Messages in this thread Patch in this message | | | Subject | Re: [PATCH v6 1/2] drivers/coresight: Add UltraSoc System Memory Buffer driver | From | "liuqi (BA)" <> | Date | Wed, 8 Jun 2022 18:00:33 +0800 |
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Hi Suzuki, On 2022/6/7 16:33, Suzuki K Poulose wrote: > Hi Qi > > On 06/06/2022 14:02, Qi Liu wrote: >> This patch adds driver for UltraSoc SMB(System Memory Buffer) >> device. SMB provides a way to buffer messages from ETM, and >> store these CPU instructions in system memory. > > nit: "CPU instruction trace" in system memory. > >> >> SMB is developed by UltraSoc technology, which is acquired by >> Siemens, and we still use "UltraSoc" to name driver. >> >> Signed-off-by: Qi Liu <liuqi115@huawei.com> >> Tested-by: JunHao He <hejunhao2@hisilicon.com> >> --- >> drivers/hwtracing/coresight/Kconfig | 10 + >> drivers/hwtracing/coresight/Makefile | 1 + >> drivers/hwtracing/coresight/ultrasoc-smb.c | 663 +++++++++++++++++++++ >> drivers/hwtracing/coresight/ultrasoc-smb.h | 110 ++++ >> 4 files changed, 784 insertions(+) >> create mode 100644 drivers/hwtracing/coresight/ultrasoc-smb.c >> create mode 100644 drivers/hwtracing/coresight/ultrasoc-smb.h >> >> diff --git a/drivers/hwtracing/coresight/Kconfig >> b/drivers/hwtracing/coresight/Kconfig >> index 514a9b8086e3..4380eb1a0a73 100644 >> --- a/drivers/hwtracing/coresight/Kconfig >> +++ b/drivers/hwtracing/coresight/Kconfig > > ... > >> diff --git a/drivers/hwtracing/coresight/Makefile >> b/drivers/hwtracing/coresight/Makefile >> index b6c4a48140ec..344dba8d6ff8 100644 >> --- a/drivers/hwtracing/coresight/Makefile >> +++ b/drivers/hwtracing/coresight/Makefile >> @@ -27,3 +27,4 @@ obj-$(CONFIG_CORESIGHT_CTI) += coresight-cti.o >> obj-$(CONFIG_CORESIGHT_TRBE) += coresight-trbe.o >> coresight-cti-y := coresight-cti-core.o coresight-cti-platform.o \ >> coresight-cti-sysfs.o >> +obj-$(CONFIG_ULTRASOC_SMB) += ultrasoc-smb.o >> diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c >> b/drivers/hwtracing/coresight/ultrasoc-smb.c >> new file mode 100644 >> index 000000000000..44b4bceb6f28 >> --- /dev/null >> +++ b/drivers/hwtracing/coresight/ultrasoc-smb.c > > ... > >> +static int smb_open(struct inode *inode, struct file *file) >> +{ >> + struct smb_drv_data *drvdata = container_of(file->private_data, >> + struct smb_drv_data, miscdev); >> + unsigned long flags; >> + int ret = 0; >> + >> + spin_lock_irqsave(&drvdata->spinlock, flags); >> + >> + if (local_read(&drvdata->reading)) { >> + ret = -EBUSY; >> + goto out; >> + } >> + >> + if (drvdata->mode == CS_MODE_PERF) { >> + ret = -EINVAL; >> + goto out; >> + } >> + >> +out: >> + spin_unlock_irqrestore(&drvdata->spinlock, flags); >> + return ret; >> +} >> + >> +static ssize_t smb_read(struct file *file, char __user *data, size_t >> len, >> + loff_t *ppos) >> +{ >> + struct smb_drv_data *drvdata = container_of(file->private_data, >> + struct smb_drv_data, miscdev); >> + struct smb_data_buffer *sdb = &drvdata->sdb; >> + struct device *dev = &drvdata->csdev->dev; >> + unsigned long flags; >> + int to_copy = 0; >> + >> + spin_lock_irqsave(&drvdata->spinlock, flags); >> + >> + if (atomic_read(drvdata->csdev->refcnt)) { >> + spin_unlock_irqrestore(&drvdata->spinlock, flags); >> + return -EBUSY; >> + } >> + >> + if (local_cmpxchg(&drvdata->reading, 0, 1)) { >> + spin_unlock_irqrestore(&drvdata->spinlock, flags); >> + return -EBUSY; >> + } >> + > > Shouldn't this be done in smb_open() ? Otherwise, a subsequent read > will fail with EBUSY ? > i.e, > fd = open(/dev/ultra_smb0, ..); > > # size of the SMB buffer = 1M, > size = read(fd, buf, SZ_4K); > /* Do something the buf */ > if (size >= 0) > size = read(fd, buf, SZ_4K); > > ^^ This would fail, isn't it ? >
Yes, I'll change it to: static int smb_open(struct inode *inode, struct file *file) { struct smb_drv_data *drvdata = container_of(file->private_data, struct smb_drv_data, miscdev); unsigned long flags; int ret = 0;
spin_lock_irqsave(&drvdata->spinlock, flags);
if (local_read(&drvdata->reading)) { ret = -EBUSY; goto out; }
if (drvdata->mode != CS_MODE_DISABLED) { ret = -EBUSY; goto out; }
local_set(&drvdata->reading, 1); out: spin_unlock_irqrestore(&drvdata->spinlock, flags); return ret; }
So SMB data can only be read when SMB is disabled, and could be read subsequently.
