Add support for UltraSoc System Memory Buffer.
Change since v12:
- Modify the code style and add "#ifdef CONFIG_ACPI" according to Jonathan's comment.
- Address the comments from Yicong.
- Link: https://lore.kernel.org/lkml/[email protected]/
Change since v11:
- Modify the code style and rename the macro according to Jonathan's comment.
- Link: https://lore.kernel.org/lkml/[email protected]/
Change since v10:
- Rebase onto v6.1-rc4, included similar sysfs register accessors (as same as James's patch)
- Link: https://lore.kernel.org/lkml/[email protected]/
Change since v9:
- Update the Contact tag in SMB document.
- Replace the spinlock with mutex.
- Do some clean-ups in "smb_enable()" and "smb_release()".
- Use classic memory mapped interface.
- Link: https://lore.kernel.org/linux-arm-kernel/[email protected]/
Change since v8:
- Insert a blank line at the end of the config tag in Kconfig according to Randy's comment.
- Link: https://lore.kernel.org/linux-arm-kernel/[email protected]/
Change since v7:
- Use the macros for register bit flags and numbers of resource.
- Cleanup punctuation.
- Update the Date tag and the KernelVersion tag in the document.
- Link: https://lore.kernel.org/lkml/[email protected]/
Change since v6:
- Modify the code style and driver description according to Suzuki's comment.
- Modify configuration of "drvdata->reading", to void problems in open/read
concurrency scenario.
- Rename the macro of "SMB_FLOW_MASK".
- Use the "handle->head" to determine the page number and offset.
- Link: https://lore.kernel.org/linux-arm-kernel/[email protected]/
Change since v5:
- Address the comments from Suzuki, add some comments in SMB document, and modify
configuration of "drvdata->reading", to void problems in multi-core concurrency scenario
- Link: https://lore.kernel.org/linux-arm-kernel/[email protected]/
Change since v4:
- Add a simple document of SMB driver according to Suzuki's comment.
- Address the comments from Suzuki.
- Link: https://lore.kernel.org/linux-arm-kernel/[email protected]/
Change since v3:
- Modify the file header according to community specifications.
- Address the comments from Mathieu.
- Link: https://lore.kernel.org/linux-arm-kernel/[email protected]/
Change since v2:
- Move ultrasoc driver to drivers/hwtracing/coresight by Mathieu's comment.
- Link: https://lists.linaro.org/pipermail/coresight/2021-November/007310.html
Change since v1:
- Drop the document of UltraSoc according to Mathieu's comment.
- Add comments to explain some private hardware settings.
- Address the comments from Mathieu.
- Link: https://lists.linaro.org/pipermail/coresight/2021-August/006842.html
Change since RFC:
- Move driver to drivers/hwtracing/coresight/ultrasoc.
- Remove ultrasoc-axi-com.c, as AXI-COM doesn't need to be configured in
basic tracing function.
- Remove ultrasoc.c as SMB does not need to register with the ultrasoc core.
- Address the comments from Mathieu and Suzuki.
- Link: https://lists.linaro.org/pipermail/coresight/2021-June/006535.html
Qi Liu (2):
drivers/coresight: Add UltraSoc System Memory Buffer driver
Documentation: Add document for UltraSoc SMB drivers
.../sysfs-bus-coresight-devices-ultra_smb | 31 +
.../trace/coresight/ultrasoc-smb.rst | 82 +++
drivers/hwtracing/coresight/Kconfig | 11 +
drivers/hwtracing/coresight/Makefile | 1 +
drivers/hwtracing/coresight/ultrasoc-smb.c | 646 ++++++++++++++++++
drivers/hwtracing/coresight/ultrasoc-smb.h | 120 ++++
6 files changed, 891 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-bus-coresight-devices-ultra_smb
create mode 100644 Documentation/trace/coresight/ultrasoc-smb.rst
create mode 100644 drivers/hwtracing/coresight/ultrasoc-smb.c
create mode 100644 drivers/hwtracing/coresight/ultrasoc-smb.h
--
2.33.0
From: Qi Liu <[email protected]>
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 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 <[email protected]>
Signed-off-by: Junhao He <[email protected]>
Tested-by: JunHao He <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
---
drivers/hwtracing/coresight/Kconfig | 11 +
drivers/hwtracing/coresight/Makefile | 1 +
drivers/hwtracing/coresight/ultrasoc-smb.c | 656 +++++++++++++++++++++
drivers/hwtracing/coresight/ultrasoc-smb.h | 120 ++++
4 files changed, 788 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 45c1eb5dfcb7..cb17c207a728 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -201,4 +201,15 @@ config CORESIGHT_TRBE
To compile this driver as a module, choose M here: the module will be
called coresight-trbe.
+
+config ULTRASOC_SMB
+ tristate "Ultrasoc system memory buffer drivers"
+ depends on ARM64 && CORESIGHT_LINKS_AND_SINKS
+ help
+ This driver provides support for the Ultrasoc system memory buffer (SMB).
+ SMB is responsible for receiving the trace data from Coresight ETM devices
+ and storing them to a system buffer.
+
+ To compile this driver as a module, choose M here: the module will be
+ called ultrasoc-smb.
endif
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..1957796cbab2
--- /dev/null
+++ b/drivers/hwtracing/coresight/ultrasoc-smb.c
@@ -0,0 +1,656 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * Siemens System Memory Buffer driver.
+ * Copyright(c) 2022, HiSilicon Limited.
+ */
+
+#include <linux/atomic.h>
+#include <linux/acpi.h>
+#include <linux/circ_buf.h>
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+
+#include "coresight-etm-perf.h"
+#include "coresight-priv.h"
+#include "ultrasoc-smb.h"
+
+DEFINE_CORESIGHT_DEVLIST(sink_devs, "ultra_smb");
+
+#define ULTRASOC_SMB_DSM_UUID "82ae1283-7f6a-4cbe-aa06-53e8fb24db18"
+
+static bool smb_buffer_is_empty(struct smb_drv_data *drvdata)
+{
+ u32 buf_status = readl(drvdata->base + SMB_LB_INT_STS_REG);
+
+ return !FIELD_GET(SMB_LB_INT_STS_NOT_EMPTY_MSK, buf_status);
+}
+
+static void smb_buffer_sync_status(struct smb_drv_data *drvdata)
+{
+ struct smb_data_buffer *sdb = &drvdata->sdb;
+
+ sdb->wr_offset = readl(drvdata->base + SMB_LB_WR_ADDR_REG) -
+ sdb->start_addr;
+ sdb->rd_offset = readl(drvdata->base + SMB_LB_RD_ADDR_REG) -
+ sdb->start_addr;
+ sdb->full = sdb->wr_offset == sdb->rd_offset &&
+ !smb_buffer_is_empty(drvdata);
+}
+
+static void smb_reset_buffer_status(struct smb_drv_data *drvdata)
+{
+ /* All other bits are reserved and shall be 0 */
+ writel(SMB_LB_INT_STS_RESET, drvdata->base + SMB_LB_INT_STS_REG);
+}
+
+/* Purge data remaining in hardware path in case them influence next trace */
+static void smb_purge_data(struct smb_drv_data *drvdata)
+{
+ /* All other bits are reserved and shall be 0 */
+ writel(SMB_LB_PURGE_PURGED, drvdata->base + SMB_LB_PURGE_REG);
+}
+
+static void smb_update_data_size(struct smb_drv_data *drvdata)
+{
+ struct smb_data_buffer *sdb = &drvdata->sdb;
+
+ smb_purge_data(drvdata);
+ smb_buffer_sync_status(drvdata);
+ if (sdb->full) {
+ sdb->data_size = sdb->buf_size;
+ return;
+ }
+
+ sdb->data_size = CIRC_CNT(sdb->wr_offset, sdb->rd_offset,
+ sdb->buf_size);
+}
+
+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);
+ int ret = 0;
+
+ mutex_lock(&drvdata->mutex);
+
+ if (drvdata->reading) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ if (atomic_read(drvdata->csdev->refcnt)) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ drvdata->reading = true;
+out:
+ mutex_unlock(&drvdata->mutex);
+
+ 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;
+ ssize_t to_copy = 0;
+
+ mutex_lock(&drvdata->mutex);
+
+ if (!len)
+ goto out;
+
+ /*
+ * In sysfs mode, size need to be update in the following two cases:
+ * 1) Start dumping data.
+ * 2) End dump data, make sure there is no remaining data in
+ * the hardware path. Because the remaining data cannot be purged
+ * when the buffer is full.
