On 14/04/22 17:41, Balasubramani Vivekanandan wrote:
> On 04.04.2022 15:01, Mullati Siva wrote:
>> From: Siva Mullati <siva.mull...@intel.com>
>>
>> Convert CT commands and descriptors to use iosys_map rather
>> than plain pointer and save it in the intel_guc_ct_buffer struct.
>> This will help with ct_write and ct_read for cmd send and receive
>> after the initialization by abstracting the IO vs system memory.
>>
>> Signed-off-by: Siva Mullati <siva.mull...@intel.com>
>> ---
>> drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 200 +++++++++++++---------
>> drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h | 9 +-
>> 2 files changed, 127 insertions(+), 82 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
>> b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
>> index f01325cd1b62..64568dc90b05 100644
>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
>> @@ -44,6 +44,11 @@ static inline struct drm_device *ct_to_drm(struct
>> intel_guc_ct *ct)
>> #define CT_PROBE_ERROR(_ct, _fmt, ...) \
>> i915_probe_error(ct_to_i915(ct), "CT: " _fmt, ##__VA_ARGS__)
>>
>> +#define ct_desc_read(desc_map_, field_) \
>> + iosys_map_rd_field(desc_map_, 0, struct guc_ct_buffer_desc, field_)
>> +#define ct_desc_write(desc_map_, field_, val_) \
>> + iosys_map_wr_field(desc_map_, 0, struct guc_ct_buffer_desc, field_,
>> val_)
>> +
> Did you try to make the change Lucas mentioned in his comment on rev0,
> to pass `struct guc_ct_buffer_desc *` as first argument to the above
> macros? Was it not feasible?
It is not feasible.
>> /**
>> * DOC: CTB Blob
>> *
>> @@ -76,6 +81,11 @@ static inline struct drm_device *ct_to_drm(struct
>> intel_guc_ct *ct)
>> #define CTB_G2H_BUFFER_SIZE (4 * CTB_H2G_BUFFER_SIZE)
>> #define G2H_ROOM_BUFFER_SIZE (CTB_G2H_BUFFER_SIZE / 4)
>>
>> +#define CTB_SEND_DESC_OFFSET 0u
>> +#define CTB_RECV_DESC_OFFSET (CTB_DESC_SIZE)
>> +#define CTB_SEND_CMDS_OFFSET (2 * CTB_DESC_SIZE)
>> +#define CTB_RECV_CMDS_OFFSET (2 * CTB_DESC_SIZE +
>> CTB_H2G_BUFFER_SIZE)
>> +
>> struct ct_request {
>> struct list_head link;
>> u32 fence;
>> @@ -113,9 +123,9 @@ void intel_guc_ct_init_early(struct intel_guc_ct *ct)
>> init_waitqueue_head(&ct->wq);
>> }
>>
>> -static void guc_ct_buffer_desc_init(struct guc_ct_buffer_desc *desc)
>> +static void guc_ct_buffer_desc_init(struct iosys_map *desc)
>> {
>> - memset(desc, 0, sizeof(*desc));
>> + iosys_map_memset(desc, 0, 0, sizeof(struct guc_ct_buffer_desc));
>> }
>>
>> static void guc_ct_buffer_reset(struct intel_guc_ct_buffer *ctb)
>> @@ -128,17 +138,18 @@ static void guc_ct_buffer_reset(struct
>> intel_guc_ct_buffer *ctb)
>> space = CIRC_SPACE(ctb->tail, ctb->head, ctb->size) - ctb->resv_space;
>> atomic_set(&ctb->space, space);
>>
>> - guc_ct_buffer_desc_init(ctb->desc);
>> + guc_ct_buffer_desc_init(&ctb->desc_map);
>> }
>>
>> static void guc_ct_buffer_init(struct intel_guc_ct_buffer *ctb,
>> - struct guc_ct_buffer_desc *desc,
>> - u32 *cmds, u32 size_in_bytes, u32 resv_space)
>> + struct iosys_map *desc,
>> + struct iosys_map *cmds,
>> + u32 size_in_bytes, u32 resv_space)
>> {
>> GEM_BUG_ON(size_in_bytes % 4);
>>
>> - ctb->desc = desc;
>> - ctb->cmds = cmds;
>> + ctb->desc_map = *desc;