>> + if (!sdb->data_size) { >> + smb_update_data_size(drvdata); >> + if (!sdb->data_size) >> + goto out; >> + } >> + >> + to_copy = min(sdb->data_size, len); >> + >> + /* Copy parts of trace data when read pointer wrap around SMB >> buffer */ >> + if (sdb->rd_offset + to_copy > sdb->buf_size) >> + to_copy = sdb->buf_size - sdb->rd_offset; >> + >> + if (copy_to_user(data, (void *)sdb->buf_base + sdb->rd_offset, >> + to_copy)) { >> + dev_dbg(dev, "Failed to copy data to user.\n"); >> + to_copy = -EFAULT; >> + goto out; >> + } >> + >> + *ppos += to_copy; >> + sdb->data_size -= to_copy; >> + sdb->rd_offset += to_copy; >> + sdb->rd_offset %= sdb->buf_size; >> + writel(sdb->start_addr + sdb->rd_offset, >> + drvdata->base + SMB_LB_RD_ADDR); >> + dev_dbg(dev, "%d bytes copied.\n", to_copy); >> +out: >> + if (!sdb->data_size) >> + smb_reset_buffer_status(drvdata); >> + spin_unlock_irqrestore(&drvdata->spinlock, flags); >> + return to_copy; >> +} >> + [...] >> + >> +static int smb_set_perf_buffer(struct perf_output_handle *handle) >> +{ >> + struct cs_buffers *buf = etm_perf_sink_config(handle); >> + u32 head; >> + >> + if (!buf) >> + return -EINVAL; >> + >> + /* Wrap head around to the amount of space we have */ >> + head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1); >> + >> + /* Find the page to write to and offset within that page */ >> + buf->cur = head / PAGE_SIZE; >> + buf->offset = head % PAGE_SIZE; >> + > > I believe these fields should be dropped and instead use the > handle->head, to determine the page number and offset. See the > TMC-ETR driver for e.g.
got it, I'll do this next time.
> >> + local_set(&buf->data_size, 0); >> + >> + return 0; >> +} >> +
[...] >> + >> +static int smb_enable(struct coresight_device *csdev, u32 mode, void >> *data) >> +{ >> + struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); >> + int ret; >> + >> + /* Do nothing if trace data is reading by other interface now */ >> + if (local_read(&drvdata->reading)) >> + return -EBUSY; >> + > > Is there global switch for all the inports ? Or is there a control for > individual inports to the SMB ? Do we need additional information here > to enable the corresponding port ?
There is a global switch to enable and disable all the inports in smb_config_inport() when probe the SMB driver.
> >> + switch (mode) { >> + case CS_MODE_SYSFS: >> + ret = smb_enable_sysfs(csdev); >> + break; >> + case CS_MODE_PERF: >> + ret = smb_enable_perf(csdev, data); >> + break; >> + default: >> + ret = -EINVAL; >> + break; >> + } >> + >> + if (ret) >> + return ret; >> + dev_dbg(&csdev->dev, "Ultrasoc SMB enabled.\n"); >> + >> + return 0; >> +} >> + >> + >> +static void smb_free_buffer(void *config) >> +{ >> + struct cs_buffers *buf = config; >> + >> + kfree(buf); >> +} >> + >> +static void smb_sync_perf_buffer(struct smb_drv_data *drvdata, >> + struct cs_buffers *buf, >> + unsigned long data_size) > > You may need to pass the aux_handle here, to determine the handle->head > and the size. See my comments above. ok, I'll do this next time, thanks.
