| Message ID | 20250212114918.548431-6-lcherian@marvell.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Coresight for Kernel panic and watchdog reset | expand |
On 12/02/2025 11:49, Linu Cherian wrote: > * Add support for reading crashdata using special device files. > The special device files /dev/crash_tmc_xxx would be available > for read file operation only when the crash data is valid. > > * User can read the crash data as below > > For example, for reading crash data from tmc_etf sink > > #dd if=/dev/crash_tmc_etfXX of=~/cstrace.bin > > Signed-off-by: Anil Kumar Reddy <areddy3@marvell.com> > Signed-off-by: Tanmay Jagdale <tanmay@marvell.com> > Signed-off-by: Linu Cherian <lcherian@marvell.com> > --- > Changelog from v13: > * Changed the log levels of crc error check failure prints from dev_dbg to > dev_err > * Added CRC recalculation upon barrier packet insertion for overflow > cases, this fixes wrong crc check failures for subsequent boots > * Add metadata valid flag checks for successfully opening crashdata files > * Report to the user during probe if valid crash tracedata is found > * Few other trivial cleanups > > .../hwtracing/coresight/coresight-tmc-core.c | 226 +++++++++++++++++- > .../hwtracing/coresight/coresight-tmc-etr.c | 22 +- > drivers/hwtracing/coresight/coresight-tmc.h | 14 +- > 3 files changed, 259 insertions(+), 3 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c > index c6224eed705d..045d37606750 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-core.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c > @@ -105,6 +105,128 @@ u32 tmc_get_memwidth_mask(struct tmc_drvdata *drvdata) > return mask; > } > > +static bool is_tmc_crashdata_valid(struct tmc_drvdata *drvdata) > +{ > + struct tmc_crash_metadata *mdata; > + > + if (!tmc_has_reserved_buffer(drvdata) || > + !tmc_has_crash_mdata_buffer(drvdata)) > + return false; > + > + mdata = drvdata->crash_mdata.vaddr; > + > + /* Check version match */ > + if (mdata->version != CS_CRASHDATA_VERSION) > + return false; > + > + /* Check for valid metadata */ > + if (!mdata->valid) { > + dev_dbg(&drvdata->csdev->dev, > + "Data invalid in tmc crash metadata\n"); > + return false; > + } > + > + /* > + * Buffer address given by metadata for retrieval of trace data > + * from previous boot is expected to be same as the reserved > + * trace buffer memory region provided through DTS > + */ > + if (drvdata->resrv_buf.paddr != mdata->trace_paddr) { > + dev_dbg(&drvdata->csdev->dev, > + "Trace buffer address of previous boot invalid\n"); > + return false; > + } > + > + /* Check data integrity of metadata */ > + if (mdata->crc32_mdata != find_crash_metadata_crc(mdata)) { > + dev_err(&drvdata->csdev->dev, > + "CRC mismatch in tmc crash metadata\n"); > + return false; > + } > + /* Check data integrity of tracedata */ > + if (mdata->crc32_tdata != find_crash_tracedata_crc(drvdata, mdata)) { > + dev_err(&drvdata->csdev->dev, > + "CRC mismatch in tmc crash tracedata\n"); > + return false; > + } > + > + return true; > +} > + > +static inline ssize_t tmc_get_resvbuf_trace(struct tmc_drvdata *drvdata, > + loff_t pos, size_t len, char **bufpp) > +{ > + s64 offset; > + ssize_t actual = len; > + struct tmc_resrv_buf *rbuf = &drvdata->resrv_buf; > + > + if (pos + actual > rbuf->len) > + actual = rbuf->len - pos; > + if (actual <= 0) > + return 0; > + > + /* Compute the offset