[PATCH 0/3] drm/i915: Fix header test and log spam on !x86

[PATCH 0/3] drm/i915: Fix header test and log spam on !x86

[Lucas De Marchi]

Some minor fixes and changes to help porting i915 to arm64, or even
anything !x86.

Lucas De Marchi (3):
  drm: Stop spamming log with drm_cache message
  drm/i915: Do not spam log with missiing arch support
  drm/i915: Fix header test for !CONFIG_X86

 drivers/gpu/drm/drm_cache.c    | 3 ---
 drivers/gpu/drm/i915/i915_mm.h | 2 +-
 2 files changed, 1 insertion(+), 4 deletions(-)

-- 
2.34.1

[PATCH 1/3] drm: Stop spamming log with drm_cache message

[Lucas De Marchi]

Only x86 and in some cases PPC have support added in drm_cache.c for the
clflush class of functions. However warning once is sufficient to taint
the log instead of spamming it with "Architecture has no drm_cache.c
support" every few millisecond.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
---
 drivers/gpu/drm/drm_cache.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
index f19d9acbe959..2d5a4c463a4f 100644
--- a/drivers/gpu/drm/drm_cache.c
+++ b/drivers/gpu/drm/drm_cache.c
@@ -112,7 +112,6 @@ drm_clflush_pages(struct page *pages[], unsigned long num_pages)
 		kunmap_atomic(page_virtual);
 	}
 #else
-	pr_err("Architecture has no drm_cache.c support\n");
 	WARN_ON_ONCE(1);
 #endif
 }
@@ -143,7 +142,6 @@ drm_clflush_sg(struct sg_table *st)
 	if (wbinvd_on_all_cpus())
 		pr_err("Timed out waiting for cache flush\n");
 #else
-	pr_err("Architecture has no drm_cache.c support\n");
 	WARN_ON_ONCE(1);
 #endif
 }
@@ -177,7 +175,6 @@ drm_clflush_virt_range(void *addr, unsigned long length)
 	if (wbinvd_on_all_cpus())
 		pr_err("Timed out waiting for cache flush\n");
 #else
-	pr_err("Architecture has no drm_cache.c support\n");
 	WARN_ON_ONCE(1);
 #endif
 }
-- 
2.34.1

Re: [Intel-gfx] [PATCH 1/3] drm: Stop spamming log with drm_cache message

[Jani Nikula]

On Tue, 25 Jan 2022, Lucas De Marchi <lucas.demarchi@intel.com> wrote:
> Only x86 and in some cases PPC have support added in drm_cache.c for the
> clflush class of functions. However warning once is sufficient to taint
> the log instead of spamming it with "Architecture has no drm_cache.c
> support" every few millisecond.
>
> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Cc: Maxime Ripard <mripard@kernel.org>
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: David Airlie <airlied@linux.ie>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
> ---
>  drivers/gpu/drm/drm_cache.c | 3 ---
>  1 file changed, 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
> index f19d9acbe959..2d5a4c463a4f 100644
> --- a/drivers/gpu/drm/drm_cache.c
> +++ b/drivers/gpu/drm/drm_cache.c
> @@ -112,7 +112,6 @@ drm_clflush_pages(struct page *pages[], unsigned long num_pages)
>  		kunmap_atomic(page_virtual);
>  	}
>  #else
> -	pr_err("Architecture has no drm_cache.c support\n");
>  	WARN_ON_ONCE(1);

An alternative would be to replace the two lines with:

	WARN_ONCE(1, "Architecture has no drm_cache.c support\n");

But I'm not insisting.

BR,
Jani.


>  #endif
>  }
> @@ -143,7 +142,6 @@ drm_clflush_sg(struct sg_table *st)
>  	if (wbinvd_on_all_cpus())
>  		pr_err("Timed out waiting for cache flush\n");
>  #else
> -	pr_err("Architecture has no drm_cache.c support\n");
>  	WARN_ON_ONCE(1);
>  #endif
>  }
> @@ -177,7 +175,6 @@ drm_clflush_virt_range(void *addr, unsigned long length)
>  	if (wbinvd_on_all_cpus())
>  		pr_err("Timed out waiting for cache flush\n");
>  #else
> -	pr_err("Architecture has no drm_cache.c support\n");
>  	WARN_ON_ONCE(1);
>  #endif
>  }

