ret = -ENOMEM;
> + goto err;
> + }
> +
> + if (ctrl->has_rmr) {
> + phys_addr_t base = ctrl->rmr_addr + i * ctrl->buflet_size;
> +
> + buflet->dma = base;
> + buflet->addr = memremap(base, ctrl->buflet_size, MEMREMAP_WB);
> + } else {
> + buflet->addr = dma_alloc_coherent(dev, ctrl->buflet_size,
> + &buflet->dma, GFP_KERNEL);
> + }
> +
> + if (!buflet->addr) {
> + kfree(buflet);
> + ret = -ENOMEM;
> + goto err;
> + }
> +
> + memset(buflet->addr, 0, buflet->size);
> +
> + buflet->index = i;
> + buflet->size = ctrl->buflet_size;
> + list_add_tail(&buflet->list, &ctrl->trace_buf);
> + }
> +
> + return 0;
> +err:
> + hisi_ptt_free_trace_buf(hisi_ptt);
> + return ret;
> +}
> +
> +static void hisi_ptt_trace_end(struct hisi_ptt *hisi_ptt)
> +{
> + writel(0, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
> + hisi_ptt->trace_ctrl.status = HISI_PTT_TRACE_STATUS_OFF;
> +}
> +
> +static int hisi_ptt_trace_start(struct hisi_ptt *hisi_ptt)
> +{
> + struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
> + struct hisi_ptt_dma_buflet *cur;
> + u32 val;
> +
> + /* Check device idle before start trace */
> + if (hisi_ptt_wait_trace_hw_idle(hisi_ptt)) {
> + pci_err(hisi_ptt->pdev, "Failed to start trace, the device is still busy.\n");
> + return -EBUSY;
> + }
> +
> + /* Reset the DMA before start tracing */
> + val = readl(hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
> + val |= HISI_PTT_TRACE_CTRL_RST;
> + writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
> +
> + /*
> + * We'll be in the perf context where preemption is disabled,
> + * so use busy loop here.
> + */
> + mdelay(HISI_PTT_RESET_WAIT_MS);
> +
> + val = readl(hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
> + val &= ~HISI_PTT_TRACE_CTRL_RST;
> + writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
> +
> + /* clear the interrupt status */
> + writel(HISI_PTT_TRACE_INT_STAT_MASK, hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
> + writel(0, hisi_ptt->iobase + HISI_PTT_TRACE_INT_MASK);
> +
> + list_for_each_entry(cur, &ctrl->trace_buf, list) {
> + writel(lower_32_bits(cur->dma),
> + hisi_ptt->iobase + HISI_PTT_TRACE_ADDR_BASE_LO_0 +
> + cur->index * HISI_PTT_TRACE_ADDR_STRIDE);
> + writel(upper_32_bits(cur->dma),
> + hisi_ptt->iobase + HISI_PTT_TRACE_ADDR_BASE_HI_0 +
> + cur->index * HISI_PTT_TRACE_ADDR_STRIDE);
> + }
> + writel(ctrl->buflet_size, hisi_ptt->iobase + HISI_PTT_TRACE_ADDR_SIZE);
> +
> + /* set the trace control register */
> + val = FIELD_PREP(HISI_PTT_TRACE_CTRL_TYPE_SEL, ctrl->type);
> + val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_RXTX_SEL, ctrl->direction);
> + val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_DATA_FORMAT, ctrl->format);
> + val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_TARGET_SEL, hisi_ptt->trace_ctrl.filter);
> + if (!hisi_ptt->trace_ctrl.is_port)
> + val |= HISI_PTT_TRACE_CTRL_FILTER_MODE;
> +
> + val |= HISI_PTT_TRACE_CTRL_EN;
> + writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
> +
> + ctrl->status = HISI_PTT_TRACE_STATUS_ON;
> +
> + return 0;
> +}
> +
> +static int hisi_ptt_update_aux(struct hisi_ptt *hisi_ptt, int index, bool stop)
> +{
> + struct perf_output_handle *handle = &hisi_ptt->trace_ctrl.handle;
> + struct perf_event *event = handle->event;
> + struct hisi_ptt_dma_buflet *cur;
> + struct hisi_ptt_pmu_buf *buf;
> +
> + buf = perf_get_aux(handle);
> + if (!buf || !handle->size)
> + return -EINVAL;
> +
> + list_for_each_entry(cur, &hisi_ptt->trace_ctrl.trace_buf, list)
> + if (cur->index == index)
> + break;
> +
> + memcpy(buf->base + buf->pos, cur->addr, cur->size);
> + memset(cur->addr, 0, cur->size);
> + buf->pos += cur->size;
> +
> + if (stop) {
> + perf_aux_output_end(handle, buf->pos);
> + } else if (buf->length - buf->pos < cur->size) {
> + perf_aux_output_skip(handle, buf->length - buf->pos);
> + perf_aux_output_end(handle, buf->pos);
> +
> + buf = perf_aux_output_begin(handle, event);
> + if (!buf)
> + return -EINVAL;
> +
> + buf->pos = handle->head % buf->length;
> + if (buf->length - buf->pos < cur->size) {
> + perf_aux_output_end(handle, 0);
> + return -EINVAL;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static irqreturn_t hisi_ptt_isr(int irq, void *context)
> +{
> + struct hisi_ptt *hisi_ptt = context;
> + u32 status, buf_idx;
> +
> + status = readl(hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
> + buf_idx = ffs(status) - 1;
> +
> + /* Clear the interrupt status of buflet @buf_idx */
> + writel(status, hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
> +
> + /*
> + * Update the AUX buffer and cache the current buflet index,
> + * as we need to know this and save the data when the trace
> + * is ended out of the interrupt handler. End the trace
> + * if the updating fails.
