drm/radeon: add 2-level VM pagetables support v9

PDE/PTE update code uses CP ring for memory writes.
All page table entries are preallocated for now in alloc_pt().

It is made as whole because it's hard to divide it to several patches
that compile and doesn't break anything being applied separately.

Tested on cayman card.

v2: rebased on top of "refactor set_page chipset interface v3",
    code cleanups

v3: switched offsets calc macros to inline funcs where possible,
    remove pd_addr from radeon_vm, switched RADEON_BLOCK_SIZE define,
    to 9 (and PTE_COUNT to 1 << BLOCK_SIZE)

v4 (ck): move "incr" documentation to previous patch, cleanup and
         document RADEON_VM_* constants, change commit message to
         our usual format, simplify patch allot by removing
         everything current not necessary, disable SI workaround.

v5: (agd5f): Fix typo in tables_size calculation in
             radeon_vm_alloc_pt().  Second line should have been
             '+=' rather than '='.

v6: fix npdes calculation. In scenario when pfns to be mapped overlap
two PDE spans:

   +-----------+-------------+
   | PDE span  | PDE span    |
   +-----------+----+--------+
          |         |
          +---------+
          | pfns    |
          +---------+

the following npdes calculation gives incorrect result:

npdes = (nptes >> RADEON_VM_BLOCK_SIZE) + 1;

For the case above picture it should give npdes = 2, but gives one.

This patch corrects it by rounding last pfn up to 512 border,
first - down to 512 border and then subtracting and dividing by 512.

v7: Make npde calculation clearer, fix ndw calculation.

v8: (agd5f): reserve enough for 2 full VM PTs, add some
             additional comments.

v9: fix typo in npde calculation

Signed-off-by: Dmitry Cherkasov <Dmitrii.Cherkasov@amd.com>
Signed-off-by: Christian König <deathsimple@vodafone.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 67 insertions, 24 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_gart.c b/drivers/gpu/drm/radeon/radeon_gart.c
index bb9fc594779c..753b7ca3c807 100644
--- a/drivers/gpu/drm/radeon/radeon_gart.c
+++ b/drivers/gpu/drm/radeon/radeon_gart.c
@@ -423,6 +423,18 @@ void radeon_gart_fini(struct radeon_device *rdev)
  */
 
 /**
+ * radeon_vm_directory_size - returns the size of the page directory in bytes
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Calculate the size of the page directory in bytes (cayman+).
+ */
+static unsigned radeon_vm_directory_size(struct radeon_device *rdev)
+{
+        return (rdev->vm_manager.max_pfn >> RADEON_VM_BLOCK_SIZE) * 8;
+}
+
+/**
  * radeon_vm_manager_init - init the vm manager
  *
  * @rdev: radeon_device pointer
@@ -435,11 +447,15 @@ int radeon_vm_manager_init(struct radeon_device *rdev)
         struct radeon_vm *vm;
         struct radeon_bo_va *bo_va;
         int r;
+        unsigned size;
 
         if (!rdev->vm_manager.enabled) {
                 /* allocate enough for 2 full VM pts */
+                size = RADEON_GPU_PAGE_ALIGN(radeon_vm_directory_size(rdev));
+                size += RADEON_GPU_PAGE_ALIGN(rdev->vm_manager.max_pfn * 8);
+                size *= 2;
                 r = radeon_sa_bo_manager_init(rdev, &rdev->vm_manager.sa_manager,
-                                              rdev->vm_manager.max_pfn * 8 * 2,
+                                              size,
                                               RADEON_GEM_DOMAIN_VRAM);
                 if (r) {
                         dev_err(rdev->dev, "failed to allocate vm bo (%dKB)\n",
@@ -490,7 +506,6 @@ static void radeon_vm_free_pt(struct radeon_device *rdev,
 
         list_del_init(&vm->list);
         radeon_sa_bo_free(rdev, &vm->sa_bo, vm->fence);
-        vm->pt = NULL;
 
         list_for_each_entry(bo_va, &vm->va, vm_list) {
                 bo_va->valid = false;
@@ -546,11 +561,17 @@ int radeon_vm_alloc_pt(struct radeon_device *rdev, struct radeon_vm *vm)
 {
         struct radeon_vm *vm_evict;
         int r;
+        u64 *pd_addr;
+        int tables_size;
 
         if (vm == NULL) {
                 return -EINVAL;
         }
 
+        /* allocate enough to cover the current VM size */
+        tables_size = RADEON_GPU_PAGE_ALIGN(radeon_vm_directory_size(rdev));
+        tables_size += RADEON_GPU_PAGE_ALIGN(vm->last_pfn * 8);
+
         if (vm->sa_bo != NULL) {
                 /* update lru */
                 list_del_init(&vm->list);
@@ -560,8 +581,7 @@ int radeon_vm_alloc_pt(struct radeon_device *rdev, struct radeon_vm *vm)
 
 retry:
         r = radeon_sa_bo_new(rdev, &rdev->vm_manager.sa_manager, &vm->sa_bo,
-                             RADEON_GPU_PAGE_ALIGN(vm->last_pfn * 8),
-                             RADEON_GPU_PAGE_SIZE, false);
+                             tables_size, RADEON_GPU_PAGE_SIZE, false);
         if (r == -ENOMEM) {
                 if (list_empty(&rdev->vm_manager.lru_vm)) {
                         return r;
@@ -576,9 +596,9 @@ retry:
                 return r;
         }
 