>> + ctb->cmds_map = *cmds;
>> ctb->size = size_in_bytes / 4;
>> ctb->resv_space = resv_space / 4;
>>
>> @@ -218,12 +229,13 @@ static int ct_register_buffer(struct intel_guc_ct *ct,
>> bool send,
>> int intel_guc_ct_init(struct intel_guc_ct *ct)
>> {
>> struct intel_guc *guc = ct_to_guc(ct);
>> - struct guc_ct_buffer_desc *desc;
>> + struct iosys_map blob_map;
>> + struct iosys_map desc_map;
>> + struct iosys_map cmds_map;
>> u32 blob_size;
>> u32 cmds_size;
>> u32 resv_space;
>> void *blob;
>> - u32 *cmds;
>> int err;
>>
>> err = i915_inject_probe_error(guc_to_gt(guc)->i915, -ENXIO);
>> @@ -242,27 +254,35 @@ int intel_guc_ct_init(struct intel_guc_ct *ct)
>>
>> CT_DEBUG(ct, "base=%#x size=%u\n", intel_guc_ggtt_offset(guc, ct->vma),
>> blob_size);
>>
>> - /* store pointers to desc and cmds for send ctb */
>> - desc = blob;
>> - cmds = blob + 2 * CTB_DESC_SIZE;
>> + if (i915_gem_object_is_lmem(ct->vma->obj))
>> + iosys_map_set_vaddr_iomem(&blob_map,
>> + (void __iomem *)blob);
>> + else
>> + iosys_map_set_vaddr(&blob_map, blob);
>> +
>> + /* store sysmap to desc_map and cmds_map for send ctb */
>> + desc_map = IOSYS_MAP_INIT_OFFSET(&blob_map, CTB_SEND_DESC_OFFSET);
>> + cmds_map = IOSYS_MAP_INIT_OFFSET(&blob_map, CTB_SEND_CMDS_OFFSET);
>> cmds_size = CTB_H2G_BUFFER_SIZE;
>> resv_space = 0;
>> - CT_DEBUG(ct, "%s desc %#tx cmds %#tx size %u/%u\n", "send",
>> - ptrdiff(desc, blob), ptrdiff(cmds, blob), cmds_size,
>> - resv_space);
>> + CT_DEBUG(ct, "%s desc %#x cmds %#x size %u/%u\n", "send",
>> + CTB_SEND_DESC_OFFSET, (u32)CTB_SEND_CMDS_OFFSET,
>> + cmds_size, resv_space);
>>
>> - guc_ct_buffer_init(&ct->ctbs.send, desc, cmds, cmds_size, resv_space);
>> + guc_ct_buffer_init(&ct->ctbs.send,
>> + &desc_map, &cmds_map, cmds_size, resv_space);
>>
>> - /* store pointers to desc and cmds for recv ctb */
>> - desc = blob + CTB_DESC_SIZE;
>> - cmds = blob + 2 * CTB_DESC_SIZE + CTB_H2G_BUFFER_SIZE;
>> + /* store sysmap to desc_map and cmds_map for recv ctb */
>> + desc_map = IOSYS_MAP_INIT_OFFSET(&blob_map, CTB_RECV_DESC_OFFSET);
>> + cmds_map = IOSYS_MAP_INIT_OFFSET(&blob_map, CTB_RECV_CMDS_OFFSET);
>> cmds_size = CTB_G2H_BUFFER_SIZE;
>> resv_space = G2H_ROOM_BUFFER_SIZE;
>> - CT_DEBUG(ct, "%s desc %#tx cmds %#tx size %u/%u\n", "recv",
>> - ptrdiff(desc, blob), ptrdiff(cmds, blob), cmds_size,
>> - resv_space);
>> + CT_DEBUG(ct, "%s desc %#x cmds %#x size %u/%u\n", "recv",
>> + (u32)CTB_RECV_DESC_OFFSET, (u32)CTB_RECV_CMDS_OFFSET,
>> + cmds_size, resv_space);
>>
>> - guc_ct_buffer_init(&ct->ctbs.recv, desc, cmds, cmds_size, resv_space);
>> + guc_ct_buffer_init(&ct->ctbs.recv,
>> + &desc_map, &cmds_map, cmds_size, resv_space);
>>
>> return 0;
>> }
>> @@ -279,6 +299,10 @@ void intel_guc_ct_fini(struct intel_guc_ct *ct)
>>
>> tasklet_kill(&ct->receive_tasklet);
>> i915_vma_unpin_and_release(&ct->vma, I915_VMA_RELEASE_MAP);
>> + iosys_map_clear(&ct->ctbs.send.desc_map);
>> + iosys_map_clear(&ct->ctbs.send.cmds_map);
>> + iosys_map_clear(&ct->ctbs.recv.desc_map);
>> + iosys_map_clear(&ct->ctbs.recv.cmds_map);
> I think there is no need of clearing the iosys_map when were are zeroing
> the complete structure area below.
