Commit c8185520 authored by Chris Wilson's avatar Chris Wilson

drm/i915/gtt: Make sure the gen6 ppgtt is bound before first use

As we remove the struct_mutex protection from around the vma pinning,
counters need to be atomic and aware that there may be multiple threads
simultaneously active.
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190913064200.24297-1-chris@chris-wilson.co.uk
parent 0b8d6273
......@@ -1790,6 +1790,8 @@ static void gen6_ppgtt_cleanup(struct i915_address_space *vm)
gen6_ppgtt_free_pd(ppgtt);
free_scratch(vm);
mutex_destroy(&ppgtt->pin_mutex);
kfree(ppgtt->base.pd);
}
......@@ -1895,7 +1897,7 @@ static struct i915_vma *pd_vma_create(struct gen6_ppgtt *ppgtt, int size)
int gen6_ppgtt_pin(struct i915_ppgtt *base)
{
struct gen6_ppgtt *ppgtt = to_gen6_ppgtt(base);
int err;
int err = 0;
GEM_BUG_ON(ppgtt->base.vm.closed);
......@@ -1905,24 +1907,26 @@ int gen6_ppgtt_pin(struct i915_ppgtt *base)
* (When vma->pin_count becomes atomic, I expect we will naturally
* need a larger, unpacked, type and kill this redundancy.)
*/
if (ppgtt->pin_count++)
if (atomic_add_unless(&ppgtt->pin_count, 1, 0))
return 0;
if (mutex_lock_interruptible(&ppgtt->pin_mutex))
return -EINTR;
/*
* PPGTT PDEs reside in the GGTT and consists of 512 entries. The
* allocator works in address space sizes, so it's multiplied by page
* size. We allocate at the top of the GTT to avoid fragmentation.
*/
if (!atomic_read(&ppgtt->pin_count)) {
err = i915_vma_pin(ppgtt->vma,
0, GEN6_PD_ALIGN,
PIN_GLOBAL | PIN_HIGH);
if (err)
goto unpin;
return 0;
}
if (!err)
atomic_inc(&ppgtt->pin_count);
mutex_unlock(&ppgtt->pin_mutex);
unpin:
ppgtt->pin_count = 0;
return err;
}
......@@ -1930,10 +1934,8 @@ void gen6_ppgtt_unpin(struct i915_ppgtt *base)
{
struct gen6_ppgtt *ppgtt = to_gen6_ppgtt(base);
GEM_BUG_ON(!ppgtt->pin_count);
if (--ppgtt->pin_count)
return;
GEM_BUG_ON(!atomic_read(&ppgtt->pin_count));
if (atomic_dec_and_test(&ppgtt->pin_count))
i915_vma_unpin(ppgtt->vma);
}
......@@ -1941,11 +1943,11 @@ void gen6_ppgtt_unpin_all(struct i915_ppgtt *base)
{
struct gen6_ppgtt *ppgtt = to_gen6_ppgtt(base);
if (!ppgtt->pin_count)
if (!atomic_read(&ppgtt->pin_count))
return;
ppgtt->pin_count = 0;
i915_vma_unpin(ppgtt->vma);
atomic_set(&ppgtt->pin_count, 0);
}
static struct i915_ppgtt *gen6_ppgtt_create(struct drm_i915_private *i915)
......@@ -1958,6 +1960,8 @@ static struct i915_ppgtt *gen6_ppgtt_create(struct drm_i915_private *i915)
if (!ppgtt)
return ERR_PTR(-ENOMEM);
mutex_init(&ppgtt->pin_mutex);
ppgtt_init(&ppgtt->base, &i915->gt);
ppgtt->base.vm.top = 1;
......
......@@ -437,7 +437,9 @@ struct gen6_ppgtt {
struct i915_vma *vma;
gen6_pte_t __iomem *pd_addr;
unsigned int pin_count;
atomic_t pin_count;
struct mutex pin_mutex;
bool scan_for_unused_pt;
};
......
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