[PATCH] drm/i915: Page table helpers

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



These page table helpers make the code much cleaner. There is some
room to use the arch/x86 header files. The reason I've opted not to is
in several cases, the definitions are dictated by the CONFIG_ options
which do not always indicate the restrictions in the GPU.

Signed-off-by: Ben Widawsky <ben@xxxxxxxxxxxx>
---

I have this patch queued up for the next round of /stuff/ I am working on. If
you want to pull it into this series, it's fine by me. As I deal with the code
more, it does become more obvious what looks good, and what does not.

---

 drivers/gpu/drm/i915/i915_gem_gtt.c | 115 +++++++++++++++++++++++++-----------
 1 file changed, 81 insertions(+), 34 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index aa3ef7f..43d9129 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -30,8 +30,6 @@
 #include "i915_trace.h"
 #include "intel_drv.h"
 
-#define GEN6_PPGTT_PD_ENTRIES 512
-#define I915_PPGTT_PT_ENTRIES (PAGE_SIZE / sizeof(gen6_gtt_pte_t))
 typedef uint64_t gen8_gtt_pte_t;
 typedef gen8_gtt_pte_t gen8_ppgtt_pde_t;
 
@@ -51,6 +49,27 @@ typedef gen8_gtt_pte_t gen8_ppgtt_pde_t;
 #define GEN6_PTE_ADDR_ENCODE(addr)	GEN6_GTT_ADDR_ENCODE(addr)
 #define HSW_PTE_ADDR_ENCODE(addr)	HSW_GTT_ADDR_ENCODE(addr)
 
+/* GEN6 PPGTT resembles a 2 level page table:
+ * 31:22 | 21:12 |  11:0
+ *  PDE  |  PTE  | offset
+ */
+#define GEN6_PDE_SHIFT			22
+#define GEN6_PPGTT_PD_ENTRIES		512
+#define GEN6_PDE_MASK			(GEN6_PPGTT_PD_ENTRIES-1)
+#define GEN6_PTE_SHIFT			12
+#define GEN6_PPGTT_PT_ENTRIES (PAGE_SIZE / sizeof(gen6_gtt_pte_t))
+#define GEN6_PTE_MASK			(GEN6_PPGTT_PT_ENTRIES-1)
+
+static inline uint32_t gen6_pte_index(uint32_t address)
+{
+	return (address >> GEN6_PTE_SHIFT) & GEN6_PTE_MASK;
+}
+
+static inline uint32_t gen6_pde_index(uint32_t address)
+{
+	return (address >> GEN6_PDE_SHIFT) & GEN6_PDE_MASK;
+}
+
 /* Cacheability Control is a 4-bit value. The low three bits are stored in *
  * bits 3:1 of the PTE, while the fourth bit is stored in bit 11 of the PTE.
  */
@@ -63,6 +82,11 @@ typedef gen8_gtt_pte_t gen8_ppgtt_pde_t;
 #define HSW_WT_ELLC_LLC_AGE0		HSW_CACHEABILITY_CONTROL(0x6)
 #define HSW_WT_ELLC_LLC_AGE3		HSW_CACHEABILITY_CONTROL(0x7)
 
+#define PPAT_UNCACHED_INDEX		(_PAGE_PWT | _PAGE_PCD)
+#define PPAT_CACHED_PDE_INDEX		0 /* WB LLC */
+#define PPAT_CACHED_INDEX		_PAGE_PAT /* WB LLCeLLC */
+#define PPAT_DISPLAY_ELLC_INDEX		_PAGE_PCD /* WT eLLC */
+
 #define GEN8_PTES_PER_PAGE		(PAGE_SIZE / sizeof(gen8_gtt_pte_t))
 #define GEN8_PDES_PER_PAGE		(PAGE_SIZE / sizeof(gen8_ppgtt_pde_t))
 
@@ -71,6 +95,10 @@ typedef gen8_gtt_pte_t gen8_ppgtt_pde_t;
  * PDPE  |  PDE  |  PTE  | offset
  * The difference as compared to normal x86 3 level page table is the PDPEs are
  * programmed via register.
+ *
+ * The x86 pagetable code is flexible in its ability to handle varying page
+ * table depths via abstracted PGDIR/PUD/PMD/PTE. I've opted to not do this and
+ * instead replicate the interesting functionality.
  */
 #define GEN8_PDPE_SHIFT			30
 #define GEN8_PDPE_MASK			0x3
@@ -79,10 +107,31 @@ typedef gen8_gtt_pte_t gen8_ppgtt_pde_t;
 #define GEN8_PTE_SHIFT			12
 #define GEN8_PTE_MASK			0x1ff
 
