[PATCH 1/1] iommu/vt-d: Fix build error of pasid_enable_wpe() with !X86

[PATCH 1/1] iommu/vt-d: Fix build error of pasid_enable_wpe() with !X86

[Lu Baolu]

Commit f68c7f539b6e9 ("iommu/vt-d: Enable write protect for supervisor
SVM") added pasid_enable_wpe() which hit below compile error with !X86.

../drivers/iommu/intel/pasid.c: In function 'pasid_enable_wpe':
../drivers/iommu/intel/pasid.c:554:22: error: implicit declaration of function 'read_cr0' [-Werror=implicit-function-declaration]
  554 |  unsigned long cr0 = read_cr0();
      |                      ^~~~~~~~
In file included from ../include/linux/build_bug.h:5,
                 from ../include/linux/bits.h:22,
                 from ../include/linux/bitops.h:6,
                 from ../drivers/iommu/intel/pasid.c:12:
../drivers/iommu/intel/pasid.c:557:23: error: 'X86_CR0_WP' undeclared (first use in this function)
  557 |  if (unlikely(!(cr0 & X86_CR0_WP))) {
      |                       ^~~~~~~~~~
../include/linux/compiler.h:78:42: note: in definition of macro 'unlikely'
   78 | # define unlikely(x) __builtin_expect(!!(x), 0)
      |                                          ^
../drivers/iommu/intel/pasid.c:557:23: note: each undeclared identifier is reported only once for each function it appears in
  557 |  if (unlikely(!(cr0 & X86_CR0_WP))) {
      |                       ^~~~~~~~~~
../include/linux/compiler.h:78:42: note: in definition of macro 'unlikely'
   78 | # define unlikely(x) __builtin_expect(!!(x), 0)
      |

Add the missing dependency.

Cc: Sanjay Kumar <sanjay.k.kumar@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Fixes: f68c7f539b6e9 ("iommu/vt-d: Enable write protect for supervisor SVM")
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/intel/pasid.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index 477b2e1d303c..72646bafc52f 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -551,6 +551,7 @@ static void pasid_flush_caches(struct intel_iommu *iommu,
 
 static inline int pasid_enable_wpe(struct pasid_entry *pte)
 {
+#ifdef CONFIG_X86
 	unsigned long cr0 = read_cr0();
 
 	/* CR0.WP is normally set but just to be sure */
@@ -558,6 +559,7 @@ static inline int pasid_enable_wpe(struct pasid_entry *pte)
 		pr_err_ratelimited("No CPU write protect!\n");
 		return -EINVAL;
 	}
+#endif
 	pasid_set_wpe(pte);
 
 	return 0;
-- 
2.25.1

Re: [PATCH 1/1] iommu/vt-d: Fix build error of pasid_enable_wpe() with !X86

[Randy Dunlap]

On 4/10/21 11:23 PM, Lu Baolu wrote:
> Commit f68c7f539b6e9 ("iommu/vt-d: Enable write protect for supervisor
> SVM") added pasid_enable_wpe() which hit below compile error with !X86.
> 
> ../drivers/iommu/intel/pasid.c: In function 'pasid_enable_wpe':
> ../drivers/iommu/intel/pasid.c:554:22: error: implicit declaration of function 'read_cr0' [-Werror=implicit-function-declaration]
>   554 |  unsigned long cr0 = read_cr0();
>       |                      ^~~~~~~~
> In file included from ../include/linux/build_bug.h:5,
>                  from ../include/linux/bits.h:22,
>                  from ../include/linux/bitops.h:6,
>                  from ../drivers/iommu/intel/pasid.c:12:
> ../drivers/iommu/intel/pasid.c:557:23: error: 'X86_CR0_WP' undeclared (first use in this function)
>   557 |  if (unlikely(!(cr0 & X86_CR0_WP))) {
>       |                       ^~~~~~~~~~
> ../include/linux/compiler.h:78:42: note: in definition of macro 'unlikely'
>    78 | # define unlikely(x) __builtin_expect(!!(x), 0)
>       |                                          ^
> ../drivers/iommu/intel/pasid.c:557:23: note: each undeclared identifier is reported only once for each function it appears in
>   557 |  if (unlikely(!(cr0 & X86_CR0_WP))) {
>       |                       ^~~~~~~~~~
> ../include/linux/compiler.h:78:42: note: in definition of macro 'unlikely'
>    78 | # define unlikely(x) __builtin_expect(!!(x), 0)
>       |
> 
> Add the missing dependency.
> 
> Cc: Sanjay Kumar <sanjay.k.kumar@intel.com>
> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Cc: Randy Dunlap <rdunlap@infradead.org>
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Randy Dunlap <rdunlap@infradead.org>
> Fixes: f68c7f539b6e9 ("iommu/vt-d: Enable write protect for supervisor SVM")
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>

Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested


Thanks.

> ---
>  drivers/iommu/intel/pasid.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
> index 477b2e1d303c..72646bafc52f 100644
> --- a/drivers/iommu/intel/pasid.c
> +++ b/drivers/iommu/intel/pasid.c
> @@ -551,6 +551,7 @@ static void pasid_flush_caches(struct intel_iommu *iommu,
>  
>  static inline int pasid_enable_wpe(struct pasid_entry *pte)
>  {
> +#ifdef CONFIG_X86
>  	unsigned long cr0 = read_cr0();
>  
>  	/* CR0.WP is normally set but just to be sure */
> @@ -558,6 +559,7 @@ static inline int pasid_enable_wpe(struct pasid_entry *pte)
>  		pr_err_ratelimited("No CPU write protect!\n");
>  		return -EINVAL;
>  	}
> +#endif
>  	pasid_set_wpe(pte);
>  
>  	return 0;
> 


-- 
~Randy

Re: [PATCH 1/1] iommu/vt-d: Fix build error of pasid_enable_wpe() with !X86

[Joerg Roedel]

On Sun, Apr 11, 2021 at 02:23:12PM +0800, Lu Baolu wrote:
>  drivers/iommu/intel/pasid.c | 2 ++
>  1 file changed, 2 insertions(+)

Applied, thanks.