GuC may return not only small data encoded in the status dword,
but can also append additional data into the response message.
We will copy this extra data into provided buffer, and use
number of received data dwords as new success return value.
v2: fix timeout and checkpatch warnings (Michal)
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx>
Cc: Oscar Mateo <oscar.mateo@xxxxxxxxx>
Cc: Michel Thierry <michel.thierry@xxxxxxxxx>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@xxxxxxxxx>
---
drivers/gpu/drm/i915/intel_guc_ct.c | 121 ++++++++++++++++++++++++++++++++----
drivers/gpu/drm/i915/intel_guc_ct.h | 5 ++
2 files changed, 115 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_guc_ct.c b/drivers/gpu/drm/i915/intel_guc_ct.c
index 235446e..3187bf2 100644
--- a/drivers/gpu/drm/i915/intel_guc_ct.c
+++ b/drivers/gpu/drm/i915/intel_guc_ct.c
@@ -24,6 +24,14 @@
#include "i915_drv.h"
#include "intel_guc_ct.h"
+struct ct_request {
+ struct list_head link;
+ u32 fence;
+ u32 status;
+ u32 response_len;
+ u32 *response_buf;
+};
+
enum { CTB_SEND = 0, CTB_RECV = 1 };
enum { CTB_OWNER_HOST = 0 };
@@ -32,6 +40,9 @@ void intel_guc_ct_init_early(struct intel_guc_ct *ct)
{
/* we're using static channel owners */
ct->host_channel.owner = CTB_OWNER_HOST;
+
+ spin_lock_init(&ct->lock);
+ INIT_LIST_HEAD(&ct->pending_requests);
}
static inline const char *guc_ct_buffer_type_to_str(u32 type)
@@ -265,7 +276,8 @@ static u32 ctch_get_next_fence(struct intel_guc_ct_channel *ctch)
static int ctb_write(struct intel_guc_ct_buffer *ctb,
const u32 *action,
u32 len /* in dwords */,
- u32 fence)
+ u32 fence,
+ bool send_response)
{
struct guc_ct_buffer_desc *desc = ctb->desc;
u32 head = desc->head / 4; /* in dwords */
@@ -301,6 +313,7 @@ static int ctb_write(struct intel_guc_ct_buffer *ctb,
*/
header = (len << GUC_CT_MSG_LEN_SHIFT) |
(GUC_CT_MSG_WRITE_FENCE_TO_DESC) |
+ (send_response ? GUC_CT_MSG_SEND_STATUS : 0) |
(action[0] << GUC_CT_MSG_ACTION_SHIFT);
cmds[tail] = header;
@@ -367,14 +380,49 @@ static int wait_for_desc_update(struct guc_ct_buffer_desc *desc,
return err;
}
+/**
+ * Wait for the Guc response.
+ * @req: pointer to pending request
+ * @status: placeholder for status
+ *
+ * We will update request status from the response message handler.
+ * Returns:
+ * 0 response received (status is valid)
+ * -ETIMEDOUT no response within hardcoded timeout
+ */
+static int wait_for_response_msg(struct ct_request *req, u32 *status)
+{
+ int err;
+
+ /*
+ * Fast commands should complete in less than 10us, so sample quickly
+ * up to that length of time, then switch to a slower sleep-wait loop.
+ * No GuC command should ever take longer than 10ms.