Yes, I have updated this in latest revision.
>> memset(ct, 0, sizeof(*ct));
>> }
>>
>> @@ -291,8 +315,8 @@ void intel_guc_ct_fini(struct intel_guc_ct *ct)
>> int intel_guc_ct_enable(struct intel_guc_ct *ct)
>> {
>> struct intel_guc *guc = ct_to_guc(ct);
>> + struct iosys_map blob_map;
>> u32 base, desc, cmds, size;
>> - void *blob;
>> int err;
>>
>> GEM_BUG_ON(ct->enabled);
>> @@ -302,9 +326,14 @@ int intel_guc_ct_enable(struct intel_guc_ct *ct)
>> GEM_BUG_ON(!i915_gem_object_has_pinned_pages(ct->vma->obj));
>> base = intel_guc_ggtt_offset(guc, ct->vma);
>>
>> + if (i915_gem_object_is_lmem(ct->vma->obj))
>> + iosys_map_set_vaddr_iomem(&blob_map, (void __iomem *)
>> + __px_vaddr(ct->vma->obj));
>> + else
>> + iosys_map_set_vaddr(&blob_map, __px_vaddr(ct->vma->obj));
>> +
>> /* blob should start with send descriptor */
>> - blob = __px_vaddr(ct->vma->obj);
>> - GEM_BUG_ON(blob != ct->ctbs.send.desc);
>> + GEM_BUG_ON(!iosys_map_is_equal(&blob_map, &ct->ctbs.send.desc_map));
>>
>> /* (re)initialize descriptors */
>> guc_ct_buffer_reset(&ct->ctbs.send);
>> @@ -314,15 +343,15 @@ int intel_guc_ct_enable(struct intel_guc_ct *ct)
>> * Register both CT buffers starting with RECV buffer.
>> * Descriptors are in first half of the blob.
>> */
>> - desc = base + ptrdiff(ct->ctbs.recv.desc, blob);
>> - cmds = base + ptrdiff(ct->ctbs.recv.cmds, blob);
>> + desc = base + CTB_RECV_DESC_OFFSET;
>> + cmds = base + CTB_RECV_CMDS_OFFSET;
>> size = ct->ctbs.recv.size * 4;
>> err = ct_register_buffer(ct, false, desc, cmds, size);
>> if (unlikely(err))
>> goto err_out;
>>
>> - desc = base + ptrdiff(ct->ctbs.send.desc, blob);
>> - cmds = base + ptrdiff(ct->ctbs.send.cmds, blob);
>> + desc = base + CTB_SEND_DESC_OFFSET;
>> + cmds = base + CTB_SEND_CMDS_OFFSET;
>> size = ct->ctbs.send.size * 4;
>> err = ct_register_buffer(ct, true, desc, cmds, size);
>> if (unlikely(err))
>> @@ -371,31 +400,33 @@ static int ct_write(struct intel_guc_ct *ct,
>> u32 fence, u32 flags)
>> {
>> struct intel_guc_ct_buffer *ctb = &ct->ctbs.send;
>> - struct guc_ct_buffer_desc *desc = ctb->desc;
>> u32 tail = ctb->tail;
>> u32 size = ctb->size;
>> u32 header;
>> u32 hxg;
>> u32 type;
>> - u32 *cmds = ctb->cmds;
>> + u32 status = ct_desc_read(&ctb->desc_map, status);
>> unsigned int i;
>>
>> - if (unlikely(desc->status))
