drm/i915/guc: Add fetch of hwconfig blob

Implement support for fetching the hardware description table from the
GuC. The call is made twice - once without a destination buffer to
query the size and then a second time to fill in the buffer.

The table is stored in the GT structure so that it can be fetched once
at driver load time. Keeping inside a GuC structure would mean it
would be release and reloaded on a GuC reset (part of a full GT
reset). However, the table does not change just because the GT has been
reset and the GuC reloaded. Also, dynamic memory allocations inside
the reset path are a problem.

Note that the table is only available on ADL-P and later platforms.

v2 (John's v2 patch):
 * Move to GT level to avoid memory allocation during reset path (and
   unnecessary re-read of the table on a reset).

v5 (of Jordan's posting):
 * Various changes made by Jordan and recommended by Michal
   - Makefile ordering
   - Adjust "struct intel_guc_hwconfig hwconfig" comment
   - Set Copyright year to 2022 in intel_guc_hwconfig.c/.h
   - Drop inline from hwconfig_to_guc()
   - Replace hwconfig param with guc in __guc_action_get_hwconfig()
   - Move zero size check into guc_hwconfig_discover_size()
   - Change comment to say zero size offset/size is needed to get size
   - Add has_guc_hwconfig to devinfo and drop has_table()
   - Change drm_err to notice in __uc_init_hw() and use %pe

v6 (of Jordan's posting):
 * Added a couple more small changes recommended by Michal
 * Merge in John's v2 patch, but note:
   - Using drm_notice as recommended by Michal
   - Reverted Michal's suggestion of using devinfo

v7 (of Jordan's posting):
 * Change back to drm_err as preferred by John

Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Acked-by: Jon Bloomfield <jon.bloomfield@intel.com>
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220306232157.1174335-2-jordan.l.justen@intel.com

drivers/gpu/drm/i915/Makefile

@@ -187,6 +187,7 @@ i915-y += gt/uc/intel_uc.o \
 	  gt/uc/intel_guc_ct.o \
 	  gt/uc/intel_guc_debugfs.o \
 	  gt/uc/intel_guc_fw.o \
+	  gt/uc/intel_guc_hwconfig.o \
 	  gt/uc/intel_guc_log.o \
 	  gt/uc/intel_guc_log_debugfs.o \
 	  gt/uc/intel_guc_rc.o \

drivers/gpu/drm/i915/gt/intel_gt.c

@@ -718,6 +718,11 @@ int intel_gt_init(struct intel_gt *gt)
 	if (err)
 		goto err_uc_init;
 
+	err = intel_gt_init_hwconfig(gt);
+	if (err)
+		drm_err(&gt->i915->drm, "Failed to retrieve hwconfig table: %pe\n",
+			ERR_PTR(err));
+
 	err = __engines_record_defaults(gt);
 	if (err)
 		goto err_gt;
@@ -799,6 +804,7 @@ void intel_gt_driver_release(struct intel_gt *gt)
 	intel_gt_pm_fini(gt);
 	intel_gt_fini_scratch(gt);
 	intel_gt_fini_buffer_pool(gt);
+	intel_gt_fini_hwconfig(gt);
 }
 
 void intel_gt_driver_late_release(struct intel_gt *gt)

drivers/gpu/drm/i915/gt/intel_gt_types.h

@@ -20,6 +20,7 @@
 #include "i915_vma.h"
 #include "intel_engine_types.h"
 #include "intel_gt_buffer_pool_types.h"
+#include "intel_hwconfig.h"
 #include "intel_llc_types.h"
 #include "intel_reset_types.h"
 #include "intel_rc6_types.h"
@@ -204,6 +205,9 @@ struct intel_gt {
 		struct sseu_dev_info sseu;
 
 		unsigned long mslice_mask;
+
+		/** @hwconfig: hardware configuration data */
+		struct intel_hwconfig hwconfig;
 	} info;
 
 	struct {

drivers/gpu/drm/i915/gt/intel_hwconfig.h

@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#ifndef _INTEL_HWCONFIG_H_
+#define _INTEL_HWCONFIG_H_
+
+#include <linux/types.h>
+
+struct intel_gt;
+
+struct intel_hwconfig {
+	u32 size;
+	void *ptr;
+};
+
+int intel_gt_init_hwconfig(struct intel_gt *gt);
+void intel_gt_fini_hwconfig(struct intel_gt *gt);
+
+#endif /* _INTEL_HWCONFIG_H_ */

drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h

@@ -129,6 +129,7 @@ enum intel_guc_action {
 	INTEL_GUC_ACTION_ENGINE_FAILURE_NOTIFICATION = 0x1009,
 	INTEL_GUC_ACTION_SETUP_PC_GUCRC = 0x3004,
 	INTEL_GUC_ACTION_AUTHENTICATE_HUC = 0x4000,
+	INTEL_GUC_ACTION_GET_HWCONFIG = 0x4100,
 	INTEL_GUC_ACTION_REGISTER_CONTEXT = 0x4502,
 	INTEL_GUC_ACTION_DEREGISTER_CONTEXT = 0x4503,
 	INTEL_GUC_ACTION_DEREGISTER_CONTEXT_DONE = 0x4600,

