drm/i915/guc: Make GuC log sizes runtime configurable

The GuC log buffer sizes had to be configured statically at compile
time. This can be quite troublesome when needing to get larger logs
out of a released driver. So re-organise the code to allow a boot time
module parameter override.
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220728022028.2190627-7-John.C.Harrison@Intel.com

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

@@ -224,53 +224,22 @@ static u32 guc_ctl_feature_flags(struct intel_guc *guc)
 
 static u32 guc_ctl_log_params_flags(struct intel_guc *guc)
 {
-	u32 offset = intel_guc_ggtt_offset(guc, guc->log.vma) >> PAGE_SHIFT;
-	u32 flags;
-
-	#if (((CRASH_BUFFER_SIZE) % SZ_1M) == 0)
-	#define LOG_UNIT SZ_1M
-	#define LOG_FLAG GUC_LOG_LOG_ALLOC_UNITS
-	#else
-	#define LOG_UNIT SZ_4K
-	#define LOG_FLAG 0
-	#endif
-
-	#if (((CAPTURE_BUFFER_SIZE) % SZ_1M) == 0)
-	#define CAPTURE_UNIT SZ_1M
-	#define CAPTURE_FLAG GUC_LOG_CAPTURE_ALLOC_UNITS
-	#else
-	#define CAPTURE_UNIT SZ_4K
-	#define CAPTURE_FLAG 0
-	#endif
-
-	BUILD_BUG_ON(!CRASH_BUFFER_SIZE);
-	BUILD_BUG_ON(!IS_ALIGNED(CRASH_BUFFER_SIZE, LOG_UNIT));
-	BUILD_BUG_ON(!DEBUG_BUFFER_SIZE);
-	BUILD_BUG_ON(!IS_ALIGNED(DEBUG_BUFFER_SIZE, LOG_UNIT));
-	BUILD_BUG_ON(!CAPTURE_BUFFER_SIZE);
-	BUILD_BUG_ON(!IS_ALIGNED(CAPTURE_BUFFER_SIZE, CAPTURE_UNIT));
-
-	BUILD_BUG_ON((CRASH_BUFFER_SIZE / LOG_UNIT - 1) >
-			(GUC_LOG_CRASH_MASK >> GUC_LOG_CRASH_SHIFT));
-	BUILD_BUG_ON((DEBUG_BUFFER_SIZE / LOG_UNIT - 1) >
-			(GUC_LOG_DEBUG_MASK >> GUC_LOG_DEBUG_SHIFT));
-	BUILD_BUG_ON((CAPTURE_BUFFER_SIZE / CAPTURE_UNIT - 1) >
-			(GUC_LOG_CAPTURE_MASK >> GUC_LOG_CAPTURE_SHIFT));
+	struct intel_guc_log *log = &guc->log;
+	u32 offset, flags;
+
+	GEM_BUG_ON(!log->sizes_initialised);
+
+	offset = intel_guc_ggtt_offset(guc, log->vma) >> PAGE_SHIFT;
 
 	flags = GUC_LOG_VALID |
 		GUC_LOG_NOTIFY_ON_HALF_FULL |
-		CAPTURE_FLAG |
-		LOG_FLAG |
-		((CRASH_BUFFER_SIZE / LOG_UNIT - 1) << GUC_LOG_CRASH_SHIFT) |
-		((DEBUG_BUFFER_SIZE / LOG_UNIT - 1) << GUC_LOG_DEBUG_SHIFT) |
-		((CAPTURE_BUFFER_SIZE / CAPTURE_UNIT - 1) << GUC_LOG_CAPTURE_SHIFT) |
+		log->sizes[GUC_LOG_SECTIONS_DEBUG].flag |
+		log->sizes[GUC_LOG_SECTIONS_CAPTURE].flag |
+		(log->sizes[GUC_LOG_SECTIONS_CRASH].count << GUC_LOG_CRASH_SHIFT) |
+		(log->sizes[GUC_LOG_SECTIONS_DEBUG].count << GUC_LOG_DEBUG_SHIFT) |
+		(log->sizes[GUC_LOG_SECTIONS_CAPTURE].count << GUC_LOG_CAPTURE_SHIFT) |
 		(offset << GUC_LOG_BUF_ADDR_SHIFT);
 
