[PATCH v3 03/17] drm/i915/gen8: Abstract PDP usage

Michel Thierry
2015-07-01T15:27:38Z

Up until now, ppgtt->pdp has always been the root of our page tables.
Legacy 32b addresses acted like it had 1 PDP with 4 PDPEs.

In preparation for 4 level page tables, we need to stop use ppgtt->pdp
directly unless we know it's what we want. The future structure will use
ppgtt->pml4 for the top level, and the pdp is just one of the entries
being pointed to by a pml4e.

v2: Updated after dynamic page allocation changes.
v3: Rebase after s/page_tables/page_table/.
v4: Rebase after changes in "Dynamic page table allocations" patch.
v5: Rebase after Mika's ppgtt cleanup / scratch merge patch series.
v6: Rebase after final merged version of Mika's ppgtt/scratch patches.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Michel Thierry <michel.thierry@intel.com> (v2+)
---
drivers/gpu/drm/i915/i915_gem_gtt.c | 136 +++++++++++++++++++++++-------------
1 file changed, 88 insertions(+), 48 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index cdcc778..41a18ff 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -529,6 +529,25 @@ static void gen8_initialize_pd(struct i915_address_space *vm,
fill_px(vm->dev, pd, scratch_pde);
}

+/* It's likely we'll map more than one page table at a time. This function will
+ * save us unnecessary kmap calls, but do no more functionally than multiple
+ * calls to pde_encode. The ppgtt is only needed to reuse the kunmap macro. */
+static void gen8_map_pagetable_range(struct i915_hw_ppgtt *ppgtt,
+ struct i915_page_directory *pd,
+ uint64_t start,
+ uint64_t length)
+{
+ gen8_pde_t * const page_directory = kmap_px(pd);
+ struct i915_page_table *pt;
+ uint64_t temp, pde;
+
+ gen8_for_each_pde(pt, pd, start, length, temp, pde)
+ page_directory[pde] = gen8_pde_encode(px_dma(pt),
+ I915_CACHE_LLC);
+
+ kunmap_px(ppgtt, page_directory);
+}
+
static int __pdp_init(struct drm_device *dev,
struct i915_page_directory_pointer *pdp)
{
@@ -616,6 +635,7 @@ static void gen8_ppgtt_clear_range(struct i915_address_space *vm,
{
struct i915_hw_ppgtt *ppgtt =
container_of(vm, struct i915_hw_ppgtt, base);
+ struct i915_page_directory_pointer *pdp = &ppgtt->pdp; /* FIXME: 48b */
gen8_pte_t *pt_vaddr, scratch_pte;
unsigned pdpe = start >> GEN8_PDPE_SHIFT & GEN8_PDPE_MASK;
unsigned pde = start >> GEN8_PDE_SHIFT & GEN8_PDE_MASK;
@@ -630,10 +650,10 @@ static void gen8_ppgtt_clear_range(struct i915_address_space *vm,
struct i915_page_directory *pd;
struct i915_page_table *pt;

- if (WARN_ON(!ppgtt->pdp.page_directory[pdpe]))
+ if (WARN_ON(!pdp->page_directory[pdpe]))
break;

- pd = ppgtt->pdp.page_directory[pdpe];
+ pd = pdp->page_directory[pdpe];

if (WARN_ON(!pd->page_table[pde]))
break;
@@ -671,6 +691,7 @@ static void gen8_ppgtt_insert_entries(struct i915_address_space *vm,
{
struct i915_hw_ppgtt *ppgtt =
container_of(vm, struct i915_hw_ppgtt, base);
+ struct i915_page_directory_pointer *pdp = &ppgtt->pdp; /* FIXME: 48b */
gen8_pte_t *pt_vaddr;
unsigned pdpe = start >> GEN8_PDPE_SHIFT & GEN8_PDPE_MASK;
unsigned pde = start >> GEN8_PDE_SHIFT & GEN8_PDE_MASK;
@@ -681,7 +702,7 @@ static void gen8_ppgtt_insert_entries(struct i915_address_space *vm,

for_each_sg_page(pages->sgl, &sg_iter, pages->nents, 0) {
if (pt_vaddr == NULL) {
- struct i915_page_directory *pd = ppgtt->pdp.page_directory[pdpe];
+ struct i915_page_directory *pd = pdp->page_directory[pdpe];
struct i915_page_table *pt = pd->page_table[pde];
pt_vaddr = kmap_px(pt);
}
@@ -763,23 +784,28 @@ static void gen8_ppgtt_cleanup(struct i915_address_space *vm)
container_of(vm, struct i915_hw_ppgtt, base);
int i;

