diff mbox series

[V1,07/10] arch/kmap: Ensure kmap_prot visibility

Message ID 20200430203845.582900-8-ira.weiny@intel.com
State New
Headers show
Series Remove duplicated kmap code | expand

Commit Message

Ira Weiny April 30, 2020, 8:38 p.m. UTC 
From: Ira Weiny <ira.weiny@intel.com>

We want to support kmap_atomic_prot() on all architectures and it makes
sense to define kmap_atomic() to use the default kmap_prot.

So we ensure all arch's have a globally available kmap_prot either as a
define or exported symbol.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 arch/microblaze/include/asm/highmem.h | 2 +-
 arch/microblaze/mm/init.c             | 3 ---
 arch/powerpc/include/asm/highmem.h    | 2 +-
 arch/powerpc/mm/mem.c                 | 3 ---
 arch/sparc/mm/highmem.c               | 1 +
 5 files changed, 3 insertions(+), 8 deletions(-)

Comments

Christoph Hellwig May 1, 2020, 8:44 a.m. UTC | #1 
> --- a/arch/sparc/mm/highmem.c
> +++ b/arch/sparc/mm/highmem.c
> @@ -33,6 +33,7 @@
>  #include <asm/vaddrs.h>
>  
>  pgprot_t kmap_prot;
> +EXPORT_SYMBOL(kmap_prot);

Btw, I don't see why sparc needs this as a variable, as there is just
a single assignment to it.

If sparc is sorted out we can always make it a define, and use a define
for kmap_prot that defaults to PAGE_KERNEL, avoiding a little
more duplication.
Ira Weiny May 1, 2020, 3:35 p.m. UTC | #2 
On Fri, May 01, 2020 at 01:44:46AM -0700, Christoph Hellwig wrote:
> > --- a/arch/sparc/mm/highmem.c
> > +++ b/arch/sparc/mm/highmem.c
> > @@ -33,6 +33,7 @@
> >  #include <asm/vaddrs.h>
> >  
> >  pgprot_t kmap_prot;
> > +EXPORT_SYMBOL(kmap_prot);
> 
> Btw, I don't see why sparc needs this as a variable, as there is just
> a single assignment to it.

Because sparc uses non-standard defines which I'm not familiar with.

        kmap_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE);

SRMMU_ET_PTE and friends are defined in 

arch/sparc/include/asm/pgtsrmmu.h

Since I can't readily test sparc this was easier to put out than let 0-day
crank on the entire series checking if including that header in the common
header chain would be an issue.

> 
> If sparc is sorted out we can always make it a define, and use a define
> for kmap_prot that defaults to PAGE_KERNEL, avoiding a little
> more duplication.

Agreed.  But it seems easier as a follow up (for me with 0-day).  Perhaps
someone from sparc can weigh in on the specifics of those defines and why they
are different from the normal ones?  Or even provide a follow on patch?

Ira
diff mbox series

Patch

diff --git a/arch/microblaze/include/asm/highmem.h b/arch/microblaze/include/asm/highmem.h
index 5fc56b0107be..66521fdc3a47 100644
--- a/arch/microblaze/include/asm/highmem.h
+++ b/arch/microblaze/include/asm/highmem.h
@@ -25,8 +25,8 @@ 
 #include <linux/uaccess.h>
 #include <asm/fixmap.h>
 
+#define kmap_prot		PAGE_KERNEL
 extern pte_t *kmap_pte;
-extern pgprot_t kmap_prot;
 extern pte_t *pkmap_page_table;
 
 /*
diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c
index 1ffbfa96b9b8..a467686c13af 100644
--- a/arch/microblaze/mm/init.c
+++ b/arch/microblaze/mm/init.c
@@ -49,8 +49,6 @@  unsigned long lowmem_size;
 #ifdef CONFIG_HIGHMEM
 pte_t *kmap_pte;
 EXPORT_SYMBOL(kmap_pte);
-pgprot_t kmap_prot;
-EXPORT_SYMBOL(kmap_prot);
 
 static inline pte_t *virt_to_kpte(unsigned long vaddr)
 {
@@ -68,7 +66,6 @@  static void __init highmem_init(void)
 	pkmap_page_table = virt_to_kpte(PKMAP_BASE);
 
 	kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
-	kmap_prot = PAGE_KERNEL;
 }
 
 static void highmem_setup(void)
diff --git a/arch/powerpc/include/asm/highmem.h b/arch/powerpc/include/asm/highmem.h
index 1845fbd7ce61..d264aebcaa9b 100644
--- a/arch/powerpc/include/asm/highmem.h
+++ b/arch/powerpc/include/asm/highmem.h
@@ -29,8 +29,8 @@ 
 #include <asm/page.h>
 #include <asm/fixmap.h>
 
+#define kmap_prot		PAGE_KERNEL
 extern pte_t *kmap_pte;
-extern pgprot_t kmap_prot;
 extern pte_t *pkmap_page_table;
 
 /*
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 041ed7cfd341..3f642b058731 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -64,8 +64,6 @@  bool init_mem_is_free;
 #ifdef CONFIG_HIGHMEM
 pte_t *kmap_pte;
 EXPORT_SYMBOL(kmap_pte);
-pgprot_t kmap_prot;
-EXPORT_SYMBOL(kmap_prot);
 #endif
 
 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
@@ -245,7 +243,6 @@  void __init paging_init(void)
 	pkmap_page_table = virt_to_kpte(PKMAP_BASE);
 
 	kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
-	kmap_prot = PAGE_KERNEL;
 #endif /* CONFIG_HIGHMEM */
 
 	printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
diff --git a/arch/sparc/mm/highmem.c b/arch/sparc/mm/highmem.c
index 469786bc430f..9f06d75e88e1 100644
--- a/arch/sparc/mm/highmem.c
+++ b/arch/sparc/mm/highmem.c
@@ -33,6 +33,7 @@ 
 #include <asm/vaddrs.h>
 
 pgprot_t kmap_prot;
+EXPORT_SYMBOL(kmap_prot);
 
 static pte_t *kmap_pte;