x86, PAT: Remove duplicate memtype reserve in devmem mmap

/dev/mem mmap code was doing memtype reserve/free for a while now.
Recently we added memtype tracking in remap_pfn_range, and /dev/mem mmap
uses it indirectly. So, we don't need seperate tracking in /dev/mem code
any more. That means another ~100 lines of code removed :-).

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20090409212709.085210000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 2 insertions, 89 deletions

diff --git a/arch/x86/include/asm/pat.h b/arch/x86/include/asm/pat.h
index 2cd07b9422f4..7af14e512f97 100644
--- a/arch/x86/include/asm/pat.h
+++ b/arch/x86/include/asm/pat.h
@@ -18,9 +18,5 @@ extern int free_memtype(u64 start, u64 end);
 
 extern int kernel_map_sync_memtype(u64 base, unsigned long size,
                 unsigned long flag);
-extern void map_devmem(unsigned long pfn, unsigned long size,
-                       struct pgprot vma_prot);
-extern void unmap_devmem(unsigned long pfn, unsigned long size,
-                         struct pgprot vma_prot);
 
 #endif /* _ASM_X86_PAT_H */
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 8d3de9580508..cc5e0e24e443 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -536,9 +536,7 @@ static inline int range_is_allowed(unsigned long pfn, unsigned long size)
 int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
                                 unsigned long size, pgprot_t *vma_prot)
 {
-        u64 offset = ((u64) pfn) << PAGE_SHIFT;
-        unsigned long flags = -1;
-        int retval;
+        unsigned long flags = _PAGE_CACHE_WB;
 
         if (!range_is_allowed(pfn, size))
                 return 0;
@@ -566,65 +564,11 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
         }
 #endif
 
-        /*
-         * With O_SYNC, we can only take UC_MINUS mapping. Fail if we cannot.
-         *
-         * Without O_SYNC, we want to get
-         * - WB for WB-able memory and no other conflicting mappings
-         * - UC_MINUS for non-WB-able memory with no other conflicting mappings
-         * - Inherit from confliting mappings otherwise
-         */
-        if (flags != -1) {
-                retval = reserve_memtype(offset, offset + size, flags, NULL);
-        } else {
-                retval = reserve_memtype(offset, offset + size,
-                                        _PAGE_CACHE_WB, &flags);
-        }
-
-        if (retval < 0)
-                return 0;
-
-        if (((pfn < max_low_pfn_mapped) ||
-             (pfn >= (1UL<<(32 - PAGE_SHIFT)) && pfn < max_pfn_mapped)) &&
-            ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) {
-                free_memtype(offset, offset + size);
-                printk(KERN_INFO
-                "%s:%d /dev/mem ioremap_change_attr failed %s for %Lx-%Lx\n",
-                        current->comm, current->pid,
-                        cattr_name(flags),
-                        offset, (unsigned long long)(offset + size));
-                return 0;
-        }
-
         *vma_prot = __pgprot((pgprot_val(*vma_prot) & ~_PAGE_CACHE_MASK) |
                              flags);
         return 1;
 }
 
-void map_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
-{
-        unsigned long want_flags = (pgprot_val(vma_prot) & _PAGE_CACHE_MASK);
-        u64 addr = (u64)pfn << PAGE_SHIFT;
-        unsigned long flags;
-
-        reserve_memtype(addr, addr + size, want_flags, &flags);
-        if (flags != want_flags) {
-                printk(KERN_INFO
-                "%s:%d /dev/mem expected mapping type %s for %Lx-%Lx, got %s\n",
-                        current->comm, current->pid,
-                        cattr_name(want_flags),
-                        addr, (unsigned long long)(addr + size),
-                        cattr_name(flags));
-        }
-}
-
-void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
-{
-        u64 addr = (u64)pfn << PAGE_SHIFT;
-
-        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.
@@ -662,8 +606,8 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot,
 {
         int is_ram = 0;
         int ret;
-        unsigned long flags;
         unsigned long want_flags = (pgprot_val(*vma_prot) & _PAGE_CACHE_MASK);
+        unsigned long flags = want_flags;
 
         is_ram = pat_pagerange_is_ram(paddr, paddr + size);
 
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 3586b3b3df3f..8f05c38c2f06 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -301,33 +301,7 @@ static inline int private_mapping_ok(struct vm_area_struct *vma)
 }
 #endif
 
-void __attribute__((weak))
-map_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)
-{
-        /* nothing. architectures can override. */
-}
-
-void __attribute__((weak))
-unmap_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)
-{
-        /* nothing. architectures can override. */
-}
-
-static void mmap_mem_open(struct vm_area_struct *vma)
-{
-        map_devmem(vma->vm_pgoff,  vma->vm_end - vma->vm_start,
-                        vma->vm_page_prot);
-}
-
-static void mmap_mem_close(struct vm_area_struct *vma)
-{
-        unmap_devmem(vma->vm_pgoff,  vma->vm_end - vma->vm_start,
-                        vma->vm_page_prot);
-}
-
 static struct vm_operations_struct mmap_mem_ops = {
-        .open  = mmap_mem_open,
-        .close = mmap_mem_close,
 #ifdef CONFIG_HAVE_IOREMAP_PROT
         .access = generic_access_phys
 #endif
@@ -362,7 +336,6 @@ static int mmap_mem(struct file * file, struct vm_area_struct * vma)
                             vma->vm_pgoff,
                             size,
                             vma->vm_page_prot)) {
-                unmap_devmem(vma->vm_pgoff, size, vma->vm_page_prot);
                 return -EAGAIN;
         }
         return 0;