gpu/drm, x86, PAT: routine to keep identity map in sync

Add a function to check and keep identity maps in sync, when changing
any memory type. One of the follow on patches will also use this
routine.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Eric Anholt <eric@anholt.net>
Cc: Keith Packard <keithp@keithp.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/include/asm/pat.h b/arch/x86/include/asm/pat.h
index b8493b3b98901c811add567762a22b73aaa85c9a..abb3c29fc9d5c6cd725cdf51db028e97d78e89de 100644 (file)
--- a/arch/x86/include/asm/pat.h
+++ b/arch/x86/include/asm/pat.h
@@ -19,4 +19,7 @@ extern int free_memtype(u64 start, u64 end);
 
 extern void pat_disable(char *reason);
 
+extern int kernel_map_sync_memtype(u64 base, unsigned long size,
+               unsigned long flag);
+
 #endif /* _ASM_X86_PAT_H */

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index aebbf67a79d02326724e91065180675ecb525637..399383c6f614b817c7acd70f1e0cf5d99a3fc12e 100644 (file)
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -624,6 +624,33 @@ void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
        free_memtype(addr, addr + size);
 }
 
+/*
+ * Change the memory type for the physial address range in kernel identity
+ * mapping space if that range is a part of identity map.
+ */
+int kernel_map_sync_memtype(u64 base, unsigned long size, unsigned long flags)
+{
+       unsigned long id_sz;
+
+       if (!pat_enabled || base >= __pa(high_memory))
+               return 0;
+
+       id_sz = (__pa(high_memory) < base + size) ?
+                               __pa(high_memory) - base :
+                               size;
+
+       if (ioremap_change_attr((unsigned long)__va(base), id_sz, flags) < 0) {
+               printk(KERN_INFO
+                       "%s:%d ioremap_change_attr failed %s "
+                       "for %Lx-%Lx\n",
+                       current->comm, current->pid,
+                       cattr_name(flags),
+                       base, (unsigned long long)(base + size));
+               return -EINVAL;
+       }
+       return 0;
+}
+
 /*
  * Internal interface to reserve a range of physical memory with prot.
  * Reserved non RAM regions only and after successful reserve_memtype,
@@ -633,7 +660,7 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot,
                                int strict_prot)
 {
        int is_ram = 0;
-       int id_sz, ret;
+       int ret;
        unsigned long flags;
        unsigned long want_flags = (pgprot_val(*vma_prot) & _PAGE_CACHE_MASK);
 
@@ -670,23 +697,8 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot,
                                     flags);
        }
 
-       /* Need to keep identity mapping in sync */
-       if (paddr >= __pa(high_memory))
-               return 0;
-
-       id_sz = (__pa(high_memory) < paddr + size) ?
-                               __pa(high_memory) - paddr :
-                               size;
-
-       if (ioremap_change_attr((unsigned long)__va(paddr), id_sz, flags) < 0) {
+       if (kernel_map_sync_memtype(paddr, size, flags) < 0) {
                free_memtype(paddr, paddr + size);
-               printk(KERN_ERR
-                       "%s:%d reserve_pfn_range ioremap_change_attr failed %s "
-                       "for %Lx-%Lx\n",
-                       current->comm, current->pid,
-                       cattr_name(flags),
-                       (unsigned long long)paddr,
-                       (unsigned long long)(paddr + size));
                return -EINVAL;
        }
        return 0;