* [PATCH] drm/i915: drop various VLAs in i915_debugfs.c
@ 2018-03-13 19:51 Salvatore Mesoraca
2018-03-14 12:17 ` Jani Nikula
` (2 more replies)
0 siblings, 3 replies; 10+ messages in thread
From: Salvatore Mesoraca @ 2018-03-13 19:51 UTC (permalink / raw)
To: linux-kernel
Cc: dri-devel, intel-gfx, kernel-hardening, David Airlie, Jani Nikula,
Joonas Lahtinen, Kees Cook, Rodrigo Vivi, Salvatore Mesoraca
Avoid 3 VLAs[1] by using real constant expressions instead of variables.
The compiler should be able to optimize the original code and avoid using
any actual VLAs. Anyway this change is useful because it will avoid a false
positives with -Wvla, it might also help the compiler generating better
code.
[1] https://lkml.org/lkml/2018/3/7/621
Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com>
---
drivers/gpu/drm/i915/i915_debugfs.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index e968aea..bf0a8e3 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -4259,19 +4259,20 @@ static ssize_t cur_wm_latency_write(struct file *file, const char __user *ubuf,
i915_cache_sharing_get, i915_cache_sharing_set,
"%llu\n");
+#define CHERRYVIEW_SS_MAX 2
+
static void cherryview_sseu_device_status(struct drm_i915_private *dev_priv,
struct sseu_dev_info *sseu)
{
- int ss_max = 2;
int ss;
- u32 sig1[ss_max], sig2[ss_max];
+ u32 sig1[CHERRYVIEW_SS_MAX], sig2[CHERRYVIEW_SS_MAX];
sig1[0] = I915_READ(CHV_POWER_SS0_SIG1);
sig1[1] = I915_READ(CHV_POWER_SS1_SIG1);
sig2[0] = I915_READ(CHV_POWER_SS0_SIG2);
sig2[1] = I915_READ(CHV_POWER_SS1_SIG2);
- for (ss = 0; ss < ss_max; ss++) {
+ for (ss = 0; ss < CHERRYVIEW_SS_MAX; ss++) {
unsigned int eu_cnt;
if (sig1[ss] & CHV_SS_PG_ENABLE)
@@ -4290,15 +4291,17 @@ static void cherryview_sseu_device_status(struct drm_i915_private *dev_priv,
}
}
+#define GEN10_S_MAX 6
+#define GEN10_SS_MAX 4
+
static void gen10_sseu_device_status(struct drm_i915_private *dev_priv,
struct sseu_dev_info *sseu)
{
const struct intel_device_info *info = INTEL_INFO(dev_priv);
- int s_max = 6, ss_max = 4;
int s, ss;
- u32 s_reg[s_max], eu_reg[2 * s_max], eu_mask[2];
+ u32 s_reg[GEN10_S_MAX], eu_reg[2 * GEN10_S_MAX], eu_mask[2];
- for (s = 0; s < s_max; s++) {
+ for (s = 0; s < GEN10_S_MAX; s++) {
/*
* FIXME: Valid SS Mask respects the spec and read
* only valid bits for those registers, excluding reserverd
@@ -4320,7 +4323,7 @@ static void gen10_sseu_device_status(struct drm_i915_private *dev_priv,
GEN9_PGCTL_SSB_EU210_ACK |
GEN9_PGCTL_SSB_EU311_ACK;
- for (s = 0; s < s_max; s++) {
+ for (s = 0; s < GEN10_S_MAX; s++) {
if ((s_reg[s] & GEN9_PGCTL_SLICE_ACK) == 0)
/* skip disabled slice */
continue;
@@ -4328,7 +4331,7 @@ static void gen10_sseu_device_status(struct drm_i915_private *dev_priv,
sseu->slice_mask |= BIT(s);
sseu->subslice_mask = info->sseu.subslice_mask;
- for (ss = 0; ss < ss_max; ss++) {
+ for (ss = 0; ss < GEN10_SS_MAX; ss++) {
unsigned int eu_cnt;
if (!(s_reg[s] & (GEN9_PGCTL_SS_ACK(ss))))
@@ -4345,12 +4348,15 @@ static void gen10_sseu_device_status(struct drm_i915_private *dev_priv,
}
}
+#define GEN9_S_MAX 3
+#define GEN9_SS_MAX 4
+
static void gen9_sseu_device_status(struct drm_i915_private *dev_priv,
struct sseu_dev_info *sseu)
{
- int s_max = 3, ss_max = 4;
+ int s_max = GEN9_S_MAX, ss_max = GEN9_SS_MAX;
int s, ss;
- u32 s_reg[s_max], eu_reg[2*s_max], eu_mask[2];
+ u32 s_reg[GEN9_S_MAX], eu_reg[2*GEN9_S_MAX], eu_mask[2];
/* BXT has a single slice and at most 3 subslices. */
if (IS_GEN9_LP(dev_priv)) {
