OpenCloudOS-Kernel/drivers/hwtracing/coresight/coresight-tmc-etr.c

333 lines
8.0 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright(C) 2016 Linaro Limited. All rights reserved.
* Author: Mathieu Poirier <mathieu.poirier@linaro.org>
*/
#include <linux/coresight.h>
#include <linux/dma-mapping.h>
#include "coresight-priv.h"
#include "coresight-tmc.h"
static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata)
{
u32 axictl, sts;
/* Zero out the memory to help with debug */
memset(drvdata->vaddr, 0, drvdata->size);
CS_UNLOCK(drvdata->base);
/* Wait for TMCSReady bit to be set */
tmc_wait_for_tmcready(drvdata);
writel_relaxed(drvdata->size / 4, drvdata->base + TMC_RSZ);
writel_relaxed(TMC_MODE_CIRCULAR_BUFFER, drvdata->base + TMC_MODE);
axictl = readl_relaxed(drvdata->base + TMC_AXICTL);
axictl &= ~TMC_AXICTL_CLEAR_MASK;
axictl |= (TMC_AXICTL_PROT_CTL_B1 | TMC_AXICTL_WR_BURST_16);
axictl |= TMC_AXICTL_AXCACHE_OS;
if (tmc_etr_has_cap(drvdata, TMC_ETR_AXI_ARCACHE)) {
axictl &= ~TMC_AXICTL_ARCACHE_MASK;
axictl |= TMC_AXICTL_ARCACHE_OS;
}
writel_relaxed(axictl, drvdata->base + TMC_AXICTL);
tmc_write_dba(drvdata, drvdata->paddr);
/*
* If the TMC pointers must be programmed before the session,
* we have to set it properly (i.e, RRP/RWP to base address and
* STS to "not full").
*/
if (tmc_etr_has_cap(drvdata, TMC_ETR_SAVE_RESTORE)) {
tmc_write_rrp(drvdata, drvdata->paddr);
tmc_write_rwp(drvdata, drvdata->paddr);
sts = readl_relaxed(drvdata->base + TMC_STS) & ~TMC_STS_FULL;
writel_relaxed(sts, drvdata->base + TMC_STS);
}
writel_relaxed(TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI |
TMC_FFCR_FON_FLIN | TMC_FFCR_FON_TRIG_EVT |
TMC_FFCR_TRIGON_TRIGIN,
drvdata->base + TMC_FFCR);
writel_relaxed(drvdata->trigger_cntr, drvdata->base + TMC_TRG);
tmc_enable_hw(drvdata);
CS_LOCK(drvdata->base);
}
static void tmc_etr_dump_hw(struct tmc_drvdata *drvdata)
{
const u32 *barrier;
u32 val;
u32 *temp;
u64 rwp;
rwp = tmc_read_rwp(drvdata);
val = readl_relaxed(drvdata->base + TMC_STS);
/*
* Adjust the buffer to point to the beginning of the trace data
* and update the available trace data.
*/
if (val & TMC_STS_FULL) {
drvdata->buf = drvdata->vaddr + rwp - drvdata->paddr;
drvdata->len = drvdata->size;
barrier = barrier_pkt;
temp = (u32 *)drvdata->buf;
while (*barrier) {
*temp = *barrier;
temp++;
barrier++;
}
} else {
drvdata->buf = drvdata->vaddr;
drvdata->len = rwp - drvdata->paddr;
}
}
static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
{
CS_UNLOCK(drvdata->base);
tmc_flush_and_stop(drvdata);
/*
* When operating in sysFS mode the content of the buffer needs to be
* read before the TMC is disabled.
*/
if (drvdata->mode == CS_MODE_SYSFS)
tmc_etr_dump_hw(drvdata);
tmc_disable_hw(drvdata);
CS_LOCK(drvdata->base);
}
static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
{
int ret = 0;
bool used = false;
unsigned long flags;
void __iomem *vaddr = NULL;
dma_addr_t paddr = 0;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
/*
* If we don't have a buffer release the lock and allocate memory.
* Otherwise keep the lock and move along.
*/
spin_lock_irqsave(&drvdata->spinlock, flags);
if (!drvdata->vaddr) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
/*
* Contiguous memory can't be allocated while a spinlock is
* held. As such allocate memory here and free it if a buffer
* has already been allocated (from a previous session).
*/
vaddr = dma_alloc_coherent(drvdata->dev, drvdata->size,
&paddr, GFP_KERNEL);
if (!vaddr)
return -ENOMEM;
/* Let's try again */
spin_lock_irqsave(&drvdata->spinlock, flags);
}
if (drvdata->reading) {
ret = -EBUSY;
goto out;
}
/*
* In sysFS mode we can have multiple writers per sink. Since this
* sink is already enabled no memory is needed and the HW need not be
* touched.
