drm/i915/gtt: Generalize alloc_pd

Allocate all page directory variants with alloc_pd. As
the lvl3 and lvl4 variants differ in manipulation, we
need to check for existence of backing phys page before accessing
it.

v2: use err in returns

Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190614164350.30415-5-mika.kuoppala@linux.intel.com

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index afdd3e5261d0b35e86caccdf7c62e6ba13b8a28d..ec00fccd0c6ff62b0fa079af61bff189f124c98c 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -720,10 +720,17 @@ static struct i915_page_directory *alloc_pd(struct i915_address_space *vm)
        return pd;
 }
 
+static inline bool pd_has_phys_page(const struct i915_page_directory * const pd)
+{
+       return pd->base.page;
+}
+
 static void free_pd(struct i915_address_space *vm,
                    struct i915_page_directory *pd)
 {
-       cleanup_px(vm, pd);
+       if (likely(pd_has_phys_page(pd)))
+               cleanup_px(vm, pd);
+
        kfree(pd);
 }
 
@@ -735,37 +742,12 @@ static void init_pd_with_page(struct i915_address_space *vm,
        memset_p(pd->entry, pt, 512);
 }
 
-static struct i915_page_directory *alloc_pdp(struct i915_address_space *vm)
-{
-       struct i915_page_directory *pdp;
-
-       pdp = __alloc_pd();
-       if (!pdp)
-               return ERR_PTR(-ENOMEM);
-
-       if (i915_vm_is_4lvl(vm)) {
-               if (unlikely(setup_px(vm, pdp))) {
-                       kfree(pdp);
-                       return ERR_PTR(-ENOMEM);
-               }
-       }
-
-       return pdp;
-}
-
-static void free_pdp(struct i915_address_space *vm,
-                    struct i915_page_directory *pdp)
-{
-       if (i915_vm_is_4lvl(vm))
-               cleanup_px(vm, pdp);
-
-       kfree(pdp);
-}
-
 static void init_pd(struct i915_address_space *vm,
                    struct i915_page_directory * const pd,
                    struct i915_page_directory * const to)
 {
+       GEM_DEBUG_BUG_ON(!pd_has_phys_page(pd));
+
        fill_px(vm, pd, gen8_pdpe_encode(px_dma(to), I915_CACHE_LLC));
        memset_p(pd->entry, to, 512);
 }
@@ -843,14 +825,13 @@ static bool gen8_ppgtt_clear_pd(struct i915_address_space *vm,
        return !atomic_read(&pd->used);
 }
 
-static void gen8_ppgtt_set_pdpe(struct i915_address_space *vm,
-                               struct i915_page_directory *pdp,
+static void gen8_ppgtt_set_pdpe(struct i915_page_directory *pdp,
                                struct i915_page_directory *pd,
                                unsigned int pdpe)
 {
        gen8_ppgtt_pdpe_t *vaddr;
 
-       if (!i915_vm_is_4lvl(vm))
+       if (!pd_has_phys_page(pdp))
                return;
 
        vaddr = kmap_atomic_px(pdp);
@@ -878,7 +859,7 @@ static bool gen8_ppgtt_clear_pdp(struct i915_address_space *vm,
 
                spin_lock(&pdp->lock);
                if (!atomic_read(&pd->used)) {
-                       gen8_ppgtt_set_pdpe(vm, pdp, vm->scratch_pd, pdpe);
+                       gen8_ppgtt_set_pdpe(pdp, vm->scratch_pd, pdpe);
                        pdp->entry[pdpe] = vm->scratch_pd;
 
                        GEM_BUG_ON(!atomic_read(&pdp->used));
@@ -939,7 +920,7 @@ static void gen8_ppgtt_clear_4lvl(struct i915_address_space *vm,
                }
                spin_unlock(&pml4->lock);
                if (free)
-                       free_pdp(vm, pdp);
+                       free_pd(vm, pdp);
        }
 }
 
@@ -1243,7 +1224,7 @@ static int gen8_init_scratch(struct i915_address_space *vm)
        }
 
        if (i915_vm_is_4lvl(vm)) {
-               vm->scratch_pdp = alloc_pdp(vm);
+               vm->scratch_pdp = alloc_pd(vm);
                if (IS_ERR(vm->scratch_pdp)) {
                        ret = PTR_ERR(vm->scratch_pdp);
                        goto free_pd;
@@ -1305,7 +1286,7 @@ static void gen8_free_scratch(struct i915_address_space *vm)
                return;
 
        if (i915_vm_is_4lvl(vm))
-               free_pdp(vm, vm->scratch_pdp);
+               free_pd(vm, vm->scratch_pdp);
        free_pd(vm, vm->scratch_pd);
        free_pt(vm, vm->scratch_pt);
        cleanup_scratch_page(vm);
@@ -1325,7 +1306,7 @@ static void gen8_ppgtt_cleanup_3lvl(struct i915_address_space *vm,
                free_pd(vm, pdp->entry[i]);
        }
 
-       free_pdp(vm, pdp);
+       free_pd(vm, pdp);
 }
 
 static void gen8_ppgtt_cleanup_4lvl(struct i915_ppgtt *ppgtt)
@@ -1432,7 +1413,7 @@ static int gen8_ppgtt_alloc_pdp(struct i915_address_space *vm,
 