+ */
+ 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_REG);
+ dev_dbg(dev, "%zu bytes copied\n", to_copy);
+out:
+ if (!sdb->data_size)
+ smb_reset_buffer_status(drvdata);
+ mutex_unlock(&drvdata->mutex);
+
+ return to_copy;
+}
+
+static int smb_release(struct inode *inode, struct file *file)
+{
+ struct smb_drv_data *drvdata = container_of(file->private_data,
+ struct smb_drv_data, miscdev);
+
+ mutex_lock(&drvdata->mutex);
+ drvdata->reading = false;
+ mutex_unlock(&drvdata->mutex);
+
+ return 0;
+}
+
+static const struct file_operations smb_fops = {
+ .owner = THIS_MODULE,
+ .open = smb_open,
+ .read = smb_read,
+ .release = smb_release,
+ .llseek = no_llseek,
+};
+
+static ssize_t buf_size_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct smb_drv_data *drvdata = dev_get_drvdata(dev->parent);
+
+ return sysfs_emit(buf, "0x%lx\n", drvdata->sdb.buf_size);
+}
+static DEVICE_ATTR_RO(buf_size);
+
+static struct attribute *smb_sink_attrs[] = {
+ coresight_simple_reg32(read_pos, SMB_LB_RD_ADDR_REG),
+ coresight_simple_reg32(write_pos, SMB_LB_WR_ADDR_REG),
+ coresight_simple_reg32(buf_status, SMB_LB_INT_STS_REG),
+ &dev_attr_buf_size.attr,
+ NULL
+};
+
+static const struct attribute_group smb_sink_group = {
+ .attrs = smb_sink_attrs,
+ .name = "mgmt",
+};
+
+static const struct attribute_group *smb_sink_groups[] = {
+ &smb_sink_group,
+ NULL
+};
+
+static void smb_enable_hw(struct smb_drv_data *drvdata)
+{
+ writel(SMB_GLB_EN_HW_ENABLE, drvdata->base + SMB_GLB_EN_REG);
+}
+
+static void smb_disable_hw(struct smb_drv_data *drvdata)
+{
+ writel(0x0, drvdata->base + SMB_GLB_EN_REG);
+}
+
+static void smb_enable_sysfs(struct coresight_device *csdev)
+{
+ struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ if (drvdata->mode != CS_MODE_DISABLED)
+ return;
+
+ smb_enable_hw(drvdata);
+ drvdata->mode = CS_MODE_SYSFS;
+}
+
+static int smb_enable_perf(struct coresight_device *csdev, void *data)
+{
+ struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
+ struct perf_output_handle *handle = data;
+ struct cs_buffers *buf = etm_perf_sink_config(handle);
+ pid_t pid;
+
+ if (!buf)
+ return -EINVAL;
+
+ /* Get a handle on the pid of the target process */
+ pid = buf->pid;
+
+ /* Device is already in used by other session */
+ if (drvdata->pid != -1 && drvdata->pid != pid)
+ return -EBUSY;
+
+ if (drvdata->pid == -1) {
+ smb_enable_hw(drvdata);
+ drvdata->pid = pid;
+ drvdata->mode = CS_MODE_PERF;
+ }
+
+ 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 = 0;
+
+ mutex_lock(&drvdata->mutex);
+
+ /* Do nothing, the trace data is reading by other interface now */
+ if (drvdata->reading) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ /* Do nothing, the SMB is already enabled as other mode */
+ if (drvdata->mode != CS_MODE_DISABLED && drvdata->mode != mode) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ switch (mode) {
+ case CS_MODE_SYSFS:
+ smb_enable_sysfs(csdev);
+ break;
+ case CS_MODE_PERF:
+ ret = smb_enable_perf(csdev, data);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ if (ret)
+ goto out;
+
+ atomic_inc(csdev->refcnt);
+
+ dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n");
+out:
+ mutex_unlock(&drvdata->mutex);
+
+ return ret;
+}
+
+static int smb_disable(struct coresight_device *csdev)
+{
+ struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
+ int ret = 0;
+
+ mutex_lock(&drvdata->mutex);
+
+ if (drvdata->reading) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ if (atomic_dec_return(csdev->refcnt)) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ /* Complain if we (somehow) got out of sync */
+ WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
+
+ smb_disable_hw(drvdata);
+ smb_purge_data(drvdata);
+
+ /* Dissociate from the target process. */
+ drvdata->pid = -1;
+ drvdata->mode = CS_MODE_DISABLED;
+
+ dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n");
+out:
+ mutex_unlock(&drvdata->mutex);
+
+ return ret;
+}
+
+static void *smb_alloc_buffer(struct coresight_device *csdev,
+ struct perf_event *event, void **pages,
+ int nr_pages, bool overwrite)
+{
+ struct cs_buffers *buf;
+ int node;
+
+ node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu);
+ buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
+ if (!buf)
+ return NULL;
+
+ buf->snapshot = overwrite;
+ buf->nr_pages = nr_pages;
+ buf->data_pages = pages;
+ buf->pid = task_pid_nr(event->owner);
+
+ return buf;
+}
+
+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 head,
+ unsigned long data_size)
+{
+ struct smb_data_buffer *sdb = &drvdata->sdb;
+ char **dst_pages = (char **)buf->data_pages;
+ unsigned long to_copy;
+ long pg_idx, pg_offset;
+
+ pg_idx = head >> PAGE_SHIFT;
+ pg_offset = head & (PAGE_SIZE - 1);
+
+ while (data_size) {
+ unsigned long pg_space = PAGE_SIZE - pg_offset;
+
+ /* Copy parts of trace data when read pointer wrap around */
+ if (sdb->rd_offset + pg_space > sdb->buf_size)
+ to_copy = sdb->buf_size - sdb->rd_offset;
+ else
+ to_copy = min(data_size, pg_space);
+
+ memcpy(dst_pages[pg_idx] + pg_offset,
+ sdb->buf_base + sdb->rd_offset, to_copy);
+
+ pg_offset += to_copy;
+ if (pg_offset >= PAGE_SIZE) {
+ pg_offset = 0;
+ pg_idx++;
+ pg_idx %= 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_REG);
+
+ /*
+ * 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_REG),
+ drvdata->base + SMB_LB_RD_ADDR_REG);
+ }
+ smb_reset_buffer_status(drvdata);
+}
+
+static unsigned long smb_update_buffer(struct coresight_device *csdev,
+ struct perf_output_handle *handle,
+ void *sink_config)
+{
+ struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
+ struct smb_data_buffer *sdb = &drvdata->sdb;
+ struct cs_buffers *buf = sink_config;
+ unsigned long data_size = 0;
+ bool lost = false;
+
+ if (!buf)
+ return 0;
+
+ mutex_lock(&drvdata->mutex);
+
+ /* Don't do anything if another tracer is using this sink. */
+ if (atomic_read(csdev->refcnt) != 1)
+ goto out;
+
+ smb_disable_hw(drvdata);
+ smb_update_data_size(drvdata);
+ data_size = sdb->data_size;
+
+ /*
+ * The SMB buffer may be bigger than the space available in the
+ * perf ring buffer (handle->size). If so advance the offset so
+ * that we get the latest trace data.
+ */
+ if (data_size > handle->size) {
+ sdb->rd_offset += data_size - handle->size;
+ sdb->rd_offset %= sdb->buf_size;
+ data_size = handle->size;
+ lost = true;
+ }
+
+ smb_sync_perf_buffer(drvdata, buf, handle->head, data_size);
+ if (!buf->snapshot && lost)
+ perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
+
+ smb_enable_hw(drvdata);
+out:
+ mutex_unlock(&drvdata->mutex);
+
+ return data_size;
+}
+
+static const struct coresight_ops_sink smb_cs_ops = {
+ .enable = smb_enable,
+ .disable = smb_disable,
+ .alloc_buffer = smb_alloc_buffer,
+ .free_buffer = smb_free_buffer,
+ .update_buffer = smb_update_buffer,
+};
+
+static const struct coresight_ops cs_ops = {
+ .sink_ops = &smb_cs_ops,
+};
+
+static int smb_init_data_buffer(struct platform_device *pdev,
+ struct smb_data_buffer *sdb)
+{
+ struct resource *res;
+ void *base;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, SMB_BUF_ADDR_RES);
+ if (IS_ERR(res)) {
+ dev_err(&pdev->dev, "SMB device failed to get resource\n");
+ return -EINVAL;
+ }
+
+ sdb->start_addr = FIELD_GET(SMB_BUF_ADDR_LO_MSK, res->start);
+ sdb->buf_size = resource_size(res);
+ if (sdb->buf_size == 0)
+ return -EINVAL;
+
+ /*
+ * This is a chunk of memory, use classic mapping with better
+ * performance.
+ */
+ base = devm_memremap(&pdev->dev, sdb->start_addr, sdb->buf_size,
+ MEMREMAP_WB);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ sdb->buf_base = base;
+
+ return 0;
+}
+
+static void smb_init_hw(struct smb_drv_data *drvdata)
+{
+ /* First disable SMB and clear the status of SMB buffer */
+ smb_reset_buffer_status(drvdata);
+ smb_disable_hw(drvdata);
+ smb_purge_data(drvdata);
+
+ writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG);
+ writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG);
+ writel(SMB_GLB_CFG_DEFAULT, drvdata->base + SMB_GLB_CFG_REG);
+ writel(SMB_GLB_INT_CFG, drvdata->base + SMB_GLB_INT_REG);
+ writel(SMB_LB_INT_CTRL_CFG, drvdata->base + SMB_LB_INT_CTRL_REG);
+}
+
+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);
+ if (!desc.name) {
+ dev_err(&pdev->dev, "Failed to alloc coresight device name");
+ return -ENOMEM;
+ }
+ desc.access = CSDEV_ACCESS_IOMEM(drvdata->base);
+
+ 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");
+ return -ENODEV;
+ }
+
+ ACPI_FREE(obj);
+
+ return 0;
+}
+
+static int smb_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct smb_drv_data *drvdata;
+ int ret;
+
+ drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+ if (!drvdata)
+ return -ENOMEM;
+
+ drvdata->base = devm_platform_ioremap_resource(pdev, SMB_REG_ADDR_RES);
+ if (IS_ERR(drvdata->base)) {
+ dev_err(dev, "Failed to ioremap resource\n");
+ return PTR_ERR(drvdata->base);
+ }
+
+ ret = smb_init_data_buffer(pdev, &drvdata->sdb);
+ if (ret) {
+ dev_err(dev, "Failed to init buffer, ret = %d\n", ret);
+ return ret;
+ }
+
+ smb_init_hw(drvdata);
+ mutex_init(&drvdata->mutex);
+ drvdata->pid = -1;
+
+ ret = smb_register_sink(pdev, drvdata);
+ if (ret) {
+ dev_err(dev, "Failed to register SMB sink\n");
+ return ret;
+ }
+
+ ret = smb_config_inport(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;
+}
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id ultrasoc_smb_acpi_match[] = {
+ {"HISI03A1", 0},
+ {}
+};
+MODULE_DEVICE_TABLE(acpi, ultrasoc_smb_acpi_match);
+#endif
+
+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 CoreSight driver");
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_AUTHOR("Jonathan Zhou <[email protected]>");
+MODULE_AUTHOR("Qi Liu <[email protected]>");
diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.h b/drivers/hwtracing/coresight/ultrasoc-smb.h
new file mode 100644
index 000000000000..bb5c9f6e81b3
--- /dev/null
+++ b/drivers/hwtracing/coresight/ultrasoc-smb.h
@@ -0,0 +1,120 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */
+/*
+ * Siemens System Memory Buffer driver.
+ * Copyright(c) 2022, HiSilicon Limited.