> + */
> + if (hisi_ptt_update_aux(hisi_ptt, buf_idx, false))
> + hisi_ptt_trace_end(hisi_ptt);
> + else
> + hisi_ptt->trace_ctrl.buf_index = (buf_idx + 1) % HISI_PTT_TRACE_BUFLETS_CNT;
> +
> + return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t hisi_ptt_irq(int irq, void *context)
> +{
> + struct hisi_ptt *hisi_ptt = context;
> + u32 status;
> +
> + status = readl(hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
> + if (!(status & HISI_PTT_TRACE_INT_STAT_MASK))
> + return IRQ_NONE;
> +
> + return IRQ_WAKE_THREAD;
> +}
> +
> +static void hisi_ptt_irq_free_vectors(void *pdev)
> +{
> + pci_free_irq_vectors(pdev);
> +}
> +
> +static int hisi_ptt_register_irq(struct hisi_ptt *hisi_ptt)
> +{
> + struct pci_dev *pdev = hisi_ptt->pdev;
> + int ret;
> +
> + ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
> + if (ret < 0) {
> + pci_err(pdev, "failed to allocate irq vector, ret = %d.\n", ret);
> + return ret;
> + }
> +
> + ret = devm_add_action_or_reset(&pdev->dev, hisi_ptt_irq_free_vectors, pdev);
> + if (ret < 0)
> + return ret;
> +
> + ret = devm_request_threaded_irq(&pdev->dev,
> + pci_irq_vector(pdev, HISI_PTT_TRACE_DMA_IRQ),
> + hisi_ptt_irq, hisi_ptt_isr, 0,
> + "hisi-ptt", hisi_ptt);
> + if (ret) {
> + pci_err(pdev, "failed to request irq %d, ret = %d.\n",
> + pci_irq_vector(pdev, HISI_PTT_TRACE_DMA_IRQ), ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static void hisi_ptt_update_filters(struct work_struct *work)
> +{
> + struct delayed_work *delayed_work = to_delayed_work(work);
> + struct hisi_ptt_filter_update_info info;
> + struct hisi_ptt_filter_desc *filter;
> + struct list_head *target_list;
> + struct hisi_ptt *hisi_ptt;
> +
> + hisi_ptt = container_of(delayed_work, struct hisi_ptt, work);
> +
> + if (!mutex_trylock(&hisi_ptt->mutex)) {
> + schedule_delayed_work(&hisi_ptt->work, HISI_PTT_WORK_DELAY_MS);
> + return;
> + }
> +
> + while (kfifo_get(&hisi_ptt->filter_update_kfifo, &info)) {
> + target_list = info.is_port ? &hisi_ptt->port_filters :
> + &hisi_ptt->req_filters;
> +
> + if (info.is_add) {
> + filter = kzalloc(sizeof(*filter), GFP_KERNEL);
> + if (!filter)
> + continue;
> +
> + filter->pdev = info.pdev;
> + filter->val = info.val;
> +
> + list_add_tail(&filter->list, target_list);
> + } else {
> + list_for_each_entry(filter, target_list, list)
> + if (filter->val == info.val) {
> + list_del(&filter->list);
> + kfree(filter);
> + break;
> + }
> + }
> +
> + /* Update the available port mask */
> + if (!info.is_port)
> + continue;
> +
> + if (info.is_add)
> + hisi_ptt->port_mask |= info.val;
> + else
> + hisi_ptt->port_mask &= ~info.val;
> + }
> +
> + mutex_unlock(&hisi_ptt->mutex);
> +}
> +
> +static void hisi_ptt_update_fifo_in(struct hisi_ptt *hisi_ptt,
> + struct hisi_ptt_filter_update_info *info)
> +{
> + struct pci_dev *root_port = pcie_find_root_port(info->pdev);
> +