*/
if (drvdata->mode == CS_MODE_SYSFS)
goto out;
/*
* If drvdata::vaddr == NULL, use the memory allocated above.
* Otherwise a buffer still exists from a previous session, so
* simply use that.
*/
if (drvdata->vaddr == NULL) {
used = true;
drvdata->vaddr = vaddr;
drvdata->paddr = paddr;
drvdata->buf = drvdata->vaddr;
}
drvdata->mode = CS_MODE_SYSFS;
tmc_etr_enable_hw(drvdata);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
/* Free memory outside the spinlock if need be */
if (!used && vaddr)
dma_free_coherent(drvdata->dev, drvdata->size, vaddr, paddr);
if (!ret)
dev_info(drvdata->dev, "TMC-ETR enabled\n");
return ret;
}
static int tmc_enable_etr_sink_perf(struct coresight_device *csdev)
{
int ret = 0;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
if (drvdata->reading) {
ret = -EINVAL;
goto out;
}
/*
* In Perf mode there can be only one writer per sink. There
* is also no need to continue if the ETR is already operated
* from sysFS.
*/
if (drvdata->mode != CS_MODE_DISABLED) {
ret = -EINVAL;
goto out;
}
drvdata->mode = CS_MODE_PERF;
tmc_etr_enable_hw(drvdata);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
return ret;
}
static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
{
switch (mode) {
case CS_MODE_SYSFS:
return tmc_enable_etr_sink_sysfs(csdev);
case CS_MODE_PERF:
return tmc_enable_etr_sink_perf(csdev);
}
/* We shouldn't be here */
return -EINVAL;
}
static void tmc_disable_etr_sink(struct coresight_device *csdev)
{
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
if (drvdata->reading) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
return;
}
/* Disable the TMC only if it needs to */
if (drvdata->mode != CS_MODE_DISABLED) {
tmc_etr_disable_hw(drvdata);
drvdata->mode = CS_MODE_DISABLED;
}
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "TMC-ETR disabled\n");
}
static const struct coresight_ops_sink tmc_etr_sink_ops = {
.enable = tmc_enable_etr_sink,
.disable = tmc_disable_etr_sink,
};
const struct coresight_ops tmc_etr_cs_ops = {
.sink_ops = &tmc_etr_sink_ops,
};
int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
{
int ret = 0;
unsigned long flags;
/* config types are set a boot time and never change */
if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR))
return -EINVAL;
spin_lock_irqsave(&drvdata->spinlock, flags);
if (drvdata->reading) {
ret = -EBUSY;
goto out;
}
/* Don't interfere if operated from Perf */
if (drvdata->mode == CS_MODE_PERF) {
ret = -EINVAL;
goto out;
}
/* If drvdata::buf is NULL the trace data has been read already */
if (drvdata->buf == NULL) {
ret = -EINVAL;
goto out;
}
/* Disable the TMC if need be */
if (drvdata->mode == CS_MODE_SYSFS)
tmc_etr_disable_hw(drvdata);
drvdata->reading = true;
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
return ret;
}
int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
{
unsigned long flags;
dma_addr_t paddr;
void __iomem *vaddr = NULL;
/* config types are set a boot time and never change */
if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR))
return -EINVAL;
spin_lock_irqsave(&drvdata->spinlock, flags);
/* RE-enable the TMC if need be */
if (drvdata->mode == CS_MODE_SYSFS) {
/*
* The trace run will continue with the same allocated trace
coresight: Fix erroneous memset in tmc_read_unprepare_etr At the end of a trace collection, we try to clear the entire buffer and enable the ETR back if it was already enabled. But, we would have adjusted the drvdata->buf to point to the beginning of the trace data in the trace buffer @drvdata->vaddr. So, the following code which clears the buffer is dangerous and can cause crashes, like below : memset(drvdata->buf, 0, drvdata->size); Unable to handle kernel paging request at virtual address ffffff800a145000 pgd = ffffffc974726000 *pgd=00000009f3e91003, *pud=00000009f3e91003, *pmd=0000000000000000 PREEMPT SMP Modules linked in: CPU: 4 PID: 1692 Comm: dd Not tainted 4.7.0-rc2+ #1721 Hardware name: ARM Juno development board (r0) (DT) task: ffffffc9734a0080 ti: ffffffc974460000 task.ti: ffffffc974460000 PC is at __memset+0x1ac/0x200 LR is at tmc_read_unprepare_etr+0x144/0x1bc pc : [<ffffff80083a05ac>] lr : [<ffffff800859c984>] pstate: 200001c5 ... [<ffffff80083a05ac>] __memset+0x1ac/0x200 [<ffffff800859b2e4>] tmc_release+0x90/0x94 [<ffffff8008202f58>] __fput+0xa8/0x1ec [<ffffff80082030f4>] ____fput+0xc/0x14 [<ffffff80080c3ef8>] task_work_run+0xb0/0xe4 [<ffffff8008088bf4>] do_notify_resume+0x64/0x6c [<ffffff8008084d5c>] work_pending+0x10/0x14 Code: 91010108 54ffff4a 8b040108 cb050042 (d50b7428) Since we clear the buffer anyway in the following call to tmc_etr_enable_hw(), remove the erroneous memset(). Fixes: commit de5461970b3e9e1 ("coresight: tmc: allocating memory when needed") Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-15 01:17:14 +08:00
* buffer. The trace buffer is cleared in tmc_etr_enable_hw(),
* so we don't have to explicitly clear it. Also, since the
* tracer is still enabled drvdata::buf can't be NULL.