-	#undef LOG_UNIT
-	#undef LOG_FLAG
-	#undef CAPTURE_UNIT
-	#undef CAPTURE_FLAG
-
 	return flags;
 }
 

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

@@ -656,16 +656,17 @@ static void check_guc_capture_size(struct intel_guc *guc)
 	struct drm_i915_private *i915 = guc_to_gt(guc)->i915;
 	int min_size = guc_capture_output_min_size_est(guc);
 	int spare_size = min_size * GUC_CAPTURE_OVERBUFFER_MULTIPLIER;
+	u32 buffer_size = intel_guc_log_section_size_capture(&guc->log);
 
 	if (min_size < 0)
 		drm_warn(&i915->drm, "Failed to calculate GuC error state capture buffer minimum size: %d!\n",
 			 min_size);
-	else if (min_size > CAPTURE_BUFFER_SIZE)
+	else if (min_size > buffer_size)
 		drm_warn(&i915->drm, "GuC error state capture buffer is too small: %d < %d\n",
-			 CAPTURE_BUFFER_SIZE, min_size);
-	else if (spare_size > CAPTURE_BUFFER_SIZE)
+			 buffer_size, min_size);
+	else if (spare_size > buffer_size)
 		drm_notice(&i915->drm, "GuC error state capture buffer maybe too small: %d < %d (min = %d)\n",
-			   CAPTURE_BUFFER_SIZE, spare_size, min_size);
+			   buffer_size, spare_size, min_size);
 }
 
 /*
@@ -1294,7 +1295,8 @@ static void __guc_capture_process_output(struct intel_guc *guc)
 
 	log_buf_state = guc->log.buf_addr +
 			(sizeof(struct guc_log_buffer_state) * GUC_CAPTURE_LOG_BUFFER);
-	src_data = guc->log.buf_addr + intel_guc_get_log_buffer_offset(GUC_CAPTURE_LOG_BUFFER);
+	src_data = guc->log.buf_addr +
+		   intel_guc_get_log_buffer_offset(&guc->log, GUC_CAPTURE_LOG_BUFFER);
 
 	/*
 	 * Make a copy of the state structure, inside GuC log buffer
@@ -1302,7 +1304,7 @@ static void __guc_capture_process_output(struct intel_guc *guc)
 	 * from it multiple times.
 	 */
 	memcpy(&log_buf_state_local, log_buf_state, sizeof(struct guc_log_buffer_state));
-	buffer_size = intel_guc_get_log_buffer_size(GUC_CAPTURE_LOG_BUFFER);
+	buffer_size = intel_guc_get_log_buffer_size(&guc->log, GUC_CAPTURE_LOG_BUFFER);
 	read_offset = log_buf_state_local.read_ptr;
 	write_offset = log_buf_state_local.sampled_write_ptr;
 	full_count = log_buf_state_local.buffer_full_cnt;

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

@@ -13,8 +13,158 @@
 #include "intel_guc_capture.h"
 #include "intel_guc_log.h"
 
+#if defined(CONFIG_DRM_I915_DEBUG_GUC)
+#define GUC_LOG_DEFAULT_CRASH_BUFFER_SIZE	SZ_2M
+#define GUC_LOG_DEFAULT_DEBUG_BUFFER_SIZE	SZ_16M
+#define GUC_LOG_DEFAULT_CAPTURE_BUFFER_SIZE	SZ_4M
+#elif defined(CONFIG_DRM_I915_DEBUG_GEM)
+#define GUC_LOG_DEFAULT_CRASH_BUFFER_SIZE	SZ_1M
+#define GUC_LOG_DEFAULT_DEBUG_BUFFER_SIZE	SZ_2M
+#define GUC_LOG_DEFAULT_CAPTURE_BUFFER_SIZE	SZ_4M
+#else
+#define GUC_LOG_DEFAULT_CRASH_BUFFER_SIZE	SZ_8K
+#define GUC_LOG_DEFAULT_DEBUG_BUFFER_SIZE	SZ_64K
+#define GUC_LOG_DEFAULT_CAPTURE_BUFFER_SIZE	SZ_2M
+#endif
+
 static void guc_log_copy_debuglogs_for_relay(struct intel_guc_log *log);
 