-#define PPAT_UNCACHED_INDEX		(_PAGE_PWT | _PAGE_PCD)
-#define PPAT_CACHED_PDE_INDEX		0 /* WB LLC */
-#define PPAT_CACHED_INDEX		_PAGE_PAT /* WB LLCeLLC */
-#define PPAT_DISPLAY_ELLC_INDEX		_PAGE_PCD /* WT eLLC */
+static inline uint32_t gen8_pte_index(uint64_t address)
+{
+	return (address >> GEN8_PTE_SHIFT) & GEN8_PTE_MASK;
+}
+
+static inline uint32_t gen8_pde_index(uint64_t address)
+{
+	return (address >> GEN8_PDE_SHIFT) & GEN8_PDE_MASK;
+}
+
+static inline uint32_t gen8_pdpe_index(uint64_t address)
+{
+	return (address >> GEN8_PDPE_SHIFT) & GEN8_PDPE_MASK;
+}
+
+static inline uint32_t gen8_pml4e_index(uint64_t address)
+{
+	BUG();
+}
+
+/* Useful for 3 level page table functions */
+static inline uint32_t gen8_pde_count(uint64_t start, uint64_t length)
+{
+	return ((length - start) / PAGE_SIZE) << GEN8_PDE_SHIFT;
+}
 
 static void ppgtt_bind_vma(struct i915_vma *vma,
 			   enum i915_cache_level cache_level,
@@ -274,9 +323,9 @@ static void gen8_ppgtt_clear_range(struct i915_address_space *vm,
 	struct i915_hw_ppgtt *ppgtt =
 		container_of(vm, struct i915_hw_ppgtt, base);
 	gen8_gtt_pte_t *pt_vaddr, scratch_pte;
-	unsigned pdpe = start >> GEN8_PDPE_SHIFT & GEN8_PDPE_MASK;
-	unsigned pde = start >> GEN8_PDE_SHIFT & GEN8_PDE_MASK;
-	unsigned pte = start >> GEN8_PTE_SHIFT & GEN8_PTE_MASK;
+	unsigned pdpe = gen8_pdpe_index(start);
+	unsigned pde = gen8_pde_index(start);
+	unsigned pte = gen8_pte_index(start);
 	unsigned num_entries = (length - start) >> PAGE_SHIFT;
 	unsigned last_pte, i;
 
@@ -315,9 +364,9 @@ static void gen8_ppgtt_insert_entries(struct i915_address_space *vm,
 	struct i915_hw_ppgtt *ppgtt =
 		container_of(vm, struct i915_hw_ppgtt, base);
 	gen8_gtt_pte_t *pt_vaddr;
-	unsigned pdpe = start >> GEN8_PDPE_SHIFT & GEN8_PDPE_MASK;
-	unsigned pde = start >> GEN8_PDE_SHIFT & GEN8_PDE_MASK;
-	unsigned pte = start >> GEN8_PTE_SHIFT & GEN8_PTE_MASK;
+	unsigned pdpe = gen8_pdpe_index(start);
+	unsigned pde = gen8_pde_index(start);
+	unsigned pte = gen8_pte_index(start);
 	struct sg_page_iter sg_iter;
 
 	pt_vaddr = NULL;
@@ -661,9 +710,9 @@ static void gen6_dump_ppgtt(struct i915_hw_ppgtt *ppgtt, struct seq_file *m)
 		seq_printf(m, "\tPDE: %x\n", pd_entry);
 