+ */
+
+#ifndef _ULTRASOC_SMB_H
+#define _ULTRASOC_SMB_H
+
+#include <linux/miscdevice.h>
+#include <linux/mutex.h>
+
+/* Offset of SMB global registers */
+#define SMB_GLB_CFG_REG 0x00
+#define SMB_GLB_EN_REG 0x04
+#define SMB_GLB_INT_REG 0x08
+
+/* Offset of SMB logical buffer registers */
+#define SMB_LB_CFG_LO_REG 0x40
+#define SMB_LB_CFG_HI_REG 0x44
+#define SMB_LB_INT_CTRL_REG 0x48
+#define SMB_LB_INT_STS_REG 0x4c
+#define SMB_LB_RD_ADDR_REG 0x5c
+#define SMB_LB_WR_ADDR_REG 0x60
+#define SMB_LB_PURGE_REG 0x64
+
+/* Set global config register */
+#define SMB_GLB_CFG_BURST_LEN_MSK GENMASK(11, 4)
+#define SMB_GLB_CFG_IDLE_PRD_MSK GENMASK(15, 12)
+#define SMB_GLB_CFG_MEM_WR_MSK GENMASK(21, 16)
+#define SMB_GLB_CFG_MEM_RD_MSK GENMASK(27, 22)
+#define SMB_GLB_CFG_DEFAULT (FIELD_PREP(SMB_GLB_CFG_BURST_LEN_MSK, 0xf) | \
+ FIELD_PREP(SMB_GLB_CFG_IDLE_PRD_MSK, 0xf) | \
+ FIELD_PREP(SMB_GLB_CFG_MEM_WR_MSK, 0x3) | \
+ FIELD_PREP(SMB_GLB_CFG_MEM_RD_MSK, 0x1b))
+
+#define SMB_GLB_EN_HW_ENABLE BIT(0)
+
+/* Set global interrupt control register */
+#define SMB_GLB_INT_EN BIT(0)
+#define SMB_GLB_INT_PULSE BIT(1) /* Interrupt type: 1 - Pulse */
+#define SMB_GLB_INT_ACT_H BIT(2) /* Interrupt polarity: 1 - Active high */
+#define SMB_GLB_INT_CFG (SMB_GLB_INT_EN | SMB_GLB_INT_PULSE | \
+ SMB_GLB_INT_ACT_H)
+
+/* Set logical buffer config register lower 32 bits */
+#define SMB_LB_CFG_LO_EN BIT(0)
+#define SMB_LB_CFG_LO_SINGLE_END BIT(1)
+#define SMB_LB_CFG_LO_INIT BIT(8)
+#define SMB_LB_CFG_LO_CONT BIT(11)
+#define SMB_LB_CFG_LO_FLOW_MSK GENMASK(19, 16)
+#define SMB_LB_CFG_LO_DEFAULT (SMB_LB_CFG_LO_EN | SMB_LB_CFG_LO_SINGLE_END | \
+ SMB_LB_CFG_LO_INIT | SMB_LB_CFG_LO_CONT | \
+ FIELD_PREP(SMB_LB_CFG_LO_FLOW_MSK, 0xf))
+
+/* Set logical buffer config register upper 32 bits */
+#define SMB_LB_CFG_HI_RANGE_UP_MSK GENMASK(15, 8)
+#define SMB_LB_CFG_HI_DEFAULT FIELD_PREP(SMB_LB_CFG_HI_RANGE_UP_MSK, 0xff)
+
+/* Set logical buffer interrupt control register */
+#define SMB_LB_INT_CTRL_EN BIT(0)
+#define SMB_LB_INT_CTRL_BUF_NOTE_MSK GENMASK(11, 8)
+#define SMB_LB_INT_CTRL_CFG (SMB_LB_INT_CTRL_EN | \
+ FIELD_PREP(SMB_LB_INT_CTRL_BUF_NOTE_MSK, 0xf))
+
+/* Set logical buffer interrupt status register */
+#define SMB_LB_INT_STS_NOT_EMPTY_MSK BIT(0)
+#define SMB_LB_INT_STS_BUF_RESET_MSK GENMASK(3, 0)
+#define SMB_LB_INT_STS_RESET FIELD_PREP(SMB_LB_INT_STS_BUF_RESET_MSK, 0xf)
+
+#define SMB_LB_PURGE_PURGED BIT(0)
+
+#define SMB_REG_ADDR_RES 0
+#define SMB_BUF_ADDR_RES 1
+#define SMB_BUF_ADDR_LO_MSK GENMASK(31, 0)
+
+/**
+ * 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, only used 32bits.
+ * @buf_size: Size of the buffer.
+ * @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.
+ * @full: Trace data overflow.
+ */
+struct smb_data_buffer {
+ void *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.
+ * @mutex: Control data access to one at a time.
+ * @reading: Synchronise user space access to SMB buffer.
+ * @pid: Process ID of the process being monitored by the
+ * session that is using this component.
+ * @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;
+ struct mutex mutex;
+ bool reading;
+ pid_t pid;
+ u32 mode;
+};
+
+#endif
--
2.33.0
From: Qi Liu <[email protected]>
This patch bring in documentation for UltraSoc SMB drivers.
It simply describes the device, sysfs interface and the
firmware bindings.
Signed-off-by: Qi Liu <[email protected]>
Signed-off-by: Junhao He <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
---
.../sysfs-bus-coresight-devices-ultra_smb | 31 +++++++
.../trace/coresight/ultrasoc-smb.rst | 82 +++++++++++++++++++
2 files changed, 113 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-bus-coresight-devices-ultra_smb
create mode 100644 Documentation/trace/coresight/ultrasoc-smb.rst
diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-ultra_smb b/Documentation/ABI/testing/sysfs-bus-coresight-devices-ultra_smb
new file mode 100644
index 000000000000..deaefd508105
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-ultra_smb
@@ -0,0 +1,31 @@
+What: /sys/bus/coresight/devices/ultra_smb<N>/enable_sink
+Date: November 2022
+KernelVersion: 6.2
+Contact: Junhao He <[email protected]>
+Description: (RW) Add/remove a SMB device from a trace path. There can be
+ multiple sources for a single SMB device.
+
+What: /sys/bus/coresight/devices/ultra_smb<N>/mgmt/buf_size
+Date: November 2022
+KernelVersion: 6.2
+Contact: Junhao He <[email protected]>
+Description: (Read) Shows the buffer size of each UltraSoc SMB device.
+
+What: /sys/bus/coresight/devices/ultra_smb<N>/mgmt/buf_status
+Date: November 2022
+KernelVersion: 6.2
+Contact: Junhao He <[email protected]>
+Description: (Read) Shows the value held by UltraSoc SMB status register.
+ BIT(0) is zero means buffer is empty.
+
+What: /sys/bus/coresight/devices/ultra_smb<N>/mgmt/read_pos
+Date: November 2022
+KernelVersion: 6.2
+Contact: Junhao He <[email protected]>
+Description: (Read) Shows the value held by UltraSoc SMB Read Pointer register.
+
+What: /sys/bus/coresight/devices/ultra_smb<N>/mgmt/write_pos
+Date: November 2022
+KernelVersion: 6.2
+Contact: Junhao He <[email protected]>
+Description: (Read) Shows the value held by UltraSoc SMB Write Pointer register.
diff --git a/Documentation/trace/coresight/ultrasoc-smb.rst b/Documentation/trace/coresight/ultrasoc-smb.rst
new file mode 100644
index 000000000000..b7fe3f5c7f53
--- /dev/null
+++ b/Documentation/trace/coresight/ultrasoc-smb.rst
@@ -0,0 +1,82 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+======================================
+UltraSoc - HW Assisted Tracing on SoC
+======================================
+ :Author: Qi Liu <[email protected]>
+ :Date: March 2022
+
+Introduction
+------------
+
+UltraSoc SMB is a per SCCL(Super CPU Cluster) hardware, and it provides a
+way to buffer and store CPU trace messages in a region of shared system
+memory. SMB is plugged as a coresight sink device and the corresponding
+trace generators (ETM) are plugged in as source devices.
+
+Sysfs files and directories
+---------------------------
+
+The SMB devices appear on the existing coresight bus alongside the other
+coresight devices::
+
+ $# ls /sys/bus/coresight/devices/
+ ultra_smb0 ultra_smb1 ultra_smb2 ultra_smb3
+
+The ``ultra_smb<N>`` named SMB associated with SCCL.::
+
+ $# ls /sys/bus/coresight/devices/ultra_smb0
+ enable_sink mgmt
+ $# ls /sys/bus/coresight/devices/ultra_smb0/mgmt
+ buf_size buf_status read_pos write_pos
+
+*Key file items are:-*
+ * ``read_pos``: Shows the value held by UltraSoc SMB Read Pointer register.
+ * ``write_pos``: Shows the value held by UltraSoc SMB Write Pointer register.
+ * ``buf_status``: Shows the value held by UltraSoc SMB status register.
+ BIT(0) is zero means buffer is empty.
+ * ``buf_size``: Shows the buffer size of each UltraSoc SMB device.
+
+Firmware Bindings
+---------------------------
+
+SMB device is only supported with ACPI, and ACPI binding of SMB device
+describes SMB device indentifier, resource information and graph structure.
+
+SMB is identified by ACPI HID "HISI03A1", resource of device is declared using
+the _CRS method. Each SMB must present two base address, the first one is the
+configuration base address of SMB device, the second one is the 32bits base
+address of shared system memory.
+
+examples::
+
+ Device(USMB) { \
+ Name(_HID, "HISI03A1") \
+ Name(_CRS, ResourceTemplate() { \
+ QWordMemory (ResourceConsumer, , MinFixed, MaxFixed, NonCacheable, \
+ ReadWrite, 0x0, 0x95100000, 0x951FFFFF, 0x0, 0x100000) \
+ QWordMemory (ResourceConsumer, , MinFixed, MaxFixed, Cacheable, \
+ ReadWrite, 0x0, 0x50000000, 0x53FFFFFF, 0x0, 0x4000000) \
+ }) \
+ Name(_DSD, Package() { \
+ ToUUID("ab02a46b-74c7-45a2-bd68-f7d344ef2153"), \
+ /* Use CoreSight Graph ACPI bindings to describe connections topology */
+ Package() { \
+ 0, \
+ 1, \
+ Package() { \
+ 1, \
+ ToUUID("3ecbc8b6-1d0e-4fb3-8107-e627f805c6cd"), \
+ 8, \
+ Package() {0x8, 0, \_SB.S00.SL11.CL28.F008, 0}, \
+ Package() {0x9, 0, \_SB.S00.SL11.CL29.F009, 0}, \
+ Package() {0xa, 0, \_SB.S00.SL11.CL2A.F010, 0}, \
+ Package() {0xb, 0, \_SB.S00.SL11.CL2B.F011, 0}, \
+ Package() {0xc, 0, \_SB.S00.SL11.CL2C.F012, 0}, \
+ Package() {0xd, 0, \_SB.S00.SL11.CL2D.F013, 0}, \
+ Package() {0xe, 0, \_SB.S00.SL11.CL2E.F014, 0}, \
+ Package() {0xf, 0, \_SB.S00.SL11.CL2F.F015, 0}, \
+ } \
+ } \
+ }) \
+ }
--
2.33.0
On Mon, Nov 14, 2022 at 05:03:16PM +0800, Junhao He wrote:
> diff --git a/Documentation/trace/coresight/ultrasoc-smb.rst b/Documentation/trace/coresight/ultrasoc-smb.rst
> new file mode 100644
> index 000000000000..b7fe3f5c7f53
> --- /dev/null
> +++ b/Documentation/trace/coresight/ultrasoc-smb.rst
> @@ -0,0 +1,82 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +======================================
> +UltraSoc - HW Assisted Tracing on SoC
> +======================================
> + :Author: Qi Liu <[email protected]>
> + :Date: March 2022
> +
> +Introduction
> +------------
> +
> +UltraSoc SMB is a per SCCL(Super CPU Cluster) hardware, and it provides a
> +way to buffer and store CPU trace messages in a region of shared system
> +memory. SMB is plugged as a coresight sink device and the corresponding
> +trace generators (ETM) are plugged in as source devices.