+struct guc_log_section {
+	u32 max;
+	u32 flag;
+	u32 default_val;
+	const char *name;
+};
+
+static s32 scale_log_param(struct intel_guc_log *log, const struct guc_log_section *section,
+			   s32 param)
+{
+	/* -1 means default */
+	if (param < 0)
+		return section->default_val;
+
+	/* Check for 32-bit overflow */
+	if (param >= SZ_4K) {
+		drm_err(&guc_to_gt(log_to_guc(log))->i915->drm, "Size too large for GuC %s log: %dMB!",
+			section->name, param);
+		return section->default_val;
+	}
+
+	/* Param units are 1MB */
+	return param * SZ_1M;
+}
+
+static void _guc_log_init_sizes(struct intel_guc_log *log)
+{
+	struct intel_guc *guc = log_to_guc(log);
+	struct drm_i915_private *i915 = guc_to_gt(guc)->i915;
+	static const struct guc_log_section sections[GUC_LOG_SECTIONS_LIMIT] = {
+		{
+			GUC_LOG_CRASH_MASK >> GUC_LOG_CRASH_SHIFT,
+			GUC_LOG_LOG_ALLOC_UNITS,
+			GUC_LOG_DEFAULT_CRASH_BUFFER_SIZE,
+			"crash dump"
+		},
+		{
+			GUC_LOG_DEBUG_MASK >> GUC_LOG_DEBUG_SHIFT,
+			GUC_LOG_LOG_ALLOC_UNITS,
+			GUC_LOG_DEFAULT_DEBUG_BUFFER_SIZE,
+			"debug",
+		},
+		{
+			GUC_LOG_CAPTURE_MASK >> GUC_LOG_CAPTURE_SHIFT,
+			GUC_LOG_CAPTURE_ALLOC_UNITS,
+			GUC_LOG_DEFAULT_CAPTURE_BUFFER_SIZE,
+			"capture",
+		}
+	};
+	s32 params[GUC_LOG_SECTIONS_LIMIT] = {
+		i915->params.guc_log_size_crash,
+		i915->params.guc_log_size_debug,
+		i915->params.guc_log_size_capture,
+	};
+	int i;
+
+	for (i = 0; i < GUC_LOG_SECTIONS_LIMIT; i++)
+		log->sizes[i].bytes = scale_log_param(log, sections + i, params[i]);
+
+	/* If debug size > 1MB then bump default crash size to keep the same units */
+	if (log->sizes[GUC_LOG_SECTIONS_DEBUG].bytes >= SZ_1M &&
+	    (i915->params.guc_log_size_crash == -1) &&
+	    GUC_LOG_DEFAULT_CRASH_BUFFER_SIZE < SZ_1M)
+		log->sizes[GUC_LOG_SECTIONS_CRASH].bytes = SZ_1M;
+
+	/* Prepare the GuC API structure fields: */
+	for (i = 0; i < GUC_LOG_SECTIONS_LIMIT; i++) {
+		/* Convert to correct units */
+		if ((log->sizes[i].bytes % SZ_1M) == 0) {
+			log->sizes[i].units = SZ_1M;
+			log->sizes[i].flag = sections[i].flag;
+		} else {
+			log->sizes[i].units = SZ_4K;
+			log->sizes[i].flag = 0;
+		}
+
+		if (!IS_ALIGNED(log->sizes[i].bytes, log->sizes[i].units))