 		pt_vaddr = kmap_atomic(ppgtt->pt_pages[pde]);
-		for (pte = 0; pte < I915_PPGTT_PT_ENTRIES; pte+=4) {
+		for (pte = 0; pte < GEN6_PPGTT_PT_ENTRIES; pte+=4) {
 			unsigned long va =
-				(pde * PAGE_SIZE * I915_PPGTT_PT_ENTRIES) +
+				(pde * PAGE_SIZE * GEN6_PPGTT_PT_ENTRIES) +
 				(pte * PAGE_SIZE);
 			int i;
 			bool found = false;
@@ -938,29 +987,28 @@ static void gen6_ppgtt_clear_range(struct i915_address_space *vm,
 	struct i915_hw_ppgtt *ppgtt =
 		container_of(vm, struct i915_hw_ppgtt, base);
 	gen6_gtt_pte_t *pt_vaddr, scratch_pte;
-	unsigned first_entry = start >> PAGE_SHIFT;
+	unsigned pde = gen6_pde_index(start);
 	unsigned num_entries = (length - start) >> PAGE_SHIFT;
-	unsigned act_pt = first_entry / I915_PPGTT_PT_ENTRIES;
-	unsigned first_pte = first_entry % I915_PPGTT_PT_ENTRIES;
+	unsigned pte = gen6_pte_index(start);
 	unsigned last_pte, i;
 
 	scratch_pte = vm->pte_encode(vm->scratch.addr, I915_CACHE_LLC, true);
 
 	while (num_entries) {
-		last_pte = first_pte + num_entries;
-		if (last_pte > I915_PPGTT_PT_ENTRIES)
-			last_pte = I915_PPGTT_PT_ENTRIES;
+		last_pte = pte + num_entries;
+		if (last_pte > GEN6_PPGTT_PT_ENTRIES)
+			last_pte = GEN6_PPGTT_PT_ENTRIES;
 
-		pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pt]);
+		pt_vaddr = kmap_atomic(ppgtt->pt_pages[pde]);
 
-		for (i = first_pte; i < last_pte; i++)
+		for (i = pte; i < last_pte; i++)
 			pt_vaddr[i] = scratch_pte;
 
 		kunmap_atomic(pt_vaddr);
 
-		num_entries -= last_pte - first_pte;
-		first_pte = 0;
-		act_pt++;
+		num_entries -= last_pte - pte;
+		pte = 0;
+		pde++;
 	}
 }
 
@@ -972,24 +1020,23 @@ static void gen6_ppgtt_insert_entries(struct i915_address_space *vm,
 	struct i915_hw_ppgtt *ppgtt =
 		container_of(vm, struct i915_hw_ppgtt, base);
 	gen6_gtt_pte_t *pt_vaddr;
-	unsigned first_entry = start >> PAGE_SHIFT;
-	unsigned act_pt = first_entry / I915_PPGTT_PT_ENTRIES;
-	unsigned act_pte = first_entry % I915_PPGTT_PT_ENTRIES;
+	unsigned pde = gen6_pde_index(start);
+	unsigned pte = gen6_pte_index(start);
 	struct sg_page_iter sg_iter;
 
 	pt_vaddr = NULL;
 	for_each_sg_page(pages->sgl, &sg_iter, pages->nents, 0) {
 		if (pt_vaddr == NULL)
-			pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pt]);
+			pt_vaddr = kmap_atomic(ppgtt->pt_pages[pde]);
 
-		pt_vaddr[act_pte] =
+		pt_vaddr[pte] =
 			vm->pte_encode(sg_page_iter_dma_address(&sg_iter),
 				       cache_level, true);
-		if (++act_pte == I915_PPGTT_PT_ENTRIES) {
+		if (++pte == GEN6_PPGTT_PT_ENTRIES) {
 			kunmap_atomic(pt_vaddr);
 			pt_vaddr = NULL;
-			act_pt++;
-			act_pte = 0;
+			pde++;
+			pte = 0;
 		}
 	}
 	if (pt_vaddr)
@@ -1173,7 +1220,7 @@ static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
 	ppgtt->base.cleanup = gen6_ppgtt_cleanup;
 	ppgtt->base.scratch = dev_priv->gtt.base.scratch;
 	ppgtt->base.start = 0;
-	ppgtt->base.total = GEN6_PPGTT_PD_ENTRIES * I915_PPGTT_PT_ENTRIES * PAGE_SIZE;
+	ppgtt->base.total = GEN6_PPGTT_PD_ENTRIES * GEN6_PPGTT_PT_ENTRIES * PAGE_SIZE;
 	ppgtt->debug_dump = gen6_dump_ppgtt;
 
 	ppgtt->pd_offset =
-- 
1.9.0

_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
http://lists.freedesktop.org/mailman/listinfo/intel-gfx




[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]
  Powered by Linux