From: Ian Pratt This patch adds ARCH_HAS_DEV_MEM, enabling per-architecture implementations of /dev/mem and thus avoids a number of messy #ifdef's. Although the mmap case can be solved easily be simply using io_remap_page_range instead of remap_pfn_range on all architecutres, we need to support read/write of /dev/mem in order for dmidecode etc to work. These changes are more messy, and we believe warrant making /dev/mem arch specific, which also cleans up uncached_access too. Signed-off-by: Ian Pratt Signed-off-by: Andrew Morton --- 25-akpm/drivers/char/mem.c | 11 ++++++++--- 1 files changed, 8 insertions(+), 3 deletions(-) diff -puN drivers/char/mem.c~xen-vmm-4-has_arch_dev_mem drivers/char/mem.c --- 25/drivers/char/mem.c~xen-vmm-4-has_arch_dev_mem 2004-12-07 23:41:32.164651912 -0800 +++ 25-akpm/drivers/char/mem.c 2004-12-07 23:41:32.169651152 -0800 @@ -143,7 +143,7 @@ static ssize_t do_write_mem(void *p, uns return written; } - +#ifndef ARCH_HAS_DEV_MEM /* * This funcion reads the *physical* memory. The f_pos points directly to the * memory location. @@ -189,8 +189,9 @@ static ssize_t write_mem(struct file * f return -EFAULT; return do_write_mem(__va(p), p, buf, count, ppos); } +#endif -static int mmap_mem(struct file * file, struct vm_area_struct * vma) +static int mmap_kmem(struct file * file, struct vm_area_struct * vma) { #ifdef pgprot_noncached unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; @@ -567,7 +568,7 @@ static int open_port(struct inode * inod return capable(CAP_SYS_RAWIO) ? 0 : -EPERM; } -#define mmap_kmem mmap_mem +#define mmap_mem mmap_kmem #define zero_lseek null_lseek #define full_lseek null_lseek #define write_zero write_null @@ -575,6 +576,7 @@ static int open_port(struct inode * inod #define open_mem open_port #define open_kmem open_mem +#ifndef ARCH_HAS_DEV_MEM static struct file_operations mem_fops = { .llseek = memory_lseek, .read = read_mem, @@ -582,6 +584,9 @@ static struct file_operations mem_fops = .mmap = mmap_mem, .open = open_mem, }; +#else +extern struct file_operations mem_fops; +#endif static struct file_operations kmem_fops = { .llseek = memory_lseek, _