+			drm_err(&i915->drm, "Mis-aligned GuC log %s size: 0x%X vs 0x%X!",
+				sections[i].name, log->sizes[i].bytes, log->sizes[i].units);
+		log->sizes[i].count = log->sizes[i].bytes / log->sizes[i].units;
+
+		if (!log->sizes[i].count) {
+			drm_err(&i915->drm, "Zero GuC log %s size!", sections[i].name);
+		} else {
+			/* Size is +1 unit */
+			log->sizes[i].count--;
+		}
+
+		/* Clip to field size */
+		if (log->sizes[i].count > sections[i].max) {
+			drm_err(&i915->drm, "GuC log %s size too large: %d vs %d!",
+				sections[i].name, log->sizes[i].count + 1, sections[i].max + 1);
+			log->sizes[i].count = sections[i].max;
+		}
+	}
+
+	if (log->sizes[GUC_LOG_SECTIONS_CRASH].units != log->sizes[GUC_LOG_SECTIONS_DEBUG].units) {
+		drm_err(&i915->drm, "Unit mis-match for GuC log crash and debug sections: %d vs %d!",
+			log->sizes[GUC_LOG_SECTIONS_CRASH].units,
+			log->sizes[GUC_LOG_SECTIONS_DEBUG].units);
+		log->sizes[GUC_LOG_SECTIONS_CRASH].units = log->sizes[GUC_LOG_SECTIONS_DEBUG].units;
+		log->sizes[GUC_LOG_SECTIONS_CRASH].count = 0;
+	}
+
+	log->sizes_initialised = true;
+}
+
+static void guc_log_init_sizes(struct intel_guc_log *log)
+{
+	if (log->sizes_initialised)
+		return;
+
+	_guc_log_init_sizes(log);
+}
+
+static u32 intel_guc_log_section_size_crash(struct intel_guc_log *log)
+{
+	guc_log_init_sizes(log);
+
+	return log->sizes[GUC_LOG_SECTIONS_CRASH].bytes;
+}
+
+static u32 intel_guc_log_section_size_debug(struct intel_guc_log *log)
+{
+	guc_log_init_sizes(log);
+
+	return log->sizes[GUC_LOG_SECTIONS_DEBUG].bytes;
+}
+
+u32 intel_guc_log_section_size_capture(struct intel_guc_log *log)
+{
+	guc_log_init_sizes(log);
+
+	return log->sizes[GUC_LOG_SECTIONS_CAPTURE].bytes;
+}
+
 static u32 intel_guc_log_size(struct intel_guc_log *log)
 {
 	/*
@@ -38,7 +188,10 @@ static u32 intel_guc_log_size(struct intel_guc_log *log)
 	 *  |         Capture logs          |
 	 *  +===============================+ + CAPTURE_SIZE
 	 */
-	return PAGE_SIZE + CRASH_BUFFER_SIZE + DEBUG_BUFFER_SIZE + CAPTURE_BUFFER_SIZE;
+	return PAGE_SIZE +
+		intel_guc_log_section_size_crash(log) +
+		intel_guc_log_section_size_debug(log) +
+		intel_guc_log_section_size_capture(log);
 }
 