drivers/gpu/drm/i915/gt/uc/abi/guc_errors_abi.h

@@ -8,6 +8,10 @@
 
 enum intel_guc_response_status {
 	INTEL_GUC_RESPONSE_STATUS_SUCCESS = 0x0,
+	INTEL_GUC_RESPONSE_NOT_SUPPORTED = 0x20,
+	INTEL_GUC_RESPONSE_NO_ATTRIBUTE_TABLE = 0x201,
+	INTEL_GUC_RESPONSE_NO_DECRYPTION_KEY = 0x202,
+	INTEL_GUC_RESPONSE_DECRYPTION_FAILED = 0x204,
 	INTEL_GUC_RESPONSE_STATUS_GENERIC_FAIL = 0xF000,
 };
 

drivers/gpu/drm/i915/gt/uc/intel_guc_hwconfig.c

@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#include "gt/intel_gt.h"
+#include "gt/intel_hwconfig.h"
+#include "i915_drv.h"
+#include "i915_memcpy.h"
+
+/*
+ * GuC has a blob containing hardware configuration information (HWConfig).
+ * This is formatted as a simple and flexible KLV (Key/Length/Value) table.
+ *
+ * For example, a minimal version could be:
+ *   enum device_attr {
+ *     ATTR_SOME_VALUE = 0,
+ *     ATTR_SOME_MASK  = 1,
+ *   };
+ *
+ *   static const u32 hwconfig[] = {
+ *     ATTR_SOME_VALUE,
+ *     1,		// Value Length in DWords
+ *     8,		// Value
+ *
+ *     ATTR_SOME_MASK,
+ *     3,
+ *     0x00FFFFFFFF, 0xFFFFFFFF, 0xFF000000,
+ *   };
+ *
+ * The attribute ids are defined in a hardware spec.
+ */
+
+static int __guc_action_get_hwconfig(struct intel_guc *guc,
+				     u32 ggtt_offset, u32 ggtt_size)
+{
+	u32 action[] = {
+		INTEL_GUC_ACTION_GET_HWCONFIG,
+		lower_32_bits(ggtt_offset),
+		upper_32_bits(ggtt_offset),
+		ggtt_size,
+	};
+	int ret;
+
+	ret = intel_guc_send_mmio(guc, action, ARRAY_SIZE(action), NULL, 0);
+	if (ret == -ENXIO)
+		return -ENOENT;
+
+	return ret;
+}
+
+static int guc_hwconfig_discover_size(struct intel_guc *guc, struct intel_hwconfig *hwconfig)
+{
+	int ret;
+
+	/*
+	 * Sending a query with zero offset and size will return the
+	 * size of the blob.
+	 */
+	ret = __guc_action_get_hwconfig(guc, 0, 0);
+	if (ret < 0)
+		return ret;
+
+	if (ret == 0)
+		return -EINVAL;
+
+	hwconfig->size = ret;
+	return 0;
+}
+
+static int guc_hwconfig_fill_buffer(struct intel_guc *guc, struct intel_hwconfig *hwconfig)
+{
+	struct i915_vma *vma;
+	u32 ggtt_offset;
+	void *vaddr;
+	int ret;
+
+	GEM_BUG_ON(!hwconfig->size);
+
+	ret = intel_guc_allocate_and_map_vma(guc, hwconfig->size, &vma, &vaddr);
+	if (ret)
+		return ret;
+
+	ggtt_offset = intel_guc_ggtt_offset(guc, vma);
+
+	ret = __guc_action_get_hwconfig(guc, ggtt_offset, hwconfig->size);
+	if (ret >= 0)
+		memcpy(hwconfig->ptr, vaddr, hwconfig->size);
+
+	i915_vma_unpin_and_release(&vma, I915_VMA_RELEASE_MAP);
+
+	return ret;
+}
+
+static bool has_table(struct drm_i915_private *i915)
+{
+	if (IS_ALDERLAKE_P(i915))
+		return true;
+
+	return false;
+}
+
+/**
+ * intel_guc_hwconfig_init - Initialize the HWConfig
+ *
+ * Retrieve the HWConfig table from the GuC and save it locally.
+ * It can then be queried on demand by other users later on.
+ */
+static int guc_hwconfig_init(struct intel_gt *gt)
+{
+	struct intel_hwconfig *hwconfig = &gt->info.hwconfig;
+	struct intel_guc *guc = &gt->uc.guc;
+	int ret;
+
+	if (!has_table(gt->i915))
+		return 0;
+
+	ret = guc_hwconfig_discover_size(guc, hwconfig);
+	if (ret)
+		return ret;
+
+	hwconfig->ptr = kmalloc(hwconfig->size, GFP_KERNEL);
+	if (!hwconfig->ptr) {
+		hwconfig->size = 0;
+		return -ENOMEM;
+	}
+
+	ret = guc_hwconfig_fill_buffer(guc, hwconfig);
+	if (ret < 0) {
+		intel_gt_fini_hwconfig(gt);
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * intel_gt_init_hwconfig - Initialize the HWConfig if available
+ *
+ * Retrieve the HWConfig table if available on the current platform.
+ */
+int intel_gt_init_hwconfig(struct intel_gt *gt)
+{
+	if (!intel_uc_uses_guc(&gt->uc))
+		return 0;
+
+	return guc_hwconfig_init(gt);
+}
+
+/**
+ * intel_gt_fini_hwconfig - Finalize the HWConfig
+ *
+ * Free up the memory allocation holding the table.
+ */
+void intel_gt_fini_hwconfig(struct intel_gt *gt)
+{
+	struct intel_hwconfig *hwconfig = &gt->info.hwconfig;
+
+	kfree(hwconfig->ptr);
+	hwconfig->size = 0;
+	hwconfig->ptr = NULL;
+}