*/
tmc_etr_enable_hw(drvdata);
} else {
/*
* The ETR is not tracing and the buffer was just read.
* As such prepare to free the trace buffer.
*/
vaddr = drvdata->vaddr;
paddr = drvdata->paddr;
coresight: Fix tmc_read_unprepare_etr At the end of the trace capture, we free the allocated memory, resetting the drvdata->buf to NULL, to indicate that trace data was collected and the next trace session should allocate the memory in tmc_enable_etr_sink_sysfs. The tmc_enable_etr_sink_sysfs, we only allocate memory if drvdata->vaddr is not NULL (which is not performed at the end of previous session). This can cause, drvdata->vaddr getting assigned NULL and later we do memset() which causes a crash as below : Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = ffffffc9747f0000 [00000000] *pgd=00000009f402e003, *pud=00000009f402e003, *pmd=0000000000000000 Internal error: Oops: 96000046 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 1592 Comm: bash Not tainted 4.7.0-rc1+ #1712 Hardware name: ARM Juno development board (r0) (DT) task: ffffffc078fe0080 ti: ffffffc974178000 task.ti: ffffffc974178000 PC is at __memset+0x1ac/0x200 LR is at tmc_enable_etr_sink+0xf8/0x304 pc : [<ffffff80083a002c>] lr : [<ffffff800859be44>] pstate: 400001c5 sp : ffffffc97417bc00 x29: ffffffc97417bc00 x28: ffffffc974178000 Call trace: Exception stack(0xffffffc97417ba40 to 0xffffffc97417bb60) ba40: 0000000000000001 ffffffc974a5d098 ffffffc97417bc00 ffffff80083a002c ba60: ffffffc974a5d118 0000000000000000 0000000000000000 0000000000000000 ba80: 0000000000000001 0000000000000000 ffffff800859bdec 0000000000000040 baa0: ffffff8008b45b58 00000000000001c0 ffffffc97417baf0 ffffff80080eddb4 bac0: 0000000000000003 ffffffc078fe0080 ffffffc078fe0960 ffffffc078fe0940 bae0: 0000000000000000 0000000000000000 00000000007fffc0 0000000000000004 bb00: 0000000000000000 0000000000000040 000000000000003f 0000000000000000 bb20: 0000000000000000 0000000000000000 0000000000000000 0000000000000001 bb40: ffffffc078fe0960 0000000000000018 ffffffffffffffff 0008669628000000 [<ffffff80083a002c>] __memset+0x1ac/0x200 [<ffffff8008599814>] coresight_enable_path+0xa8/0x1dc [<ffffff8008599b10>] coresight_enable+0x88/0x1b8 [<ffffff8008599d88>] enable_source_store+0x3c/0x6c [<ffffff800845eaf4>] dev_attr_store+0x18/0x28 [<ffffff80082829e8>] sysfs_kf_write+0x54/0x64 [<ffffff8008281c30>] kernfs_fop_write+0x148/0x1d8 [<ffffff8008200128>] __vfs_write+0x28/0x110 [<ffffff8008200e88>] vfs_write+0xa0/0x198 [<ffffff80082021b0>] SyS_write+0x44/0xa0 [<ffffff8008084e70>] el0_svc_naked+0x24/0x28 Code: 91010108 54ffff4a 8b040108 cb050042 (d50b7428) This patch fixes the issue by clearing the drvdata->vaddr while we free the allocated buffer at the end of a session, so that we allocate the memory again. Cc: mathieu.poirier@linaro.org Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-15 01:17:13 +08:00
drvdata->buf = drvdata->vaddr = NULL;
}
drvdata->reading = false;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
/* Free allocated memory out side of the spinlock */
if (vaddr)
dma_free_coherent(drvdata->dev, drvdata->size, vaddr, paddr);
return 0;
}