--
1.9.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* Re: [PATCH] drm/i915: drop various VLAs in i915_debugfs.c
2018-03-13 19:51 [PATCH] drm/i915: drop various VLAs in i915_debugfs.c Salvatore Mesoraca
2018-03-14 12:17 ` Jani Nikula
@ 2018-03-14 12:17 ` Jani Nikula
2018-03-14 19:55 ` ✗ Fi.CI.BAT: failure for " Patchwork
2 siblings, 0 replies; 10+ messages in thread
From: Jani Nikula @ 2018-03-14 12:17 UTC (permalink / raw)
To: Salvatore Mesoraca, linux-kernel
Cc: dri-devel, intel-gfx, kernel-hardening, David Airlie,
Joonas Lahtinen, Kees Cook, Rodrigo Vivi
On Tue, 13 Mar 2018, Salvatore Mesoraca <s.mesoraca16@gmail.com> wrote:
> Avoid 3 VLAs[1] by using real constant expressions instead of variables.
> The compiler should be able to optimize the original code and avoid using
> any actual VLAs. Anyway this change is useful because it will avoid a false
> positives with -Wvla, it might also help the compiler generating better
> code.
Thanks for your patch. However, Chris beat you to it with:
7aa0b14ede64 ("drm/i915: Remove variable length arrays from sseu debugfs
printers")
as well as adding -Wvla to our subdir-ccflags-y to prevent more from
cropping up:
c5c2b11894f4 ("drm/i915: Warn against variable length arrays")
BR,
Jani.
--
Jani Nikula, Intel Open Source Technology Center
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH] drm/i915: drop various VLAs in i915_debugfs.c
@ 2018-03-14 12:17 ` Jani Nikula
0 siblings, 0 replies; 10+ messages in thread
From: Jani Nikula @ 2018-03-14 12:17 UTC (permalink / raw)
To: Salvatore Mesoraca, linux-kernel
Cc: dri-devel, intel-gfx, kernel-hardening, David Airlie,
Joonas Lahtinen, Kees Cook, Rodrigo Vivi, Salvatore Mesoraca
On Tue, 13 Mar 2018, Salvatore Mesoraca <s.mesoraca16@gmail.com> wrote:
> Avoid 3 VLAs[1] by using real constant expressions instead of variables.
> The compiler should be able to optimize the original code and avoid using
> any actual VLAs. Anyway this change is useful because it will avoid a false
> positives with -Wvla, it might also help the compiler generating better
> code.
Thanks for your patch. However, Chris beat you to it with:
7aa0b14ede64 ("drm/i915: Remove variable length arrays from sseu debugfs
printers")
as well as adding -Wvla to our subdir-ccflags-y to prevent more from
cropping up:
c5c2b11894f4 ("drm/i915: Warn against variable length arrays")
BR,
Jani.
--
Jani Nikula, Intel Open Source Technology Center
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH] drm/i915: drop various VLAs in i915_debugfs.c
@ 2018-03-14 12:17 ` Jani Nikula
0 siblings, 0 replies; 10+ messages in thread
From: Jani Nikula @ 2018-03-14 12:17 UTC (permalink / raw)
To: linux-kernel
Cc: Salvatore Mesoraca, Kees Cook, kernel-hardening, David Airlie,
intel-gfx, dri-devel, Rodrigo Vivi
On Tue, 13 Mar 2018, Salvatore Mesoraca <s.mesoraca16@gmail.com> wrote:
> Avoid 3 VLAs[1] by using real constant expressions instead of variables.
> The compiler should be able to optimize the original code and avoid using
> any actual VLAs. Anyway this change is useful because it will avoid a false
> positives with -Wvla, it might also help the compiler generating better
> code.
Thanks for your patch. However, Chris beat you to it with:
7aa0b14ede64 ("drm/i915: Remove variable length arrays from sseu debugfs
printers")
as well as adding -Wvla to our subdir-ccflags-y to prevent more from
cropping up:
c5c2b11894f4 ("drm/i915: Warn against variable length arrays")
BR,
Jani.