from which we read the data */ > + offset = rbuf->offset + pos; > + if (offset >= rbuf->size) > + offset -= rbuf->size; > + > + /* Adjust the length to limit this transaction to end of buffer */ > + actual = (actual < (rbuf->size - offset)) ? > + actual : rbuf->size - offset; > + > + *bufpp = (char *)rbuf->vaddr + offset; > + > + return actual; > +} > + > +static int tmc_prepare_crashdata(struct tmc_drvdata *drvdata) > +{ > + char *bufp; > + ssize_t len; > + u32 status, size; > + u64 rrp, rwp, dba; > + struct tmc_resrv_buf *rbuf; > + struct tmc_crash_metadata *mdata; > + > + mdata = drvdata->crash_mdata.vaddr; > + rbuf = &drvdata->resrv_buf; > + > + rrp = mdata->tmc_rrp; > + rwp = mdata->tmc_rwp; > + dba = mdata->tmc_dba; > + status = mdata->tmc_sts; > + size = mdata->tmc_ram_size << 2; > + > + /* Sync the buffer pointers */ > + rbuf->offset = rrp - dba; > + if (status & TMC_STS_FULL) > + rbuf->len = size; > + else > + rbuf->len = rwp - rrp; > + > + /* Additional sanity checks for validating metadata */ > + if ((rbuf->offset > size) || > + (rbuf->len > size)) { > + dev_dbg(&drvdata->csdev->dev, > + "Offset and length invalid in tmc crash metadata\n"); > + return -EINVAL; > + } > + > + if (status & TMC_STS_FULL) { > + len = tmc_get_resvbuf_trace(drvdata, 0x0, > + CORESIGHT_BARRIER_PKT_SIZE, &bufp); > + if (len >= CORESIGHT_BARRIER_PKT_SIZE) { > + coresight_insert_barrier_packet(bufp); > + /* Recalculate crc */ > + mdata->crc32_tdata = find_crash_tracedata_crc(drvdata, > + mdata); > + mdata->crc32_mdata = find_crash_metadata_crc(mdata); > + } > + } > + > + return 0; > +} > + > static int tmc_read_prepare(struct tmc_drvdata *drvdata) > { > int ret = 0; > @@ -223,6 +345,84 @@ static const struct file_operations tmc_fops = { > .release = tmc_release, > }; > > +static int tmc_crashdata_open(struct inode *inode, struct file *file) > +{ > + int err = 0; > + unsigned long flags; > + struct tmc_resrv_buf *rbuf; > + struct tmc_crash_metadata *mdata; > + struct tmc_drvdata *drvdata = container_of(file->private_data, > + struct tmc_drvdata, > + crashdev); > + > + mdata = drvdata->crash_mdata.vaddr; > + rbuf = &drvdata->resrv_buf; > + > + spin_lock_irqsave(&drvdata->spinlock, flags); > + if (mdata->valid) > + rbuf->reading = true; > + else > + err = -ENOENT; > + spin_unlock_irqrestore(&drvdata->spinlock, flags); > + if (err) > + goto exit; > + > + nonseekable_open(inode, file); > + dev_dbg(&drvdata->csdev->dev, "%s: successfully opened\n", __func__); > +exit: > + return err; > +} > + > +static ssize_t tmc_crashdata_read(struct file *file, char __user *data, > + size_t len, loff_t *ppos) > +{ > + char *bufp; > + ssize_t actual; > + struct tmc_drvdata *drvdata = container_of(file->private_data, > + struct tmc_drvdata, > + crashdev); > + > + actual = tmc_get_resvbuf_trace(drvdata, *ppos, len, &bufp); > + if (actual <= 0) > + return 0; > + > + if (copy_to_user(data, bufp, actual)) { > + dev_dbg(&drvdata->csdev->dev, > + "%s: copy_to_user failed\n", __func__); > + return -EFAULT; > + } > + > + *ppos += actual; > + dev_dbg(&drvdata->csdev->dev, "%zu bytes copied\n", actual); > + > + return actual; > +} > + > +static int tmc_crashdata_release(struct inode *inode, struct file *file) > +{ > + int ret = 0; > + unsigned long flags; > + struct tmc_resrv_buf *rbuf; > + struct tmc_drvdata *drvdata = container_of(file->private_data, > + struct