From 4d0be09b136481ffc17c08399d612276f18607d6 Mon Sep 17 00:00:00 2001
From: Rob Clark <robdclark@chromium.org>
Date: Thu, 3 Mar 2022 16:52:16 -0800
Subject: drm/msm: Add SYSPROF param (v2)
Git-commit: 90f45c42d7d7b0ec0fd797485c07fc421c474e12
Patch-mainline: v5.18-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
Add a SYSPROF param for system profiling tools like Mesa's pps-producer
(perfetto) to control behavior related to system-wide performance
counter collection. In particular, for profiling, one wants to ensure
that GPU context switches do not effect perfcounter state, and might
want to suppress suspend (which would cause counters to lose state).
v2: Swap the order in msm_file_private_set_sysprof() [sboyd] and
initialize the sysprof_active refcount to one (because the under/
overflow checking in refcount_t doesn't expect a 0->1 transition)
meaning that values greater than 1 means sysprof is active.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220304005317.776110-4-robdclark@gmail.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/msm/adreno/adreno_gpu.c | 4 +++
drivers/gpu/drm/msm/msm_drv.c | 8 +++++
drivers/gpu/drm/msm/msm_gpu.c | 2 ++
drivers/gpu/drm/msm/msm_gpu.h | 27 +++++++++++++++++
drivers/gpu/drm/msm/msm_submitqueue.c | 39 +++++++++++++++++++++++++
include/uapi/drm/msm_drm.h | 1 +
6 files changed, 81 insertions(+)
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index 6a37d409653b..c91ea363c373 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -287,6 +287,10 @@ int adreno_set_param(struct msm_gpu *gpu, struct msm_file_private *ctx,
uint32_t param, uint64_t value)
{
switch (param) {
+ case MSM_PARAM_SYSPROF:
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ return msm_file_private_set_sysprof(ctx, gpu, value);
default:
DBG("%s: invalid param: %u", gpu->name, param);
return -EINVAL;
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index a081d92b1c18..3fb793393f33 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -561,8 +561,16 @@ static void context_close(struct msm_file_private *ctx)
static void msm_postclose(struct drm_device *dev, struct drm_file *file)
{
+ struct msm_drm_private *priv = dev->dev_private;
struct msm_file_private *ctx = file->driver_priv;
+ /*
+ * It is not possible to set sysprof param to non-zero if gpu
+ * is not initialized:
+ */
+ if (priv->gpu)
+ msm_file_private_set_sysprof(ctx, priv->gpu, 0);
+
context_close(ctx);
}
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index bacdabbaad96..faf0c242874e 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -959,6 +959,8 @@ int msm_gpu_init(struct drm_device *drm, struct platform_device *pdev,
gpu->nr_rings = nr_rings;
+ refcount_set(&gpu->sysprof_active, 1);
+
return 0;
fail:
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index 07ee6573a301..02419f2ca2bc 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -159,6 +159,13 @@ struct msm_gpu {
struct msm_ringbuffer *rb[MSM_GPU_MAX_RINGS];
int nr_rings;
+ /**
+ * sysprof_active:
+ *
+ * The count of contexts that have enabled system profiling.
+ */
+ refcount_t sysprof_active;
+
/**
* cur_ctx_seqno:
*
@@ -329,6 +336,24 @@ struct msm_file_private {
struct kref ref;
int seqno;
+ /**
+ * sysprof:
+ *
+ * The value of MSM_PARAM_SYSPROF set by userspace. This is
+ * intended to be used by system profiling tools like Mesa's
+ * pps-producer (perfetto), and restricted to CAP_SYS_ADMIN.
+ *
+ * Setting a value of 1 will preserve performance counters across
+ * context switches. Setting a value of 2 will in addition
+ * suppress suspend. (Performance counters lose state across
+ * power collapse, which is undesirable for profiling in some
+ * cases.)
+ *
+ * The value automatically reverts to zero when the drm device
+ * file is closed.
+ */
+ int sysprof;
+
/**
* entities:
*
@@ -525,6 +550,8 @@ void msm_submitqueue_close(struct msm_file_private *ctx);
void msm_submitqueue_destroy(struct kref *kref);
+int msm_file_private_set_sysprof(struct msm_file_private *ctx,
+ struct msm_gpu *gpu, int sysprof);
void __msm_file_private_destroy(struct kref *kref);
static inline void msm_file_private_put(struct msm_file_private *ctx)
diff --git a/drivers/gpu/drm/msm/msm_submitqueue.c b/drivers/gpu/drm/msm/msm_submitqueue.c
index 7cb158bcbcf6..79b6ccd6ce64 100644
--- a/drivers/gpu/drm/msm/msm_submitqueue.c
+++ b/drivers/gpu/drm/msm/msm_submitqueue.c
@@ -7,6 +7,45 @@
#include "msm_gpu.h"
+int msm_file_private_set_sysprof(struct msm_file_private *ctx,
+ struct msm_gpu *gpu, int sysprof)
+{
+ /*
+ * Since pm_runtime and sysprof_active are both refcounts, we
+ * call apply the new value first, and then unwind the previous
+ * value
+ */
+
+ switch (sysprof) {
+ default:
+ return -EINVAL;
+ case 2:
+ pm_runtime_get_sync(&gpu->pdev->dev);
+ fallthrough;
+ case 1:
+ refcount_inc(&gpu->sysprof_active);
+ fallthrough;
+ case 0:
+ break;
+ }
+
+ /* unwind old value: */
+ switch (ctx->sysprof) {
+ case 2:
+ pm_runtime_put_autosuspend(&gpu->pdev->dev);
+ fallthrough;
+ case 1:
+ refcount_dec(&gpu->sysprof_active);
+ fallthrough;
+ case 0:
+ break;
+ }
+
+ ctx->sysprof = sysprof;
+
+ return 0;
+}
+
void __msm_file_private_destroy(struct kref *kref)
{
struct msm_file_private *ctx = container_of(kref,
diff --git a/include/uapi/drm/msm_drm.h b/include/uapi/drm/msm_drm.h
index cf5de53836e7..2ee03ba08681 100644
--- a/include/uapi/drm/msm_drm.h
+++ b/include/uapi/drm/msm_drm.h
@@ -81,6 +81,7 @@ struct drm_msm_timespec {
#define MSM_PARAM_PP_PGTABLE 0x08 /* RO: Deprecated, always returns zero */
#define MSM_PARAM_FAULTS 0x09 /* RO */
#define MSM_PARAM_SUSPENDS 0x0a /* RO */
+#define MSM_PARAM_SYSPROF 0x0b /* WO: 1 preserves perfcntrs, 2 also disables suspend */
/* For backwards compat. The original support for preemption was based on
* a single ring per priority level so # of priority levels equals the #
--
2.38.1