-        vm->pt = radeon_sa_bo_cpu_addr(vm->sa_bo);
-        vm->pt_gpu_addr = radeon_sa_bo_gpu_addr(vm->sa_bo);
-        memset(vm->pt, 0, RADEON_GPU_PAGE_ALIGN(vm->last_pfn * 8));
+        pd_addr = radeon_sa_bo_cpu_addr(vm->sa_bo);
+        vm->pd_gpu_addr = radeon_sa_bo_gpu_addr(vm->sa_bo);
+        memset(pd_addr, 0, tables_size);
 
         list_add_tail(&vm->list, &rdev->vm_manager.lru_vm);
         return radeon_vm_bo_update_pte(rdev, vm, rdev->ring_tmp_bo.bo,
@@ -866,8 +886,9 @@ int radeon_vm_bo_update_pte(struct radeon_device *rdev,
         struct radeon_ring *ring = &rdev->ring[ridx];
         struct radeon_semaphore *sem = NULL;
         struct radeon_bo_va *bo_va;
-        unsigned ngpu_pages, ndw;
-        uint64_t pfn, addr;
+        unsigned nptes, npdes, ndw;
+        uint64_t pe, addr;
+        uint64_t pfn;
         int r;
 
         /* nothing to do if vm isn't bound */
@@ -889,10 +910,8 @@ int radeon_vm_bo_update_pte(struct radeon_device *rdev,
         if ((bo_va->valid && mem) || (!bo_va->valid && mem == NULL))
                 return 0;
 
-        ngpu_pages = radeon_bo_ngpu_pages(bo);
         bo_va->flags &= ~RADEON_VM_PAGE_VALID;
         bo_va->flags &= ~RADEON_VM_PAGE_SYSTEM;
-        pfn = bo_va->soffset / RADEON_GPU_PAGE_SIZE;
         if (mem) {
                 addr = mem->start << PAGE_SHIFT;
                 if (mem->mem_type != TTM_PL_SYSTEM) {
@@ -921,9 +940,26 @@ int radeon_vm_bo_update_pte(struct radeon_device *rdev,
         }
 
         /* estimate number of dw needed */
+        /* reserve space for 32-bit padding */
         ndw = 32;
-        ndw += (ngpu_pages >> 12) * 3;
-        ndw += ngpu_pages * 2;
+
+        nptes = radeon_bo_ngpu_pages(bo);
+
+        pfn = (bo_va->soffset / RADEON_GPU_PAGE_SIZE);
+
+        /* handle cases where a bo spans several pdes  */
+        npdes = (ALIGN(pfn + nptes, RADEON_VM_PTE_COUNT) -
+                 (pfn & ~(RADEON_VM_PTE_COUNT - 1))) >> RADEON_VM_BLOCK_SIZE;
+
+        /* reserve space for one header for every 2k dwords */
+        ndw += (nptes >> 11) * 3;
+        /* reserve space for pte addresses */
+        ndw += nptes * 2;
+
+        /* reserve space for one header for every 2k dwords */
+        ndw += (npdes >> 11) * 3;
+        /* reserve space for pde addresses */
+        ndw += npdes * 2;
 
         r = radeon_ring_lock(rdev, ring, ndw);
         if (r) {
@@ -935,8 +971,22 @@ int radeon_vm_bo_update_pte(struct radeon_device *rdev,
                 radeon_fence_note_sync(vm->fence, ridx);
         }
 
-        radeon_asic_vm_set_page(rdev, vm->pt_gpu_addr + pfn * 8, addr,
-                                ngpu_pages, RADEON_GPU_PAGE_SIZE, bo_va->flags);
+        /* update page table entries */
+        pe = vm->pd_gpu_addr;
+        pe += radeon_vm_directory_size(rdev);
+        pe += (bo_va->soffset / RADEON_GPU_PAGE_SIZE) * 8;
+
+        radeon_asic_vm_set_page(rdev, pe, addr, nptes,
+                                RADEON_GPU_PAGE_SIZE, bo_va->flags);
+
+        /* update page directory entries */
+        addr = pe;
+
+        pe = vm->pd_gpu_addr;
+        pe += ((bo_va->soffset / RADEON_GPU_PAGE_SIZE) >> RADEON_VM_BLOCK_SIZE) * 8;
+
+        radeon_asic_vm_set_page(rdev, pe, addr, npdes,
+                                RADEON_VM_PTE_COUNT * 8, RADEON_VM_PAGE_VALID);
 
         radeon_fence_unref(&vm->fence);
         r = radeon_fence_emit(rdev, &vm->fence, ridx);
@@ -1018,18 +1068,11 @@ int radeon_vm_init(struct radeon_device *rdev, struct radeon_vm *vm)
 
         vm->id = 0;
         vm->fence = NULL;
+        vm->last_pfn = 0;
         mutex_init(&vm->mutex);
         INIT_LIST_HEAD(&vm->list);
         INIT_LIST_HEAD(&vm->va);
-        /* SI requires equal sized PTs for all VMs, so always set
-         * last_pfn to max_pfn.  cayman allows variable sized
-         * pts so we can grow then as needed.  Once we switch
-         * to two level pts we can unify this again.
-         */
-        if (rdev->family >= CHIP_TAHITI)
-                vm->last_pfn = rdev->vm_manager.max_pfn;
-        else
-                vm->last_pfn = 0;
+
         /* map the ib pool buffer at 0 in virtual address space, set
          * read only
          */