[RFC 2/2] drm/msm: add sudo flag to submit ioctl
Rob Clark
robdclark at gmail.com
Wed Dec 13 20:12:57 UTC 2017
This flags cause cmdstream to be executed from the ringbuffer (RB)
instead of IB1. Normally not something you'd ever want to do, but
it is super useful for firmware debugging.
Hidden behind CAP_SYS_ADMIN and a default=n kconfig option, to prevent
it from being used on accident.
Signed-off-by: Rob Clark <robdclark at gmail.com>
---
drivers/gpu/drm/msm/Kconfig | 13 +++++++
drivers/gpu/drm/msm/adreno/a5xx_gpu.c | 65 +++++++++++++++++++++++++++++++++++
drivers/gpu/drm/msm/msm_gem.h | 1 +
drivers/gpu/drm/msm/msm_gem_submit.c | 9 +++++
include/uapi/drm/msm_drm.h | 2 ++
5 files changed, 90 insertions(+)
diff --git a/drivers/gpu/drm/msm/Kconfig b/drivers/gpu/drm/msm/Kconfig
index 99d39b2aefa6..733d878e1180 100644
--- a/drivers/gpu/drm/msm/Kconfig
+++ b/drivers/gpu/drm/msm/Kconfig
@@ -28,6 +28,19 @@ config DRM_MSM_REGISTER_LOGGING
that can be parsed by envytools demsm tool. If enabled, register
logging can be switched on via msm.reglog=y module param.
+config DRM_MSM_GPU_SUDO
+ bool "Enable SUDO flag on submits"
+ depends on DRM_MSM && EXPERT
+ default n
+ help
+ Enable userspace that has CAP_SYS_ADMIN to submit GPU commands
+ that are run from RB instead of IB1. This essentially gives
+ userspace kernel level access, but is useful for firmware
+ debugging.
+
+ Only use this if you really know what you are doing. This should
+ *not* be enabled for production kernels. If unsure, say N.
+
config DRM_MSM_HDMI_HDCP
bool "Enable HDMI HDCP support in MSM DRM driver"
depends on DRM_MSM && QCOM_SCM
diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
index 44d3c6a129c9..644ef5367423 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
@@ -138,6 +138,65 @@ static void a5xx_flush(struct msm_gpu *gpu, struct msm_ringbuffer *ring)
gpu_write(gpu, REG_A5XX_CP_RB_WPTR, wptr);
}
+static void a5xx_submit_in_rb(struct msm_gpu *gpu, struct msm_gem_submit *submit,
+ struct msm_file_private *ctx)
+{
+ struct msm_drm_private *priv = gpu->dev->dev_private;
+ struct msm_ringbuffer *ring = submit->ring;
+ struct msm_gem_object *obj;
+ uint32_t *ptr, dwords;
+ unsigned int i;
+
+ for (i = 0; i < submit->nr_cmds; i++) {
+ switch (submit->cmd[i].type) {
+ case MSM_SUBMIT_CMD_IB_TARGET_BUF:
+ break;
+ case MSM_SUBMIT_CMD_CTX_RESTORE_BUF:
+ if (priv->lastctx == ctx)
+ break;
+ case MSM_SUBMIT_CMD_BUF:
+ /* copy commands into RB: */
+ obj = submit->bos[submit->cmd[i].idx].obj;
+ dwords = submit->cmd[i].size;
+
+ ptr = msm_gem_get_vaddr(&obj->base);
+
+ /* _get_vaddr() shouldn't fail at this point,
+ * since we've already mapped it once in
+ * submit_reloc()
+ */
+ if (WARN_ON(!ptr))
+ return;
+
+ for (i = 0; i < dwords; i++) {
+ /* normally the OUT_PKTn() would wait
+ * for space for the packet. But since
+ * we just OUT_RING() the whole thing,
+ * need to call adreno_wait_ring()
+ * ourself:
+ */
+ adreno_wait_ring(ring, 1);
+ OUT_RING(ring, ptr[i]);
+ }
+
+ msm_gem_put_vaddr(&obj->base);
+
+ break;
+ }
+ }
+
+ a5xx_flush(gpu, ring);
+ a5xx_preempt_trigger(gpu);
+
+ /* we might not necessarily have a cmd from userspace to
+ * trigger an event to know that submit has completed, so
+ * do this manually:
+ */
+ a5xx_idle(gpu, ring);
+ ring->memptrs->fence = submit->seqno;
+ msm_gpu_retire(gpu);
+}
+
static void a5xx_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit,
struct msm_file_private *ctx)
{
@@ -147,6 +206,12 @@ static void a5xx_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit,
struct msm_ringbuffer *ring = submit->ring;
unsigned int i, ibs = 0;
+ if (IS_ENABLED(CONFIG_DRM_MSM_GPU_SUDO) && submit->in_rb) {
+ priv->lastctx = NULL;
+ a5xx_submit_in_rb(gpu, submit, ctx);
+ return;
+ }
+
OUT_PKT7(ring, CP_PREEMPT_ENABLE_GLOBAL, 1);
OUT_RING(ring, 0x02);
diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h
index 7087639932a2..dd2f8b419495 100644
--- a/drivers/gpu/drm/msm/msm_gem.h
+++ b/drivers/gpu/drm/msm/msm_gem.h
@@ -147,6 +147,7 @@ struct msm_gem_submit {
struct pid *pid; /* submitting process */
bool valid; /* true if no cmdstream patching needed */
bool dumped; /* true if already dumped */
+ bool in_rb; /* "sudo" mode, copy cmds into RB */
struct msm_ringbuffer *ring;
unsigned int nr_cmds;
unsigned int nr_bos;
diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index da8187f760ce..c07635afd98f 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -431,6 +431,12 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
if (MSM_PIPE_FLAGS(args->flags) & ~MSM_SUBMIT_FLAGS)
return -EINVAL;
+ if (args->flags & MSM_SUBMIT_SUDO) {
+ if (!IS_ENABLED(CONFIG_DRM_MSM_GPU_SUDO) ||
+ !capable(CAP_SYS_ADMIN))
+ return -EINVAL;
+ }
+
queue = msm_submitqueue_get(ctx, args->queueid);
if (!queue)
return -ENOENT;
@@ -472,6 +478,9 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
goto out_unlock;
}
+ if (args->flags & MSM_SUBMIT_SUDO)
+ submit->in_rb = true;
+
ret = submit_lookup_objects(submit, args, file);
if (ret)
goto out;
diff --git a/include/uapi/drm/msm_drm.h b/include/uapi/drm/msm_drm.h
index bbbaffad772d..c06d0a5bdd80 100644
--- a/include/uapi/drm/msm_drm.h
+++ b/include/uapi/drm/msm_drm.h
@@ -201,10 +201,12 @@ struct drm_msm_gem_submit_bo {
#define MSM_SUBMIT_NO_IMPLICIT 0x80000000 /* disable implicit sync */
#define MSM_SUBMIT_FENCE_FD_IN 0x40000000 /* enable input fence_fd */
#define MSM_SUBMIT_FENCE_FD_OUT 0x20000000 /* enable output fence_fd */
+#define MSM_SUBMIT_SUDO 0x10000000 /* run submitted cmds from RB */
#define MSM_SUBMIT_FLAGS ( \
MSM_SUBMIT_NO_IMPLICIT | \
MSM_SUBMIT_FENCE_FD_IN | \
MSM_SUBMIT_FENCE_FD_OUT | \
+ MSM_SUBMIT_SUDO | \
0)
/* Each cmdstream submit consists of a table of buffers involved, and
--
2.13.6
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