>> + if (unlikely(status))
>> goto corrupted;
>>
>> GEM_BUG_ON(tail > size);
>>
>> #ifdef CONFIG_DRM_I915_DEBUG_GUC
>> - if (unlikely(tail != READ_ONCE(desc->tail))) {
>> + if (unlikely(tail != ct_desc_read(&ctb->desc_map, tail))) {
>> CT_ERROR(ct, "Tail was modified %u != %u\n",
>> - desc->tail, tail);
>> - desc->status |= GUC_CTB_STATUS_MISMATCH;
>> + ct_desc_read(&ctb->desc_map, tail), tail);
>> + status |= GUC_CTB_STATUS_MISMATCH;
>> + ct_desc_write(&ctb->desc_map, status, status);
>> goto corrupted;
>> }
>> - if (unlikely(READ_ONCE(desc->head) >= size)) {
>> + if (unlikely(ct_desc_read(&ctb->desc_map, head) >= size)) {
>> CT_ERROR(ct, "Invalid head offset %u >= %u)\n",
>> - desc->head, size);
>> - desc->status |= GUC_CTB_STATUS_OVERFLOW;
>> + ct_desc_read(&ctb->desc_map, head), size);
> Can we avoid reading the head from ctb->desc_map twice? Since each
> iosys_map read translates to memcpy, it is better to avoid repeating if
> we can cache from the earlier read.
Do you see real need of having a variable to cache value locally, considering
the path is very unlikely to hit.
>> + status = ct_desc_read(&ctb->desc_map, status) |
>> + GUC_CTB_STATUS_OVERFLOW;
> Same here, can we avoid reading status since we already have it read. We
> can do the same like how it is done for the GUC_CTB_STATUS_MISMATCH case.
Addressed in latest patch
>> + ct_desc_write(&ctb->desc_map, status, status);
>> goto corrupted;
>> }
>> #endif
>> @@ -418,14 +449,14 @@ static int ct_write(struct intel_guc_ct *ct,
>> CT_DEBUG(ct, "writing (tail %u) %*ph %*ph %*ph\n",
>> tail, 4, &header, 4, &hxg, 4 * (len - 1), &action[1]);
>>
>> - cmds[tail] = header;
>> + iosys_map_wr(&ctb->cmds_map, 4 * tail, u32, header);
> I prefer not to use the MAGIC number. My suggestion is to use
> sizeof(tail) since we need the offset in bytes.
I tried avoiding it, can't use sizeof(tail). Here tail is just an index which
might be a misleading if we use it in this case, cmds would have been the right
one but this has been changed to iosys map. Currently updated with sizeof(u32).
>> tail = (tail + 1) % size;
>>
>> - cmds[tail] = hxg;
>> + iosys_map_wr(&ctb->cmds_map, 4 * tail, u32, hxg);
> MAGIC number again. There are numerous places in the patch, where
> numbers are used. I prefer to remove it.