> + if (!root_port)
> + return;
> +
> + info->port_devid = PCI_DEVID(root_port->bus->number, root_port->devfn);
> + if (info->port_devid < hisi_ptt->lower ||
> + info->port_devid > hisi_ptt->upper)
> + return;
> +
> + info->is_port = pci_pcie_type(info->pdev) == PCI_EXP_TYPE_ROOT_PORT;
> + info->val = hisi_ptt_get_filter_val(info->pdev);
> +
> + if (kfifo_in_spinlocked(&hisi_ptt->filter_update_kfifo, info, 1,
> + &hisi_ptt->filter_update_lock))
> + schedule_delayed_work(&hisi_ptt->work, 0);
> + else
> + pci_warn(hisi_ptt->pdev,
> + "filter update fifo overflow for target %s\n",
> + pci_name(info->pdev));
> +}
> +
> +/*
> + * A PCI bus notifier is used here for dynamically updating the filter
> + * list.
> + */
> +static int hisi_ptt_notifier_call(struct notifier_block *nb, unsigned long action,
> + void *data)
> +{
> + struct hisi_ptt *hisi_ptt = container_of(nb, struct hisi_ptt, hisi_ptt_nb);
> + struct hisi_ptt_filter_update_info info;
> + struct device *dev = data;
> + struct pci_dev *pdev = to_pci_dev(dev);
> +
> + info.pdev = pdev;
> +
> + switch (action) {
> + case BUS_NOTIFY_ADD_DEVICE:
> + info.is_add = true;
> + break;
> + case BUS_NOTIFY_DEL_DEVICE:
> + info.is_add = false;
> + break;
> + default:
> + return 0;
> + }
> +
> + hisi_ptt_update_fifo_in(hisi_ptt, &info);
> +
> + return 0;
> +}
> +
> +static int hisi_ptt_init_filters(struct pci_dev *pdev, void *data)
> +{
> + struct hisi_ptt_filter_update_info info = {
> + .pdev = pdev,
> + .is_add = true,
> + };
> + struct hisi_ptt *hisi_ptt = data;
> +
> + hisi_ptt_update_fifo_in(hisi_ptt, &info);
> +
> + return 0;
> +}
> +
> +static void hisi_ptt_release_filters(struct hisi_ptt *hisi_ptt)
> +{
> + struct hisi_ptt_filter_desc *filter, *tfilter;
> +
> + list_for_each_entry_safe(filter, tfilter, &hisi_ptt->req_filters, list) {
> + list_del(&filter->list);
> + kfree(filter);
> + }
> +
> + list_for_each_entry_safe(filter, tfilter, &hisi_ptt->port_filters, list) {
> + list_del(&filter->list);
> + kfree(filter);
> + }
> +}
> +
> +static void hisi_ptt_init_ctrls(struct hisi_ptt *hisi_ptt)
> +{
> + struct pci_dev *pdev = hisi_ptt->pdev;
> + struct pci_bus *bus;
> + u32 reg;
> +
> + INIT_DELAYED_WORK(&hisi_ptt->work, hisi_ptt_update_filters);
> + spin_lock_init(&hisi_ptt->filter_update_lock);
> + INIT_KFIFO(hisi_ptt->filter_update_kfifo);
> + INIT_LIST_HEAD(&hisi_ptt->port_filters);
> + INIT_LIST_HEAD(&hisi_ptt->req_filters);
> +
> + /*
> + * The device range register provides the information about the
> + * root ports which the RCiEP can control and trace. The RCiEP
> + * and the root ports it support are on the same PCIe core, with
> + * same domain number but maybe different bus number. The device
> + * range register will tell us which root ports we can support,
> + * Bit[31:16] indicates the upper BDF numbers of the root port,
> + * while Bit[15:0] indicates the lower.