 /**
@@ -165,7 +318,8 @@ static void guc_move_to_next_buf(struct intel_guc_log *log)
 	smp_wmb();
 
 	/* All data has been written, so now move the offset of sub buffer. */
-	relay_reserve(log->relay.channel, log->vma->obj->base.size - CAPTURE_BUFFER_SIZE);
+	relay_reserve(log->relay.channel, log->vma->obj->base.size -
+					  intel_guc_log_section_size_capture(log));
 
 	/* Switch to the next sub buffer */
 	relay_flush(log->relay.channel);
@@ -210,15 +364,16 @@ bool intel_guc_check_log_buf_overflow(struct intel_guc_log *log,
 	return overflow;
 }
 
-unsigned int intel_guc_get_log_buffer_size(enum guc_log_buffer_type type)
+unsigned int intel_guc_get_log_buffer_size(struct intel_guc_log *log,
+					   enum guc_log_buffer_type type)
 {
 	switch (type) {
 	case GUC_DEBUG_LOG_BUFFER:
-		return DEBUG_BUFFER_SIZE;
+		return intel_guc_log_section_size_debug(log);
 	case GUC_CRASH_DUMP_LOG_BUFFER:
-		return CRASH_BUFFER_SIZE;
+		return intel_guc_log_section_size_crash(log);
 	case GUC_CAPTURE_LOG_BUFFER:
-		return CAPTURE_BUFFER_SIZE;
+		return intel_guc_log_section_size_capture(log);
 	default:
 		MISSING_CASE(type);
 	}
@@ -226,7 +381,8 @@ unsigned int intel_guc_get_log_buffer_size(enum guc_log_buffer_type type)
 	return 0;
 }
 
-size_t intel_guc_get_log_buffer_offset(enum guc_log_buffer_type type)
+size_t intel_guc_get_log_buffer_offset(struct intel_guc_log *log,
+				       enum guc_log_buffer_type type)
 {
 	enum guc_log_buffer_type i;
 	size_t offset = PAGE_SIZE;/* for the log_buffer_states */
@@ -234,7 +390,7 @@ size_t intel_guc_get_log_buffer_offset(enum guc_log_buffer_type type)
 	for (i = GUC_DEBUG_LOG_BUFFER; i < GUC_MAX_LOG_BUFFER; ++i) {
 		if (i == type)
 			break;
-		offset += intel_guc_get_log_buffer_size(i);
+		offset += intel_guc_get_log_buffer_size(log, i);
 	}
 
 	return offset;
@@ -285,7 +441,7 @@ static void _guc_log_copy_debuglogs_for_relay(struct intel_guc_log *log)
 		 */
 		memcpy(&log_buf_state_local, log_buf_state,
 		       sizeof(struct guc_log_buffer_state));
-		buffer_size = intel_guc_get_log_buffer_size(type);
+		buffer_size = intel_guc_get_log_buffer_size(log, type);
 		read_offset = log_buf_state_local.read_ptr;
 		write_offset = log_buf_state_local.sampled_write_ptr;
 		full_cnt = log_buf_state_local.buffer_full_cnt;
@@ -400,7 +556,7 @@ static int guc_log_relay_create(struct intel_guc_log *log)
 	  * Keep the size of sub buffers same as shared log buffer
 	  * but GuC log-events excludes the error-state-capture logs
 	  */
-	subbuf_size = log->vma->size - CAPTURE_BUFFER_SIZE;
+	subbuf_size = log->vma->size - intel_guc_log_section_size_capture(log);
 
 	/*
 	 * Store up to 8 snapshots, which is large enough to buffer sufficient

drivers/gpu/drm/i915/gt/uc/intel_guc_log.h

@@ -15,20 +15,6 @@
 
 struct intel_guc;
 
-#if defined(CONFIG_DRM_I915_DEBUG_GUC)
-#define CRASH_BUFFER_SIZE	SZ_2M
-#define DEBUG_BUFFER_SIZE	SZ_16M
-#define CAPTURE_BUFFER_SIZE	SZ_4M
-#elif defined(CONFIG_DRM_I915_DEBUG_GEM)
-#define CRASH_BUFFER_SIZE	SZ_1M
-#define DEBUG_BUFFER_SIZE	SZ_2M
-#define CAPTURE_BUFFER_SIZE	SZ_4M
-#else
-#define CRASH_BUFFER_SIZE	SZ_8K
-#define DEBUG_BUFFER_SIZE	SZ_64K
-#define CAPTURE_BUFFER_SIZE	SZ_2M
-#endif
-
 /*
  * While we're using plain log level in i915, GuC controls are much more...
  * "elaborate"? We have a couple of bits for verbosity, separate bit for actual
@@ -46,10 +32,30 @@ struct intel_guc;
 #define GUC_VERBOSITY_TO_LOG_LEVEL(x)	((x) + 2)
 #define GUC_LOG_LEVEL_MAX GUC_VERBOSITY_TO_LOG_LEVEL(GUC_LOG_VERBOSITY_MAX)
 