>> tail = (tail + 1) % size;
>>
>> for (i = 1; i < len; i++) {
>> - cmds[tail] = action[i];
>> + iosys_map_wr(&ctb->cmds_map, 4 * tail, u32, action[i]);
>> tail = (tail + 1) % size;
>> }
>> GEM_BUG_ON(tail > size);
>> @@ -442,13 +473,14 @@ static int ct_write(struct intel_guc_ct *ct,
>> atomic_sub(len + GUC_CTB_HDR_LEN, &ctb->space);
>>
>> /* now update descriptor */
>> - WRITE_ONCE(desc->tail, tail);
>> + ct_desc_write(&ctb->desc_map, tail, tail);
>>
>> return 0;
>>
>> corrupted:
>> CT_ERROR(ct, "Corrupted descriptor head=%u tail=%u status=%#x\n",
>> - desc->head, desc->tail, desc->status);
>> + ct_desc_read(&ctb->desc_map, head),
>> ct_desc_read(&ctb->desc_map, tail),
>> + ct_desc_read(&ctb->desc_map, status));
>> ctb->broken = true;
>> return -EPIPE;
>> }
>> @@ -499,20 +531,22 @@ static inline bool ct_deadlocked(struct intel_guc_ct
>> *ct)
>> bool ret = ktime_ms_delta(ktime_get(), ct->stall_time) > timeout;
>>
>> if (unlikely(ret)) {
>> - struct guc_ct_buffer_desc *send = ct->ctbs.send.desc;
>> - struct guc_ct_buffer_desc *recv = ct->ctbs.send.desc;
>> -
>> CT_ERROR(ct, "Communication stalled for %lld ms, desc
>> status=%#x,%#x\n",
>> ktime_ms_delta(ktime_get(), ct->stall_time),
>> - send->status, recv->status);
>> + ct_desc_read(&ct->ctbs.send.desc_map, status),
>> + ct_desc_read(&ct->ctbs.recv.desc_map, status));
>> CT_ERROR(ct, "H2G Space: %u (Bytes)\n",
>> atomic_read(&ct->ctbs.send.space) * 4);
>> - CT_ERROR(ct, "Head: %u (Dwords)\n", ct->ctbs.send.desc->head);
>> - CT_ERROR(ct, "Tail: %u (Dwords)\n", ct->ctbs.send.desc->tail);
>> + CT_ERROR(ct, "Head: %u (Dwords)\n",
>> + ct_desc_read(&ct->ctbs.send.desc_map, head));
>> + CT_ERROR(ct, "Tail: %u (Dwords)\n",
>> + ct_desc_read(&ct->ctbs.send.desc_map, tail));
>> CT_ERROR(ct, "G2H Space: %u (Bytes)\n",
>> atomic_read(&ct->ctbs.recv.space) * 4);
>> - CT_ERROR(ct, "Head: %u\n (Dwords)", ct->ctbs.recv.desc->head);
>> - CT_ERROR(ct, "Tail: %u\n (Dwords)", ct->ctbs.recv.desc->tail);
>> + CT_ERROR(ct, "Head: %u\n (Dwords)",
>> + ct_desc_read(&ct->ctbs.recv.desc_map, head));
>> + CT_ERROR(ct, "Tail: %u\n (Dwords)",
>> + ct_desc_read(&ct->ctbs.recv.desc_map, tail));
>>
>> ct->ctbs.send.broken = true;
>> }
>> @@ -549,18 +583,19 @@ static inline void g2h_release_space(struct
>> intel_guc_ct *ct, u32 g2h_len_dw)
>> static inline bool h2g_has_room(struct intel_guc_ct *ct, u32 len_dw)
>> {
>> struct intel_guc_ct_buffer *ctb = &ct->ctbs.send;
>> - struct guc_ct_buffer_desc *desc = ctb->desc;
>> u32 head;
>> u32 space;
>> + u32 status = ct_desc_read(&ctb->desc_map, status);
>>
>> if (atomic_read(&ctb->space) >= len_dw)
>> return true;
>>
>> - head = READ_ONCE(desc->head);
>> + head = ct_desc_read(&ctb->desc_map, head);
>> if (unlikely(head > ctb->size)) {
>> CT_ERROR(ct, "Invalid head offset %u >= %u)\n",
>> head, ctb->size);
>> - desc->status |= GUC_CTB_STATUS_OVERFLOW;
>> + status |= GUC_CTB_STATUS_OVERFLOW;
>> + ct_desc_write(&ctb->desc_map, status, status);
>> ctb->broken = true;
>> return false;
>> }
>> @@ -803,11 +838,10 @@ static void ct_free_msg(struct ct_incoming_msg *msg)
>> static int ct_read(struct intel_guc_ct *ct, struct ct_incoming_msg **msg)
