From: Michal Wajdeczko <michal.wajdeczko@intel.com>
Date: Mon, 26 Mar 2018 19:48:18 +0000
Subject: drm/i915/guc: Add documentation for MMIO based communication
Git-commit: 4d82a174847b1b2d5e541ca7040398ac56efed7b
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
As we are going to extend our use of MMIO based communication,
try to explain its mechanics and update corresponding definitions.
v2: fix checkpatch MACRO_ARG_REUSE
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Cc: Kelvin Gardiner <kelvin.gardiner@intel.com>
Reviewed-by: Michel Thierry <michel.thierry@intel.com> #1
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180326194829.58836-2-michal.wajdeczko@intel.com
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/i915/intel_guc.c | 20 +++----
drivers/gpu/drm/i915/intel_guc_ct.c | 2
drivers/gpu/drm/i915/intel_guc_fwif.h | 88 +++++++++++++++++++++++++++-------
3 files changed, 82 insertions(+), 28 deletions(-)
--- a/drivers/gpu/drm/i915/intel_guc.c
+++ b/drivers/gpu/drm/i915/intel_guc.c
@@ -329,6 +329,9 @@ int intel_guc_send_mmio(struct intel_guc
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(HAS_GUC_CT(dev_priv) &&
*action != INTEL_GUC_ACTION_REGISTER_COMMAND_TRANSPORT_BUFFER &&
@@ -350,18 +353,15 @@ int intel_guc_send_mmio(struct intel_guc
*/
ret = __intel_wait_for_register_fw(dev_priv,
guc_send_reg(guc, 0),
- INTEL_GUC_RECV_MASK,
- INTEL_GUC_RECV_MASK,
+ INTEL_GUC_MSG_TYPE_MASK,
+ INTEL_GUC_MSG_TYPE_RESPONSE <<
+ INTEL_GUC_MSG_TYPE_SHIFT,
10, 10, &status);
- if (status != INTEL_GUC_STATUS_SUCCESS) {
- /*
- * Either the GuC explicitly returned an error (which
- * we convert to -EIO here) or no response at all was
- * received within the timeout limit (-ETIMEDOUT)
- */
- if (ret != -ETIMEDOUT)
- ret = -EIO;
+ /* If GuC explicitly returned an error, convert it to -EIO */
+ if (!ret && !INTEL_GUC_MSG_IS_RESPONSE_SUCCESS(status))
+ ret = -EIO;
+ if (ret) {
DRM_DEBUG_DRIVER("INTEL_GUC_SEND: Action 0x%X failed;"
" ret=%d status=0x%08X response=0x%08X\n",
action[0], ret, status,
--- a/drivers/gpu/drm/i915/intel_guc_ct.c
+++ b/drivers/gpu/drm/i915/intel_guc_ct.c
@@ -398,7 +398,7 @@ static int ctch_send(struct intel_guc *g
err = wait_for_response(desc, fence, status);
if (unlikely(err))
return err;
- if (*status != INTEL_GUC_STATUS_SUCCESS)
+ if (!INTEL_GUC_MSG_IS_RESPONSE_SUCCESS(*status))
return -EIO;
return 0;
}
--- a/drivers/gpu/drm/i915/intel_guc_fwif.h
+++ b/drivers/gpu/drm/i915/intel_guc_fwif.h
@@ -560,7 +560,68 @@ struct guc_shared_ctx_data {
struct guc_ctx_report preempt_ctx_report[GUC_MAX_ENGINES_NUM];
} __packed;
-/* This Action will be programmed in C180 - SOFT_SCRATCH_O_REG */
+/**
+ * DOC: 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.
+ *
+ * For Gen9+, GuC uses software scratch registers 0xC180-0xC1B8
+ *
+ * +-----------+---------+---------+---------+
+ * | MMIO[0] | MMIO[1] | ... | MMIO[n] |
+ * +-----------+---------+---------+---------+
+ * | header | optional payload |
+ * +======+====+=========+=========+=========+
+ * | 31:28|type| | | |
+ * +------+----+ | | |
+ * | 27:16|data| | | |
+ * +------+----+ | | |
+ * | 15:0|code| | | |
+ * +------+----+---------+---------+---------+
+ *
+ * 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**
+ *
+ * The following message **types** are supported:
+ *
+ * - **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.
+ *
+ * - **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.