+enum {
+	GUC_LOG_SECTIONS_CRASH,
+	GUC_LOG_SECTIONS_DEBUG,
+	GUC_LOG_SECTIONS_CAPTURE,
+	GUC_LOG_SECTIONS_LIMIT
+};
+
 struct intel_guc_log {
 	u32 level;
+
+	/* Allocation settings */
+	struct {
+		s32 bytes;	/* Size in bytes */
+		s32 units;	/* GuC API units - 1MB or 4KB */
+		s32 count;	/* Number of API units */
+		u32 flag;	/* GuC API units flag */
+	} sizes[GUC_LOG_SECTIONS_LIMIT];
+	bool sizes_initialised;
+
+	/* Combined buffer allocation */
 	struct i915_vma *vma;
 	void *buf_addr;
+
+	/* RelayFS support */
 	struct {
 		bool buf_in_use;
 		bool started;
@@ -58,6 +64,7 @@ struct intel_guc_log {
 		struct mutex lock;
 		u32 full_count;
 	} relay;
+
 	/* logging related stats */
 	struct {
 		u32 sampled_overflow;
@@ -69,8 +76,9 @@ struct intel_guc_log {
 void intel_guc_log_init_early(struct intel_guc_log *log);
 bool intel_guc_check_log_buf_overflow(struct intel_guc_log *log, enum guc_log_buffer_type type,
 				      unsigned int full_cnt);
-unsigned int intel_guc_get_log_buffer_size(enum guc_log_buffer_type type);
-size_t intel_guc_get_log_buffer_offset(enum guc_log_buffer_type type);
+unsigned int intel_guc_get_log_buffer_size(struct intel_guc_log *log,
+					   enum guc_log_buffer_type type);
+size_t intel_guc_get_log_buffer_offset(struct intel_guc_log *log, enum guc_log_buffer_type type);
 int intel_guc_log_create(struct intel_guc_log *log);
 void intel_guc_log_destroy(struct intel_guc_log *log);
 
@@ -92,4 +100,6 @@ void intel_guc_log_info(struct intel_guc_log *log, struct drm_printer *p);
 int intel_guc_log_dump(struct intel_guc_log *log, struct drm_printer *p,
 		       bool dump_load_err);
 
+u32 intel_guc_log_section_size_capture(struct intel_guc_log *log);
+
 #endif

drivers/gpu/drm/i915/i915_params.c

@@ -171,6 +171,18 @@ i915_param_named(guc_log_level, int, 0400,
 	"GuC firmware logging level. Requires GuC to be loaded. "
 	"(-1=auto [default], 0=disable, 1..4=enable with verbosity min..max)");
 
+i915_param_named(guc_log_size_crash, int, 0400,
+	"GuC firmware logging buffer size for crash dumps (in MB)"
+	"(-1=auto [default], NB: max = 4, other restrictions apply)");
+
+i915_param_named(guc_log_size_debug, int, 0400,
+	"GuC firmware logging buffer size for debug logs (in MB)"
+	"(-1=auto [default], NB: max = 16, other restrictions apply)");
+
+i915_param_named(guc_log_size_capture, int, 0400,
+	"GuC error capture register dump buffer size (in MB)"
+	"(-1=auto [default], NB: max = 4, other restrictions apply)");
+
 i915_param_named_unsafe(guc_firmware_path, charp, 0400,
 	"GuC firmware path to use instead of the default one");
 

drivers/gpu/drm/i915/i915_params.h

@@ -61,6 +61,9 @@ struct drm_printer;
 	param(int, invert_brightness, 0, 0600) \
 	param(int, enable_guc, -1, 0400) \
 	param(int, guc_log_level, -1, 0400) \
+	param(int, guc_log_size_crash, -1, 0400) \
+	param(int, guc_log_size_debug, -1, 0400) \
+	param(int, guc_log_size_capture, -1, 0400) \
 	param(char *, guc_firmware_path, NULL, 0400) \
 	param(char *, huc_firmware_path, NULL, 0400) \
 	param(char *, dmc_firmware_path, NULL, 0400) \