[PATCH v5 02/19] drm/i915/gen8: Make pdp allocation more dynamic

Michel Thierry
2015-07-16T09:33:53Z

This transitional patch doesn't do much for the existing code. However,
it should make upcoming patches to use the full 48b address space a bit
easier.

v2: Renamed pdp_free to be similar to pd/pt (unmap_and_free_pdp).
v3: To facilitate testing, 48b mode will be available on Broadwell and
GEN9+, when i915.enable_ppgtt = 3.
v4: Rebase after s/page_tables/page_table/, added extra information
about 4-level page table formats and use IS_ENABLED macro.
v5: Check CONFIG_X86_64 instead of CONFIG_64BIT.
v6: Rebase after Mika's ppgtt cleanup / scratch merge patch series, and
follow
his nomenclature in pdp functions (there is no alloc_pdp yet).
v7: Rebase after merged version of Mika's ppgtt cleanup patch series.
v8: Rebase after final merged version of Mika's ppgtt/scratch patches.
v9: Introduce PML4 (and 48-bit checks) until next patch (Akash).
v10: Also use test_bit to detect when pd/pt are already allocated (Akash)

Cc: Akash Goel <akash.goel@intel.com>
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 | 86 +++++++++++++++++++++++++++++--------
drivers/gpu/drm/i915/i915_gem_gtt.h | 17 +++++---
2 files changed, 80 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 0a68343..5913653 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -522,6 +522,43 @@ static void gen8_initialize_pd(struct i915_address_space *vm,
fill_px(vm->dev, pd, scratch_pde);
}

+static int __pdp_init(struct drm_device *dev,
+ struct i915_page_directory_pointer *pdp)
+{
+ size_t pdpes = I915_PDPES_PER_PDP(dev);
+
+ pdp->used_pdpes = kcalloc(BITS_TO_LONGS(pdpes),
+ sizeof(unsigned long),
+ GFP_KERNEL);
+ if (!pdp->used_pdpes)
+ return -ENOMEM;
+
+ pdp->page_directory = kcalloc(pdpes, sizeof(*pdp->page_directory),
+ GFP_KERNEL);
+ if (!pdp->page_directory) {
+ kfree(pdp->used_pdpes);
+ /* the PDP might be the statically allocated top level. Keep it
+ * as clean as possible */
+ pdp->used_pdpes = NULL;
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static void __pdp_fini(struct i915_page_directory_pointer *pdp)
+{
+ kfree(pdp->used_pdpes);
+ kfree(pdp->page_directory);
+ pdp->page_directory = NULL;
+}
+
+static void free_pdp(struct drm_device *dev,
+ struct i915_page_directory_pointer *pdp)
+{
+ __pdp_fini(pdp);
+}
+
/* Broadwell Page Directory Pointer Descriptors */
static int gen8_write_pdp(struct drm_i915_gem_request *req,
unsigned entry,
@@ -720,7 +757,8 @@ 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, GEN8_LEGACY_PDPES) {
+ 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;

@@ -729,6 +767,7 @@ static void gen8_ppgtt_cleanup(struct i915_address_space *vm)
free_pd(ppgtt->base.dev, ppgtt->pdp.page_directory[i]);
}

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

@@ -763,7 +802,7 @@ static int gen8_ppgtt_alloc_pagetabs(struct i915_hw_ppgtt *ppgtt,

gen8_for_each_pde(pt, pd, start, length, temp, pde) {
/* Don't reallocate page tables */
- if (pt) {
+ if (test_bit(pde, pd->used_pdes)) {
/* Scratch is never allocated this way */
WARN_ON(pt == ppgtt->base.scratch_pt);
continue;
@@ -820,11 +859,12 @@ static int gen8_ppgtt_alloc_page_directories(struct i915_hw_ppgtt *ppgtt,
struct i915_page_directory *pd;
uint64_t temp;
uint32_t pdpe;
+ uint32_t pdpes = I915_PDPES_PER_PDP(dev);