tmc_drvdata, > + crashdev); > + > + rbuf = &drvdata->resrv_buf; > + spin_lock_irqsave(&drvdata->spinlock, flags); > + rbuf->reading = false; > + spin_unlock_irqrestore(&drvdata->spinlock, flags); > + > + dev_dbg(&drvdata->csdev->dev, "%s: released\n", __func__); > + return ret; > +} > + > +static const struct file_operations tmc_crashdata_fops = { > + .owner = THIS_MODULE, > + .open = tmc_crashdata_open, > + .read = tmc_crashdata_read, > + .release = tmc_crashdata_release, > +}; > + > static enum tmc_mem_intf_width tmc_get_memwidth(u32 devid) > { > enum tmc_mem_intf_width memwidth; > @@ -532,6 +732,22 @@ static u32 tmc_etr_get_max_burst_size(struct device *dev) > return burst_size; > } > > +static void register_crash_dev_interface(struct tmc_drvdata *drvdata, > + const char *name) > +{ > + drvdata->crashdev.name = > + devm_kasprintf(&drvdata->csdev->dev, GFP_KERNEL, "%s_%s", "crash", name); > + drvdata->crashdev.minor = MISC_DYNAMIC_MINOR; > + drvdata->crashdev.fops = &tmc_crashdata_fops; > + if (misc_register(&drvdata->crashdev)) { > + dev_dbg(&drvdata->csdev->dev, > + "Failed to setup user interface for crashdata\n"); > + drvdata->crashdev.fops = NULL; > + } else > + dev_info(&drvdata->csdev->dev, > + "Valid crash tracedata found\n"); > +} > + > static int __tmc_probe(struct device *dev, struct resource *res) > { > int ret = 0; > @@ -632,9 +848,15 @@ static int __tmc_probe(struct device *dev, struct resource *res) > drvdata->miscdev.minor = MISC_DYNAMIC_MINOR; > drvdata->miscdev.fops = &tmc_fops; > ret = misc_register(&drvdata->miscdev); > - if (ret) > + if (ret) { > coresight_unregister(drvdata->csdev); > + goto out; > + } > + > out: > + if (is_tmc_crashdata_valid(drvdata) && > + !tmc_prepare_crashdata(drvdata)) > + register_crash_dev_interface(drvdata, desc.name); > return ret; > } > > @@ -687,6 +909,8 @@ static void __tmc_remove(struct device *dev) > * handler to this device is closed. > */ > misc_deregister(&drvdata->miscdev); > + if (drvdata->crashdev.fops) > + misc_deregister(&drvdata->crashdev); > coresight_unregister(drvdata->csdev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c > index fb944a68a11c..c92556e1b4db 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c > @@ -2012,6 +2012,26 @@ static ssize_t buf_mode_preferred_show(struct device *dev, > return sysfs_emit(buf, "%s\n", buf_modes_str[drvdata->etr_mode]); > } > > +static int buf_mode_set_resrv(struct tmc_drvdata *drvdata) > +{ > + int err = -EBUSY; > + unsigned long flags; > + struct tmc_resrv_buf *rbuf; > + > + rbuf = &drvdata->resrv_buf; > + > + /* Ensure there are no active crashdata read sessions */ > + spin_lock_irqsave(&drvdata->spinlock, flags); > + if (!rbuf->reading) { > + tmc_crashdata_set_invalid(drvdata); > + rbuf->len = 0; > + drvdata->etr_mode = ETR_MODE_RESRV; > + err = 0; > + } > + spin_unlock_irqrestore(&drvdata->spinlock, flags); > + return err; > +} > + > static ssize_t buf_mode_preferred_store(struct device *dev, > struct device_attribute *attr, > const char *buf, size_t size) > @@ -2027,7 +2047,7 @@ static ssize_t buf_mode_preferred_store(struct device *dev, > else if (sysfs_streq(buf, buf_modes_str[ETR_MODE_CATU]) && buf_hw.has_catu) > drvdata->etr_mode = ETR_MODE_CATU; > else if (sysfs_streq(buf, buf_modes_str[ETR_MODE_RESRV]) && buf_hw.has_resrv) > - drvdata->etr_mode = ETR_MODE_RESRV; > + return buf_mode_set_resrv(drvdata) ? : size; > else if (sysfs_streq(buf, buf_modes_str[ETR_MODE_AUTO])) > drvdata->etr_mode = ETR_MODE_AUTO; > else > diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h > index d76e83fc840b..e3707b69abff 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc.h > +++ b/drivers/hwtracing/coresight/coresight-tmc.h > @@ -195,11 +195,17 @@ struct etr_buf { > * @paddr : Start address of reserved memory region. > * @vaddr : Corresponding CPU virtual address. > * @size : Size of reserved memory region. > + * @offset : Offset of the trace data in the buffer for consumption. > + * @reading : Flag to indicate if reading is active > + * @len : Available trace data @buf (may round up to the beginning). > */ > struct tmc_resrv_buf { > phys_addr_t paddr; > void *vaddr; > size_t size; > + unsigned long offset; > + bool reading; > + s64 len; > }; > > /** > @@ -208,6 +214,8 @@ struct tmc_resrv_buf { > * @base: memory mapped base address for this component. > * @csdev: component vitals needed by the framework. > * @miscdev: specifics to handle "/dev/xyz.tmc" entry. > + * @crashdev: specifics to handle "/dev/crash_tmc_xyz" entry for reading > + * crash tracedata. > * @spinlock: only one at a time pls. > * @pid: Process ID of the process that owns the session that is using > * this component. For example this would be the pid of the Perf > @@ -227,7 +235,7 @@ struct tmc_resrv_buf { > * @idr_mutex: Access serialisation for idr. > * @sysfs_buf: SYSFS buffer for ETR. > * @perf_buf: PERF buffer for ETR. > - * @resrv_buf: Used by ETR as hardware trace buffer and for trace data > + * @resrv_buf: Used by ETR as hardware trace buffer and for trace data > * retention (after crash) only when ETR_MODE_RESRV buffer > * mode is enabled. Used by ETF for trace data retention > * (after crash) by default. > @@ -239,6 +247,7 @@ struct tmc_drvdata { > void __iomem *base; > struct coresight_device *csdev; > struct miscdevice miscdev; > + struct miscdevice crashdev; > spinlock_t spinlock; > pid_t pid; > bool reading; > @@ -309,6 +318,8 @@ void tmc_flush_and_stop(struct tmc_drvdata *drvdata); > void tmc_enable_hw(struct tmc_drvdata *drvdata); > void tmc_disable_hw(struct tmc_drvdata *drvdata); > u32 tmc_get_memwidth_mask(struct tmc_drvdata *drvdata); > +int tmc_read_prepare_crashdata(struct tmc_drvdata *drvdata); > +int tmc_read_unprepare_crashdata(struct tmc_drvdata *drvdata); This is no longer required. I can fix this up at my end. Suzuki > > /* ETB/ETF functions */ > int tmc_read_prepare_etb(struct tmc_drvdata *drvdata); > @@ -371,6 +382,7 @@ void tmc_sg_table_sync_data_range(struct tmc_sg_table *table, > u64 offset, u64 size); > ssize_t tmc_sg_table_get_data(struct tmc_sg_table *sg_table, > u64 offset, size_t len, char **bufpp); > + > static inline unsigned long > tmc_sg_table_buf_size(struct tmc_sg_table *sg_table) > {
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c index c6224eed705d..045d37606750 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-core.c +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c @@ -105,6 +105,128 @@ u32 tmc_get_memwidth_mask(struct tmc_drvdata *drvdata) return mask; } +static bool is_tmc_crashdata_valid(struct tmc_drvdata *drvdata) +{ + struct tmc_crash_metadata *mdata; + + if (!tmc_has_reserved_buffer(drvdata) || + !tmc_has_crash_mdata_buffer(drvdata)) + return false; + + mdata = drvdata->crash_mdata.vaddr; + + /* Check version match */ + if (mdata->version != CS_CRASHDATA_VERSION) + return false; + + /* Check for valid metadata */ + if (!mdata->valid) { + dev_dbg(&drvdata->csdev->dev, + "Data invalid in tmc crash metadata\n"); + return false; + } + + /* + * Buffer address given by metadata for retrieval of trace data + * from previous boot is expected to be same as the reserved + * trace buffer memory region provided through DTS + */ + if (drvdata->resrv_buf.paddr != mdata->trace_paddr) { + dev_dbg(&drvdata->csdev->dev, + "Trace buffer address of previous boot invalid\n"); + return false; + } + + /* Check data integrity of metadata */ + if (mdata->crc32_mdata != find_crash_metadata_crc(mdata)) { + dev_err(&drvdata->csdev->dev, + "CRC mismatch in tmc crash metadata\n"); + return false; + } + /* Check data integrity of tracedata */ + if (mdata->crc32_tdata != find_crash_tracedata_crc(drvdata, mdata)) { + dev_err(&drvdata->csdev->dev, + "CRC mismatch in tmc crash tracedata\n"); + return false; + } + + return true; +} + +static inline ssize_t tmc_get_resvbuf_trace(struct tmc_drvdata *drvdata, + loff_t pos, size_t len, char **bufpp) +{ + s64 offset; + ssize_t actual = len; + struct tmc_resrv_buf *rbuf = &drvdata->resrv_buf; + + if (pos + actual > rbuf->len) + actual = rbuf->len - pos; + if (actual <= 0) + return 0; + + /* Compute the offset from which we read the data */ + offset = rbuf->offset + pos; + if (offset >= rbuf->size) + offset -= rbuf->size; + + /* Adjust the length to limit this transaction to end of buffer */ + actual = (actual < (rbuf->size - offset)) ? + actual : rbuf->size - offset; + + *bufpp = (char *)rbuf->vaddr + offset; + + return actual; +} + +static int tmc_prepare_crashdata(struct tmc_drvdata *drvdata) +{ + char *bufp; + ssize_t len; + u32 status, size; + u64 rrp, rwp, dba; + struct tmc_resrv_buf *rbuf; + struct tmc_crash_metadata *mdata; + + mdata = drvdata->crash_mdata.vaddr; + rbuf = &drvdata->resrv_buf; + + rrp = mdata->tmc_rrp; + rwp = mdata->tmc_rwp; + dba = mdata->tmc_dba; + status = mdata->tmc_sts; + size = mdata->tmc_ram_size << 2; + + /* Sync the buffer pointers */ + rbuf->offset = rrp - dba; + if (status & TMC_STS_FULL) + rbuf->len = size; + else + rbuf->len = rwp - rrp; + + /* Additional sanity checks for validating metadata */ + if ((rbuf->offset > size) || + (rbuf->len > size)) { + dev_dbg(&drvdata->csdev->dev, + "Offset and length invalid in tmc crash metadata\n"); + return -EINVAL; + } + + if (status & TMC_STS_FULL) { + len = tmc_get_resvbuf_trace(drvdata, 0x0, + CORESIGHT_BARRIER_PKT_SIZE, &bufp); + if (len >= CORESIGHT_BARRIER_PKT_SIZE) { + coresight_insert_barrier_packet(bufp); + /* Recalculate crc */ + mdata->crc32_tdata = find_crash_tracedata_crc(drvdata, + mdata); + mdata->crc32_mdata = find_crash_metadata_crc(mdata); + } + } + + return 0; +} + static int tmc_read_prepare(struct tmc_drvdata *drvdata) { int ret = 0; @@ -223,6 +345,84 @@ static const struct file_operations tmc_fops = { .release = tmc_release, }; +static int tmc_crashdata_open(struct inode *inode, struct file *file) +{ + int err = 0; + unsigned long flags; + struct tmc_resrv_buf *rbuf; + struct tmc_crash_metadata *mdata; + struct tmc_drvdata *drvdata = container_of(file->private_data, + struct tmc_drvdata, + crashdev); + + mdata = drvdata->crash_mdata.vaddr; + rbuf = &drvdata->resrv_buf; + + spin_lock_irqsave(&drvdata->spinlock, flags); + if (mdata->valid) + rbuf->reading = true; + else + err = -ENOENT; + spin_unlock_irqrestore(&drvdata->spinlock, flags); + if (err) + goto exit; + + nonseekable_open(inode, file); + dev_dbg(&drvdata->csdev->dev, "%s: successfully opened\n", __func__); +exit: + return err; +} + +static ssize_t tmc_crashdata_read(struct file *file, char __user *data, + size_t len, loff_t *ppos) +{ + char *bufp; + ssize_t actual; + struct tmc_drvdata *drvdata = container_of(file->private_data, + struct tmc_drvdata, + crashdev); + + actual = tmc_get_resvbuf_trace(drvdata, *ppos, len, &bufp); + if (actual <= 0) + return 0; + + if (copy_to_user(data, bufp, actual)) { + dev_dbg(&drvdata->csdev->dev, + "%s: copy_to_user failed\n", __func__); + return -EFAULT; + } + + *ppos += actual; + dev_dbg(&drvdata->csdev->dev, "%zu bytes copied\n", actual); + + return actual; +} + +static int tmc_crashdata_release(struct inode *inode, struct file *file) +{ + int ret = 0; + unsigned long flags; + struct tmc_resrv_buf *rbuf; + struct tmc_drvdata *drvdata = container_of(file->private_data, + struct tmc_drvdata, + crashdev); + + rbuf = &drvdata->resrv_buf; + spin_lock_irqsave(&drvdata->spinlock, flags); + rbuf->reading = false; + spin_unlock_irqrestore(&drvdata->spinlock, flags); + + dev_dbg(&drvdata->csdev->dev, "%s: released\n", __func__); + return ret; +} + +static const struct file_operations tmc_crashdata_fops = { + .owner = THIS_MODULE, + .open = tmc_crashdata_open, + .read = tmc_crashdata_read, + .release = tmc_crashdata_release, +}; + static enum tmc_mem_intf_width tmc_get_memwidth(u32 devid) { enum tmc_mem_intf_width memwidth; @@ -532,6 +732,22 @@ static u32 tmc_etr_get_max_burst_size(struct device *dev) return burst_size; } +static void register_crash_dev_interface(struct tmc_drvdata *drvdata, + const char *name) +{ + drvdata->crashdev.name = + devm_kasprintf(&drvdata->csdev->dev, GFP_KERNEL, "%s_%s", "crash", name); + drvdata->crashdev.minor = MISC_DYNAMIC_MINOR; + drvdata->crashdev.fops = &tmc_crashdata_fops; + if (misc_register(&drvdata->crashdev)) { + dev_dbg(&drvdata->csdev->dev, + "Failed to setup user interface for crashdata\n"); + drvdata->crashdev.fops = NULL; + } else + dev_info(&drvdata->csdev->dev, + "Valid crash tracedata found\n"); +} + static int __tmc_probe(struct device *dev, struct resource *res) { int ret = 0; @@ -632,9 +848,15 @@ static int __tmc_probe(struct device *dev, struct resource *res) drvdata->miscdev.minor = MISC_DYNAMIC_MINOR; drvdata->miscdev.fops = &tmc_fops; ret = misc_register(&drvdata->miscdev); - if (ret) + if (ret) { coresight_unregister(drvdata->csdev); + goto out; + } + out: + if (is_tmc_crashdata_valid(drvdata) && + !tmc_prepare_crashdata(drvdata)) + register_crash_dev_interface(drvdata, desc.name); return ret; } @@ -687,6 +909,8 @@ static void __tmc_remove(struct device *dev) * handler to this device is closed. */ misc_deregister(&drvdata->miscdev); + if (drvdata->crashdev.fops) + misc_deregister(&drvdata->crashdev); coresight_unregister(drvdata->csdev); } diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index fb944a68a11c..c92556e1b4db 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -2012,6 +2012,26 @@ static ssize_t buf_mode_preferred_show(struct device *dev, return sysfs_emit(buf, "%s\n", buf_modes_str[drvdata->etr_mode]); } +static int buf_mode_set_resrv(struct tmc_drvdata *drvdata) +{ + int err = -EBUSY; + unsigned long