> + */
> + reg = readl(hisi_ptt->iobase + HISI_PTT_DEVICE_RANGE);
> + hisi_ptt->upper = reg >> 16;
> + hisi_ptt->lower = reg & 0xffff;
> + hisi_ptt->busnr = PCI_BUS_NUM(hisi_ptt->upper);
> +
> + reg = readl(hisi_ptt->iobase + HISI_PTT_LOCATION);
> + hisi_ptt->core_id = FIELD_GET(HISI_PTT_CORE_ID, reg);
> + hisi_ptt->sicl_id = FIELD_GET(HISI_PTT_SICL_ID, reg);
> +
> + bus = pci_find_bus(pci_domain_nr(pdev->bus), hisi_ptt->busnr);
> + if (bus)
> + pci_walk_bus(bus, hisi_ptt_init_filters, hisi_ptt);

What happens if bus is NULL? Should this be reported to the caller and cause
hisi_ptt_probe() to fail? Please add a comment that describes the scenario.

> +
> + /* Initialize trace controls */
> + INIT_LIST_HEAD(&hisi_ptt->trace_ctrl.trace_buf);
> + hisi_ptt->trace_ctrl.buflet_size = HISI_PTT_TRACE_BUFLET_SIZE;
> + hisi_ptt->trace_ctrl.default_cpu = cpumask_first(cpumask_of_node(dev_to_node(&pdev->dev)));
> +}
> +
> +#define HISI_PTT_PMU_FILTER_IS_PORT BIT(19)
> +#define HISI_PTT_PMU_FILTER_VAL_MASK GENMASK(15, 0)
> +#define HISI_PTT_PMU_DIRECTION_MASK GENMASK(23, 20)
> +#define HISI_PTT_PMU_TYPE_MASK GENMASK(31, 24)
> +#define HISI_PTT_PMU_FORMAT_MASK GENMASK(35, 32)
> +
> +static ssize_t available_filters_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct hisi_ptt *hisi_ptt = to_hisi_ptt(dev_get_drvdata(dev));
> + struct hisi_ptt_filter_desc *filter;
> + int pos = 0;
> +
> + if (list_empty(&hisi_ptt->port_filters))
> + return sysfs_emit(buf, "#### No available filter ####\n");
> +
> + mutex_lock(&hisi_ptt->mutex);
> + pos += sysfs_emit_at(buf, pos, "#### Root Ports ####\n");
> + list_for_each_entry(filter, &hisi_ptt->port_filters, list)
> + pos += sysfs_emit_at(buf, pos, "%s 0x%05lx\n",
> + pci_name(filter->pdev),
> + hisi_ptt_get_filter_val(filter->pdev) |
> + HISI_PTT_PMU_FILTER_IS_PORT);
> +
> + pos += sysfs_emit_at(buf, pos, "#### Requesters ####\n");
> + list_for_each_entry(filter, &hisi_ptt->req_filters, list)
> + pos += sysfs_emit_at(buf, pos, "%s 0x%05x\n",
> + pci_name(filter->pdev),
> + hisi_ptt_get_filter_val(filter->pdev));
> +
> + mutex_unlock(&hisi_ptt->mutex);
> + return pos;
> +}
> +static DEVICE_ATTR_ADMIN_RO(available_filters);
> +
> +PMU_FORMAT_ATTR(filter, "config:0-19");
> +PMU_FORMAT_ATTR(direction, "config:20-23");
> +PMU_FORMAT_ATTR(type, "config:24-31");
> +PMU_FORMAT_ATTR(format, "config:32-35");
> +
> +static struct attribute *hisi_ptt_pmu_format_attrs[] = {
> + &format_attr_filter.attr,
> + &format_attr_direction.attr,
> + &format_attr_type.attr,
> + &format_attr_format.attr,
> + NULL
> +};
> +
> +static struct attribute_group hisi_ptt_pmu_format_group = {
> + .name = "format",
> + .attrs = hisi_ptt_pmu_format_attrs,
> +};
> +
> +static struct attribute *hisi_ptt_pmu_filter_attrs[] = {
> + &dev_attr_available_filters.attr,
> + NULL
> +};
> +
> +static struct attribute_group hisi_ptt_pmu_filter_group = {
> + .attrs = hisi_ptt_pmu_filter_attrs,
> +};
> +
> +static const struct attribute_group *hisi_ptt_pmu_groups[] = {
> + &hisi_ptt_pmu_format_group,
> + &hisi_ptt_pmu_filter_group,
> + NULL
> +};
> +
> +/*
> + * The supported value of the direction parameter. See hisi_ptt.rst
> + * documentation for more details.