- WARN_ON(!bitmap_empty(new_pds, GEN8_LEGACY_PDPES));
+ WARN_ON(!bitmap_empty(new_pds, pdpes));

gen8_for_each_pdpe(pd, pdp, start, length, temp, pdpe) {
- if (pd)
+ if (test_bit(pdpe, pdp->used_pdpes))
continue;

pd = alloc_pd(dev);
@@ -839,18 +879,19 @@ static int gen8_ppgtt_alloc_page_directories(struct i915_hw_ppgtt *ppgtt,
return 0;

unwind_out:
- for_each_set_bit(pdpe, new_pds, GEN8_LEGACY_PDPES)
+ for_each_set_bit(pdpe, new_pds, pdpes)
free_pd(dev, pdp->page_directory[pdpe]);

return -ENOMEM;
}

static void
-free_gen8_temp_bitmaps(unsigned long *new_pds, unsigned long **new_pts)
+free_gen8_temp_bitmaps(unsigned long *new_pds, unsigned long **new_pts,
+ uint32_t pdpes)
{
int i;

- for (i = 0; i < GEN8_LEGACY_PDPES; i++)
+ for (i = 0; i < pdpes; i++)
kfree(new_pts[i]);
kfree(new_pts);
kfree(new_pds);
@@ -861,23 +902,24 @@ free_gen8_temp_bitmaps(unsigned long *new_pds, unsigned long **new_pts)
*/
static
int __must_check alloc_gen8_temp_bitmaps(unsigned long **new_pds,
- unsigned long ***new_pts)
+ unsigned long ***new_pts,
+ uint32_t pdpes)
{
int i;
unsigned long *pds;
unsigned long **pts;

- pds = kcalloc(BITS_TO_LONGS(GEN8_LEGACY_PDPES), sizeof(unsigned long), GFP_KERNEL);
+ pds = kcalloc(BITS_TO_LONGS(pdpes), sizeof(unsigned long), GFP_KERNEL);
if (!pds)
return -ENOMEM;

- pts = kcalloc(GEN8_LEGACY_PDPES, sizeof(unsigned long *), GFP_KERNEL);
+ pts = kcalloc(pdpes, sizeof(unsigned long *), GFP_KERNEL);
if (!pts) {
kfree(pds);
return -ENOMEM;
}

- for (i = 0; i < GEN8_LEGACY_PDPES; i++) {
+ for (i = 0; i < pdpes; i++) {
pts[i] = kcalloc(BITS_TO_LONGS(I915_PDES),
sizeof(unsigned long), GFP_KERNEL);
if (!pts[i])
@@ -890,7 +932,7 @@ int __must_check alloc_gen8_temp_bitmaps(unsigned long **new_pds,
return 0;

err_out:
- free_gen8_temp_bitmaps(pds, pts);
+ free_gen8_temp_bitmaps(pds, pts, pdpes);
return -ENOMEM;
}

@@ -916,6 +958,7 @@ static int gen8_alloc_va_range(struct i915_address_space *vm,
const uint64_t orig_length = length;
uint64_t temp;
uint32_t pdpe;
+ uint32_t pdpes = I915_PDPES_PER_PDP(ppgtt->base.dev);
int ret;

/* Wrap is never okay since we can only represent 48b, and we don't
@@ -927,7 +970,7 @@ static int gen8_alloc_va_range(struct i915_address_space *vm,
if (WARN_ON(start + length > ppgtt->base.total))
return -ENODEV;

- ret = alloc_gen8_temp_bitmaps(&new_page_dirs, &new_page_tables);
+ ret = alloc_gen8_temp_bitmaps(&new_page_dirs, &new_page_tables, pdpes);
if (ret)
return ret;

