[PATCH v4 5/7] drm/amdkfd: Change range granularity update bitmap_map

[Philip Yang]

When changing the svm range granularity, update the svm range
bitmap_map based on new range granularity.

Signed-off-by: Philip Yang <philip.y...@amd.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 49 +++++++++++++++++++++++++++-
 1 file changed, 48 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 7a30c3e58234..ebc4cce801bf 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -757,6 +757,53 @@ svm_range_check_attr(struct kfd_process *p,
        return 0;
 }
 
+static void
+svm_range_change_granularity(struct svm_range *prange, u8 value)
+{
+       struct kfd_process *p = container_of(prange->svms, struct kfd_process, 
svms);
+       u32 new_nbits, old_nbits, i, n;
+       unsigned long *new_bits, *old_bits;
+       u32 gpuidx;
+
+       if (prange->granularity == value)
+               return;
+
+       old_nbits = svm_range_map_nbits(prange->start, prange->last, 
prange->granularity);
+       new_nbits = svm_range_map_nbits(prange->start, prange->last, value);
+       if (new_nbits > old_nbits) {
+               n = new_nbits / old_nbits;
+               if (new_nbits % old_nbits)
+                       n++;
+       } else {
+               n = old_nbits / new_nbits;
+               if (old_nbits % new_nbits)
+                       n++;
+       }
+
+       pr_debug("prange 0x%p [0x%lx 0x%lx] bitmap_map nbits %d -> %d\n",
+                prange, prange->start, prange->last, old_nbits, new_nbits);
+
+       for_each_set_bit(gpuidx, p->svms.bitmap_supported, p->n_pdds) {
+               old_bits = prange->bitmap_map[gpuidx];
+               if (bitmap_empty(old_bits, old_nbits))
+                       continue;
+
+               new_bits = bitmap_zalloc(new_nbits, GFP_KERNEL);
+               if (!new_bits)
+                       return;
+
+               for_each_set_bit(i, old_bits, old_nbits) {
+                       if (new_nbits > old_nbits)
+                               bitmap_set(new_bits, i * n, n);
+                       else
+                               bitmap_set(new_bits, i / n, 1);
+               }
+               prange->bitmap_map[gpuidx] = new_bits;
+               bitmap_free(old_bits);
+       }
+       prange->granularity = value;
+}
+
 static void
 svm_range_apply_attrs(struct kfd_process *p, struct svm_range *prange,
                      uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs,
@@ -801,7 +848,7 @@ svm_range_apply_attrs(struct kfd_process *p, struct 
svm_range *prange,
                        prange->flags &= ~attrs[i].value;
                        break;
                case KFD_IOCTL_SVM_ATTR_GRANULARITY:
-                       prange->granularity = min_t(uint32_t, attrs[i].value, 
0x3F);
+                       svm_range_change_granularity(prange, min_t(u32, 
attrs[i].value, 0x3F));
                        break;
                default:
                        WARN_ONCE(1, "svm_range_check_attrs wasn't called?");
-- 
2.35.1