[Intel-gfx] [RFC PATCH 21/97] drm/i915/guc: Update MMIO based communication
Matthew Brost
matthew.brost at intel.com
Thu May 6 19:13:35 UTC 2021
From: Michal Wajdeczko <michal.wajdeczko at intel.com>
The MMIO based Host-to-GuC communication protocol has been
updated to use unified HXG messages.
Update our intel_guc_send_mmio() function by correctly handle
BUSY, RETRY and FAILURE replies. Also update our documentation.
GuC: 55.0.0
Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
Signed-off-by: Matthew Brost <matthew.brost at intel.com>
Cc: Piotr Piórkowski <piotr.piorkowski at intel.com>
Cc: Michal Winiarski <michal.winiarski at intel.com>
---
.../gt/uc/abi/guc_communication_mmio_abi.h | 47 ++++--------
drivers/gpu/drm/i915/gt/uc/intel_guc.c | 75 ++++++++++++++-----
2 files changed, 70 insertions(+), 52 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_mmio_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_mmio_abi.h
index be066a62e9e0..fef51499386b 100644
--- a/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_mmio_abi.h
+++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_mmio_abi.h
@@ -7,44 +7,27 @@
#define _ABI_GUC_COMMUNICATION_MMIO_ABI_H
/**
- * DOC: MMIO based communication
+ * DOC: GuC MMIO based communication
*
- * The MMIO based communication between Host and GuC uses software scratch
- * registers, where first register holds data treated as message header,
- * and other registers are used to hold message payload.
+ * The MMIO based communication between Host and GuC relies on special
+ * hardware registers which format could be defined by the software
+ * (so called scratch registers).
*
- * For Gen9+, GuC uses software scratch registers 0xC180-0xC1B8,
- * but no H2G command takes more than 8 parameters and the GuC FW
- * itself uses an 8-element array to store the H2G message.
- *
- * +-----------+---------+---------+---------+
- * | MMIO[0] | MMIO[1] | ... | MMIO[n] |
- * +-----------+---------+---------+---------+
- * | header | optional payload |
- * +======+====+=========+=========+=========+
- * | 31:28|type| | | |
- * +------+----+ | | |
- * | 27:16|data| | | |
- * +------+----+ | | |
- * | 15:0|code| | | |
- * +------+----+---------+---------+---------+
+ * Each MMIO based message, both Host to GuC (H2G) and GuC to Host (G2H)
+ * messages, which maximum length depends on number of available scratch
+ * registers, is directly written into those scratch registers.
*
- * The message header consists of:
- *
- * - **type**, indicates message type
- * - **code**, indicates message code, is specific for **type**
- * - **data**, indicates message data, optional, depends on **code**
+ * For Gen9+, there are 16 software scratch registers 0xC180-0xC1B8,
+ * but no H2G command takes more than 8 parameters and the GuC firmware
+ * itself uses an 8-element array to store the H2G message.
*
- * The following message **types** are supported:
+ * For Gen11+, there are additional 4 registers 0x190240-0x19024C, which
+ * are, regardless on lower count, preffered over legacy ones.
*
- * - **REQUEST**, indicates Host-to-GuC request, requested GuC action code
- * must be priovided in **code** field. Optional action specific parameters
- * can be provided in remaining payload registers or **data** field.
+ * The MMIO based communication is mainly used during driver initialization
+ * phase to setup the CTB based communication that will be used afterwards.
*
- * - **RESPONSE**, indicates GuC-to-Host response from earlier GuC request,
- * action response status will be provided in **code** field. Optional
- * response data can be returned in remaining payload registers or **data**
- * field.
+ * Format of the MMIO messages follows definitions of `HXG Message`_.
*/
#define GUC_MAX_MMIO_MSG_LEN 8
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.c b/drivers/gpu/drm/i915/gt/uc/intel_guc.c
index ab2c8fe8cdfa..454c8d886499 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.c
@@ -385,29 +385,27 @@ void intel_guc_fini(struct intel_guc *guc)
/*
* This function implements the MMIO based host to GuC interface.
