Merge branch 'master' of git://eden-feed.erg.abdn.ac.uk/net-next-2.6

[mirror_ubuntu-artful-kernel.git] / drivers / char / mem.c

diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 83495885ada0e00fbf0ce33b13d03cc7ac746082..934ffafedaea207131f7d193bed9e75c929f4db9 100644 (file)
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -41,36 +41,7 @@
  */
 static inline int uncached_access(struct file *file, unsigned long addr)
 {
-#if defined(__i386__) && !defined(__arch_um__)
-       /*
-        * On the PPro and successors, the MTRRs are used to set
-        * memory types for physical addresses outside main memory,
-        * so blindly setting PCD or PWT on those pages is wrong.
-        * For Pentiums and earlier, the surround logic should disable
-        * caching for the high addresses through the KEN pin, but
-        * we maintain the tradition of paranoia in this code.
-        */
-       if (file->f_flags & O_SYNC)
-               return 1;
-       return !( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) ||
-                 test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) ||
-                 test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) ||
-                 test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability) )
-         && addr >= __pa(high_memory);
-#elif defined(__x86_64__) && !defined(__arch_um__)
-       /* 
-        * This is broken because it can generate memory type aliases,
-        * which can cause cache corruptions
-        * But it is only available for root and we have to be bug-to-bug
-        * compatible with i386.
-        */
-       if (file->f_flags & O_SYNC)
-               return 1;
-       /* same behaviour as i386. PAT always set to cached and MTRRs control the
-          caching behaviour. 
-          Hopefully a full PAT implementation will fix that soon. */      
-       return 0;
-#elif defined(CONFIG_IA64)
+#if defined(CONFIG_IA64)
        /*
         * On ia64, we ignore O_SYNC because we cannot tolerate memory attribute aliases.
         */
@@ -283,6 +254,12 @@ static ssize_t write_mem(struct file * file, const char __user * buf,
        return written;
 }
 
+int __attribute__((weak)) phys_mem_access_prot_allowed(struct file *file,
+       unsigned long pfn, unsigned long size, pgprot_t *vma_prot)
+{
+       return 1;
+}
+
 #ifndef __HAVE_PHYS_MEM_ACCESS_PROT
 static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
                                     unsigned long size, pgprot_t vma_prot)
@@ -323,6 +300,35 @@ 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
+};
+
 static int mmap_mem(struct file * file, struct vm_area_struct * vma)
 {
        size_t size = vma->vm_end - vma->vm_start;
@@ -336,20 +342,29 @@ static int mmap_mem(struct file * file, struct vm_area_struct * vma)
        if (!range_is_allowed(vma->vm_pgoff, size))
                return -EPERM;
 
+       if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size,
+                                               &vma->vm_page_prot))
+               return -EINVAL;
+
        vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
                                                 size,
                                                 vma->vm_page_prot);
 
+       vma->vm_ops = &mmap_mem_ops;
+
        /* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */
        if (remap_pfn_range(vma,
                            vma->vm_start,
                            vma->vm_pgoff,
                            size,
-                           vma->vm_page_prot))
+                           vma->vm_page_prot)) {
+               unmap_devmem(vma->vm_pgoff, size, vma->vm_page_prot);
                return -EAGAIN;
+       }
        return 0;
 }
 
+#ifdef CONFIG_DEVKMEM
 static int mmap_kmem(struct file * file, struct vm_area_struct * vma)
 {
        unsigned long pfn;
@@ -370,6 +385,7 @@ static int mmap_kmem(struct file * file, struct vm_area_struct * vma)
        vma->vm_pgoff = pfn;
        return mmap_mem(file, vma);
 }
+#endif
 
 #ifdef CONFIG_CRASH_DUMP
 /*
@@ -408,6 +424,7 @@ static ssize_t read_oldmem(struct file *file, char __user *buf,
 extern long vread(char *buf, char *addr, unsigned long count);
 extern long vwrite(char *buf, char *addr, unsigned long count);
 
+#ifdef CONFIG_DEVKMEM
 /*
  * This function reads the *virtual* memory as seen by the kernel.
  */
@@ -612,6 +629,7 @@ static ssize_t write_kmem(struct file * file, const char __user * buf,
        *ppos = p;
        return virtr + wrote;
 }
+#endif
 
 #ifdef CONFIG_DEVPORT
 static ssize_t read_port(struct file * file, char __user * buf,
@@ -789,6 +807,7 @@ static const struct file_operations mem_fops = {
        .get_unmapped_area = get_unmapped_area_mem,
 };
 
+#ifdef CONFIG_DEVKMEM
 static const struct file_operations kmem_fops = {
        .llseek         = memory_lseek,
        .read           = read_kmem,
@@ -797,6 +816,7 @@ static const struct file_operations kmem_fops = {
        .open           = open_kmem,
        .get_unmapped_area = get_unmapped_area_mem,
 };
+#endif
 
 static const struct file_operations null_fops = {
        .llseek         = null_lseek,
@@ -875,11 +895,13 @@ static int memory_open(struct inode * inode, struct file * filp)
                        filp->f_mapping->backing_dev_info =
                                &directly_mappable_cdev_bdi;
                        break;
+#ifdef CONFIG_DEVKMEM
                case 2:
                        filp->f_op = &kmem_fops;
                        filp->f_mapping->backing_dev_info =
                                &directly_mappable_cdev_bdi;
                        break;
+#endif
                case 3:
                        filp->f_op = &null_fops;
                        break;
@@ -928,7 +950,9 @@ static const struct {
        const struct file_operations    *fops;
 } devlist[] = { /* list of minor devices */
        {1, "mem",     S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops},
+#ifdef CONFIG_DEVKMEM
        {2, "kmem",    S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops},
+#endif
        {3, "null",    S_IRUGO | S_IWUGO,           &null_fops},
 #ifdef CONFIG_DEVPORT
        {4, "port",    S_IRUSR | S_IWUSR | S_IRGRP, &port_fops},