gpu: nvgpu: Deterministic submit fix

Fix some simple pointer arithmetic errors in the deterministic submit
path. The lockless allocator was doing a subtraction to determine the
correct offset of the element to free. However, this subtraction was
using the base address and a numeric offset - not a pointer offset. Thus
the difference computed was in bytes not in elements of the block size.

The fix is simple: just divide by the block size.

Also this modifies the debugging statement a bit so that a bit more
information is printed at more useful times.

Lastly, a pointer to numeric cast was fixed in the fence code.

Change-Id: I514724205f1b73805b21e979481a13ac689f3482
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1538905
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: svccoveritychecker <svccoveritychecker@nvidia.com>
Reviewed-by: Aingara Paramakuru <aparamakuru@nvidia.com>
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: Konsta Holtta <kholtta@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 9 insertions, 4 deletions

diff --git a/drivers/gpu/nvgpu/common/mm/lockless_allocator.c b/drivers/gpu/nvgpu/common/mm/lockless_allocator.c
index 944b4b0f..2a569efd 100644
--- a/drivers/gpu/nvgpu/common/mm/lockless_allocator.c
+++ b/drivers/gpu/nvgpu/common/mm/lockless_allocator.c
@@ -66,12 +66,16 @@ static u64 nvgpu_lockless_alloc(struct nvgpu_allocator *a, u64 len)
                 if (ret == head) {
                         addr = pa->base + head * pa->blk_size;
                         atomic_inc(&pa->nr_allocs);
-                        alloc_dbg(a, "Alloc node # %d @ addr 0x%llx\n", head,
-                                  addr);
                         break;
                 }
                 head = ACCESS_ONCE(pa->head);
         }
+
+        if (addr)
+                alloc_dbg(a, "Alloc node # %d @ addr 0x%llx\n", head, addr);
+        else
+                alloc_dbg(a, "Alloc failed!\n");
+
         return addr;
 }
 
@@ -81,7 +85,9 @@ static void nvgpu_lockless_free(struct nvgpu_allocator *a, u64 addr)
         int head, ret;
         u64 cur_idx;
 
-        cur_idx = addr - pa->base;
+        cur_idx = (addr - pa->base) / pa->blk_size;
+
+        alloc_dbg(a, "Free node # %llu @ addr 0x%llx\n", cur_idx, addr);
 
         while (1) {
                 head = ACCESS_ONCE(pa->head);
@@ -89,7 +95,6 @@ static void nvgpu_lockless_free(struct nvgpu_allocator *a, u64 addr)
                 ret = cmpxchg(&pa->head, head, cur_idx);
                 if (ret == head) {
                         atomic_dec(&pa->nr_allocs);
-                        alloc_dbg(a, "Free node # %llu\n", cur_idx);
                         break;
                 }
         }