[PATCH v5 1/6] drm/xe: add xe_device_wa infrastructure

Lucas De Marchi lucas.demarchi at intel.com
Wed Jul 2 21:57:34 UTC 2025


On Wed, Jul 02, 2025 at 12:30:31PM -0700, Matt Atwood wrote:
>There are some workarounds that must be applied before gt init,
>wa_150154044425 for example. Instead of sprinkling them conditionally
>throughout the driver as we did for i915 generate an oob.rules file
>reusing the RTP infrastructure to make these easier to track.
>
>v2: rename xe_soc_wa to xe_device_wa
>v5: derive prefix from argument rather then hard coding the values.
>
>Signed-off-by: Matt Atwood <matthew.s.atwood at intel.com>
>---
> drivers/gpu/drm/xe/Makefile               | 11 ++++++-
> drivers/gpu/drm/xe/xe_device_wa_oob.rules |  0
> drivers/gpu/drm/xe/xe_gen_wa_oob.c        | 38 ++++++++++++++++++-----
> 3 files changed, 41 insertions(+), 8 deletions(-)
> create mode 100644 drivers/gpu/drm/xe/xe_device_wa_oob.rules
>
>diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
>index 1d97e5b63f4e..48d4aa9d4ecc 100644
>--- a/drivers/gpu/drm/xe/Makefile
>+++ b/drivers/gpu/drm/xe/Makefile
>@@ -21,6 +21,15 @@ $(obj)/generated/%_wa_oob.c $(obj)/generated/%_wa_oob.h: $(obj)/xe_gen_wa_oob \
> 		 $(src)/xe_wa_oob.rules
> 	$(call cmd,wa_oob)
>
>+generated_device_oob := $(obj)/generated/xe_device_wa_oob.c $(obj)/generated/xe_device_wa_oob.h
>+quiet_cmd_device_wa_oob = GEN     $(notdir $(generated_device_oob))
>+      cmd_device_wa_oob = mkdir -p $(@D); $^ $(generated_device_oob)
>+$(obj)/generated/%_device_wa_oob.c $(obj)/generated/%_device_wa_oob.h: $(obj)/xe_gen_wa_oob \
>+		 $(src)/xe_device_wa_oob.rules
>+	$(call cmd,device_wa_oob)
>+
>+
>+

drop these several newlines.

> # Please keep these build lists sorted!
>
> # core driver code
>@@ -340,4 +349,4 @@ $(obj)/%.hdrtest: $(src)/%.h FORCE
> 	$(call if_changed_dep,hdrtest)
>
> uses_generated_oob := $(addprefix $(obj)/, $(xe-y))
>-$(uses_generated_oob): $(obj)/generated/xe_wa_oob.h
>+$(uses_generated_oob): $(obj)/generated/xe_wa_oob.h $(obj)/generated/xe_device_wa_oob.h
>diff --git a/drivers/gpu/drm/xe/xe_device_wa_oob.rules b/drivers/gpu/drm/xe/xe_device_wa_oob.rules
>new file mode 100644
>index 000000000000..e69de29bb2d1
>diff --git a/drivers/gpu/drm/xe/xe_gen_wa_oob.c b/drivers/gpu/drm/xe/xe_gen_wa_oob.c
>index ed9183599e31..341840926f60 100644
>--- a/drivers/gpu/drm/xe/xe_gen_wa_oob.c
>+++ b/drivers/gpu/drm/xe/xe_gen_wa_oob.c

All the changes in this files should be a prep commit: they can be done
regardless of having device_wa_oob

>@@ -18,8 +18,8 @@
> 	" *\n" \
> 	" * This file was generated from rules: %s\n" \
> 	" */\n" \
>-	"#ifndef _GENERATED_XE_WA_OOB_\n" \
>-	"#define _GENERATED_XE_WA_OOB_\n" \
>+	"#ifndef _GENERATED_%s_\n" \
>+	"#define _GENERATED_%s_\n" \
> 	"\n" \
> 	"enum {\n"
>
>@@ -52,7 +52,7 @@ static char *strip(char *line, size_t linelen)
> }
>
> #define MAX_LINE_LEN 4096
>-static int parse(FILE *input, FILE *csource, FILE *cheader)
>+static int parse(FILE *input, FILE *csource, FILE *cheader, char *prefix)
> {
> 	char line[MAX_LINE_LEN + 1];
> 	char *name, *prev_name = NULL, *rules;
>@@ -96,7 +96,7 @@ static int parse(FILE *input, FILE *csource, FILE *cheader)
> 		}
>
> 		if (name) {
>-			fprintf(cheader, "\tXE_WA_OOB_%s = %u,\n", name, idx);
>+			fprintf(cheader, "\t%s_%s = %u,\n", prefix, name, idx);
>
> 			/* Close previous entry before starting a new one */
> 			if (idx)
>@@ -118,7 +118,26 @@ static int parse(FILE *input, FILE *csource, FILE *cheader)
> 	if (idx)
> 		fprintf(csource, ") },\n");
>
>-	fprintf(cheader, "\t_XE_WA_OOB_COUNT = %u\n", idx);
>+	fprintf(cheader, "\t_%s_COUNT = %u\n", prefix, idx);
>+
>+	return 0;
>+}
>+
>+static int fn_to_prefix(const char *fn, char *prefix, size_t size)
>+{
>+	if (!strncpy(prefix, fn, size - 1))
>+		return -ENAMETOOLONG;