> +
> +Sysfs files and directories
> +---------------------------
> +
> +The SMB devices appear on the existing coresight bus alongside the other
> +coresight devices::
> +
> + $# ls /sys/bus/coresight/devices/
> + ultra_smb0 ultra_smb1 ultra_smb2 ultra_smb3
> +
> +The ``ultra_smb<N>`` named SMB associated with SCCL.::
> +
> + $# ls /sys/bus/coresight/devices/ultra_smb0
> + enable_sink mgmt
> + $# ls /sys/bus/coresight/devices/ultra_smb0/mgmt
> + buf_size buf_status read_pos write_pos
> +
> +*Key file items are:-*
> + * ``read_pos``: Shows the value held by UltraSoc SMB Read Pointer register.
> + * ``write_pos``: Shows the value held by UltraSoc SMB Write Pointer register.
> + * ``buf_status``: Shows the value held by UltraSoc SMB status register.
> + BIT(0) is zero means buffer is empty.
> + * ``buf_size``: Shows the buffer size of each UltraSoc SMB device.
The key list above doesn't look right, so I have applied the fixup:
---- >8 ----
diff --git a/Documentation/trace/coresight/ultrasoc-smb.rst b/Documentation/trace/coresight/ultrasoc-smb.rst
index b7fe3f5c7f53f7..5d0fa1a76b04d1 100644
--- a/Documentation/trace/coresight/ultrasoc-smb.rst
+++ b/Documentation/trace/coresight/ultrasoc-smb.rst
@@ -30,11 +30,12 @@ The ``ultra_smb<N>`` named SMB associated with SCCL.::
$# ls /sys/bus/coresight/devices/ultra_smb0/mgmt
buf_size buf_status read_pos write_pos
-*Key file items are:-*
+Key file items are:
+
* ``read_pos``: Shows the value held by UltraSoc SMB Read Pointer register.
* ``write_pos``: Shows the value held by UltraSoc SMB Write Pointer register.
* ``buf_status``: Shows the value held by UltraSoc SMB status register.
- BIT(0) is zero means buffer is empty.
+ BIT(0) is zero means buffer is empty.
* ``buf_size``: Shows the buffer size of each UltraSoc SMB device.
Firmware Bindings
> +
> +Firmware Bindings
> +---------------------------
> +
> +SMB device is only supported with ACPI, and ACPI binding of SMB device
> +describes SMB device indentifier, resource information and graph structure.
> +
> +SMB is identified by ACPI HID "HISI03A1", resource of device is declared using
> +the _CRS method. Each SMB must present two base address, the first one is the
> +configuration base address of SMB device, the second one is the 32bits base
> +address of shared system memory.
> +
> +examples::
> +
> + Device(USMB) { \
> + Name(_HID, "HISI03A1") \
> + Name(_CRS, ResourceTemplate() { \
> + QWordMemory (ResourceConsumer, , MinFixed, MaxFixed, NonCacheable, \
> + ReadWrite, 0x0, 0x95100000, 0x951FFFFF, 0x0, 0x100000) \
> + QWordMemory (ResourceConsumer, , MinFixed, MaxFixed, Cacheable, \
> + ReadWrite, 0x0, 0x50000000, 0x53FFFFFF, 0x0, 0x4000000) \
> + }) \
> + Name(_DSD, Package() { \
> + ToUUID("ab02a46b-74c7-45a2-bd68-f7d344ef2153"), \
> + /* Use CoreSight Graph ACPI bindings to describe connections topology */
> + Package() { \
> + 0, \
> + 1, \
> + Package() { \
> + 1, \
> + ToUUID("3ecbc8b6-1d0e-4fb3-8107-e627f805c6cd"), \
> + 8, \
> + Package() {0x8, 0, \_SB.S00.SL11.CL28.F008, 0}, \
> + Package() {0x9, 0, \_SB.S00.SL11.CL29.F009, 0}, \
> + Package() {0xa, 0, \_SB.S00.SL11.CL2A.F010, 0}, \
> + Package() {0xb, 0, \_SB.S00.SL11.CL2B.F011, 0}, \
> + Package() {0xc, 0, \_SB.S00.SL11.CL2C.F012, 0}, \
> + Package() {0xd, 0, \_SB.S00.SL11.CL2D.F013, 0}, \
> + Package() {0xe, 0, \_SB.S00.SL11.CL2E.F014, 0}, \
> + Package() {0xf, 0, \_SB.S00.SL11.CL2F.F015, 0}, \
> + } \
> + } \
> + }) \
> + }
The rest of wordings also read a rather weird. What about below instead?
---- >8 ----
diff --git a/Documentation/trace/coresight/ultrasoc-smb.rst b/Documentation/trace/coresight/ultrasoc-smb.rst
index 5d0fa1a76b04d1..eee32cbf90d2ea 100644
--- a/Documentation/trace/coresight/ultrasoc-smb.rst
+++ b/Documentation/trace/coresight/ultrasoc-smb.rst
@@ -9,21 +9,21 @@ UltraSoc - HW Assisted Tracing on SoC
Introduction
------------
-UltraSoc SMB is a per SCCL(Super CPU Cluster) hardware, and it provides a
+UltraSoc SMB is a per SCCL (Super CPU Cluster) hardware. It provides a
way to buffer and store CPU trace messages in a region of shared system
-memory. SMB is plugged as a coresight sink device and the corresponding
-trace generators (ETM) are plugged in as source devices.
+memory. The device acts as a coresight sink device and the
+corresponding trace generators (ETM) are attached as source devices.
Sysfs files and directories
---------------------------
-The SMB devices appear on the existing coresight bus alongside the other
-coresight devices::
+The SMB devices appear on the existing coresight bus alongside other
+devices::
$# ls /sys/bus/coresight/devices/
ultra_smb0 ultra_smb1 ultra_smb2 ultra_smb3
-The ``ultra_smb<N>`` named SMB associated with SCCL.::
+The ``ultra_smb<N>`` names SMB device associated with SCCL.::
$# ls /sys/bus/coresight/devices/ultra_smb0
enable_sink mgmt
@@ -32,24 +32,23 @@ The ``ultra_smb<N>`` named SMB associated with SCCL.::
Key file items are:
- * ``read_pos``: Shows the value held by UltraSoc SMB Read Pointer register.
- * ``write_pos``: Shows the value held by UltraSoc SMB Write Pointer register.
- * ``buf_status``: Shows the value held by UltraSoc SMB status register.
- BIT(0) is zero means buffer is empty.
- * ``buf_size``: Shows the buffer size of each UltraSoc SMB device.
+ * ``read_pos``: Shows the value on the read pointer register.
+ * ``write_pos``: Shows the value on the write pointer register.
+ * ``buf_status``: Shows the value on the status register.
+ BIT(0) is zero value which means the buffer is empty.
+ * ``buf_size``: Shows the buffer size of each device.
Firmware Bindings
----------------------------
+-----------------
-SMB device is only supported with ACPI, and ACPI binding of SMB device
-describes SMB device indentifier, resource information and graph structure.
+The device is only supported with ACPI. Its binding describes device
+identifier, resource information and graph structure.
-SMB is identified by ACPI HID "HISI03A1", resource of device is declared using
-the _CRS method. Each SMB must present two base address, the first one is the
-configuration base address of SMB device, the second one is the 32bits base
-address of shared system memory.
+The device is identified as ACPI HID "HISI03A1". Device resources are allocated
+using the _CRS method. Each device must present two base address; the first one is the configuration base address of the device, the second one is the 32-bit
+base address of shared system memory.
-examples::
+Example::
Device(USMB) { \
Name(_HID, "HISI03A1") \
Thanks.
--
An old man doll... just what I always wanted! - Clara
On Mon, Nov 14, 2022 at 05:03:14PM +0800, Junhao He wrote:
> Add support for UltraSoc System Memory Buffer.
>
The cover letter message (aside changelogs) is short but LGTM. However,
for individual patches description, please write in imperative mood
(that is, no "This patch/commit does foo" but "Do foo" instead).
Thanks.
--
An old man doll... just what I always wanted! - Clara
On 11/15/22 14:33, hejunhao wrote:
> Hi Bagas,
>
> will apply the fix in next version.
> Thank you very much.
>
Please don't top-post, reply inline with appropriate context instead.
I had to trim all the below context as a result.
--
An old man doll... just what I always wanted! - Clara
On 14/11/2022 09:03, Junhao He wrote:
> From: Qi Liu <[email protected]>
>
> 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 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 <[email protected]>
> Signed-off-by: Junhao He <[email protected]>
> Tested-by: JunHao He <[email protected]>
> Reviewed-by: Jonathan Cameron <[email protected]>
> ---
> drivers/hwtracing/coresight/Kconfig | 11 +
> drivers/hwtracing/coresight/Makefile | 1 +
> drivers/hwtracing/coresight/ultrasoc-smb.c | 656 +++++++++++++++++++++
> drivers/hwtracing/coresight/ultrasoc-smb.h | 120 ++++
> 4 files changed, 788 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 45c1eb5dfcb7..cb17c207a728 100644
> --- a/drivers/hwtracing/coresight/Kconfig
> +++ b/drivers/hwtracing/coresight/Kconfig
> @@ -201,4 +201,15 @@ config CORESIGHT_TRBE
>
> To compile this driver as a module, choose M here: the module will be
> called coresight-trbe.
> +
> +config ULTRASOC_SMB
> + tristate "Ultrasoc system memory buffer drivers"
> + depends on ARM64 && CORESIGHT_LINKS_AND_SINKS
I still think it is not a good idea to leave the ACPI dependency out
of this. THe driver is unusable on a system without ACPI and the only
other reason to build this would when using COMPILE_TEST.
So, we could add something like :
depends on ACPI || COMPILE_TEST
depends on ARM64 && CORESIGHT_LINKS_AND_SINKS
> + help
> + This driver provides support for the Ultrasoc system memory buffer (SMB).
> + SMB is responsible for receiving the trace data from Coresight ETM devices
> + and storing them to a system buffer.
> +
> + To compile this driver as a module, choose M here: the module will be
> + called ultrasoc-smb.
> endif
> 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..1957796cbab2
> --- /dev/null
> +++ b/drivers/hwtracing/coresight/ultrasoc-smb.c
> @@ -0,0 +1,656 @@
> +// SPDX-License-Identifier: (GPL-2.0 OR MIT)
> +/*
> + * Siemens System Memory Buffer driver.
> + * Copyright(c) 2022, HiSilicon Limited.