>> {
>> struct intel_guc_ct_buffer *ctb = &ct->ctbs.recv;
>> - struct guc_ct_buffer_desc *desc = ctb->desc;
>> u32 head = ctb->head;
>> - u32 tail = READ_ONCE(desc->tail);
>> + u32 tail = ct_desc_read(&ctb->desc_map, tail);
>> u32 size = ctb->size;
>> - u32 *cmds = ctb->cmds;
>> + u32 status = ct_desc_read(&ctb->desc_map, status);
>> s32 available;
>> unsigned int len;
>> unsigned int i;
>> @@ -816,23 +850,26 @@ static int ct_read(struct intel_guc_ct *ct, struct
>> ct_incoming_msg **msg)
>> if (unlikely(ctb->broken))
>> return -EPIPE;
>>
>> - if (unlikely(desc->status))
>> + if (unlikely(status))
>> goto corrupted;
>>
>> GEM_BUG_ON(head > size);
>>
>> #ifdef CONFIG_DRM_I915_DEBUG_GUC
>> - if (unlikely(head != READ_ONCE(desc->head))) {
>> + if (unlikely(head != ct_desc_read(&ctb->desc_map, head))) {
>> CT_ERROR(ct, "Head was modified %u != %u\n",
>> - desc->head, head);
>> - desc->status |= GUC_CTB_STATUS_MISMATCH;
>> + ct_desc_read(&ctb->desc_map, head), head);
> head read twice here as well.
Same answer.
>> + status |= GUC_CTB_STATUS_MISMATCH;
>> + ct_desc_write(&ctb->desc_map, status, status);
>> goto corrupted;
>> }
>> #endif
>> if (unlikely(tail >= size)) {
>> CT_ERROR(ct, "Invalid tail offset %u >= %u)\n",
>> tail, size);
>> - desc->status |= GUC_CTB_STATUS_OVERFLOW;
>> + status = ct_desc_read(&ctb->desc_map, status) |
>> + GUC_CTB_STATUS_OVERFLOW;
> No need to read the status again as we already have it cached.
addressed.
>> + ct_desc_write(&ctb->desc_map, status, status);
>> goto corrupted;
>> }
>>
>> @@ -849,7 +886,7 @@ static int ct_read(struct intel_guc_ct *ct, struct
>> ct_incoming_msg **msg)
>> CT_DEBUG(ct, "available %d (%u:%u:%u)\n", available, head, tail, size);
>> GEM_BUG_ON(available < 0);
>>
>> - header = cmds[head];
>> + header = iosys_map_rd(&ctb->cmds_map, (4 * head), u32);
> MAGIC numbers
>> head = (head + 1) % size;
>>
>> /* message len with header */
>> @@ -857,11 +894,15 @@ static int ct_read(struct intel_guc_ct *ct, struct
>> ct_incoming_msg **msg)
>> if (unlikely(len > (u32)available)) {
>> CT_ERROR(ct, "Incomplete message %*ph %*ph %*ph\n",
>> 4, &header,
>> + 4 * (head + available - 1 > size ? size - head :
>> + available - 1), ((__px_vaddr(ct->vma->obj) +
>> + CTB_RECV_CMDS_OFFSET) + (4 * head)),
>> 4 * (head + available - 1 > size ?
>> - size - head : available - 1), &cmds[head],
>> - 4 * (head + available - 1 > size ?
>> - available - 1 - size + head : 0), &cmds[0]);
>> - desc->status |= GUC_CTB_STATUS_UNDERFLOW;
>> + available - 1 - size + head : 0),
>> + (__px_vaddr(ct->vma->obj) +
>> CTB_RECV_CMDS_OFFSET));
>> + status = ct_desc_read(&ctb->desc_map, status) |
>> + GUC_CTB_STATUS_UNDERFLOW;
> No need to read status again
>
> Regards,
> Bala
>> + ct_desc_write(&ctb->desc_map, status, status);
>> goto corrupted;
>> }
>>
>> @@ -869,17 +910,18 @@ static int ct_read(struct intel_guc_ct *ct, struct
>> ct_incoming_msg **msg)
>> if (!*msg) {
>> CT_ERROR(ct, "No memory for message %*ph %*ph %*ph\n",
>> 4, &header,
>> + 4 * (head + available - 1 > size ? size - head :
>> + available - 1), (ctb->cmds_map.vaddr + (4 *
>> head)),
>> 4 * (head + available - 1 > size ?