> >> +{ >> + struct smb_data_buffer *sdb = &drvdata->sdb; >> + char **dst_pages = (char **)buf->data_pages; >> + unsigned long page_offset = buf->offset; >> + unsigned int cur = buf->cur; >> + unsigned long to_copy; >> + >> + while (data_size) { >> + unsigned long page_space = PAGE_SIZE - page_offset; >> + >> + /* Copy parts of trace data when read pointer wrap around */ >> + if (sdb->rd_offset + page_space > sdb->buf_size) >> + to_copy = sdb->buf_size - sdb->rd_offset; >> + else >> + to_copy = min(data_size, page_space); >> + >> + memcpy_fromio(dst_pages[cur] + page_offset, >> + sdb->buf_base + sdb->rd_offset, to_copy); >> + >> + page_offset += to_copy; >> + if (page_offset >= PAGE_SIZE) { >> + page_offset = 0; >> + cur++; >> + cur %= buf->nr_pages; >> + } >> + data_size -= to_copy; >> + sdb->rd_offset += to_copy; >> + sdb->rd_offset %= sdb->buf_size; >> + } >> + >> + sdb->data_size = 0; >> + writel(sdb->start_addr + sdb->rd_offset, drvdata->base + >> SMB_LB_RD_ADDR); >> + >> + /* >> + * Data remained in link cannot be purged when SMB is full, so >> + * synchronize the read pointer to write pointer, to make sure >> + * these remained data won't influence next trace. >> + */ >> + if (sdb->full) { >> + smb_purge_data(drvdata); >> + writel(readl(drvdata->base + SMB_LB_WR_ADDR), >> + drvdata->base + SMB_LB_RD_ADDR); >> + } >> + smb_reset_buffer_status(drvdata); >> +} >> +
>> + >> +static int smb_register_sink(struct platform_device *pdev, >> + struct smb_drv_data *drvdata) >> +{ >> + struct coresight_platform_data *pdata = NULL; >> + struct coresight_desc desc = { 0 }; >> + int ret; >> + >> + pdata = coresight_get_platform_data(&pdev->dev); >> + if (IS_ERR(pdata)) >> + return PTR_ERR(pdata); >> + >> + desc.type = CORESIGHT_DEV_TYPE_SINK; >> + desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER; >> + desc.ops = &cs_ops; >> + desc.pdata = pdata; >> + desc.dev = &pdev->dev; >> + desc.groups = smb_sink_groups; >> + desc.name = coresight_alloc_device_name(&sink_devs, &pdev->dev); > > Please fill in the csdev_access method for the device. will do this next time, thanks.
Thanks, Qi > desc.access = CSDEV_ACCESS_IOMEM(drvdata->base); > >> + if (!desc.name) { >> + dev_err(&pdev->dev, "Failed to alloc coresight device name."); >> + return -ENOMEM; >> + } >> + >> + drvdata->csdev = coresight_register(&desc); >> + if (IS_ERR(drvdata->csdev)) >> + return PTR_ERR(drvdata->csdev); >> + >> + drvdata->miscdev.name = desc.name; >> + drvdata->miscdev.minor = MISC_DYNAMIC_MINOR; >> + drvdata->miscdev.fops = &smb_fops; >> + ret = misc_register(&drvdata->miscdev); >> + if (ret) { >> + coresight_unregister(drvdata->csdev); >> + dev_err(&pdev->dev, "Failed to register misc, ret=%d.\n", ret); >> + } >> + >> + return ret; >> +} >> + >> +static void smb_unregister_sink(struct smb_drv_data *drvdata) >> +{ >> + misc_deregister(&drvdata->miscdev); >> + coresight_unregister(drvdata->csdev); >> +} >> + >> +static int smb_config_inport(struct device *dev, bool enable) >> +{ >> + u64 func = enable ? 1 : 0; >> + union acpi_object *obj; >> + guid_t guid; >> + u64 rev = 0; >> + >> + /* >> + * Using DSM calls to enable/disable ultrasoc hardwares on >> + * tracing path, to prevent ultrasoc packet format being exposed. >> + */ >> + if (guid_parse(ULTRASOC_SMB_DSM_UUID, &guid)) { >> + dev_err(dev, "Get GUID failed.