I didn't suggest using strncpy(). If you do, then you need to adjust the
error handling. There are 2 problems here:

1) strncpy() doesn't return NULL on error. See CAVEATS section
    in strncpy(3) or strlcpy(3) that also documents strncpy and its
    return value:


    strcpy(3)
    strcat(3)
    strncpy(3)
    strncat(3)
           The dst pointer, which is useless.

2) prefix is on the stack in the caller, so it doesn't necessarily
    ends with '\0'. So even if you copied at most size - 1, the last
    char may not be 0 and you will have an infinity loop below.

Those 2 could be fixed by doing this instead:

diff --git a/drivers/gpu/drm/xe/xe_gen_wa_oob.c b/drivers/gpu/drm/xe/xe_gen_wa_oob.c
index 341840926f602..ed550dca5f439 100644
--- a/drivers/gpu/drm/xe/xe_gen_wa_oob.c
+++ b/drivers/gpu/drm/xe/xe_gen_wa_oob.c
@@ -125,7 +125,7 @@ static int parse(FILE *input, FILE *csource, FILE *cheader, char *prefix)
  
  static int fn_to_prefix(const char *fn, char *prefix, size_t size)
  {
-	if (!strncpy(prefix, fn, size - 1))
+	if (strlcpy(prefix, basename(fn), size) >= size)
  		return -ENAMETOOLONG;
  
  	for (char *p = prefix; *p; p++) {
@@ -168,8 +168,10 @@ int main(int argc, const char *argv[])
  		return 1;
  	}
  
-	if (fn_to_prefix(basename(args[ARGS_CHEADER].fn), prefix, sizeof(prefix)) < 0)
+	if (fn_to_prefix(args[ARGS_CHEADER].fn, prefix, sizeof(prefix)) < 0) {
+		fprintf(stderr, "ERROR: invalid header name: %s\n", args[ARGS_CHEADER].fn);
  		return 1;
+	}
  
  	for (int i = 0; i < _ARGS_COUNT; i++) {
  		args[i].f = fopen(args[i].fn, args[i].mode);

did you find any issue with strlcpy? I think it's available on all
toolchains, but maybe we need the workaround by including tools/include/linux/string.h
I tried the diff above locally and it worked for me though.

Lucas De Marchi

>+
>+	for (char *p = prefix; *p; p++) {
>+		switch (*p) {
>+		case '.':
>+			*p = '\0';
>+			return 0;
>+		default:
>+			*p = toupper(*p);
>+			break;
>+		}
>+	}
>
> 	return 0;
> }
>@@ -141,6 +160,7 @@ int main(int argc, const char *argv[])
> 		[ARGS_CHEADER] = { .fn = argv[3], .mode = "w" },
> 	};
> 	int ret = 1;
>+	char prefix[128];
>
> 	if (argc < 3) {
> 		fprintf(stderr, "ERROR: wrong arguments\n");
>@@ -148,6 +168,9 @@ int main(int argc, const char *argv[])
> 		return 1;
> 	}
>
>+	if (fn_to_prefix(basename(args[ARGS_CHEADER].fn), prefix, sizeof(prefix)) < 0)
>+		return 1;
>+
> 	for (int i = 0; i < _ARGS_COUNT; i++) {
> 		args[i].f = fopen(args[i].fn, args[i].mode);
> 		if (!args[i].f) {
>@@ -157,9 +180,10 @@ int main(int argc, const char *argv[])
> 		}
> 	}
>
>-	fprintf(args[ARGS_CHEADER].f, HEADER, args[ARGS_INPUT].fn);
>+	fprintf(args[ARGS_CHEADER].f, HEADER, args[ARGS_INPUT].fn, prefix, prefix);
>+
> 	ret = parse(args[ARGS_INPUT].f, args[ARGS_CSOURCE].f,
>-		    args[ARGS_CHEADER].f);
>+		    args[ARGS_CHEADER].f, prefix);
> 	if (!ret)
> 		fprintf(args[ARGS_CHEADER].f, FOOTER);
>
>-- 
>2.49.0
>


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