@@ -935,7 +978,7 @@ static int gen8_alloc_va_range(struct i915_address_space *vm,
ret = gen8_ppgtt_alloc_page_directories(ppgtt, &ppgtt->pdp, start, length,
new_page_dirs);
if (ret) {
- free_gen8_temp_bitmaps(new_page_dirs, new_page_tables);
+ free_gen8_temp_bitmaps(new_page_dirs, new_page_tables, pdpes);
return ret;
}

@@ -989,7 +1032,7 @@ static int gen8_alloc_va_range(struct i915_address_space *vm,
__set_bit(pdpe, ppgtt->pdp.used_pdpes);
}

- free_gen8_temp_bitmaps(new_page_dirs, new_page_tables);
+ free_gen8_temp_bitmaps(new_page_dirs, new_page_tables, pdpes);
mark_tlbs_dirty(ppgtt);
return 0;

@@ -999,10 +1042,10 @@ err_out:
free_pt(vm->dev, ppgtt->pdp.page_directory[pdpe]->page_table[temp]);
}

- for_each_set_bit(pdpe, new_page_dirs, GEN8_LEGACY_PDPES)
+ for_each_set_bit(pdpe, new_page_dirs, pdpes)
free_pd(vm->dev, ppgtt->pdp.page_directory[pdpe]);

- free_gen8_temp_bitmaps(new_page_dirs, new_page_tables);
+ free_gen8_temp_bitmaps(new_page_dirs, new_page_tables, pdpes);
mark_tlbs_dirty(ppgtt);
return ret;
}
@@ -1040,7 +1083,16 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt)

ppgtt->switch_mm = gen8_mm_switch;

+ ret = __pdp_init(false, &ppgtt->pdp);
+
+ if (ret)
+ goto free_scratch;
+
return 0;
+
+free_scratch:
+ gen8_free_scratch(&ppgtt->base);
+ return ret;
}

static void gen6_dump_ppgtt(struct i915_hw_ppgtt *ppgtt, struct seq_file *m)
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index d5bf953..87e389c 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -98,6 +98,9 @@ typedef uint64_t gen8_pde_t;
#define GEN8_LEGACY_PDPES 4
#define GEN8_PTES I915_PTES(sizeof(gen8_pte_t))

+/* FIXME: Next patch will use dev */
+#define I915_PDPES_PER_PDP(dev) GEN8_LEGACY_PDPES
+
#define PPAT_UNCACHED_INDEX (_PAGE_PWT | _PAGE_PCD)
#define PPAT_CACHED_PDE_INDEX 0 /* WB LLC */
#define PPAT_CACHED_INDEX _PAGE_PAT /* WB LLCeLLC */
@@ -241,9 +244,10 @@ struct i915_page_directory {
};

struct i915_page_directory_pointer {
- /* struct page *page; */
- DECLARE_BITMAP(used_pdpes, GEN8_LEGACY_PDPES);
- struct i915_page_directory *page_directory[GEN8_LEGACY_PDPES];
+ struct i915_page_dma base;
+
+ unsigned long *used_pdpes;
+ struct i915_page_directory **page_directory;
};

struct i915_address_space {
@@ -436,9 +440,10 @@ static inline uint32_t gen6_pde_index(uint32_t addr)
temp = min(temp, length), \
start += temp, length -= temp)

-#define gen8_for_each_pdpe(pd, pdp, start, length, temp, iter) \
- for (iter = gen8_pdpe_index(start); \
- pd = (pdp)->page_directory[iter], length > 0 && iter < GEN8_LEGACY_PDPES; \
+#define gen8_for_each_pdpe(pd, pdp, start, length, temp, iter) \
+ for (iter = gen8_pdpe_index(start); \
+ pd = (pdp)->page_directory[iter], \
+ length > 0 && (iter < I915_PDPES_PER_PDP(dev)); \
iter++, \
temp = ALIGN(start+1, 1 << GEN8_PDPE_SHIFT) - start, \
temp = min(temp, length), \