\n"); >> + return -EINVAL; >> + } >> + >> + obj = acpi_evaluate_dsm(ACPI_HANDLE(dev), &guid, rev, func, NULL); >> + if (!obj) >> + dev_err(dev, "ACPI handle failed!\n"); >> + else >> + ACPI_FREE(obj); >> + >> + return 0; >> +} >> + >> +static int smb_probe(struct platform_device *pdev) >> +{ >> + struct smb_drv_data *drvdata; >> + int ret; >> + >> + drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL); >> + if (!drvdata) >> + return -ENOMEM; >> + >> + drvdata->base = devm_platform_ioremap_resource(pdev, 0); >> + if (IS_ERR(drvdata->base)) { >> + dev_err(&pdev->dev, "Failed to ioremap resource.\n"); >> + return PTR_ERR(drvdata->base); >> + } >> + >> + ret = smb_init_data_buffer(pdev, &drvdata->sdb); >> + if (ret) { >> + dev_err(&pdev->dev, "Failed to init buffer, ret = %d.\n", ret); >> + return ret; >> + } >> + >> + smb_init_hw(drvdata); >> + spin_lock_init(&drvdata->spinlock); >> + drvdata->pid = -1; >> + >> + ret = smb_register_sink(pdev, drvdata); >> + if (ret) { >> + dev_err(&pdev->dev, "Failed to register smb sink.\n"); >> + return ret; >> + } >> + >> + ret = smb_config_inport(&pdev->dev, true); >> + if (ret) { >> + smb_unregister_sink(drvdata); >> + return ret; >> + } >> + >> + platform_set_drvdata(pdev, drvdata); >> + return 0; >> +} >> + >> +static int smb_remove(struct platform_device *pdev) >> +{ >> + struct smb_drv_data *drvdata = platform_get_drvdata(pdev); >> + int ret; >> + >> + ret = smb_config_inport(&pdev->dev, false); >> + if (ret) >> + return ret; >> + >> + smb_unregister_sink(drvdata); >> + return 0; >> +} >> + >> +static const struct acpi_device_id ultrasoc_smb_acpi_match[] = { >> + {"HISI03A1", 0}, >> + {}, >> +}; >> +MODULE_DEVICE_TABLE(acpi, ultrasoc_smb_acpi_match); >> + >> +static struct platform_driver smb_driver = { >> + .driver = { >> + .name = "ultrasoc-smb", >> + .acpi_match_table = ACPI_PTR(ultrasoc_smb_acpi_match), >> + .suppress_bind_attrs = true, >> + }, >> + .probe = smb_probe, >> + .remove = smb_remove, >> +}; >> +module_platform_driver(smb_driver); >> + >> +MODULE_DESCRIPTION("UltraSoc smb driver"); > > "UltraSoc SMB CoreSight driver" > >> +MODULE_LICENSE("Dual MIT/GPL"); >> +MODULE_AUTHOR("Jonathan Zhou <jonathan.zhouwen@huawei.com>"); >> +MODULE_AUTHOR("Qi Liu <liuqi115@huawei.com>"); > >> diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.h >> b/drivers/hwtracing/coresight/ultrasoc-smb.h >> new file mode 100644 >> index 000000000000..a01f869fe122 >> --- /dev/null >> +++ b/drivers/hwtracing/coresight/ultrasoc-smb.h >> @@ -0,0 +1,110 @@ >> +/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */ >> +/* >> + * Siemens System Memory Buffer driver. >> + * Copyright(c) 2021, HiSilicon Limited. >> + */ >> + >> +#ifndef _ULTRASOC_SMB_H >> +#define _ULTRASOC_SMB_H >> + >> +#include <linux/coresight.h> >> +#include <linux/list.h> >> +#include <linux/miscdevice.h> >> + >> +#include "coresight-etm-perf.h" >> +#include "coresight-priv.h" >> + >> +/* Offset of SMB logical buffer registers */ >> +#define SMB_CFG_REG 0x00 >> +#define SMB_GLOBAL_EN 0x04 >> +#define SMB_GLOBAL_INT 0x08 >> +#define SMB_LB_CFG_LO 0x40 >> +#define SMB_LB_CFG_HI 0x44 >> +#define SMB_LB_INT_CTRL 0x48 >> +#define SMB_LB_INT_STS 0x4c >> +#define SMB_LB_LIMIT 0x58 >> +#define SMB_LB_RD_ADDR 