- for_each_set_bit(i, ppgtt->pdp.used_pdpes,
- I915_PDPES_PER_PDP(ppgtt->base.dev)) {
- if (WARN_ON(!ppgtt->pdp.page_directory[i]))
- continue;
+ if (!USES_FULL_48BIT_PPGTT(ppgtt->base.dev)) {
+ for_each_set_bit(i, ppgtt->pdp.used_pdpes,
+ I915_PDPES_PER_PDP(ppgtt->base.dev)) {
+ if (WARN_ON(!ppgtt->pdp.page_directory[i]))
+ continue;

- gen8_free_page_tables(ppgtt->base.dev,
- ppgtt->pdp.page_directory[i]);
- free_pd(ppgtt->base.dev, ppgtt->pdp.page_directory[i]);
+ gen8_free_page_tables(ppgtt->base.dev,
+ ppgtt->pdp.page_directory[i]);
+ free_pd(ppgtt->base.dev,
+ ppgtt->pdp.page_directory[i]);
+ }
+ free_pdp(ppgtt->base.dev, &ppgtt->pdp);
+ } else {
+ WARN_ON(1); /* to be implemented later */
}

- free_pdp(ppgtt->base.dev, &ppgtt->pdp);
gen8_free_scratch(vm);
}

/**
* gen8_ppgtt_alloc_pagetabs() - Allocate page tables for VA range.
- * @ppgtt: Master ppgtt structure.
+ * @vm: Master vm structure.
* @pd: Page directory for this address range.
* @start: Starting virtual address to begin allocations.
* @length Size of the allocations.
@@ -795,13 +821,15 @@ static void gen8_ppgtt_cleanup(struct i915_address_space *vm)
*
* Return: 0 if success; negative error code otherwise.
*/
-static int gen8_ppgtt_alloc_pagetabs(struct i915_hw_ppgtt *ppgtt,
+static int gen8_ppgtt_alloc_pagetabs(struct i915_address_space *vm,
struct i915_page_directory *pd,
uint64_t start,
uint64_t length,
unsigned long *new_pts)
{
- struct drm_device *dev = ppgtt->base.dev;
+ struct i915_hw_ppgtt *ppgtt =
+ container_of(vm, struct i915_hw_ppgtt, base);
+ struct drm_device *dev = vm->dev;
struct i915_page_table *pt;
uint64_t temp;
uint32_t pde;
@@ -818,7 +846,7 @@ static int gen8_ppgtt_alloc_pagetabs(struct i915_hw_ppgtt *ppgtt,
if (IS_ERR(pt))
goto unwind_out;

- gen8_initialize_pt(&ppgtt->base, pt);
+ gen8_initialize_pt(vm, pt);
pd->page_table[pde] = pt;
__set_bit(pde, new_pts);
}
@@ -834,7 +862,7 @@ unwind_out:

/**
* gen8_ppgtt_alloc_page_directories() - Allocate page directories for VA range.
- * @ppgtt: Master ppgtt structure.
+ * @vm: Master vm structure.
* @pdp: Page directory pointer for this address range.
* @start: Starting virtual address to begin allocations.
* @length Size of the allocations.
@@ -855,17 +883,18 @@ unwind_out:
*
* Return: 0 if success; negative error code otherwise.
*/
-static int gen8_ppgtt_alloc_page_directories(struct i915_hw_ppgtt *ppgtt,
- struct i915_page_directory_pointer *pdp,
- uint64_t start,
- uint64_t length,
- unsigned long *new_pds)
+static int
+gen8_ppgtt_alloc_page_directories(struct i915_address_space *vm,
+ struct i915_page_directory_pointer *pdp,
+ uint64_t start,
+ uint64_t length,
+ unsigned long *new_pds)
{
- struct drm_device *dev = ppgtt->base.dev;
+ struct drm_device *dev = vm->dev;
struct i915_page_directory *pd;
uint64_t temp;
uint32_t pdpe;
- uint32_t pdpes = I915_PDPES_PER_PDP(ppgtt->base.dev);
+ uint32_t pdpes = I915_PDPES_PER_PDP(vm->dev);

WARN_ON(!bitmap_empty(new_pds, pdpes));

@@ -877,7 +906,7 @@ static int gen8_ppgtt_alloc_page_directories(struct i915_hw_ppgtt *ppgtt,
if (IS_ERR(pd))
goto unwind_out;

- gen8_initialize_pd(&ppgtt->base, pd);
+ gen8_initialize_pd(vm, pd);
pdp->page_directory[pdpe] = pd;
__set_bit(pdpe, new_pds);
}
@@ -952,13 +981,15 @@ static void mark_tlbs_dirty(struct i915_hw_ppgtt *ppgtt)
ppgtt->pd_dirty_rings = INTEL_INFO(ppgtt->base.dev)->ring_mask;
}