-- 
Jani Nikula, Intel Open Source Graphics Center

Re: [Intel-gfx] [PATCH 1/3] drm: Stop spamming log with drm_cache message

[Lucas De Marchi]

On Wed, Jan 26, 2022 at 08:24:54PM +0200, Jani Nikula wrote:
>On Tue, 25 Jan 2022, Lucas De Marchi <lucas.demarchi@intel.com> wrote:
>> Only x86 and in some cases PPC have support added in drm_cache.c for the
>> clflush class of functions. However warning once is sufficient to taint
>> the log instead of spamming it with "Architecture has no drm_cache.c
>> support" every few millisecond.
>>
>> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
>> Cc: Maxime Ripard <mripard@kernel.org>
>> Cc: Thomas Zimmermann <tzimmermann@suse.de>
>> Cc: David Airlie <airlied@linux.ie>
>> Cc: Daniel Vetter <daniel@ffwll.ch>
>> Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
>> ---
>>  drivers/gpu/drm/drm_cache.c | 3 ---
>>  1 file changed, 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
>> index f19d9acbe959..2d5a4c463a4f 100644
>> --- a/drivers/gpu/drm/drm_cache.c
>> +++ b/drivers/gpu/drm/drm_cache.c
>> @@ -112,7 +112,6 @@ drm_clflush_pages(struct page *pages[], unsigned long num_pages)
>>  		kunmap_atomic(page_virtual);
>>  	}
>>  #else
>> -	pr_err("Architecture has no drm_cache.c support\n");
>>  	WARN_ON_ONCE(1);
>
>An alternative would be to replace the two lines with:
>
>	WARN_ONCE(1, "Architecture has no drm_cache.c support\n");
>
>But I'm not insisting.

I actually like that suggestion. I will change that in the next version.

Thanks
Lucas De Marchi

[PATCH 2/3] drm/i915: Do not spam log with missiing arch support

[Lucas De Marchi]

Following what was done in drm_cache.c, when the stub for
remap_io_mapping() was added in commit 67c430bbaae1 ("drm/i915: Skip
remap_io_mapping() for non-x86 platforms"), it was added a log message.
However the WARN_ON_ONCE() should already be enough - we don't want to
spam the log with those messages.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
---
 drivers/gpu/drm/i915/i915_mm.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_mm.h b/drivers/gpu/drm/i915/i915_mm.h
index 76f1d53bdf34..ed04fc756271 100644
--- a/drivers/gpu/drm/i915/i915_mm.h
+++ b/drivers/gpu/drm/i915/i915_mm.h
@@ -22,7 +22,6 @@ int remap_io_mapping(struct vm_area_struct *vma,
 		     unsigned long addr, unsigned long pfn, unsigned long size,
 		     struct io_mapping *iomap)
 {
-	pr_err("Architecture has no %s() and shouldn't be calling this function\n", __func__);
 	WARN_ON_ONCE(1);
 	return 0;
 }
-- 
2.34.1

[PATCH 3/3] drm/i915: Fix header test for !CONFIG_X86

[Lucas De Marchi]

Architectures others than x86 have a stub implementation calling
WARN_ON_ONCE(). The appropriate headers need to be included, otherwise
the header-test target will fail with:

  HDRTEST drivers/gpu/drm/i915/i915_mm.h
In file included from <command-line>:
./drivers/gpu/drm/i915/i915_mm.h: In function ‘remap_io_mapping’:
./drivers/gpu/drm/i915/i915_mm.h:26:2: error: implicit declaration of function ‘WARN_ON_ONCE’ [-Werror=implicit-function-declaration]
   26 |  WARN_ON_ONCE(1);
      |  ^~~~~~~~~~~~

v2: Do not include <linux/printk.h> since call to pr_err() has been
removed

Fixes: 67c430bbaae1 ("drm/i915: Skip remap_io_mapping() for non-x86 platforms")
Cc: Siva Mullati <siva.mullati@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
---
 drivers/gpu/drm/i915/i915_mm.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/i915_mm.h b/drivers/gpu/drm/i915/i915_mm.h
index ed04fc756271..bc30581b20f6 100644
--- a/drivers/gpu/drm/i915/i915_mm.h
+++ b/drivers/gpu/drm/i915/i915_mm.h
@@ -6,6 +6,7 @@
 #ifndef __I915_MM_H__
 #define __I915_MM_H__
 
+#include <linux/bug.h>
 #include <linux/types.h>
 
 struct vm_area_struct;
-- 
2.34.1