> + */
> +static u32 hisi_ptt_trace_available_direction[] = {
> + 0,
> + 1,
> + 2,
> + 3,
> +};
> +
> +/* Different types can be set simultaneously */
> +static u32 hisi_ptt_trace_available_type[] = {
> + 1, /* posted_request */
> + 2, /* non-posted_request */
> + 4, /* completion */
> +};
> +
> +static u32 hisi_ptt_trace_availble_format[] = {
> + 0, /* 4DW */
> + 1, /* 8DW */
> +};
> +
> +/*
> + * Check whether the config is valid or not. Some configs are multi-selectable
> + * and can be set simultaneously, while some are single selectable (onehot).
> + * Use this function to check the non-onehot configs while
> + * hisi_ptt_trace_valid_config_onehot() for the onehot ones.
> + */
> +static int hisi_ptt_trace_valid_config(u32 val, u32 *available_list, u32 list_size)
> +{
> + int i;
> +
> + /*
> + * The non-onehot configs cannot be 0. Walk the available
> + * list and clear the valid bits of the config. If there
> + * is any resident bit after the walk then the config is
> + * invalid.
> + */
> + for (i = 0; i < list_size; i++)
> + val &= ~available_list[i];
> +
> + return val ? -EINVAL : 0;
> +}
> +
> +static int hisi_ptt_trace_valid_config_onehot(u32 val, u32 *available_list, u32 list_size)
> +{
> + int i, ret = -EINVAL;
> +
> + for (i = 0; i < list_size; i++)
> + if (val == available_list[i]) {
> + ret = 0;
> + break;
> + }
> +
> + return ret;
> +}
> +
> +static int hisi_ptt_trace_init_filter(struct hisi_ptt *hisi_ptt, u64 config)
> +{
> + unsigned long val, port_mask = hisi_ptt->port_mask;
> + struct hisi_ptt_filter_desc *filter;
> + int ret = -EINVAL;
> +
> + hisi_ptt->trace_ctrl.is_port = FIELD_GET(HISI_PTT_PMU_FILTER_IS_PORT, config);
> + val = FIELD_GET(HISI_PTT_PMU_FILTER_VAL_MASK, config);
> +
> + /*
> + * Port filters are defined as bit mask. For port filters, check
> + * the bits in the @val are within the range of hisi_ptt->port_mask
> + * and whether it's empty or not, otherwise user has specified
> + * some unsupported root ports.
> + *
> + * For Requester ID filters, walk the available filter list to see
> + * whether we have one matched.
> + */
> + if (hisi_ptt->trace_ctrl.is_port &&
> + bitmap_subset(&val, &port_mask, BITS_PER_LONG)) {
> + ret = 0;
> + } else {
> + list_for_each_entry(filter, &hisi_ptt->req_filters, list)
> + if (filter->val == val) {
> + ret = 0;
> + break;
> + }
> + }
> +
> + if (ret)
> + return ret;
> +
> + hisi_ptt->trace_ctrl.filter = val;
> + return 0;
> +}
> +
> +static int hisi_ptt_pmu_event_init(struct perf_event *event)
> +{
> + struct hisi_ptt *hisi_ptt = to_hisi_ptt(event->pmu);
> + struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
> + int ret;
> + u32 val;
> +
> + if (event->attr.type != hisi_ptt->hisi_ptt_pmu.type)
> + return -ENOENT;
> +
> + mutex_lock(&hisi_ptt->mutex);
> +
> + ret = hisi_ptt_trace_init_filter(hisi_ptt, event->attr.config);
> + if (ret < 0)
> + goto out;
> +
> + val = FIELD_GET(HISI_PTT_PMU_DIRECTION_MASK, event->attr.config);
> + ret = hisi_ptt_trace_valid_config_onehot(val, hisi_ptt_trace_available_direction,
> + ARRAY_SIZE(hisi_ptt_trace_available_direction));
> + if (ret < 0)
> + goto out;
> + ctrl->direction = val;
> +