--
Jani Nikula, Intel Open Source Technology Center
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH] drm/i915: drop various VLAs in i915_debugfs.c
2018-03-14 12:17 ` Jani Nikula
(?)
(?)
@ 2018-03-14 12:41 ` Salvatore Mesoraca
-1 siblings, 0 replies; 10+ messages in thread
From: Salvatore Mesoraca @ 2018-03-14 12:41 UTC (permalink / raw)
To: Jani Nikula
Cc: linux-kernel, dri-devel, intel-gfx, Kernel Hardening,
David Airlie, Joonas Lahtinen, Kees Cook, Rodrigo Vivi
2018-03-14 13:17 GMT+01:00 Jani Nikula <jani.nikula@linux.intel.com>:
> Thanks for your patch. However, Chris beat you to it with:
>
> 7aa0b14ede64 ("drm/i915: Remove variable length arrays from sseu debugfs
> printers")
I didn't notice it :)
> as well as adding -Wvla to our subdir-ccflags-y to prevent more from
> cropping up:
>
> c5c2b11894f4 ("drm/i915: Warn against variable length arrays")
Great!
Best regards,
Salvatore
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] drm/i915: drop various VLAs in i915_debugfs.c
2018-03-13 19:51 [PATCH] drm/i915: drop various VLAs in i915_debugfs.c Salvatore Mesoraca
2018-03-14 12:17 ` Jani Nikula
@ 2018-03-14 12:27 ` Joonas Lahtinen
2018-03-14 19:55 ` ✗ Fi.CI.BAT: failure for " Patchwork
2 siblings, 0 replies; 10+ messages in thread
From: Joonas Lahtinen @ 2018-03-14 12:27 UTC (permalink / raw)
To: Salvatore Mesoraca, linux-kernel
Cc: dri-devel, intel-gfx, kernel-hardening, David Airlie, Jani Nikula,
Kees Cook, Rodrigo Vivi
Quoting Salvatore Mesoraca (2018-03-13 21:51:28)
> Avoid 3 VLAs[1] by using real constant expressions instead of variables.
> The compiler should be able to optimize the original code and avoid using
> any actual VLAs. Anyway this change is useful because it will avoid a false
> positives with -Wvla, it might also help the compiler generating better
> code.
>
> [1] https://lkml.org/lkml/2018/3/7/621
>
> Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com>
> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 26 ++++++++++++++++----------
> 1 file changed, 16 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index e968aea..bf0a8e3 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -4259,19 +4259,20 @@ static ssize_t cur_wm_latency_write(struct file *file, const char __user *ubuf,
> i915_cache_sharing_get, i915_cache_sharing_set,
> "%llu\n");
>
> +#define CHERRYVIEW_SS_MAX 2
CHV_SS_MAX should be good enough. Make these function scoped (so #define
at the beginning and #undef at the end of function).
Do use ARRAY_SIZE() instead of repeating.
Regards, Joonas
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] drm/i915: drop various VLAs in i915_debugfs.c
@ 2018-03-14 12:27 ` Joonas Lahtinen
0 siblings, 0 replies; 10+ messages in thread
From: Joonas Lahtinen @ 2018-03-14 12:27 UTC (permalink / raw)
To: Salvatore Mesoraca, linux-kernel
Cc: dri-devel, intel-gfx, kernel-hardening, David Airlie, Jani Nikula,
Kees Cook, Rodrigo Vivi, Salvatore Mesoraca
Quoting Salvatore Mesoraca (2018-03-13 21:51:28)
> Avoid 3 VLAs[1] by using real constant expressions instead of variables.
> The compiler should be able to optimize the original code and avoid using
> any actual VLAs. Anyway this change is useful because it will avoid a false
> positives with -Wvla, it might also help the compiler generating better
> code.
>
> [1] https://lkml.org/lkml/2018/3/7/621
>
> Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com>
> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 26 ++++++++++++++++----------
> 1 file changed, 16 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index e968aea..bf0a8e3 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -4259,19 +4259,20 @@ static ssize_t cur_wm_latency_write(struct file *file, const char __user *ubuf,
> i915_cache_sharing_get, i915_cache_sharing_set,
> "%llu\n");
>
> +#define CHERRYVIEW_SS_MAX 2
CHV_SS_MAX should be good enough. Make these function scoped (so #define
at the beginning and #undef at the end of function).
Do use ARRAY_SIZE() instead of repeating.
