#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 };
{
/* 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 struct intel_guc *ct_to_guc(struct intel_guc_ct *ct)
static int ctb_write(struct intel_guc_ct_buffer *ctb,
const u32 *action,
u32 len /* in dwords */,
- u32 fence)
+ u32 fence,
+ bool want_response)
{
struct guc_ct_buffer_desc *desc = ctb->desc;
u32 head = desc->head / 4; /* in dwords */
*/
header = (len << GUC_CT_MSG_LEN_SHIFT) |
(GUC_CT_MSG_WRITE_FENCE_TO_DESC) |
+ (want_response ? GUC_CT_MSG_SEND_STATUS : 0) |
(action[0] << GUC_CT_MSG_ACTION_SHIFT);
cmds[tail] = header;
return err;
}
-static int ctch_send(struct intel_guc *guc,
+/**
+ * wait_for_ct_request_update - Wait for CT request state update.
+ * @req: pointer to pending request
+ * @status: placeholder for status
+ *
+ * For each sent request, Guc shall send bac CT response message.
+ * Our message handler will update status of tracked request once
+ * response message with given fence is received. Wait here and
+ * check for valid response status value.
+ *
+ * Return:
+ * * 0 response received (status is valid)
+ * * -ETIMEDOUT no response within hardcoded timeout
+ */
+static int wait_for_ct_request_update(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_MSG_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_ct *ct,
struct intel_guc_ct_channel *ctch,
const u32 *action,
u32 len,
+ u32 *response_buf,
+ u32 response_buf_size,
u32 *status)
{
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;
GEM_BUG_ON(!ctch_is_open(ctch));
GEM_BUG_ON(!len);
GEM_BUG_ON(len & ~GUC_CT_MSG_LEN_MASK);
+ GEM_BUG_ON(!response_buf && response_buf_size);
fence = ctch_get_next_fence(ctch);
- err = ctb_write(ctb, action, len, fence);
+ request.fence = fence;
+ request.status = 0;
+ request.response_len = response_buf_size;
+ request.response_buf = response_buf;
+
+ spin_lock_irqsave(&ct->lock, flags);
+ list_add_tail(&request.link, &ct->pending_requests);
+ spin_unlock_irqrestore(&ct->lock, flags);
+
+ err = ctb_write(ctb, action, len, fence, !!response_buf);
if (unlikely(err))
- return err;
+ goto unlink;
- intel_guc_notify(guc);
+ intel_guc_notify(ct_to_guc(ct));
- err = wait_for_ctb_desc_update(desc, fence, status);
+ if (response_buf)
+ err = wait_for_ct_request_update(&request, status);
+ else
+ err = wait_for_ctb_desc_update(desc, fence, status);
if (unlikely(err))
- return err;
- if (!INTEL_GUC_MSG_IS_RESPONSE_SUCCESS(*status))
- return -EIO;
+ goto unlink;
+
+ if (!INTEL_GUC_MSG_IS_RESPONSE_SUCCESS(*status)) {
+ err = -EIO;
+ goto unlink;
+ }
+
+ if (response_buf) {
+ /* There shall be no data in the status */
+ WARN_ON(INTEL_GUC_MSG_TO_DATA(request.status));
+ /* Return actual response len */
+ err = request.response_len;
+ } else {
+ /* There shall be no response payload */
+ WARN_ON(request.response_len);
+ /* Return data decoded from the status dword */
+ err = INTEL_GUC_MSG_TO_DATA(*status);
+ }
- /* Use data from the GuC status as our return value */
- return INTEL_GUC_MSG_TO_DATA(*status);
+unlink:
+ spin_lock_irqsave(&ct->lock, flags);
+ list_del(&request.link);
+ spin_unlock_irqrestore(&ct->lock, flags);
+
+ return err;
}
/*
static int intel_guc_send_ct(struct intel_guc *guc, const u32 *action, u32 len,
u32 *response_buf, u32 response_buf_size)
{
- struct intel_guc_ct_channel *ctch = &guc->ct.host_channel;
+ struct intel_guc_ct *ct = &guc->ct;
+ struct intel_guc_ct_channel *ctch = &ct->host_channel;
u32 status = ~0; /* undefined */
int ret;