+ */
+#define done INTEL_GUC_RECV_IS_RESPONSE(READ_ONCE(req->status))
+ err = wait_for_us(done, 10);
+ if (err)
+ err = wait_for(done, 10);
+#undef done
+
+ if (unlikely(err))
+ DRM_ERROR("CT: fence %u err %d\n", req->fence, err);
+
+ *status = req->status;
+ return err;
+}
+
static int ctch_send(struct intel_guc *guc,
struct intel_guc_ct_channel *ctch,
const u32 *action,
u32 len,
- u32 *status)
+ u32 *status,
+ u32 *response)
{
struct intel_guc_ct_buffer *ctb = &ctch->ctbs[CTB_SEND];
struct guc_ct_buffer_desc *desc = ctb->desc;
+ struct ct_request request;
+ unsigned long flags;
u32 fence;
int err;
@@ -383,18 +431,48 @@ static int ctch_send(struct intel_guc *guc,
GEM_BUG_ON(len & ~GUC_CT_MSG_LEN_MASK);
fence = ctch_get_next_fence(ctch);
- err = ctb_write(ctb, action, len, fence);
+ request.fence = fence;
+ request.status = 0;
+ request.response_len = 0;
+ request.response_buf = response;
+
+ spin_lock_irqsave(&guc->ct.lock, flags);
+ list_add_tail(&request.link, &guc->ct.pending_requests);
+ spin_unlock_irqrestore(&guc->ct.lock, flags);
+
+ err = ctb_write(ctb, action, len, fence, !!response);
if (unlikely(err))
- return err;
+ goto unlink;
intel_guc_notify(guc);
- err = wait_for_desc_update(desc, fence, status);
+ if (response)
+ err = wait_for_response_msg(&request, status);
+ else
+ err = wait_for_desc_update(desc, fence, status);
if (unlikely(err))
- return err;
- if (INTEL_GUC_RECV_TO_STATUS(*status) != INTEL_GUC_STATUS_SUCCESS)
- return -EIO;
- return INTEL_GUC_RECV_TO_DATA(*status);
+ goto unlink;
+
+ if (INTEL_GUC_RECV_TO_STATUS(*status) != INTEL_GUC_STATUS_SUCCESS) {
+ err = -EIO;
+ goto unlink;
+ }
+
+ if (response) {
+ /* There shall be no data in the status */
+ WARN_ON(INTEL_GUC_RECV_TO_DATA(request.status));
+ err = request.response_len;
+ } else {
+ /* Return data decoded from the status dword */
+ err = INTEL_GUC_RECV_TO_DATA(*status);
+ }
+
+unlink:
+ spin_lock_irqsave(&guc->ct.lock, flags);
+ list_del(&request.link);
+ spin_unlock_irqrestore(&guc->ct.lock, flags);
+
+ return err;
}
/*
@@ -409,7 +487,7 @@ static int intel_guc_send_ct(struct intel_guc *guc, const u32 *action, u32 len,
mutex_lock(&guc->send_mutex);
- ret = ctch_send(guc, ctch, action, len, &status);
+ ret = ctch_send(guc, ctch, action, len, &status, response);
if (unlikely(ret < 0)) {
DRM_ERROR("CT: send action %#X failed; err=%d status=%#X\n",
action[0], ret, status);
@@ -488,8 +566,12 @@ static int ctb_read(struct intel_guc_ct_buffer *ctb, u32 *data)
static int guc_handle_response(struct intel_guc *guc, const u32 *msg)
{
u32 header = msg[0];
+ u32 fence = msg[1];
u32 status = msg[2];
u32 len = ct_header_get_len(header) + 1; /* total len with header */
+ struct ct_request *req;
+ bool found = false;
+ unsigned long flags;
GEM_BUG_ON(!ct_header_is_response(header));
/* Response message shall at least include header, fence and status */
@@ -502,7 +584,24 @@ static int guc_handle_response(struct intel_guc *guc, const u32 *msg)
status = INTEL_GUC_STATUS_GENERIC_FAIL;
}
- /* XXX */
+ spin_lock_irqsave(&guc->ct.lock, flags);
+ list_for_each_entry(req, &guc->ct.pending_requests, link) {
+ if (req->fence != fence) {
+ DRM_DEBUG_DRIVER("CT: request %u awaits response\n",
+ req->fence);
+ continue;
+ }
+ req->response_len = len - 3;
+ if (req->response_buf)
+ memcpy(req->response_buf, msg + 3, 4*(len - 3));
+ WRITE_ONCE(req->status, status);
+ found = true;
+ break;
+ }
+ spin_unlock_irqrestore(&guc->ct.lock, flags);
+
+ if (!found)
+ DRM_ERROR("CT: unsolicited response %*phn\n", 4*len, msg);
return 0;
}
diff --git a/drivers/gpu/drm/i915/intel_guc_ct.h b/drivers/gpu/drm/i915/intel_guc_ct.h
index 6d97f36..557c1e8 100644
--- a/drivers/gpu/drm/i915/intel_guc_ct.h
+++ b/drivers/gpu/drm/i915/intel_guc_ct.h
@@ -71,10 +71,15 @@ struct intel_guc_ct_channel {
/** Holds all command transport channels.
*
* @host_channel: main channel used by the host
+ * @lock: spin lock for pending requests list
+ * @pending_requests: list of pending requests
*/
struct intel_guc_ct {
struct intel_guc_ct_channel host_channel;
/* other channels are tbd */
+
+ spinlock_t lock;
+ struct list_head pending_requests;
};
void intel_guc_ct_init_early(struct intel_guc_ct *ct);
--
2.7.4
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