0x5c >> +#define SMB_LB_WR_ADDR 0x60 >> +#define SMB_LB_PURGE 0x64 >> + >> +/* Set SMB_CFG_REG register */ >> +#define SMB_BURST_LEN GENMASK(7, 4) >> +#define SMB_IDLE_PRD GENMASK(15, 12) >> +#define SMB_MEM_WR GENMASK(17, 16) >> +#define SMB_MEM_RD (GENMASK(26, 25) | GENMASK(23, 22)) >> +#define SMB_GLOBAL_CFG (SMB_IDLE_PRD | SMB_MEM_WR | >> SMB_MEM_RD | \ >> + SMB_BURST_LEN) >> + >> +/* Set SMB_GLOBAL_INT register */ >> +#define SMB_INT_EN BIT(0) >> +#define SMB_INT_TYPE_PULSE BIT(1) >> +#define SMB_INT_POLARITY_HIGH BIT(2) >> +#define SMB_GLB_INT_CFG (SMB_INT_EN | SMB_INT_TYPE_PULSE | \ >> + SMB_INT_POLARITY_HIGH) >> + >> +/* Set SMB_LB_CFG_LO register */ >> +#define SMB_BUF_EN BIT(0) >> +#define SMB_BUF_SINGLE_END BIT(1) >> +#define SMB_BUF_INIT BIT(8) >> +#define SMB_BUF_CONTINUOUS BIT(11) >> +#define SMB_FLOW_MASK GENMASK(19, 16) > What does the value GENMASK(19, 16) indicate for SMB_FLOW ? That is the > value being passed down. Please add a descriptive name. > .e.g, > > #define SMB_FLOW_MODE_X GENMASK(19, 16) > > Similarly for SMB_BUF_NOTE_MASK, unless there is an explanation. > >> +#define SMB_BUF_CFG_STREAMING (SMB_BUF_INIT | SMB_BUF_CONTINUOUS >> | \ >> + SMB_FLOW_MASK | SMB_BUF_SINGLE_END | \ >> + SMB_BUF_EN) >> + >> +#define SMB_BASE_LOW_MASK GENMASK(31, 0) >> + >> +/* Set SMB_LB_CFG_HI register */ >> +#define SMB_MSG_FILTER GENMASK(15, 8) >> + >> +/* Set SMB_LB_INT_CTRL */ >> +#define SMB_BUF_INT_EN BIT(0) >> +#define SMB_BUF_NOTE_MASK GENMASK(11, 8) >> +#define SMB_BUF_INT_CFG (SMB_BUF_INT_EN | SMB_BUF_NOTE_MASK) >> + >> +/** >> + * struct smb_data_buffer - Details of the buffer used by SMB >> + * @buf_base : Memory mapped base address of SMB. >> + * @start_addr : SMB buffer start Physical address. >> + * @buf_size : Size of the buffer. > > Please align the field definitions. > >> + * @data_size : Size of Trace data copy to userspace. >> + * @rd_offset : Offset of the read pointer in the buffer. >> + * @wr_offset : Offset of the write pointer in the buffer. >> + * @status : Status of SMB buffer. >> + */ >> +struct smb_data_buffer { >> + void __iomem *buf_base; >> + u32 start_addr; >> + unsigned long buf_size; >> + unsigned long data_size; >> + unsigned long rd_offset; >> + unsigned long wr_offset; >> + bool full; >> +}; >> + >> +/** >> + * struct smb_drv_data - specifics associated to an SMB component >> + * @base: Memory mapped base address for SMB component. >> + * @csdev: Component vitals needed by the framework. >> + * @sdb: Data buffer for SMB. >> + * @miscdev: Specifics to handle "/dev/xyz.smb" entry. >> + * @spinlock: Only one at a time pls. >> + * @reading: Synchronise user space access to SMB buffer. >> + * @pid: Process ID of the process being monitored by the session >> + * that is using this component. > > Same as above. > >> + * @mode: how this SMB is being used, perf mode or sysfs mode. >> + */ >> +struct smb_drv_data { >> + void __iomem *base; >> + struct coresight_device *csdev; >> + struct smb_data_buffer sdb; >> + struct miscdevice miscdev; >> + spinlock_t spinlock; >> + local_t reading; >> + pid_t pid; >> + u32 mode; >> +}; >> + >> +#define smb_reg(name, offset) coresight_simple_reg32(struct >> smb_drv_data, name, offset) >> + >> +#endif > > Suzuki > .
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