> + val = FIELD_GET(HISI_PTT_PMU_TYPE_MASK, event->attr.config);
> +
> + ret = hisi_ptt_trace_valid_config(val, hisi_ptt_trace_available_type,
> + ARRAY_SIZE(hisi_ptt_trace_available_type));
> + if (ret < 0)
> + goto out;
> + ctrl->type = val;
> +
> + val = FIELD_GET(HISI_PTT_PMU_FORMAT_MASK, event->attr.config);
> + ret = hisi_ptt_trace_valid_config_onehot(val, hisi_ptt_trace_availble_format,
> + ARRAY_SIZE(hisi_ptt_trace_availble_format));
> + if (ret < 0)
> + goto out;
> + ctrl->format = val;
> +
> +out:
> + mutex_unlock(&hisi_ptt->mutex);
> + return ret;
> +}
> +
> +static void *hisi_ptt_pmu_setup_aux(struct perf_event *event, void **pages,
> + int nr_pages, bool overwrite)
> +{
> + struct hisi_ptt_pmu_buf *buf;
> + struct page **pagelist;
> + int i;
> +
> + if (overwrite) {
> + dev_warn(event->pmu->dev, "Overwrite mode is not supported\n");
> + return NULL;
> + }
> +
> + /* If the pages size less than buflets, we cannot start trace */
> + if (nr_pages < HISI_PTT_TRACE_BUFFER_SIZE / PAGE_SIZE)
> + return NULL;
> +
> + buf = kzalloc(sizeof(*buf), GFP_KERNEL);
> + if (!buf)
> + return NULL;
> +
> + pagelist = kcalloc(nr_pages, sizeof(*pagelist), GFP_KERNEL);
> + if (!pagelist) {
> + kfree(buf);
> + return NULL;
> + }
> +
> + for (i = 0; i < nr_pages; i++)
> + pagelist[i] = virt_to_page(pages[i]);
> +
> + buf->base = vmap(pagelist, nr_pages, VM_MAP, PAGE_KERNEL);
> + if (!buf->base) {
> + kfree(pagelist);
> + kfree(buf);
> + return NULL;
> + }
> +
> + buf->nr_pages = nr_pages;
> + buf->length = nr_pages * PAGE_SIZE;
> + buf->pos = 0;
> +
> + kfree(pagelist);
> + return buf;
> +}
> +
> +static void hisi_ptt_pmu_free_aux(void *aux)
> +{
> + struct hisi_ptt_pmu_buf *buf = aux;
> +
> + vunmap(buf->base);
> + kfree(buf);
> +}
> +
> +static void hisi_ptt_pmu_start(struct perf_event *event, int flags)
> +{
> + struct hisi_ptt *hisi_ptt = to_hisi_ptt(event->pmu);
> + struct perf_output_handle *handle = &hisi_ptt->trace_ctrl.handle;
> + struct hw_perf_event *hwc = &event->hw;
> + struct hisi_ptt_pmu_buf *buf;
> + int cpu = event->cpu;
> + int ret;
> +
> + hwc->state = 0;
> + mutex_lock(&hisi_ptt->mutex);
> + if (hisi_ptt->trace_ctrl.status == HISI_PTT_TRACE_STATUS_ON) {
> + pci_dbg(hisi_ptt->pdev, "trace has already started\n");
> + goto stop;
> + }
> +
> + if (cpu == -1)
> + cpu = hisi_ptt->trace_ctrl.default_cpu;
> +
> + /*
> + * Handle the interrupt on the same cpu which starts the trace to avoid
> + * context mismatch. Otherwise we'll trigger the WARN from the perf
> + * core in event_function_local().
> + */
> + WARN_ON(irq_set_affinity(pci_irq_vector(hisi_ptt->pdev, HISI_PTT_TRACE_DMA_IRQ),
> + cpumask_of(cpu)));
> +
> + ret = hisi_ptt_alloc_trace_buf(hisi_ptt);
> + if (ret) {
> + pci_dbg(hisi_ptt->pdev, "alloc trace buf failed, ret = %d\n", ret);
> + goto stop;
> + }
> +
> + buf = perf_aux_output_begin(handle, event);
> + if (!buf) {
> + pci_dbg(hisi_ptt->pdev, "aux output begin failed\n");
> + goto stop;
> + }
> +
> + buf->pos = handle->head % buf->length;
> +
> + ret = hisi_ptt_trace_start(hisi_ptt);
> + if (ret) {
> + pci_dbg(hisi_ptt->pdev, "trace start failed, ret = %d\n", ret);