> + */
> +
> +#include <linux/atomic.h>
> +#include <linux/acpi.h>
> +#include <linux/circ_buf.h>
> +#include <linux/err.h>
> +#include <linux/fs.h>
> +#include <linux/module.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/platform_device.h>
> +
> +#include "coresight-etm-perf.h"
> +#include "coresight-priv.h"
> +#include "ultrasoc-smb.h"
> +
> +DEFINE_CORESIGHT_DEVLIST(sink_devs, "ultra_smb");
> +
> +#define ULTRASOC_SMB_DSM_UUID "82ae1283-7f6a-4cbe-aa06-53e8fb24db18"
> +
> +static bool smb_buffer_is_empty(struct smb_drv_data *drvdata)
> +{
> + u32 buf_status = readl(drvdata->base + SMB_LB_INT_STS_REG);
> +
> + return !FIELD_GET(SMB_LB_INT_STS_NOT_EMPTY_MSK, buf_status);
> +}
> +
> +static void smb_buffer_sync_status(struct smb_drv_data *drvdata)
> +{
> + struct smb_data_buffer *sdb = &drvdata->sdb;
> +
> + sdb->wr_offset = readl(drvdata->base + SMB_LB_WR_ADDR_REG) -
> + sdb->start_addr;
> + sdb->rd_offset = readl(drvdata->base + SMB_LB_RD_ADDR_REG) -
> + sdb->start_addr;
> + sdb->full = sdb->wr_offset == sdb->rd_offset &&
> + !smb_buffer_is_empty(drvdata);
> +}
> +
> +static void smb_reset_buffer_status(struct smb_drv_data *drvdata)
> +{
> + /* All other bits are reserved and shall be 0 */
> + writel(SMB_LB_INT_STS_RESET, drvdata->base + SMB_LB_INT_STS_REG);
> +}
> +
> +/* Purge data remaining in hardware path in case them influence next trace */
minor nit:
/*
* Purge data remaining in hardware path to avoid corrupting the next
* session.
*/
> +static void smb_purge_data(struct smb_drv_data *drvdata)
> +{
> + /* All other bits are reserved and shall be 0 */
> + writel(SMB_LB_PURGE_PURGED, drvdata->base + SMB_LB_PURGE_REG);
> +}
> +
> +static void smb_update_data_size(struct smb_drv_data *drvdata)
> +{
> + struct smb_data_buffer *sdb = &drvdata->sdb;
> +
> + smb_purge_data(drvdata);
> + smb_buffer_sync_status(drvdata);
> + if (sdb->full) {
> + sdb->data_size = sdb->buf_size;
> + return;
> + }
> +
> + sdb->data_size = CIRC_CNT(sdb->wr_offset, sdb->rd_offset,
> + sdb->buf_size);
> +}
> +
> +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);
> + int ret = 0;
> +
> + mutex_lock(&drvdata->mutex);
> +
> + if (drvdata->reading) {
> + ret = -EBUSY;
> + goto out;
> + }
> +
> + if (atomic_read(drvdata->csdev->refcnt)) {
> + ret = -EBUSY;
> + goto out;
> + }
> +
> + drvdata->reading = true;
> +out:
> + mutex_unlock(&drvdata->mutex);
> +
> + 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;
> + ssize_t to_copy = 0;
> +
> + mutex_lock(&drvdata->mutex);
> +
> + if (!len)
> + goto out;
> +
> + /*
> + * In sysfs mode, size need to be update in the following two cases:
> + * 1) Start dumping data.
> + * 2) End dump data, make sure there is no remaining data in
> + * the hardware path. Because the remaining data cannot be purged
> + * when the buffer is full.
> + */
> + 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_REG);
> + dev_dbg(dev, "%zu bytes copied\n", to_copy);
> +out:
> + if (!sdb->data_size)
> + smb_reset_buffer_status(drvdata);
> + mutex_unlock(&drvdata->mutex);
> +
> + return to_copy;
> +}
> +
> +static int smb_release(struct inode *inode, struct file *file)
> +{
> + struct smb_drv_data *drvdata = container_of(file->private_data,
> + struct smb_drv_data, miscdev);
> +
> + mutex_lock(&drvdata->mutex);
> + drvdata->reading = false;
> + mutex_unlock(&drvdata->mutex);
> +
> + return 0;
> +}
> +
> +static const struct file_operations smb_fops = {
> + .owner = THIS_MODULE,
> + .open = smb_open,
> + .read = smb_read,
> + .release = smb_release,
> + .llseek = no_llseek,
> +};
> +
> +static ssize_t buf_size_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct smb_drv_data *drvdata = dev_get_drvdata(dev->parent);
> +
> + return sysfs_emit(buf, "0x%lx\n", drvdata->sdb.buf_size);
> +}
> +static DEVICE_ATTR_RO(buf_size);
> +
> +static struct attribute *smb_sink_attrs[] = {
> + coresight_simple_reg32(read_pos, SMB_LB_RD_ADDR_REG),
> + coresight_simple_reg32(write_pos, SMB_LB_WR_ADDR_REG),
> + coresight_simple_reg32(buf_status, SMB_LB_INT_STS_REG),
> + &dev_attr_buf_size.attr,
> + NULL
> +};
> +
> +static const struct attribute_group smb_sink_group = {
> + .attrs = smb_sink_attrs,
> + .name = "mgmt",
> +};
> +
> +static const struct attribute_group *smb_sink_groups[] = {
> + &smb_sink_group,
> + NULL
> +};
> +
> +static void smb_enable_hw(struct smb_drv_data *drvdata)
> +{
> + writel(SMB_GLB_EN_HW_ENABLE, drvdata->base + SMB_GLB_EN_REG);
What happens to the RD_ADDR_REG and WR_ADDR_REG at enable ? Do they
reset to the base of the buf or do we need to program at enable ?
Are there any other modes of operation ? Or is it always in circular
buffer mode ?
> +}
> +
> +static void smb_disable_hw(struct smb_drv_data *drvdata)
> +{
> + writel(0x0, drvdata->base + SMB_GLB_EN_REG);
> +}
> +
> +static void smb_enable_sysfs(struct coresight_device *csdev)
> +{
> + struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
> +
> + if (drvdata->mode != CS_MODE_DISABLED)
> + return;
> +
> + smb_enable_hw(drvdata);
> + drvdata->mode = CS_MODE_SYSFS;
> +}
> +
> +static int smb_enable_perf(struct coresight_device *csdev, void *data)
> +{
> + struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
> + struct perf_output_handle *handle = data;
> + struct cs_buffers *buf = etm_perf_sink_config(handle);
> + pid_t pid;
> +
> + if (!buf)
> + return -EINVAL;
> +
> + /* Get a handle on the pid of the target process */
> + pid = buf->pid;
> +
> + /* Device is already in used by other session */
> + if (drvdata->pid != -1 && drvdata->pid != pid)
> + return -EBUSY;
> +
> + if (drvdata->pid == -1) {
> + smb_enable_hw(drvdata);
> + drvdata->pid = pid;
> + drvdata->mode = CS_MODE_PERF;
> + }
> +
> + 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 = 0;
> +
> + mutex_lock(&drvdata->mutex);
> +
> + /* Do nothing, the trace data is reading by other interface now */
> + if (drvdata->reading) {
> + ret = -EBUSY;
> + goto out;
> + }
> +
> + /* Do nothing, the SMB is already enabled as other mode */
> + if (drvdata->mode != CS_MODE_DISABLED && drvdata->mode != mode) {
> + ret = -EBUSY;
> + goto out;
> + }
> +
> + switch (mode) {
> + case CS_MODE_SYSFS:
> + smb_enable_sysfs(csdev);
> + break;
> + case CS_MODE_PERF:
> + ret = smb_enable_perf(csdev, data);
> + break;
> + default:
> + ret = -EINVAL;
> + }
> +
> + if (ret)
> + goto out;
> +
> + atomic_inc(csdev->refcnt);
> +
> + dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n");
> +out:
> + mutex_unlock(&drvdata->mutex);
> +
> + return ret;
> +}
> +
> +static int smb_disable(struct coresight_device *csdev)
> +{
> + struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
> + int ret = 0;
> +
> + mutex_lock(&drvdata->mutex);
> +
> + if (drvdata->reading) {
> + ret = -EBUSY;
> + goto out;
> + }
> +
> + if (atomic_dec_return(csdev->refcnt)) {
> + ret = -EBUSY;
> + goto out;
> + }
> +
> + /* Complain if we (somehow) got out of sync */
> + WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
> +
> + smb_disable_hw(drvdata);
> + smb_purge_data(drvdata);
> +
> + /* Dissociate from the target process. */
> + drvdata->pid = -1;
> + drvdata->mode = CS_MODE_DISABLED;
> +
> + dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n");
> +out:
> + mutex_unlock(&drvdata->mutex);
> +
> + return ret;
> +}
> +
> +static void *smb_alloc_buffer(struct coresight_device *csdev,
> + struct perf_event *event, void **pages,
> + int nr_pages, bool overwrite)
> +{
> + struct cs_buffers *buf;
> + int node;
> +
> + node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu);
> + buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
> + if (!buf)
> + return NULL;
> +
> + buf->snapshot = overwrite;
> + buf->nr_pages = nr_pages;
> + buf->data_pages = pages;
> + buf->pid = task_pid_nr(event->owner);
> +
> + return buf;
> +}
> +
> +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 head,
> + unsigned long data_size)
> +{
> + struct smb_data_buffer *sdb = &drvdata->sdb;
> + char **dst_pages = (char **)buf->data_pages;
> + unsigned long to_copy;
> + long pg_idx, pg_offset;
> +
> + pg_idx = head >> PAGE_SHIFT;
> + pg_offset = head & (PAGE_SIZE - 1);
> +
> + while (data_size) {
> + unsigned long pg_space = PAGE_SIZE - pg_offset;
> +
> + /* Copy parts of trace data when read pointer wrap around */
> + if (sdb->rd_offset + pg_space > sdb->buf_size)
> + to_copy = sdb->buf_size - sdb->rd_offset;
> + else
> + to_copy = min(data_size, pg_space);
> +
> + memcpy(dst_pages[pg_idx] + pg_offset,
> + sdb->buf_base + sdb->rd_offset, to_copy);
> +
> + pg_offset += to_copy;
> + if (pg_offset >= PAGE_SIZE) {
> + pg_offset = 0;
> + pg_idx++;
> + pg_idx %= 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_REG);
Is this safe ? When the buffer was not full and the buffer
was not copied in full (i.e., perf_buffer < buffer_size),
the RD_ADDR_REG won't reach the WR_ADDR_REG. So can that affect
the next session ? See more below :
> +
> + /*
> + * 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_REG),
> + drvdata->base + SMB_LB_RD_ADDR_REG);
Or, in other words, shouldn't we do this irrespective of whether the
buffer->full or not ? We set the TRUNCATED flag appropriately when
there was data lost and thus we must not leave any trace from a previous
"schedule" in for the "next" collection. So, we must reset the RD/WR
registers to the base.
