From 8305216ff831ebc47d6335f577448e6c0453fc82 Mon Sep 17 00:00:00 2001 From: Dave Gordon Date: Tue, 12 Apr 2016 14:46:16 +0100 Subject: [PATCH] drm/i915: check for ERR_PTR from i915_gem_object_pin_map() The newly-introduced function i915_gem_object_pin_map() returns an ERR_PTR (not NULL) if the pin-and-map opertaion fails, so that's what we must check for. And it's nicer not to assign such a pointer-or-error to a structure being filled in until after it's been validated, so we should keep it local and avoid exporting a bogus pointer. Also, for clarity and symmetry, we should clear 'virtual_start' along with 'vma' when unmapping a ringbuffer. Signed-off-by: Dave Gordon Cc: Chris Wilson Cc: Tvrtko Ursulin Reviewed-by: Chris Wilson Signed-off-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_drv.h | 6 ++++-- drivers/gpu/drm/i915/intel_ringbuffer.c | 15 +++++++++------ 2 files changed, 13 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 85102ad75962..6f1e0f127c0a 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -3018,9 +3018,11 @@ static inline void i915_gem_object_unpin_pages(struct drm_i915_gem_object *obj) * pages and then returns a contiguous mapping of the backing storage into * the kernel address space. * - * The caller must hold the struct_mutex. + * The caller must hold the struct_mutex, and is responsible for calling + * i915_gem_object_unpin_map() when the mapping is no longer required. * - * Returns the pointer through which to access the backing storage. + * Returns the pointer through which to access the mapped object, or an + * ERR_PTR() on error. */ void *__must_check i915_gem_object_pin_map(struct drm_i915_gem_object *obj); diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 978f0b676c68..245386e20c52 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -2088,6 +2088,7 @@ void intel_unpin_ringbuffer_obj(struct intel_ringbuffer *ringbuf) i915_gem_object_unpin_map(ringbuf->obj); else iounmap(ringbuf->virtual_start); + ringbuf->virtual_start = NULL; ringbuf->vma = NULL; i915_gem_object_ggtt_unpin(ringbuf->obj); } @@ -2100,6 +2101,7 @@ int intel_pin_and_map_ringbuffer_obj(struct drm_device *dev, struct drm_i915_gem_object *obj = ringbuf->obj; /* Ring wraparound at offset 0 sometimes hangs. No idea why. */ unsigned flags = PIN_OFFSET_BIAS | 4096; + void *addr; int ret; if (HAS_LLC(dev_priv) && !obj->stolen) { @@ -2111,9 +2113,9 @@ int intel_pin_and_map_ringbuffer_obj(struct drm_device *dev, if (ret) goto err_unpin; - ringbuf->virtual_start = i915_gem_object_pin_map(obj); - if (ringbuf->virtual_start == NULL) { - ret = -ENOMEM; + addr = i915_gem_object_pin_map(obj); + if (IS_ERR(addr)) { + ret = PTR_ERR(addr); goto err_unpin; } } else { @@ -2129,14 +2131,15 @@ int intel_pin_and_map_ringbuffer_obj(struct drm_device *dev, /* Access through the GTT requires the device to be awake. */ assert_rpm_wakelock_held(dev_priv); - ringbuf->virtual_start = ioremap_wc(ggtt->mappable_base + - i915_gem_obj_ggtt_offset(obj), ringbuf->size); - if (ringbuf->virtual_start == NULL) { + addr = ioremap_wc(ggtt->mappable_base + + i915_gem_obj_ggtt_offset(obj), ringbuf->size); + if (addr == NULL) { ret = -ENOMEM; goto err_unpin; } } + ringbuf->virtual_start = addr; ringbuf->vma = i915_gem_obj_to_ggtt(obj); return 0; -- 2.25.1