*/
-int intel_guc_send_mmio(struct intel_guc *guc, const u32 *action, u32 len,
+int intel_guc_send_mmio(struct intel_guc *guc, const u32 *request, u32 len,
u32 *response_buf, u32 response_buf_size)
{
+ struct drm_i915_private *i915 = guc_to_gt(guc)->i915;
struct intel_uncore *uncore = guc_to_gt(guc)->uncore;
- u32 status;
+ u32 header;
int i;
int ret;
GEM_BUG_ON(!len);
GEM_BUG_ON(len > guc->send_regs.count);
- /* We expect only action code */
- GEM_BUG_ON(*action & ~INTEL_GUC_MSG_CODE_MASK);
-
- /* If CT is available, we expect to use MMIO only during init/fini */
- GEM_BUG_ON(*action != INTEL_GUC_ACTION_REGISTER_COMMAND_TRANSPORT_BUFFER &&
- *action != INTEL_GUC_ACTION_DEREGISTER_COMMAND_TRANSPORT_BUFFER);
+ GEM_BUG_ON(FIELD_GET(GUC_HXG_MSG_0_ORIGIN, request[0]) != GUC_HXG_ORIGIN_HOST);
+ GEM_BUG_ON(FIELD_GET(GUC_HXG_MSG_0_TYPE, request[0]) != GUC_HXG_TYPE_REQUEST);
mutex_lock(&guc->send_mutex);
intel_uncore_forcewake_get(uncore, guc->send_regs.fw_domains);
+retry:
for (i = 0; i < len; i++)
- intel_uncore_write(uncore, guc_send_reg(guc, i), action[i]);
+ intel_uncore_write(uncore, guc_send_reg(guc, i), request[i]);
intel_uncore_posting_read(uncore, guc_send_reg(guc, i - 1));
@@ -419,17 +417,54 @@ int intel_guc_send_mmio(struct intel_guc *guc, const u32 *action, u32 len,
*/
ret = __intel_wait_for_register_fw(uncore,
guc_send_reg(guc, 0),
- INTEL_GUC_MSG_TYPE_MASK,
- INTEL_GUC_MSG_TYPE_RESPONSE <<
- INTEL_GUC_MSG_TYPE_SHIFT,
- 10, 10, &status);
- /* If GuC explicitly returned an error, convert it to -EIO */
- if (!ret && !INTEL_GUC_MSG_IS_RESPONSE_SUCCESS(status))
- ret = -EIO;
+ GUC_HXG_MSG_0_ORIGIN,
+ FIELD_PREP(GUC_HXG_MSG_0_ORIGIN,
+ GUC_HXG_ORIGIN_GUC),
+ 10, 10, &header);
+ if (unlikely(ret)) {
+timeout:
+ drm_err(&i915->drm, "mmio request %#x: no reply %x\n",
+ request[0], header);
+ goto out;
+ }
- if (ret) {
- DRM_ERROR("MMIO: GuC action %#x failed with error %d %#x\n",
- action[0], ret, status);
+ if (FIELD_GET(GUC_HXG_MSG_0_TYPE, header) == GUC_HXG_TYPE_NO_RESPONSE_BUSY) {
+#define done ({ header = intel_uncore_read(uncore, guc_send_reg(guc, 0)); \
+ FIELD_GET(GUC_HXG_MSG_0_ORIGIN, header) != GUC_HXG_ORIGIN_GUC || \
+ FIELD_GET(GUC_HXG_MSG_0_TYPE, header) != GUC_HXG_TYPE_NO_RESPONSE_BUSY; })
+
+ ret = wait_for(done, 1000);
+ if (unlikely(ret))
+ goto timeout;
+ if (unlikely(FIELD_GET(GUC_HXG_MSG_0_ORIGIN, header) !=
+ GUC_HXG_ORIGIN_GUC))
+ goto proto;
+#undef done
+ }
+
+ if (FIELD_GET(GUC_HXG_MSG_0_TYPE, header) == GUC_HXG_TYPE_NO_RESPONSE_RETRY) {
+ u32 reason = FIELD_GET(GUC_HXG_RETRY_MSG_0_REASON, header);
+
+ drm_dbg(&i915->drm, "mmio request %#x: retrying, reason %u\n",
+ request[0], reason);
+ goto retry;
+ }
+
+ if (FIELD_GET(GUC_HXG_MSG_0_TYPE, header) == GUC_HXG_TYPE_RESPONSE_FAILURE) {
+ u32 hint = FIELD_GET(GUC_HXG_FAILURE_MSG_0_HINT, header);
+ u32 error = FIELD_GET(GUC_HXG_FAILURE_MSG_0_ERROR, header);
+
+ drm_err(&i915->drm, "mmio request %#x: failure %x/%u\n",
+ request[0], error, hint);
+ ret = -ENXIO;
+ goto out;
+ }
+
+ if (FIELD_GET(GUC_HXG_MSG_0_TYPE, header) != GUC_HXG_TYPE_RESPONSE_SUCCESS) {
+proto:
+ drm_err(&i915->drm, "mmio request %#x: unexpected reply %#x\n",
+ request[0], header);
+ ret = -EPROTO;
goto out;
}
@@ -442,7 +477,7 @@ int intel_guc_send_mmio(struct intel_guc *guc, const u32 *action, u32 len,
}
/* Use data from the GuC response as our return value */
- ret = INTEL_GUC_MSG_TO_DATA(status);
+ ret = FIELD_GET(GUC_HXG_RESPONSE_MSG_0_DATA0, header);
out:
intel_uncore_forcewake_put(uncore, guc->send_regs.fw_domains);
--
2.28.0
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