> + perf_aux_output_end(handle, 0);
> + goto stop;
> + }
> +
> + mutex_unlock(&hisi_ptt->mutex);
> + return;
> +stop:
> + event->hw.state |= PERF_HES_STOPPED;
> + mutex_unlock(&hisi_ptt->mutex);
> +}
> +
> +static void hisi_ptt_pmu_stop(struct perf_event *event, int flags)
> +{
> + struct hisi_ptt *hisi_ptt = to_hisi_ptt(event->pmu);
> + struct hw_perf_event *hwc = &event->hw;
> +
> + if (hwc->state & PERF_HES_STOPPED)
> + return;
> +
> + mutex_lock(&hisi_ptt->mutex);
> + if (hisi_ptt->trace_ctrl.status == HISI_PTT_TRACE_STATUS_ON) {
> + hisi_ptt_trace_end(hisi_ptt);
> + WARN(hisi_ptt_wait_trace_hw_idle(hisi_ptt), "Device is still busy");
> + hisi_ptt_update_aux(hisi_ptt, hisi_ptt->trace_ctrl.buf_index, true);
> + }
> + mutex_unlock(&hisi_ptt->mutex);
> +
> + hwc->state |= PERF_HES_STOPPED;
> + perf_event_update_userpage(event);
> + hwc->state |= PERF_HES_UPTODATE;
> +}
> +
> +static int hisi_ptt_pmu_add(struct perf_event *event, int flags)
> +{
> + struct hisi_ptt *hisi_ptt = to_hisi_ptt(event->pmu);
> + struct hw_perf_event *hwc = &event->hw;
> + int cpu = event->cpu;
> +
> + if (cpu == -1 && smp_processor_id() != hisi_ptt->trace_ctrl.default_cpu)
> + return 0;
> +
> + hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
> +
> + if (flags & PERF_EF_START) {
> + hisi_ptt_pmu_start(event, PERF_EF_RELOAD);
> + if (hwc->state & PERF_HES_STOPPED)
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static void hisi_ptt_pmu_del(struct perf_event *event, int flags)
> +{
> + hisi_ptt_pmu_stop(event, PERF_EF_UPDATE);
> +}
> +
> +static void hisi_ptt_unregister_pmu(void *priv)
> +{
> + perf_pmu_unregister(priv);
> +}
> +
> +static int hisi_ptt_register_pmu(struct hisi_ptt *hisi_ptt)
> +{
> + char *pmu_name;
> + int ret;
> +
> + hisi_ptt->hisi_ptt_pmu = (struct pmu) {
> + .module = THIS_MODULE,
> + .capabilities = PERF_PMU_CAP_EXCLUSIVE | PERF_PMU_CAP_ITRACE,
> + .task_ctx_nr = perf_sw_context,
> + .attr_groups = hisi_ptt_pmu_groups,
> + .event_init = hisi_ptt_pmu_event_init,
> + .setup_aux = hisi_ptt_pmu_setup_aux,
> + .free_aux = hisi_ptt_pmu_free_aux,
> + .start = hisi_ptt_pmu_start,
> + .stop = hisi_ptt_pmu_stop,
> + .add = hisi_ptt_pmu_add,
> + .del = hisi_ptt_pmu_del,
> + };
> +
> + pmu_name = devm_kasprintf(&hisi_ptt->pdev->dev, GFP_KERNEL, "hisi_ptt%u_%u",
> + hisi_ptt->sicl_id, hisi_ptt->core_id);
> + if (!pmu_name)
> + return -ENOMEM;
> +
> + ret = perf_pmu_register(&hisi_ptt->hisi_ptt_pmu, pmu_name, -1);
> + if (ret)
> + return ret;
> +
> + return devm_add_action_or_reset(&hisi_ptt->pdev->dev,
> + hisi_ptt_unregister_pmu,
> + &hisi_ptt->hisi_ptt_pmu);
> +}
> +
> +/*
> + * Get RMR address if provided by the firmware.
> + * Return 0 if the IOMMU doesn't present or the policy of the
> + * IOMMU domain is passthrough or we get a usable RMR region.
> + * Otherwise a negative value is returned.
> + */
> +static int hisi_ptt_get_rmr(struct hisi_ptt *hisi_ptt)
> +{
> + struct pci_dev *pdev = hisi_ptt->pdev;
> + struct iommu_domain *iommu_domain;
> + struct iommu_resv_region *region;
> + LIST_HEAD(list);
> +
> + /*
> + * Use direct DMA if IOMMU does not present or the policy of the
> + * IOMMU domain is passthrough.