> + }
> + smb_reset_buffer_status(drvdata);
> +}
> +
> +static unsigned long smb_update_buffer(struct coresight_device *csdev,
> + struct perf_output_handle *handle,
> + void *sink_config)
> +{
> + struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
> + struct smb_data_buffer *sdb = &drvdata->sdb;
> + struct cs_buffers *buf = sink_config;
> + unsigned long data_size = 0;
> + bool lost = false;
> +
> + if (!buf)
> + return 0;
> +
> + mutex_lock(&drvdata->mutex);
> +
> + /* Don't do anything if another tracer is using this sink. */
> + if (atomic_read(csdev->refcnt) != 1)
> + goto out;
> +
> + smb_disable_hw(drvdata);
> + smb_update_data_size(drvdata);
> + data_size = sdb->data_size;
> +
> + /*
> + * The SMB buffer may be bigger than the space available in the
> + * perf ring buffer (handle->size). If so advance the offset so
> + * that we get the latest trace data.
> + */
> + if (data_size > handle->size) {
> + sdb->rd_offset += data_size - handle->size;
> + sdb->rd_offset %= sdb->buf_size;
> + data_size = handle->size;
> + lost = true;
> + } > +
> + smb_sync_perf_buffer(drvdata, buf, handle->head, data_size);
> + if (!buf->snapshot && lost)
> + perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
> +
> + smb_enable_hw(drvdata);
We do not need this and could leave this disabled at this stage. The
perf session has stopped the "source" anyway.
> +out:
> + mutex_unlock(&drvdata->mutex);
> +
> + return data_size;
> +}
> +
> +static const struct coresight_ops_sink smb_cs_ops = {
> + .enable = smb_enable,
> + .disable = smb_disable,
> + .alloc_buffer = smb_alloc_buffer,
> + .free_buffer = smb_free_buffer,
> + .update_buffer = smb_update_buffer,
> +};
> +
> +static const struct coresight_ops cs_ops = {
> + .sink_ops = &smb_cs_ops,
> +};
> +
> +static int smb_init_data_buffer(struct platform_device *pdev,
> + struct smb_data_buffer *sdb)
> +{
> + struct resource *res;
> + void *base;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, SMB_BUF_ADDR_RES);
> + if (IS_ERR(res)) {
> + dev_err(&pdev->dev, "SMB device failed to get resource\n");
> + return -EINVAL;
> + }
> +
> + sdb->start_addr = FIELD_GET(SMB_BUF_ADDR_LO_MSK, res->start);
> + sdb->buf_size = resource_size(res);
> + if (sdb->buf_size == 0)
> + return -EINVAL;
> +
> + /*
> + * This is a chunk of memory, use classic mapping with better
> + * performance.
> + */
> + base = devm_memremap(&pdev->dev, sdb->start_addr, sdb->buf_size,
> + MEMREMAP_WB);
> + if (IS_ERR(base))
> + return PTR_ERR(base);
> +
> + sdb->buf_base = base;
> +
> + return 0;
> +}
> +
> +static void smb_init_hw(struct smb_drv_data *drvdata)
> +{
> + /* First disable SMB and clear the status of SMB buffer */
> + smb_reset_buffer_status(drvdata);
> + smb_disable_hw(drvdata);
> + smb_purge_data(drvdata);
> +
> + writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG);
> + writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG);
> + writel(SMB_GLB_CFG_DEFAULT, drvdata->base + SMB_GLB_CFG_REG);
> + writel(SMB_GLB_INT_CFG, drvdata->base + SMB_GLB_INT_REG);
> + writel(SMB_LB_INT_CTRL_CFG, drvdata->base + SMB_LB_INT_CTRL_REG);
Does this come with interrupt on overflow ? Do we not use this ?
Rest looks fine to me.
Suzuki
Hi Suzuki ,
On 2022/11/15 19:06, Suzuki K Poulose wrote:
> On 14/11/2022 09:03, Junhao He wrote:
>> From: Qi Liu <[email protected]>
>>
>> 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 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 <[email protected]>
>> Signed-off-by: Junhao He <[email protected]>
>> Tested-by: JunHao He <[email protected]>
>> Reviewed-by: Jonathan Cameron <[email protected]>
>> ---
>> drivers/hwtracing/coresight/Kconfig | 11 +
>> drivers/hwtracing/coresight/Makefile | 1 +
>> drivers/hwtracing/coresight/ultrasoc-smb.c | 656 +++++++++++++++++++++
>> drivers/hwtracing/coresight/ultrasoc-smb.h | 120 ++++
>> 4 files changed, 788 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 45c1eb5dfcb7..cb17c207a728 100644
>> --- a/drivers/hwtracing/coresight/Kconfig
>> +++ b/drivers/hwtracing/coresight/Kconfig
>> @@ -201,4 +201,15 @@ config CORESIGHT_TRBE
>> To compile this driver as a module, choose M here: the
>> module will be
>> called coresight-trbe.
>> +
>> +config ULTRASOC_SMB
>> + tristate "Ultrasoc system memory buffer drivers"
>> + depends on ARM64 && CORESIGHT_LINKS_AND_SINKS
>
> I still think it is not a good idea to leave the ACPI dependency out
> of this. THe driver is unusable on a system without ACPI and the only
> other reason to build this would when using COMPILE_TEST.
> So, we could add something like :
>
> depends on ACPI || COMPILE_TEST
> depends on ARM64 && CORESIGHT_LINKS_AND_SINKS
>
OK, I will do that.
Thanks.
>
>> + help
>> + This driver provides support for the Ultrasoc system memory
>> buffer (SMB).
>> + SMB is responsible for receiving the trace data from Coresight
>> ETM devices
>> + and storing them to a system buffer.
>> +
>> + To compile this driver as a module, choose M here: the module
>> will be
>> + called ultrasoc-smb.
>> endif
>> 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..1957796cbab2
>> --- /dev/null
>> +++ b/drivers/hwtracing/coresight/ultrasoc-smb.c
>> @@ -0,0 +1,656 @@
>> +// SPDX-License-Identifier: (GPL-2.0 OR MIT)
>> +/*
>> + * Siemens System Memory Buffer driver.
>> + * Copyright(c) 2022, HiSilicon Limited.
>> + */
>> +
>> +#include <linux/atomic.h>
>> +#include <linux/acpi.h>
>> +#include <linux/circ_buf.h>
>> +#include <linux/err.h>
>> +#include <linux/fs.h>
>> +#include <linux/module.h>
>> +#include <linux/mod_devicetable.h>
>> +#include <linux/platform_device.h>
>> +
>> +#include "coresight-etm-perf.h"
>> +#include "coresight-priv.h"
>> +#include "ultrasoc-smb.h"
>> +
>> +DEFINE_CORESIGHT_DEVLIST(sink_devs, "ultra_smb");
>> +
>> +#define ULTRASOC_SMB_DSM_UUID "82ae1283-7f6a-4cbe-aa06-53e8fb24db18"
>> +
>> +static bool smb_buffer_is_empty(struct smb_drv_data *drvdata)
>> +{
>> + u32 buf_status = readl(drvdata->base + SMB_LB_INT_STS_REG);
>> +
>> + return !FIELD_GET(SMB_LB_INT_STS_NOT_EMPTY_MSK, buf_status);
>> +}
>> +
>> +static void smb_buffer_sync_status(struct smb_drv_data *drvdata)
>> +{
>> + struct smb_data_buffer *sdb = &drvdata->sdb;
>> +
>> + sdb->wr_offset = readl(drvdata->base + SMB_LB_WR_ADDR_REG) -
>> + sdb->start_addr;
>> + sdb->rd_offset = readl(drvdata->base + SMB_LB_RD_ADDR_REG) -
>> + sdb->start_addr;
>> + sdb->full = sdb->wr_offset == sdb->rd_offset &&
>> + !smb_buffer_is_empty(drvdata);
>> +}
>> +
>> +static void smb_reset_buffer_status(struct smb_drv_data *drvdata)
>> +{
>> + /* All other bits are reserved and shall be 0 */
>> + writel(SMB_LB_INT_STS_RESET, drvdata->base + SMB_LB_INT_STS_REG);
>> +}
>> +
>> +/* Purge data remaining in hardware path in case them influence next
>> trace */
>
> minor nit:
>
> /*
> * Purge data remaining in hardware path to avoid corrupting the next
> * session.
> */
>
Ok, will fix it.
Thanks.
>> +static void smb_purge_data(struct smb_drv_data *drvdata)
>> +{
>> + /* All other bits are reserved and shall be 0 */
>> + writel(SMB_LB_PURGE_PURGED, drvdata->base + SMB_LB_PURGE_REG);
>> +}
>> +
>> +static void smb_update_data_size(struct smb_drv_data *drvdata)
>> +{
>> + struct smb_data_buffer *sdb = &drvdata->sdb;
>> +
>> + smb_purge_data(drvdata);
>> + smb_buffer_sync_status(drvdata);
>> + if (sdb->full) {
>> + sdb->data_size = sdb->buf_size;
>> + return;
>> + }
>> +
>> + sdb->data_size = CIRC_CNT(sdb->wr_offset, sdb->rd_offset,
>> + sdb->buf_size);
>> +}
>> +
>> +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);
>> + int ret = 0;
>> +
>> + mutex_lock(&drvdata->mutex);
>> +
>> + if (drvdata->reading) {
>> + ret = -EBUSY;
>> + goto out;
>> + }
>> +
>> + if (atomic_read(drvdata->csdev->refcnt)) {
>> + ret = -EBUSY;
>> + goto out;
>> + }
>> +
>> + drvdata->reading = true;
>> +out:
>> + mutex_unlock(&drvdata->mutex);
>> +
>> + 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;
>> + ssize_t to_copy = 0;
>> +
>> + mutex_lock(&drvdata->mutex);
>> +
>> + if (!len)
>> + goto out;
>> +
>> + /*
>> + * In sysfs mode, size need to be update in the following two
>> cases:
>> + * 1) Start dumping data.
>> + * 2) End dump data, make sure there is no remaining data in
>> + * the hardware path. Because the remaining data cannot be
>> purged
>> + * when the buffer is full.
