From: Tao Zhou <tao.zhou1@xxxxxxx>
Old CPER data will be overwritten if ring buffer is full, and read
pointer always points to CPER header.
Signed-off-by: Tao Zhou <tao.zhou1@xxxxxxx>
Reviewed-by: Hawking Zhang <Hawking.Zhang@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_cper.c | 93 ++++++++++++++++++++++++
drivers/gpu/drm/amd/amdgpu/amdgpu_cper.h | 2 +
2 files changed, 95 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cper.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cper.c
index cef7c1ec0d7c..64624b8b0cbc 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cper.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cper.c
@@ -365,6 +365,99 @@ int amdgpu_cper_generate_ce_records(struct amdgpu_device *adev,
return 0;
}
+static bool amdgpu_cper_is_hdr(struct amdgpu_ring *ring, u64 pos)
+{
+ struct cper_hdr *chdr;
+
+ chdr = (struct cper_hdr *)&(ring->ring[pos]);
+ return strcmp(chdr->signature, "CPER") ? false : true;
+}
+
+static u32 amdgpu_cper_ring_get_ent_sz(struct amdgpu_ring *ring, u64 pos)
+{
+ struct cper_hdr *chdr;
+ u64 p;
+ u32 chunk, rec_len = 0;
+
+ chdr = (struct cper_hdr *)&(ring->ring[pos]);
+ chunk = ring->ring_size - (pos << 2);
+
+ if (!strcmp(chdr->signature, "CPER")) {
+ rec_len = chdr->record_length;
+ goto calc;
+ }
+
+ /* ring buffer is not full, no cper data after ring->wptr */
+ if (ring->count_dw)
+ goto calc;
+
+ for (p = pos + 1; p <= ring->buf_mask; p++) {
+ chdr = (struct cper_hdr *)&(ring->ring[p]);
+ if (!strcmp(chdr->signature, "CPER")) {
+ rec_len = (p - pos) << 2;
+ goto calc;
+ }
+ }
+
+calc:
+ if (!rec_len)
+ return chunk;
+ else
+ return min(rec_len, chunk);
+}
+
+void amdgpu_cper_ring_write(struct amdgpu_ring *ring,
+ void *src, int count)
+{
+ u64 pos, wptr_old, rptr = *ring->rptr_cpu_addr & ring->ptr_mask;
+ u32 chunk, ent_sz;
+ u8 *s = (u8 *)src;
+
+ if (count >= ring->ring_size - 4) {
+ dev_err(ring->adev->dev,
+ "CPER data size(%d) is larger than ring size(%d)\n",
+ count, ring->ring_size - 4);
+
+ return;
+ }
+
+ wptr_old = ring->wptr;
+
+ while (count) {
+ ent_sz = amdgpu_cper_ring_get_ent_sz(ring, ring->wptr);
+ chunk = min(ent_sz, count);
+
+ memcpy(&ring->ring[ring->wptr], s, chunk);
+
+ ring->wptr += (chunk >> 2);
+ ring->wptr &= ring->ptr_mask;
+ count -= chunk;
+ s += chunk;
+ }
+
+ /* the buffer is overflow, adjust rptr */
+ if (((wptr_old < rptr) && (rptr <= ring->wptr)) ||
+ ((ring->wptr < wptr_old) && (wptr_old < rptr)) ||
+ ((rptr <= ring->wptr) && (ring->wptr < wptr_old))) {
+ pos = (ring->wptr + 1) & ring->ptr_mask;
+
+ do {
+ ent_sz = amdgpu_cper_ring_get_ent_sz(ring, pos);
+
+ rptr += (ent_sz >> 2);
+ rptr &= ring->ptr_mask;
+ *ring->rptr_cpu_addr = rptr;
+
+ pos = rptr;
+ } while (!amdgpu_cper_is_hdr(ring, rptr));
+ }
+
+ if (ring->count_dw >= (count >> 2))
+ ring->count_dw - (count >> 2);
+ else
+ ring->count_dw = 0;
+}
+
static u64 amdgpu_cper_ring_get_rptr(struct amdgpu_ring *ring)
{
return *(ring->rptr_cpu_addr);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cper.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_cper.h
index 80c8571cff9d..1fa41858f22e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cper.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cper.h
@@ -93,6 +93,8 @@ int amdgpu_cper_generate_ue_record(struct amdgpu_device *adev,
int amdgpu_cper_generate_ce_records(struct amdgpu_device *adev,
struct aca_banks *banks,
uint16_t bank_count);
+void amdgpu_cper_ring_write(struct amdgpu_ring *ring,
+ void *src, int count);
int amdgpu_cper_init(struct amdgpu_device *adev);
int amdgpu_cper_fini(struct amdgpu_device *adev);
--
2.34.1