> + */
> + iommu_domain = iommu_get_domain_for_dev(&pdev->dev);
> + if (!iommu_domain || iommu_domain->type == IOMMU_DOMAIN_IDENTITY)
> + return 0;
> +
> + iommu_get_resv_regions(&pdev->dev, &list);
> + list_for_each_entry(region, &list, list)
> + if (region->type == IOMMU_RESV_DIRECT &&
> + region->length >= HISI_PTT_TRACE_BUFFER_SIZE) {
> + hisi_ptt->trace_ctrl.has_rmr = true;
> + hisi_ptt->trace_ctrl.rmr_addr = region->start;
> + hisi_ptt->trace_ctrl.rmr_length = region->length;
> + break;
> + }
> +
> + iommu_put_resv_regions(&pdev->dev, &list);
> + return hisi_ptt->trace_ctrl.has_rmr ? 0 : -ENOMEM;
> +}
> +
> +static int hisi_ptt_probe(struct pci_dev *pdev,
> + const struct pci_device_id *id)
> +{
> + struct hisi_ptt *hisi_ptt;
> + int ret;
> +
> + hisi_ptt = devm_kzalloc(&pdev->dev, sizeof(*hisi_ptt), GFP_KERNEL);
> + if (!hisi_ptt)
> + return -ENOMEM;
> +
> + mutex_init(&hisi_ptt->mutex);
> + hisi_ptt->pdev = pdev;
> +
> + /*
> + * Lifetime of pci_dev is longer than hisi_ptt,
> + * so directly reference to the pci name string.
> + */
> + hisi_ptt->name = pci_name(hisi_ptt->pdev);
> + pci_set_drvdata(pdev, hisi_ptt);
> +
> + ret = pcim_enable_device(pdev);
> + if (ret) {
> + pci_err(pdev, "failed to enable device, ret = %d.\n", ret);
> + return ret;
> + }
> +
> + ret = pcim_iomap_regions(pdev, BIT(2), hisi_ptt->name);
> + if (ret) {
> + pci_err(pdev, "failed to remap io memory, ret = %d.\n", ret);
> + return ret;
> + }
> +
> + hisi_ptt->iobase = pcim_iomap_table(pdev)[2];
> +
> + ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64));
> + if (ret) {
> + pci_err(pdev, "failed to set 64 bit dma mask, ret = %d.\n", ret);
> + return ret;
> + }
> + pci_set_master(pdev);
> +
> + ret = hisi_ptt_register_irq(hisi_ptt);
> + if (ret)
> + return ret;
> +
> + hisi_ptt_init_ctrls(hisi_ptt);
> +
> + ret = hisi_ptt_register_pmu(hisi_ptt);
> + if (ret) {
> + pci_err(pdev, "failed to register pmu device, ret = %d", ret);
> + return ret;
> + }

If this fails the pci_free_irq_vectors() is not called.

I am out of time for today - I will continue tomorrow.

Thanks,
Mathieu

> +
> + ret = hisi_ptt_get_rmr(hisi_ptt);
> + if (ret) {
> + pci_err(pdev, "failed to get RMR region, ret = %d", ret);
> + return ret;
> + }
> +
> + /* Register the bus notifier for dynamically updating the filter list */
> + hisi_ptt->hisi_ptt_nb.notifier_call = hisi_ptt_notifier_call;
> + ret = bus_register_notifier(&pci_bus_type, &hisi_ptt->hisi_ptt_nb);
> + if (ret)
> + pci_warn(pdev, "failed to register filter update notifier, ret = %d", ret);
> +
> + return 0;
> +}
> +
> +void hisi_ptt_remove(struct pci_dev *pdev)
> +{
> + struct hisi_ptt *hisi_ptt = pci_get_drvdata(pdev);
> +
> + bus_unregister_notifier(&pci_bus_type, &hisi_ptt->hisi_ptt_nb);
> +
> + /* Cancel any work that has been queued */
> + cancel_delayed_work_sync(&hisi_ptt->work);
> +
> + if (hisi_ptt->trace_ctrl.status == HISI_PTT_TRACE_STATUS_ON)
> + hisi_ptt_trace_end(hisi_ptt);
> +
> + hisi_ptt_free_trace_buf(hisi_ptt);
> + hisi_ptt_release_filters(hisi_ptt);
> +}
> +
> +static const struct pci_device_id hisi_ptt_id_tbl[] = {
> + { PCI_DEVICE(PCI_VENDOR_ID_HUAWEI, 0xa12e) },
> + { }
> +};
> +MODULE_DEVICE_TABLE(pci, hisi_ptt_id_tbl);
> +
> +static struct pci_driver hisi_ptt_driver = {
> + .name = "hisi_ptt",
> + .id_table = hisi_ptt_id_tbl,
> + .probe = hisi_ptt_probe,
> + .remove = hisi_ptt_remove,
> +};
> +module_pci_driver(hisi_ptt_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Yicong Yang <yangyicong@hisilicon.com>");
> +MODULE_DESCRIPTION("Driver for HiSilicon PCIe tune and trace device");
> --
> 2.33.0
>

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