[Intel-gfx] [PATCH 04/61] drm/i915: Ensure we hold the object mutex in pin correctly.

Maarten Lankhorst
2020-10-02T12:59:46Z

Currently we have a lot of places where we hold the gem object lock,
but haven't yet been converted to the ww dance. Complain loudly about
those places.

i915_vma_pin shouldn't have the obj lock held, so we can do a ww dance,
while i915_vma_pin_ww should.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
---
drivers/gpu/drm/i915/gt/intel_renderstate.c | 2 +-
drivers/gpu/drm/i915/i915_vma.c | 11 ++++++++++-
drivers/gpu/drm/i915/i915_vma.h | 3 +++
3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_renderstate.c b/drivers/gpu/drm/i915/gt/intel_renderstate.c
index ea2a77c7b469..a68e5c23a67c 100644
--- a/drivers/gpu/drm/i915/gt/intel_renderstate.c
+++ b/drivers/gpu/drm/i915/gt/intel_renderstate.c
@@ -196,7 +196,7 @@ int intel_renderstate_init(struct intel_renderstate *so,
if (err)
goto err_context;

- err = i915_vma_pin(so->vma, 0, 0, PIN_GLOBAL | PIN_HIGH);
+ err = i915_vma_pin_ww(so->vma, &so->ww, 0, 0, PIN_GLOBAL | PIN_HIGH);
if (err)
goto err_context;

diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index ffb5287e055a..4ead74c5142b 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -863,6 +863,8 @@ int i915_vma_pin_ww(struct i915_vma *vma, struct i915_gem_ww_ctx *ww,
#ifdef CONFIG_PROVE_LOCKING
if (debug_locks && lockdep_is_held(&vma->vm->i915->drm.struct_mutex))
WARN_ON(!ww);
+ if (debug_locks && ww && vma->resv)
+ assert_vma_held(vma);
#endif

BUILD_BUG_ON(PIN_GLOBAL != I915_VMA_GLOBAL_BIND);
@@ -1018,8 +1020,15 @@ int i915_ggtt_pin(struct i915_vma *vma, struct i915_gem_ww_ctx *ww,

GEM_BUG_ON(!i915_vma_is_ggtt(vma));

+#ifdef CONFIG_LOCKDEP
+ WARN_ON(!ww && vma->resv && dma_resv_held(vma->resv));
+#endif
+
do {
- err = i915_vma_pin_ww(vma, ww, 0, align, flags | PIN_GLOBAL);
+ if (ww)
+ err = i915_vma_pin_ww(vma, ww, 0, align, flags | PIN_GLOBAL);
+ else
+ err = i915_vma_pin(vma, 0, align, flags | PIN_GLOBAL);
if (err != -ENOSPC) {
if (!err) {
err = i915_vma_wait_for_bind(vma);
diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
index 5b3a3c653454..838bbbeb11cc 100644
--- a/drivers/gpu/drm/i915/i915_vma.h
+++ b/drivers/gpu/drm/i915/i915_vma.h
@@ -243,6 +243,9 @@ i915_vma_pin_ww(struct i915_vma *vma, struct i915_gem_ww_ctx *ww,
static inline int __must_check
i915_vma_pin(struct i915_vma *vma, u64 size, u64 alignment, u64 flags)
{
+#ifdef CONFIG_LOCKDEP
+ WARN_ON_ONCE(vma->resv && dma_resv_held(vma->resv));
+#endif
return i915_vma_pin_ww(vma, NULL, size, alignment, flags);