mutex_lock(&guc->send_mutex);
- ret = ctch_send(guc, ctch, action, len, &status);
+ ret = ctch_send(ct, ctch, action, len, response_buf, response_buf_size,
+ &status);
if (unlikely(ret < 0)) {
DRM_ERROR("CT: send action %#X failed; err=%d status=%#X\n",
action[0], ret, status);
u32 msglen = len + 1; /* total message length including header */
u32 fence;
u32 status;
+ u32 datalen;
+ struct ct_request *req;
+ bool found = false;
GEM_BUG_ON(!ct_header_is_response(header));
+ GEM_BUG_ON(!in_irq());
/* Response payload shall at least include fence and status */
if (unlikely(len < 2)) {
fence = msg[1];
status = msg[2];
+ datalen = len - 2;
/* Format of the status follows RESPONSE message */
if (unlikely(!INTEL_GUC_MSG_IS_RESPONSE(status))) {
return -EPROTO;
}
- /* XXX */
+ spin_lock(&ct->lock);
+ list_for_each_entry(req, &ct->pending_requests, link) {
+ if (unlikely(fence != req->fence)) {
+ DRM_DEBUG_DRIVER("CT: request %u awaits response\n",
+ req->fence);
+ continue;
+ }
+ if (unlikely(datalen > req->response_len)) {
+ DRM_ERROR("CT: response %u too long %*phn\n",
+ req->fence, 4 * msglen, msg);
+ datalen = 0;
+ }
+ if (datalen)
+ memcpy(req->response_buf, msg + 3, 4 * datalen);
+ req->response_len = datalen;
+ WRITE_ONCE(req->status, status);
+ found = true;
+ break;
+ }
+ spin_unlock(&ct->lock);
+
+ if (!found)
+ DRM_ERROR("CT: unsolicited response %*phn\n", 4 * msglen, msg);
return 0;
}
u64 desc_private;
} __packed;
+/**
+ * DOC: CTB based communication
+ *
+ * The CTB (command transport buffer) communication between Host and GuC
+ * is based on u32 data stream written to the shared buffer. One buffer can
+ * be used to transmit data only in one direction (one-directional channel).
+ *
+ * Current status of the each buffer is stored in the buffer descriptor.
+ * Buffer descriptor holds tail and head fields that represents active data
+ * stream. The tail field is updated by the data producer (sender), and head
+ * field is updated by the data consumer (receiver)::
+ *
+ * +------------+
+ * | DESCRIPTOR | +=================+============+========+
+ * +============+ | | MESSAGE(s) | |
+ * | address |--------->+=================+============+========+
+ * +------------+
+ * | head | ^-----head--------^
+ * +------------+
+ * | tail | ^---------tail-----------------^
+ * +------------+
+ * | size | ^---------------size--------------------^
+ * +------------+
+ *
+ * Each message in data stream starts with the single u32 treated as a header,
+ * followed by optional set of u32 data that makes message specific payload::
+ *
+ * +------------+---------+---------+---------+
+ * | MESSAGE |
+ * +------------+---------+---------+---------+
+ * | msg[0] | [1] | ... | [n-1] |
+ * +------------+---------+---------+---------+
+ * | MESSAGE | MESSAGE PAYLOAD |
+ * + HEADER +---------+---------+---------+
+ * | | 0 | ... | n |
+ * +======+=====+=========+=========+=========+
+ * | 31:16| code| | | |
+ * +------+-----+ | | |
+ * | 15:5|flags| | | |
+ * +------+-----+ | | |
+ * | 4:0| len| | | |
+ * +------+-----+---------+---------+---------+
+ *
+ * ^-------------len-------------^
+ *
+ * The message header consists of:
+ *
+ * - **len**, indicates length of the message payload (in u32)
+ * - **code**, indicates message code
+ * - **flags**, holds various bits to control message handling
+ */
+
/*
* Describes single command transport buffer.
* Used by both guc-master and clients.
projects / mirror_ubuntu-eoan-kernel.git / commitdiff