>> + */
>> + 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_REG);
>> + dev_dbg(dev, "%zu bytes copied\n", to_copy);
>> +out:
>> + if (!sdb->data_size)
>> + smb_reset_buffer_status(drvdata);
>> + mutex_unlock(&drvdata->mutex);
>> +
>> + return to_copy;
>> +}
>> +
>> +static int smb_release(struct inode *inode, struct file *file)
>> +{
>> + struct smb_drv_data *drvdata = container_of(file->private_data,
>> + struct smb_drv_data, miscdev);
>> +
>> + mutex_lock(&drvdata->mutex);
>> + drvdata->reading = false;
>> + mutex_unlock(&drvdata->mutex);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct file_operations smb_fops = {
>> + .owner = THIS_MODULE,
>> + .open = smb_open,
>> + .read = smb_read,
>> + .release = smb_release,
>> + .llseek = no_llseek,
>> +};
>> +
>> +static ssize_t buf_size_show(struct device *dev, struct
>> device_attribute *attr,
>> + char *buf)
>> +{
>> + struct smb_drv_data *drvdata = dev_get_drvdata(dev->parent);
>> +
>> + return sysfs_emit(buf, "0x%lx\n", drvdata->sdb.buf_size);
>> +}
>> +static DEVICE_ATTR_RO(buf_size);
>> +
>> +static struct attribute *smb_sink_attrs[] = {
>> + coresight_simple_reg32(read_pos, SMB_LB_RD_ADDR_REG),
>> + coresight_simple_reg32(write_pos, SMB_LB_WR_ADDR_REG),
>> + coresight_simple_reg32(buf_status, SMB_LB_INT_STS_REG),
>> + &dev_attr_buf_size.attr,
>> + NULL
>> +};
>> +
>> +static const struct attribute_group smb_sink_group = {
>> + .attrs = smb_sink_attrs,
>> + .name = "mgmt",
>> +};
>> +
>> +static const struct attribute_group *smb_sink_groups[] = {
>> + &smb_sink_group,
>> + NULL
>> +};
>> +
>> +static void smb_enable_hw(struct smb_drv_data *drvdata)
>> +{
>> + writel(SMB_GLB_EN_HW_ENABLE, drvdata->base + SMB_GLB_EN_REG);
>
> What happens to the RD_ADDR_REG and WR_ADDR_REG at enable ? Do they
> reset to the base of the buf or do we need to program at enable ?
> Are there any other modes of operation ? Or is it always in circular
> buffer mode ?
The RD_ADDR_REG and WR_ADDR_REG register is filled in BIOS, and
WR_ADDR_REG is RO mode.
When the SMB is enabled, the values of RD_ADDR_REG and WR_ADDR_REG
remain unchanged.
UltraSoc SMB is always in circular buffer mode.
Thanks.
>> +}
>> +
>> +static void smb_disable_hw(struct smb_drv_data *drvdata)
>> +{
>> + writel(0x0, drvdata->base + SMB_GLB_EN_REG);
>> +}
>> +
>> +static void smb_enable_sysfs(struct coresight_device *csdev)
>> +{
>> + struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
>> +
>> + if (drvdata->mode != CS_MODE_DISABLED)
>> + return;
>> +
>> + smb_enable_hw(drvdata);
>> + drvdata->mode = CS_MODE_SYSFS;
>> +}
>> +
>> +static int smb_enable_perf(struct coresight_device *csdev, void *data)
>> +{
>> + struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
>> + struct perf_output_handle *handle = data;
>> + struct cs_buffers *buf = etm_perf_sink_config(handle);
>> + pid_t pid;
>> +
>> + if (!buf)
>> + return -EINVAL;
>> +
>> + /* Get a handle on the pid of the target process */
>> + pid = buf->pid;
>> +
>> + /* Device is already in used by other session */
>> + if (drvdata->pid != -1 && drvdata->pid != pid)
>> + return -EBUSY;
>> +
>> + if (drvdata->pid == -1) {
>> + smb_enable_hw(drvdata);
>> + drvdata->pid = pid;
>> + drvdata->mode = CS_MODE_PERF;
>> + }
>> +
>> + 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 = 0;
>> +
>> + mutex_lock(&drvdata->mutex);
>> +
>> + /* Do nothing, the trace data is reading by other interface now */
>> + if (drvdata->reading) {
>> + ret = -EBUSY;
>> + goto out;
>> + }
>> +
>> + /* Do nothing, the SMB is already enabled as other mode */
>> + if (drvdata->mode != CS_MODE_DISABLED && drvdata->mode != mode) {
>> + ret = -EBUSY;
>> + goto out;
>> + }
>> +
>> + switch (mode) {
>> + case CS_MODE_SYSFS:
>> + smb_enable_sysfs(csdev);
>> + break;
>> + case CS_MODE_PERF:
>> + ret = smb_enable_perf(csdev, data);
>> + break;
>> + default:
>> + ret = -EINVAL;
>> + }
>> +
>> + if (ret)
>> + goto out;
>> +
>> + atomic_inc(csdev->refcnt);
>> +
>> + dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n");
>> +out:
>> + mutex_unlock(&drvdata->mutex);
>> +
>> + return ret;
>> +}
>> +
>> +static int smb_disable(struct coresight_device *csdev)
>> +{
>> + struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
>> + int ret = 0;
>> +
>> + mutex_lock(&drvdata->mutex);
>> +
>> + if (drvdata->reading) {
>> + ret = -EBUSY;
>> + goto out;
>> + }
>> +
>> + if (atomic_dec_return(csdev->refcnt)) {
>> + ret = -EBUSY;
>> + goto out;
>> + }
>> +
>> + /* Complain if we (somehow) got out of sync */
>> + WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
>> +
>> + smb_disable_hw(drvdata);
>> + smb_purge_data(drvdata);
>> +
>> + /* Dissociate from the target process. */
>> + drvdata->pid = -1;
>> + drvdata->mode = CS_MODE_DISABLED;
>> +
>> + dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n");
>> +out:
>> + mutex_unlock(&drvdata->mutex);
>> +
>> + return ret;
>> +}
>> +
>> +static void *smb_alloc_buffer(struct coresight_device *csdev,
>> + struct perf_event *event, void **pages,
>> + int nr_pages, bool overwrite)
>> +{
>> + struct cs_buffers *buf;
>> + int node;
>> +
>> + node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu);
>> + buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
>> + if (!buf)
>> + return NULL;
>> +
>> + buf->snapshot = overwrite;
>> + buf->nr_pages = nr_pages;
>> + buf->data_pages = pages;
>> + buf->pid = task_pid_nr(event->owner);
>> +
>> + return buf;
>> +}
>> +
>> +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 head,
>> + unsigned long data_size)
>> +{
>> + struct smb_data_buffer *sdb = &drvdata->sdb;
>> + char **dst_pages = (char **)buf->data_pages;
>> + unsigned long to_copy;
>> + long pg_idx, pg_offset;
>> +
>> + pg_idx = head >> PAGE_SHIFT;
>> + pg_offset = head & (PAGE_SIZE - 1);
>> +
>> + while (data_size) {
>> + unsigned long pg_space = PAGE_SIZE - pg_offset;
>> +
>> + /* Copy parts of trace data when read pointer wrap around */
>> + if (sdb->rd_offset + pg_space > sdb->buf_size)
>> + to_copy = sdb->buf_size - sdb->rd_offset;
>> + else
>> + to_copy = min(data_size, pg_space);
>> +
>> + memcpy(dst_pages[pg_idx] + pg_offset,
>> + sdb->buf_base + sdb->rd_offset, to_copy);
>> +
>> + pg_offset += to_copy;
>> + if (pg_offset >= PAGE_SIZE) {
>> + pg_offset = 0;
>> + pg_idx++;
>> + pg_idx %= 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_REG);
>
> Is this safe ? When the buffer was not full and the buffer
> was not copied in full (i.e., perf_buffer < buffer_size),
> the RD_ADDR_REG won't reach the WR_ADDR_REG. So can that affect
> the next session ? See more below :
>
Yes, In this case. "sdb->rd_offset" will add the offset of discarded data
(buffer_size - perf_buffer) in the smb_update_buffer() function. If the
buffer
was not full, the values of RD_ADDR_REG and WR_ADDR_REG will always
be the same.
When SMB is full, the data remained in link only can be written into buffer
after updated RD_ADDR_REG, and the value of WR_ADDR_REG will be advanced.
So in this case we need synchronize the WR_ADDR_REG to RD_ADDR_REG again.
Thanks.
>> +
>> + /*
>> + * 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_REG),
>> + drvdata->base + SMB_LB_RD_ADDR_REG);
>
> Or, in other words, shouldn't we do this irrespective of whether the
> buffer->full or not ? We set the TRUNCATED flag appropriately when
> there was data lost and thus we must not leave any trace from a previous
> "schedule" in for the "next" collection. So, we must reset the RD/WR
> registers to the base.
>
Yes, You are right, but the WR_ADDR_REG register is RO mode.
Thanks.
>> + }
>
>
>> + smb_reset_buffer_status(drvdata);
>> +}
>> +
>> +static unsigned long smb_update_buffer(struct coresight_device *csdev,
>> + struct perf_output_handle *handle,
>> + void *sink_config)
>> +{
>> + struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
>> + struct smb_data_buffer *sdb = &drvdata->sdb;
>> + struct cs_buffers *buf = sink_config;
>> + unsigned long data_size = 0;
>> + bool lost = false;
>> +
>> + if (!buf)
>> + return 0;
>> +
>> + mutex_lock(&drvdata->mutex);
>> +
>> + /* Don't do anything if another tracer is using this sink. */
>> + if (atomic_read(csdev->refcnt) != 1)
>> + goto out;
>> +
>> + smb_disable_hw(drvdata);
>> + smb_update_data_size(drvdata);
>> + data_size = sdb->data_size;
>> +
>> + /*
>> + * The SMB buffer may be bigger than the space available in the
>> + * perf ring buffer (handle->size). If so advance the offset so
>> + * that we get the latest trace data.
>> + */
>> + if (data_size > handle->size) {
>> + sdb->rd_offset += data_size - handle->size;
>> + sdb->rd_offset %= sdb->buf_size;
>> + data_size = handle->size;
>> + lost = true;
>> + } > +
>> + smb_sync_perf_buffer(drvdata, buf, handle->head, data_size);
>> + if (!buf->snapshot && lost)
>> + perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
>> +
>
>> + smb_enable_hw(drvdata);
>
> We do not need this and could leave this disabled at this stage. The
> perf session has stopped the "source" anyway.
>
Yes, I will do that.
Thanks.
