From ab59753a9df09b990822b15d2593c5c98905684c Mon Sep 17 00:00:00 2001 From: Xiangfu Liu Date: Wed, 14 Sep 2011 14:29:51 +0800 Subject: [PATCH 27/32] Add DEVMEM support --- drivers/char/Kconfig | 10 ++++++++++ drivers/char/mem.c | 17 +++++++++++++++++ 2 files changed, 27 insertions(+), 0 deletions(-) diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index 49502bc..770f678 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -6,6 +6,16 @@ menu "Character devices" source "drivers/tty/Kconfig" +config DEVMEM + bool "/dev/mem virtual device support" + default y + help + Say Y here if you want to support the /dev/mem device. + Some X server drivers access the video hardware using this device. + Accessing hardware directly from user space can be useful in some + cases, but it is not without risks. + When in doubt, say "N". + config DEVKMEM bool "/dev/kmem virtual device support" default y diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 8fc04b4..eb78f37 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -86,6 +86,8 @@ void __weak unxlate_dev_mem_ptr(unsigned long phys, void *addr) { } +#ifdef CONFIG_DEVMEM + /* * This funcion reads the *physical* memory. The f_pos points directly to the * memory location. @@ -209,6 +211,10 @@ static ssize_t write_mem(struct file *file, const char __user *buf, return written; } +#endif + +#if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM) + int __weak phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, unsigned long size, pgprot_t *vma_prot) { @@ -330,6 +336,8 @@ static int mmap_mem(struct file *file, struct vm_area_struct *vma) return 0; } +#endif + #ifdef CONFIG_DEVKMEM static int mmap_kmem(struct file *file, struct vm_area_struct *vma) { @@ -693,6 +701,7 @@ static loff_t null_lseek(struct file *file, loff_t offset, int orig) return file->f_pos = 0; } +#if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM) || defined(CONFIG_DEVPORT) /* * The memory devices use the full 32/64 bits of the offset, and so we cannot * check against negative addresses: they are ok. The return value is weird, @@ -725,11 +734,15 @@ static loff_t memory_lseek(struct file *file, loff_t offset, int orig) mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); return ret; } +#endif +#if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM) || \ + defined(CONFIG_DEVPORT) || defined(CONFIG_CRASH_DUMP) static int open_port(struct inode * inode, struct file * filp) { return capable(CAP_SYS_RAWIO) ? 0 : -EPERM; } +#endif #define zero_lseek null_lseek #define full_lseek null_lseek @@ -739,6 +752,7 @@ static int open_port(struct inode * inode, struct file * filp) #define open_kmem open_mem #define open_oldmem open_mem +#ifdef CONFIG_DEVMEM static const struct file_operations mem_fops = { .llseek = memory_lseek, .read = read_mem, @@ -747,6 +761,7 @@ static const struct file_operations mem_fops = { .open = open_mem, .get_unmapped_area = get_unmapped_area_mem, }; +#endif #ifdef CONFIG_DEVKMEM static const struct file_operations kmem_fops = { @@ -850,7 +865,9 @@ static const struct memdev { const struct file_operations *fops; struct backing_dev_info *dev_info; } devlist[] = { +#ifdef CONFIG_DEVMEM [1] = { "mem", 0, &mem_fops, &directly_mappable_cdev_bdi }, +#endif #ifdef CONFIG_DEVKMEM [2] = { "kmem", 0, &kmem_fops, &directly_mappable_cdev_bdi }, #endif -- 1.7.4.1