+ */
+
+#define INTEL_GUC_MSG_TYPE_SHIFT 28
+#define INTEL_GUC_MSG_TYPE_MASK (0xF << INTEL_GUC_MSG_TYPE_SHIFT)
+#define INTEL_GUC_MSG_DATA_SHIFT 16
+#define INTEL_GUC_MSG_DATA_MASK (0xFFF << INTEL_GUC_MSG_DATA_SHIFT)
+#define INTEL_GUC_MSG_CODE_SHIFT 0
+#define INTEL_GUC_MSG_CODE_MASK (0xFFFF << INTEL_GUC_MSG_CODE_SHIFT)
+
+#define __INTEL_GUC_MSG_GET(T, m) \
+ (((m) & INTEL_GUC_MSG_ ## T ## _MASK) >> INTEL_GUC_MSG_ ## T ## _SHIFT)
+#define INTEL_GUC_MSG_TO_TYPE(m) __INTEL_GUC_MSG_GET(TYPE, m)
+#define INTEL_GUC_MSG_TO_DATA(m) __INTEL_GUC_MSG_GET(DATA, m)
+#define INTEL_GUC_MSG_TO_CODE(m) __INTEL_GUC_MSG_GET(CODE, m)
+
+enum intel_guc_msg_type {
+ INTEL_GUC_MSG_TYPE_REQUEST = 0x0,
+ INTEL_GUC_MSG_TYPE_RESPONSE = 0xF,
+};
+
+#define __INTEL_GUC_MSG_TYPE_IS(T, m) \
+ (INTEL_GUC_MSG_TO_TYPE(m) == INTEL_GUC_MSG_TYPE_ ## T)
+#define INTEL_GUC_MSG_IS_REQUEST(m) __INTEL_GUC_MSG_TYPE_IS(REQUEST, m)
+#define INTEL_GUC_MSG_IS_RESPONSE(m) __INTEL_GUC_MSG_TYPE_IS(RESPONSE, m)
+
enum intel_guc_action {
INTEL_GUC_ACTION_DEFAULT = 0x0,
INTEL_GUC_ACTION_REQUEST_PREEMPTION = 0x2,
@@ -597,24 +658,17 @@ enum intel_guc_report_status {
#define GUC_LOG_CONTROL_VERBOSITY_MASK (0xF << GUC_LOG_CONTROL_VERBOSITY_SHIFT)
#define GUC_LOG_CONTROL_DEFAULT_LOGGING (1 << 8)
-/*
- * The GuC sends its response to a command by overwriting the
- * command in SS0. The response is distinguishable from a command
- * by the fact that all the MASK bits are set. The remaining bits
- * give more detail.
- */
-#define INTEL_GUC_RECV_MASK ((u32)0xF0000000)
-#define INTEL_GUC_RECV_IS_RESPONSE(x) ((u32)(x) >= INTEL_GUC_RECV_MASK)
-#define INTEL_GUC_RECV_STATUS(x) (INTEL_GUC_RECV_MASK | (x))
-
-/* GUC will return status back to SOFT_SCRATCH_O_REG */
-enum intel_guc_status {
- INTEL_GUC_STATUS_SUCCESS = INTEL_GUC_RECV_STATUS(0x0),
- INTEL_GUC_STATUS_ALLOCATE_DOORBELL_FAIL = INTEL_GUC_RECV_STATUS(0x10),
- INTEL_GUC_STATUS_DEALLOCATE_DOORBELL_FAIL = INTEL_GUC_RECV_STATUS(0x20),
- INTEL_GUC_STATUS_GENERIC_FAIL = INTEL_GUC_RECV_STATUS(0x0000F000)
+enum intel_guc_response_status {
+ INTEL_GUC_RESPONSE_STATUS_SUCCESS = 0x0,
+ INTEL_GUC_RESPONSE_STATUS_GENERIC_FAIL = 0xF000,
};
+#define INTEL_GUC_MSG_IS_RESPONSE_SUCCESS(m) \
+ (typecheck(u32, (m)) && \
+ ((m) & (INTEL_GUC_MSG_TYPE_MASK | INTEL_GUC_MSG_CODE_MASK)) == \
+ ((INTEL_GUC_MSG_TYPE_RESPONSE << INTEL_GUC_MSG_TYPE_SHIFT) | \
+ (INTEL_GUC_RESPONSE_STATUS_SUCCESS << INTEL_GUC_MSG_CODE_SHIFT)))
+
/* This action will be programmed in C1BC - SOFT_SCRATCH_15_REG */
enum intel_guc_recv_message {
INTEL_GUC_RECV_MSG_CRASH_DUMP_POSTED = BIT(1),