>> +out:
>> + mutex_unlock(&drvdata->mutex);
>> +
>> + return data_size;
>> +}
>> +
>> +static const struct coresight_ops_sink smb_cs_ops = {
>> + .enable = smb_enable,
>> + .disable = smb_disable,
>> + .alloc_buffer = smb_alloc_buffer,
>> + .free_buffer = smb_free_buffer,
>> + .update_buffer = smb_update_buffer,
>> +};
>> +
>> +static const struct coresight_ops cs_ops = {
>> + .sink_ops = &smb_cs_ops,
>> +};
>> +
>> +static int smb_init_data_buffer(struct platform_device *pdev,
>> + struct smb_data_buffer *sdb)
>> +{
>> + struct resource *res;
>> + void *base;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM,
>> SMB_BUF_ADDR_RES);
>> + if (IS_ERR(res)) {
>> + dev_err(&pdev->dev, "SMB device failed to get resource\n");
>> + return -EINVAL;
>> + }
>> +
>> + sdb->start_addr = FIELD_GET(SMB_BUF_ADDR_LO_MSK, res->start);
>> + sdb->buf_size = resource_size(res);
>> + if (sdb->buf_size == 0)
>> + return -EINVAL;
>> +
>> + /*
>> + * This is a chunk of memory, use classic mapping with better
>> + * performance.
>> + */
>> + base = devm_memremap(&pdev->dev, sdb->start_addr, sdb->buf_size,
>> + MEMREMAP_WB);
>> + if (IS_ERR(base))
>> + return PTR_ERR(base);
>> +
>> + sdb->buf_base = base;
>> +
>> + return 0;
>> +}
>> +
>> +static void smb_init_hw(struct smb_drv_data *drvdata)
>> +{
>> + /* First disable SMB and clear the status of SMB buffer */
>> + smb_reset_buffer_status(drvdata);
>> + smb_disable_hw(drvdata);
>> + smb_purge_data(drvdata);
>> +
>> + writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG);
>> + writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG);
>> + writel(SMB_GLB_CFG_DEFAULT, drvdata->base + SMB_GLB_CFG_REG);
>> + writel(SMB_GLB_INT_CFG, drvdata->base + SMB_GLB_INT_REG);
>> + writel(SMB_LB_INT_CTRL_CFG, drvdata->base + SMB_LB_INT_CTRL_REG);
>
> Does this come with interrupt on overflow ? Do we not use this ?
>
When the buffer overflow, no interrupt will come.
Interrupt will upgrade SMB_LB_INT_STS_REG register status if start trace.
Thanks.
> Rest looks fine to me.
>
>
> Suzuki
Best regards,
HeJunhao.
> _______________________________________________
> CoreSight mailing list -- [email protected]
> To unsubscribe send an email to [email protected]
>
> .
>
On 18/11/2022 12:45, hejunhao wrote:
> Hi Suzuki ,
>
>
> On 2022/11/15 19:06, Suzuki K Poulose wrote:
>> On 14/11/2022 09:03, Junhao He wrote:
>>> From: Qi Liu <[email protected]>
>>>
>>> +static void smb_init_hw(struct smb_drv_data *drvdata)
>>> +{
>>> + /* First disable SMB and clear the status of SMB buffer */
>>> + smb_reset_buffer_status(drvdata);
>>> + smb_disable_hw(drvdata);
>>> + smb_purge_data(drvdata);
>>> +
>>> + writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG);
>>> + writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG);
>>> + writel(SMB_GLB_CFG_DEFAULT, drvdata->base + SMB_GLB_CFG_REG);
>>> + writel(SMB_GLB_INT_CFG, drvdata->base + SMB_GLB_INT_REG);
>>> + writel(SMB_LB_INT_CTRL_CFG, drvdata->base + SMB_LB_INT_CTRL_REG);
>>
>> Does this come with interrupt on overflow ? Do we not use this ?
>>
> When the buffer overflow, no interrupt will come.
> Interrupt will upgrade SMB_LB_INT_STS_REG register status if start trace.
> Thanks.
>> Rest looks fine to me.
What is the purpose of the "Interrupt" on the SMB ? It is not clear to
me.
Suzuki
On 2022/11/21 18:47, Suzuki Kuruppassery Poulose wrote:
> On 18/11/2022 12:45, hejunhao wrote:
>> Hi Suzuki ,
>>
>>
>> On 2022/11/15 19:06, Suzuki K Poulose wrote:
>>> On 14/11/2022 09:03, Junhao He wrote:
>>>> From: Qi Liu <[email protected]>
>>>>
>
>>>> +static void smb_init_hw(struct smb_drv_data *drvdata)
>>>> +{
>>>> + /* First disable SMB and clear the status of SMB buffer */
>>>> + smb_reset_buffer_status(drvdata);
>>>> + smb_disable_hw(drvdata);
>>>> + smb_purge_data(drvdata);
>>>> +
>>>> + writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG);
>>>> + writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG);
>>>> + writel(SMB_GLB_CFG_DEFAULT, drvdata->base + SMB_GLB_CFG_REG);
>>>> + writel(SMB_GLB_INT_CFG, drvdata->base + SMB_GLB_INT_REG);
>>>> + writel(SMB_LB_INT_CTRL_CFG, drvdata->base + SMB_LB_INT_CTRL_REG);
>>>
>>> Does this come with interrupt on overflow ? Do we not use this ?
>>>
>> When the buffer overflow, no interrupt will come.
>> Interrupt will upgrade SMB_LB_INT_STS_REG register status if start
>> trace.
>> Thanks.
>>> Rest looks fine to me.
>
> What is the purpose of the "Interrupt" on the SMB ? It is not clear to
> me.
The SMB_LB_INT_CTRL_REG register control the validity of both real-time
events and interrupts. When logical buffer status changes causes to issue an
interrupt at the same time as it issues a real-time event.
Real-time events are used in SMB driver, which needs to get the buffer
status.
Interrupts are used in debugger mode and cannot be registered in kernel.
..._BUF_NOTE_MASK control which events flags or interrupts are valid.
Thanks.
Best regards,
Junhao.
> Suzuki
>
> _______________________________________________
> CoreSight mailing list -- [email protected]
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On 22/11/2022 13:23, hejunhao wrote:
>
> On 2022/11/21 18:47, Suzuki Kuruppassery Poulose wrote:
>> On 18/11/2022 12:45, hejunhao wrote:
>>> Hi Suzuki ,
>>>
>>>
>>> On 2022/11/15 19:06, Suzuki K Poulose wrote:
>>>> On 14/11/2022 09:03, Junhao He wrote:
>>>>> From: Qi Liu <[email protected]>
>>>>>
>>
>>>>> +static void smb_init_hw(struct smb_drv_data *drvdata)
>>>>> +{
>>>>> + /* First disable SMB and clear the status of SMB buffer */
>>>>> + smb_reset_buffer_status(drvdata);
>>>>> + smb_disable_hw(drvdata);
>>>>> + smb_purge_data(drvdata);
>>>>> +
>>>>> + writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG);
>>>>> + writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG);
>>>>> + writel(SMB_GLB_CFG_DEFAULT, drvdata->base + SMB_GLB_CFG_REG);
>>>>> + writel(SMB_GLB_INT_CFG, drvdata->base + SMB_GLB_INT_REG);
>>>>> + writel(SMB_LB_INT_CTRL_CFG, drvdata->base + SMB_LB_INT_CTRL_REG);
>>>>
>>>> Does this come with interrupt on overflow ? Do we not use this ?
>>>>
>>> When the buffer overflow, no interrupt will come.
>>> Interrupt will upgrade SMB_LB_INT_STS_REG register status if start
>>> trace.
>>> Thanks.
>>>> Rest looks fine to me.
>>
>> What is the purpose of the "Interrupt" on the SMB ? It is not clear to
>> me.
> The SMB_LB_INT_CTRL_REG register control the validity of both real-time
> events and interrupts. When logical buffer status changes causes to
> issue an
> interrupt at the same time as it issues a real-time event.
> Real-time events are used in SMB driver, which needs to get the buffer
> status.
> Interrupts are used in debugger mode and cannot be registered in kernel.
> ..._BUF_NOTE_MASK control which events flags or interrupts are valid.
Please add this to a comment in the code above the register write.
Thanks
Suzuki
>
> Thanks.
>
> Best regards,
> Junhao.
>
>> Suzuki
>>
>> _______________________________________________
>> CoreSight mailing list -- [email protected]
>> To unsubscribe send an email to [email protected]
>
Hi Suzuki ,
On 2022/11/22 22:06, Suzuki K Poulose wrote:
> On 22/11/2022 13:23, hejunhao wrote:
>>
>> On 2022/11/21 18:47, Suzuki Kuruppassery Poulose wrote:
>>> On 18/11/2022 12:45, hejunhao wrote:
>>>> Hi Suzuki ,
>>>>
>>>>
>>>> On 2022/11/15 19:06, Suzuki K Poulose wrote:
>>>>> On 14/11/2022 09:03, Junhao He wrote:
>>>>>> From: Qi Liu <[email protected]>
>>>>>>
>>>
>>>>>> +static void smb_init_hw(struct smb_drv_data *drvdata)
>>>>>> +{
>>>>>> + /* First disable SMB and clear the status of SMB buffer */
>>>>>> + smb_reset_buffer_status(drvdata);
>>>>>> + smb_disable_hw(drvdata);
>>>>>> + smb_purge_data(drvdata);
>>>>>> +
>>>>>> + writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base +
>>>>>> SMB_LB_CFG_LO_REG);
>>>>>> + writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base +
>>>>>> SMB_LB_CFG_HI_REG);
>>>>>> + writel(SMB_GLB_CFG_DEFAULT, drvdata->base + SMB_GLB_CFG_REG);
>>>>>> + writel(SMB_GLB_INT_CFG, drvdata->base + SMB_GLB_INT_REG);
>>>>>> + writel(SMB_LB_INT_CTRL_CFG, drvdata->base +
>>>>>> SMB_LB_INT_CTRL_REG);
>>>>>
>>>>> Does this come with interrupt on overflow ? Do we not use this ?
>>>>>
>>>> When the buffer overflow, no interrupt will come.
>>>> Interrupt will upgrade SMB_LB_INT_STS_REG register status if start
>>>> trace.
>>>> Thanks.
>>>>> Rest looks fine to me.
>>>
>>> What is the purpose of the "Interrupt" on the SMB ? It is not clear to
>>> me.
>> The SMB_LB_INT_CTRL_REG register control the validity of both real-time
>> events and interrupts. When logical buffer status changes causes to
>> issue an
>> interrupt at the same time as it issues a real-time event.
>> Real-time events are used in SMB driver, which needs to get the
>> buffer status.
>> Interrupts are used in debugger mode and cannot be registered in kernel.
>> ..._BUF_NOTE_MASK control which events flags or interrupts are valid.
>
> Please add this to a comment in the code above the register write.
>
> Thanks
> Suzuki
>
Yes, thanks for the comment. I will do that.
Best regards,
Junhao.
>>
>> Thanks.
>>
>> Best regards,
>> Junhao.
>>
>>> Suzuki
>>>
>>> _______________________________________________
>>> CoreSight mailing list -- [email protected]
>>> To unsubscribe send an email to [email protected]
>>
>
> _______________________________________________
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> To unsubscribe send an email to [email protected]