flags; + struct tmc_resrv_buf *rbuf; + + rbuf = &drvdata->resrv_buf; + + /* Ensure there are no active crashdata read sessions */ + spin_lock_irqsave(&drvdata->spinlock, flags); + if (!rbuf->reading) { + tmc_crashdata_set_invalid(drvdata); + rbuf->len = 0; + drvdata->etr_mode = ETR_MODE_RESRV; + err = 0; + } + spin_unlock_irqrestore(&drvdata->spinlock, flags); + return err; +} + static ssize_t buf_mode_preferred_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) @@ -2027,7 +2047,7 @@ static ssize_t buf_mode_preferred_store(struct device *dev, else if (sysfs_streq(buf, buf_modes_str[ETR_MODE_CATU]) && buf_hw.has_catu) drvdata->etr_mode = ETR_MODE_CATU; else if (sysfs_streq(buf, buf_modes_str[ETR_MODE_RESRV]) && buf_hw.has_resrv) - drvdata->etr_mode = ETR_MODE_RESRV; + return buf_mode_set_resrv(drvdata) ? : size; else if (sysfs_streq(buf, buf_modes_str[ETR_MODE_AUTO])) drvdata->etr_mode = ETR_MODE_AUTO; else diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index d76e83fc840b..e3707b69abff 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -195,11 +195,17 @@ struct etr_buf { * @paddr : Start address of reserved memory region. * @vaddr : Corresponding CPU virtual address. * @size : Size of reserved memory region. + * @offset : Offset of the trace data in the buffer for consumption. + * @reading : Flag to indicate if reading is active + * @len : Available trace data @buf (may round up to the beginning). */ struct tmc_resrv_buf { phys_addr_t paddr; void *vaddr; size_t size; + unsigned long offset; + bool reading; + s64 len; }; /** @@ -208,6 +214,8 @@ struct tmc_resrv_buf { * @base: memory mapped base address for this component. * @csdev: component vitals needed by the framework. * @miscdev: specifics to handle "/dev/xyz.tmc" entry. + * @crashdev: specifics to handle "/dev/crash_tmc_xyz" entry for reading + * crash tracedata. * @spinlock: only one at a time pls. * @pid: Process ID of the process that owns the session that is using * this component. For example this would be the pid of the Perf @@ -227,7 +235,7 @@ struct tmc_resrv_buf { * @idr_mutex: Access serialisation for idr. * @sysfs_buf: SYSFS buffer for ETR. * @perf_buf: PERF buffer for ETR. - * @resrv_buf: Used by ETR as hardware trace buffer and for trace data + * @resrv_buf: Used by ETR as hardware trace buffer and for trace data * retention (after crash) only when ETR_MODE_RESRV buffer * mode is enabled. Used by ETF for trace data retention * (after crash) by default. @@ -239,6 +247,7 @@ struct tmc_drvdata { void __iomem *base; struct coresight_device *csdev; struct miscdevice miscdev; + struct miscdevice crashdev; spinlock_t spinlock; pid_t pid; bool reading; @@ -309,6 +318,8 @@ void tmc_flush_and_stop(struct tmc_drvdata *drvdata); void tmc_enable_hw(struct tmc_drvdata *drvdata); void tmc_disable_hw(struct tmc_drvdata *drvdata); u32 tmc_get_memwidth_mask(struct tmc_drvdata *drvdata); +int tmc_read_prepare_crashdata(struct tmc_drvdata *drvdata); +int tmc_read_unprepare_crashdata(struct tmc_drvdata *drvdata); /* ETB/ETF functions */ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata); @@ -371,6 +382,7 @@ void tmc_sg_table_sync_data_range(struct tmc_sg_table *table, u64 offset, u64 size); ssize_t tmc_sg_table_get_data(struct tmc_sg_table *sg_table, u64 offset, size_t len, char **bufpp); + static inline unsigned long tmc_sg_table_buf_size(struct tmc_sg_table *sg_table) {