-static int gen8_alloc_va_range(struct i915_address_space *vm,
- uint64_t start,
- uint64_t length)
+static int gen8_alloc_va_range_3lvl(struct i915_address_space *vm,
+ struct i915_page_directory_pointer *pdp,
+ uint64_t start,
+ uint64_t length)
{
struct i915_hw_ppgtt *ppgtt =
container_of(vm, struct i915_hw_ppgtt, base);
unsigned long *new_page_dirs, **new_page_tables;
+ struct drm_device *dev = vm->dev;
struct i915_page_directory *pd;
const uint64_t orig_start = start;
const uint64_t orig_length = length;
@@ -981,16 +1012,15 @@ static int gen8_alloc_va_range(struct i915_address_space *vm,
return ret;

/* Do the allocations first so we can easily bail out */
- ret = gen8_ppgtt_alloc_page_directories(ppgtt, &ppgtt->pdp, start, length,
- new_page_dirs);
+ ret = gen8_ppgtt_alloc_page_directories(vm, pdp, start, length,
+ new_page_dirs);
if (ret) {
free_gen8_temp_bitmaps(new_page_dirs, new_page_tables, pdpes);
return ret;
}

- /* For every page directory referenced, allocate page tables */
- gen8_for_each_pdpe(pd, &ppgtt->pdp, start, length, temp, pdpe) {
- ret = gen8_ppgtt_alloc_pagetabs(ppgtt, pd, start, length,
+ gen8_for_each_pdpe(pd, pdp, start, length, temp, pdpe) {
+ ret = gen8_ppgtt_alloc_pagetabs(vm, pd, start, length,
new_page_tables[pdpe]);
if (ret)
goto err_out;
@@ -999,10 +1029,7 @@ static int gen8_alloc_va_range(struct i915_address_space *vm,
start = orig_start;
length = orig_length;

- /* Allocations have completed successfully, so set the bitmaps, and do
- * the mappings. */
- gen8_for_each_pdpe(pd, &ppgtt->pdp, start, length, temp, pdpe) {
- gen8_pde_t *const page_directory = kmap_px(pd);
+ gen8_for_each_pdpe(pd, pdp, start, length, temp, pdpe) {
struct i915_page_table *pt;
uint64_t pd_len = length;
uint64_t pd_start = start;
@@ -1024,18 +1051,10 @@ static int gen8_alloc_va_range(struct i915_address_space *vm,

/* Our pde is now pointing to the pagetable, pt */
__set_bit(pde, pd->used_pdes);
-
- /* Map the PDE to the page table */
- page_directory[pde] = gen8_pde_encode(px_dma(pt),
- I915_CACHE_LLC);
-
- /* NB: We haven't yet mapped ptes to pages. At this
- * point we're still relying on insert_entries() */
}

- kunmap_px(ppgtt, page_directory);
-
- __set_bit(pdpe, ppgtt->pdp.used_pdpes);
+ __set_bit(pdpe, pdp->used_pdpes);
+ gen8_map_pagetable_range(ppgtt, pd, start, length);
}

free_gen8_temp_bitmaps(new_page_dirs, new_page_tables, pdpes);
@@ -1045,17 +1064,38 @@ static int gen8_alloc_va_range(struct i915_address_space *vm,
err_out:
while (pdpe--) {
for_each_set_bit(temp, new_page_tables[pdpe], I915_PDES)
- free_pt(vm->dev, ppgtt->pdp.page_directory[pdpe]->page_table[temp]);
+ free_pt(dev, pdp->page_directory[pdpe]->page_table[temp]);
}

for_each_set_bit(pdpe, new_page_dirs, pdpes)
- free_pd(vm->dev, ppgtt->pdp.page_directory[pdpe]);
+ free_pd(dev, pdp->page_directory[pdpe]);

free_gen8_temp_bitmaps(new_page_dirs, new_page_tables, pdpes);
mark_tlbs_dirty(ppgtt);
return ret;
}

+static int gen8_alloc_va_range_4lvl(struct i915_address_space *vm,
+ struct i915_pml4 *pml4,
+ uint64_t start,
+ uint64_t length)
+{
+ WARN_ON(1); /* to be implemented later */
+ return 0;
+}
+
+static int gen8_alloc_va_range(struct i915_address_space *vm,
+ uint64_t start, uint64_t length)
+{
+ struct i915_hw_ppgtt *ppgtt =
+ container_of(vm, struct i915_hw_ppgtt, base);
+
+ if (!USES_FULL_48BIT_PPGTT(vm->dev))
+ return gen8_alloc_va_range_3lvl(vm, &ppgtt->pdp, start, length);
+ else
+ return gen8_alloc_va_range_4lvl(vm, &ppgtt->pml4, start, length);
+}
+
/*
* GEN8 legacy ppgtt programming is accomplished through a max 4 PDP registers
* with a net effect resembling a 2-level page table in normal x86 terms. Each
--
2.4.5