>> - size - head : available - 1), &cmds[head],
>> - 4 * (head + available - 1 > size ?
>> - available - 1 - size + head : 0), &cmds[0]);
>> + available - 1 - size + head : 0),
>> ctb->cmds_map.vaddr);
>> return available;
>> }
>>
>> (*msg)->msg[0] = header;
>>
>> for (i = 1; i < len; i++) {
>> - (*msg)->msg[i] = cmds[head];
>> + (*msg)->msg[i] = iosys_map_rd(&ctb->cmds_map,
>> + (4 * head), u32);
>> head = (head + 1) % size;
>> }
>> CT_DEBUG(ct, "received %*ph\n", 4 * len, (*msg)->msg);
>> @@ -888,13 +930,15 @@ static int ct_read(struct intel_guc_ct *ct, struct
>> ct_incoming_msg **msg)
>> ctb->head = head;
>>
>> /* now update descriptor */
>> - WRITE_ONCE(desc->head, head);
>> + ct_desc_write(&ctb->desc_map, head, head);
>>
>> return available - len;
>>
>> corrupted:
>> CT_ERROR(ct, "Corrupted descriptor head=%u tail=%u status=%#x\n",
>> - desc->head, desc->tail, desc->status);
>> + ct_desc_read(&ctb->desc_map, head),
>> + ct_desc_read(&ctb->desc_map, tail),
>> + ct_desc_read(&ctb->desc_map, status));
>> ctb->broken = true;
>> return -EPIPE;
>> }
>> @@ -1211,13 +1255,13 @@ void intel_guc_ct_print_info(struct intel_guc_ct *ct,
>> drm_printf(p, "H2G Space: %u\n",
>> atomic_read(&ct->ctbs.send.space) * 4);
>> drm_printf(p, "Head: %u\n",
>> - ct->ctbs.send.desc->head);
>> + ct_desc_read(&ct->ctbs.send.desc_map, head));
>> drm_printf(p, "Tail: %u\n",
>> - ct->ctbs.send.desc->tail);
>> + ct_desc_read(&ct->ctbs.send.desc_map, tail));
>> drm_printf(p, "G2H Space: %u\n",
>> atomic_read(&ct->ctbs.recv.space) * 4);
>> drm_printf(p, "Head: %u\n",
>> - ct->ctbs.recv.desc->head);
>> + ct_desc_read(&ct->ctbs.recv.desc_map, head));
>> drm_printf(p, "Tail: %u\n",
>> - ct->ctbs.recv.desc->tail);
>> + ct_desc_read(&ct->ctbs.recv.desc_map, tail));
>> }
>> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
>> b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
>> index f709a19c7e21..867fe13fb47d 100644
>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h
>> @@ -7,6 +7,7 @@
>> #define _INTEL_GUC_CT_H_
>>
>> #include <linux/interrupt.h>
>> +#include <linux/iosys-map.h>
>> #include <linux/spinlock.h>
>> #include <linux/workqueue.h>
>> #include <linux/ktime.h>
>> @@ -32,8 +33,8 @@ struct drm_printer;
>> * holds the commands.
>> *
>> * @lock: protects access to the commands buffer and buffer descriptor
>> - * @desc: pointer to the buffer descriptor
>> - * @cmds: pointer to the commands buffer
>> + * @desc: iosys map to the buffer descriptor
>> + * @cmds: iosys map to the commands buffer
>> * @size: size of the commands buffer in dwords
>> * @resv_space: reserved space in buffer in dwords
>> * @head: local shadow copy of head in dwords
>> @@ -43,8 +44,8 @@ struct drm_printer;
>> */
>> struct intel_guc_ct_buffer {
>> spinlock_t lock;
>> - struct guc_ct_buffer_desc *desc;
>> - u32 *cmds;
>> + struct iosys_map desc_map;
>> + struct iosys_map cmds_map;
>> u32 size;
>> u32 resv_space;
>> u32 tail;
>> --
>> 2.33.0
>>