                        old = cmpxchg(&pdp->entry[pdpe], vm->scratch_pd, pd);
                        if (old == vm->scratch_pd) {
-                               gen8_ppgtt_set_pdpe(vm, pdp, pd, pdpe);
+                               gen8_ppgtt_set_pdpe(pdp, pd, pdpe);
                                atomic_inc(&pdp->used);
                        } else {
                                free_pd(vm, pd);
@@ -1458,7 +1439,7 @@ static int gen8_ppgtt_alloc_pdp(struct i915_address_space *vm,
 unwind_pd:
        spin_lock(&pdp->lock);
        if (atomic_dec_and_test(&pd->used)) {
-               gen8_ppgtt_set_pdpe(vm, pdp, vm->scratch_pd, pdpe);
+               gen8_ppgtt_set_pdpe(pdp, vm->scratch_pd, pdpe);
                GEM_BUG_ON(!atomic_read(&pdp->used));
                atomic_dec(&pdp->used);
                free_pd(vm, pd);
@@ -1488,13 +1469,12 @@ static int gen8_ppgtt_alloc_4lvl(struct i915_address_space *vm,
 
        spin_lock(&pml4->lock);
        gen8_for_each_pml4e(pdp, pml4, start, length, pml4e) {
-
                if (pdp == vm->scratch_pdp) {
                        struct i915_page_directory *old;
 
                        spin_unlock(&pml4->lock);
 
-                       pdp = alloc_pdp(vm);
+                       pdp = alloc_pd(vm);
                        if (IS_ERR(pdp))
                                goto unwind;
 
@@ -1504,7 +1484,7 @@ static int gen8_ppgtt_alloc_4lvl(struct i915_address_space *vm,
                        if (old == vm->scratch_pdp) {
                                gen8_ppgtt_set_pml4e(pml4, pdp, pml4e);
                        } else {
-                               free_pdp(vm, pdp);
+                               free_pd(vm, pdp);
                                pdp = old;
                        }
 
@@ -1528,7 +1508,7 @@ static int gen8_ppgtt_alloc_4lvl(struct i915_address_space *vm,
        spin_lock(&pml4->lock);
        if (atomic_dec_and_test(&pdp->used)) {
                gen8_ppgtt_set_pml4e(pml4, vm->scratch_pdp, pml4e);
-               free_pdp(vm, pdp);
+               free_pd(vm, pdp);
        }
        spin_unlock(&pml4->lock);
 unwind:
@@ -1551,7 +1531,7 @@ static int gen8_preallocate_top_level_pdp(struct i915_ppgtt *ppgtt)
                        goto unwind;
 
                init_pd_with_page(vm, pd, vm->scratch_pt);
-               gen8_ppgtt_set_pdpe(vm, pdp, pd, pdpe);
+               gen8_ppgtt_set_pdpe(pdp, pd, pdpe);
 
                atomic_inc(&pdp->used);
        }
@@ -1563,7 +1543,7 @@ static int gen8_preallocate_top_level_pdp(struct i915_ppgtt *ppgtt)
 unwind:
        start -= from;
        gen8_for_each_pdpe(pd, pdp, from, start, pdpe) {
-               gen8_ppgtt_set_pdpe(vm, pdp, vm->scratch_pd, pdpe);
+               gen8_ppgtt_set_pdpe(pdp, vm->scratch_pd, pdpe);
                free_pd(vm, pd);
        }
        atomic_set(&pdp->used, 0);
@@ -1621,13 +1601,17 @@ static struct i915_ppgtt *gen8_ppgtt_create(struct drm_i915_private *i915)
        if (err)
                goto err_free;
 
-       ppgtt->pd = alloc_pdp(&ppgtt->vm);
-       if (IS_ERR(ppgtt->pd)) {
-               err = PTR_ERR(ppgtt->pd);
-               goto err_scratch;
+       ppgtt->pd = __alloc_pd();
+       if (!ppgtt->pd) {
+               err = -ENOMEM;
+               goto err_free_scratch;
        }
 
        if (i915_vm_is_4lvl(&ppgtt->vm)) {
+               err = setup_px(&ppgtt->vm, ppgtt->pd);
+               if (err)
+                       goto err_free_pdp;
+
                init_pd(&ppgtt->vm, ppgtt->pd, ppgtt->vm.scratch_pdp);
 
                ppgtt->vm.allocate_va_range = gen8_ppgtt_alloc_4lvl;
@@ -1644,7 +1628,7 @@ static struct i915_ppgtt *gen8_ppgtt_create(struct drm_i915_private *i915)
                if (intel_vgpu_active(i915)) {
                        err = gen8_preallocate_top_level_pdp(ppgtt);
                        if (err)
-                               goto err_pdp;
+                               goto err_free_pdp;
                }
 
                ppgtt->vm.allocate_va_range = gen8_ppgtt_alloc_3lvl;
@@ -1659,9 +1643,9 @@ static struct i915_ppgtt *gen8_ppgtt_create(struct drm_i915_private *i915)
 
        return ppgtt;
 
-err_pdp:
-       free_pdp(&ppgtt->vm, ppgtt->pd);
-err_scratch:
+err_free_pdp:
+       free_pd(&ppgtt->vm, ppgtt->pd);
+err_free_scratch:
        gen8_free_scratch(&ppgtt->vm);
 err_free:
        kfree(ppgtt);