Regards, Joonas
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] drm/i915: drop various VLAs in i915_debugfs.c
@ 2018-03-14 12:27 ` Joonas Lahtinen
0 siblings, 0 replies; 10+ messages in thread
From: Joonas Lahtinen @ 2018-03-14 12:27 UTC (permalink / raw)
To: linux-kernel
Cc: Salvatore Mesoraca, Kees Cook, kernel-hardening, David Airlie,
intel-gfx, dri-devel, Rodrigo Vivi
Quoting Salvatore Mesoraca (2018-03-13 21:51:28)
> Avoid 3 VLAs[1] by using real constant expressions instead of variables.
> The compiler should be able to optimize the original code and avoid using
> any actual VLAs. Anyway this change is useful because it will avoid a false
> positives with -Wvla, it might also help the compiler generating better
> code.
>
> [1] https://lkml.org/lkml/2018/3/7/621
>
> Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com>
> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 26 ++++++++++++++++----------
> 1 file changed, 16 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index e968aea..bf0a8e3 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -4259,19 +4259,20 @@ static ssize_t cur_wm_latency_write(struct file *file, const char __user *ubuf,
> i915_cache_sharing_get, i915_cache_sharing_set,
> "%llu\n");
>
> +#define CHERRYVIEW_SS_MAX 2
CHV_SS_MAX should be good enough. Make these function scoped (so #define
at the beginning and #undef at the end of function).
Do use ARRAY_SIZE() instead of repeating.
Regards, Joonas
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] drm/i915: drop various VLAs in i915_debugfs.c
2018-03-14 12:27 ` Joonas Lahtinen
(?)
(?)
@ 2018-03-14 12:43 ` Salvatore Mesoraca
-1 siblings, 0 replies; 10+ messages in thread
From: Salvatore Mesoraca @ 2018-03-14 12:43 UTC (permalink / raw)
To: Joonas Lahtinen
Cc: linux-kernel, dri-devel, intel-gfx, Kernel Hardening,
David Airlie, Jani Nikula, Kees Cook, Rodrigo Vivi
2018-03-14 13:27 GMT+01:00 Joonas Lahtinen <joonas.lahtinen@linux.intel.com>:
> CHV_SS_MAX should be good enough. Make these function scoped (so #define
> at the beginning and #undef at the end of function).
>
> Do use ARRAY_SIZE() instead of repeating.
Thank you very much for your suggestions.
Unfortunately, it seems that someone else already fixed this issue, so
I'll just drop this patch.
Best regards,
Salvatore
^ permalink raw reply [flat|nested] 10+ messages in thread
* ✗ Fi.CI.BAT: failure for drm/i915: drop various VLAs in i915_debugfs.c
2018-03-13 19:51 [PATCH] drm/i915: drop various VLAs in i915_debugfs.c Salvatore Mesoraca
2018-03-14 12:17 ` Jani Nikula
2018-03-14 12:27 ` Joonas Lahtinen
@ 2018-03-14 19:55 ` Patchwork
2 siblings, 0 replies; 10+ messages in thread
From: Patchwork @ 2018-03-14 19:55 UTC (permalink / raw)
To: Salvatore Mesoraca; +Cc: intel-gfx
== Series Details ==
Series: drm/i915: drop various VLAs in i915_debugfs.c
URL : https://patchwork.freedesktop.org/series/39985/
State : failure
== Summary ==
Applying: drm/i915: drop various VLAs in i915_debugfs.c
error: Failed to merge in the changes.
Using index info to reconstruct a base tree...
M drivers/gpu/drm/i915/i915_debugfs.c
Falling back to patching base and 3-way merge...
Auto-merging drivers/gpu/drm/i915/i915_debugfs.c
CONFLICT (content): Merge conflict in drivers/gpu/drm/i915/i915_debugfs.c
Patch failed at 0001 drm/i915: drop various VLAs in i915_debugfs.c
The copy of the patch that failed is found in: .git/rebase-apply/patch
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply [flat|nested] 10+ messages in thread
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2018-03-13 19:51 [PATCH] drm/i915: drop various VLAs in i915_debugfs.c Salvatore Mesoraca
2018-03-14 12:17 ` Jani Nikula
2018-03-14 12:17 ` Jani Nikula
2018-03-14 12:17 ` Jani Nikula
2018-03-14 12:41 ` Salvatore Mesoraca
2018-03-14 12:27 ` Joonas Lahtinen
2018-03-14 12:27 ` Joonas Lahtinen
2018-03-14 12:27 ` Joonas Lahtinen
2018-03-14 12:43 ` Salvatore Mesoraca
2018-03-14 19:55 ` ✗ Fi.CI.BAT: failure for " Patchwork
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