Merge tag 'char-misc-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregk...

[linux-drm-fsl-dcu.git] / drivers / char / mem.c

diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 4c58333b42570d233ccfaa83dac3c67f69e73b49..297110c12635d3b8c36b53a7f089aa2666024eca 100644 (file)
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -28,7 +28,7 @@
 #include <linux/io.h>
 #include <linux/aio.h>
 
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 
 #ifdef CONFIG_IA64
 # include <linux/efi.h>
@@ -287,13 +287,24 @@ static unsigned long get_unmapped_area_mem(struct file *file,
        return pgoff << PAGE_SHIFT;
 }
 
+/* permit direct mmap, for read, write or exec */
+static unsigned memory_mmap_capabilities(struct file *file)
+{
+       return NOMMU_MAP_DIRECT |
+               NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC;
+}
+
+static unsigned zero_mmap_capabilities(struct file *file)
+{
+       return NOMMU_MAP_COPY;
+}
+
 /* can't do an in-place private mapping if there's no MMU */
 static inline int private_mapping_ok(struct vm_area_struct *vma)
 {
        return vma->vm_flags & VM_MAYSHARE;
 }
 #else
-#define get_unmapped_area_mem  NULL
 
 static inline int private_mapping_ok(struct vm_area_struct *vma)
 {
@@ -341,7 +352,6 @@ static int mmap_mem(struct file *file, struct vm_area_struct *vma)
        return 0;
 }
 
-#ifdef CONFIG_DEVKMEM
 static int mmap_kmem(struct file *file, struct vm_area_struct *vma)
 {
        unsigned long pfn;
@@ -362,9 +372,7 @@ static int mmap_kmem(struct file *file, struct vm_area_struct *vma)
        vma->vm_pgoff = pfn;
        return mmap_mem(file, vma);
 }
-#endif
 
-#ifdef CONFIG_DEVKMEM
 /*
  * This function reads the *virtual* memory as seen by the kernel.
  */
@@ -544,9 +552,7 @@ static ssize_t write_kmem(struct file *file, const char __user *buf,
        *ppos = p;
        return virtr + wrote ? : err;
 }
-#endif
 
-#ifdef CONFIG_DEVPORT
 static ssize_t read_port(struct file *file, char __user *buf,
                         size_t count, loff_t *ppos)
 {
@@ -575,6 +581,7 @@ static ssize_t write_port(struct file *file, const char __user *buf,
                return -EFAULT;
        while (count-- > 0 && i < 65536) {
                char c;
+
                if (__get_user(c, tmp)) {
                        if (tmp > buf)
                                break;
@@ -587,7 +594,6 @@ static ssize_t write_port(struct file *file, const char __user *buf,
        *ppos = i;
        return tmp-buf;
 }
-#endif
 
 static ssize_t read_null(struct file *file, char __user *buf,
                         size_t count, loff_t *ppos)
@@ -631,6 +637,7 @@ static ssize_t read_iter_zero(struct kiocb *iocb, struct iov_iter *iter)
 
        while (iov_iter_count(iter)) {
                size_t chunk = iov_iter_count(iter), n;
+
                if (chunk > PAGE_SIZE)
                        chunk = PAGE_SIZE;      /* Just for latency reasons */
                n = iov_iter_zero(chunk, iter);
@@ -715,25 +722,29 @@ static int open_port(struct inode *inode, struct file *filp)
 #define open_mem       open_port
 #define open_kmem      open_mem
 
-static const struct file_operations mem_fops = {
+static const struct file_operations __maybe_unused mem_fops = {
        .llseek         = memory_lseek,
        .read           = read_mem,
        .write          = write_mem,
        .mmap           = mmap_mem,
        .open           = open_mem,
+#ifndef CONFIG_MMU
        .get_unmapped_area = get_unmapped_area_mem,
+       .mmap_capabilities = memory_mmap_capabilities,
+#endif
 };
 
-#ifdef CONFIG_DEVKMEM
-static const struct file_operations kmem_fops = {
+static const struct file_operations __maybe_unused kmem_fops = {
        .llseek         = memory_lseek,
        .read           = read_kmem,
        .write          = write_kmem,
        .mmap           = mmap_kmem,
        .open           = open_kmem,
+#ifndef CONFIG_MMU
        .get_unmapped_area = get_unmapped_area_mem,
-};
+       .mmap_capabilities = memory_mmap_capabilities,
 #endif
+};
 
 static const struct file_operations null_fops = {
        .llseek         = null_lseek,
@@ -744,14 +755,12 @@ static const struct file_operations null_fops = {
        .splice_write   = splice_write_null,
 };
 
-#ifdef CONFIG_DEVPORT
-static const struct file_operations port_fops = {
+static const struct file_operations __maybe_unused port_fops = {
        .llseek         = memory_lseek,
        .read           = read_port,
        .write          = write_port,
        .open           = open_port,
 };
-#endif
 
 static const struct file_operations zero_fops = {
        .llseek         = zero_lseek,
@@ -760,16 +769,9 @@ static const struct file_operations zero_fops = {
        .read_iter      = read_iter_zero,
        .aio_write      = aio_write_zero,
        .mmap           = mmap_zero,
-};
-
-/*
- * capabilities for /dev/zero
- * - permits private mappings, "copies" are taken of the source of zeros
- * - no writeback happens
- */
-static struct backing_dev_info zero_bdi = {
-       .name           = "char/mem",
-       .capabilities   = BDI_CAP_MAP_COPY | BDI_CAP_NO_ACCT_AND_WRITEBACK,
+#ifndef CONFIG_MMU
+       .mmap_capabilities = zero_mmap_capabilities,
+#endif
 };
 
 static const struct file_operations full_fops = {
@@ -783,22 +785,24 @@ static const struct memdev {
        const char *name;
        umode_t mode;
        const struct file_operations *fops;
-       struct backing_dev_info *dev_info;
+       fmode_t fmode;
 } devlist[] = {
-        [1] = { "mem", 0, &mem_fops, &directly_mappable_cdev_bdi },
+#ifdef CONFIG_DEVMEM
+        [1] = { "mem", 0, &mem_fops, FMODE_UNSIGNED_OFFSET },
+#endif
 #ifdef CONFIG_DEVKMEM
-        [2] = { "kmem", 0, &kmem_fops, &directly_mappable_cdev_bdi },
+        [2] = { "kmem", 0, &kmem_fops, FMODE_UNSIGNED_OFFSET },
 #endif
-        [3] = { "null", 0666, &null_fops, NULL },
+        [3] = { "null", 0666, &null_fops, 0 },
 #ifdef CONFIG_DEVPORT
-        [4] = { "port", 0, &port_fops, NULL },
+        [4] = { "port", 0, &port_fops, 0 },
 #endif
-        [5] = { "zero", 0666, &zero_fops, &zero_bdi },
-        [7] = { "full", 0666, &full_fops, NULL },
-        [8] = { "random", 0666, &random_fops, NULL },
-        [9] = { "urandom", 0666, &urandom_fops, NULL },
+        [5] = { "zero", 0666, &zero_fops, 0 },
+        [7] = { "full", 0666, &full_fops, 0 },
+        [8] = { "random", 0666, &random_fops, 0 },
+        [9] = { "urandom", 0666, &urandom_fops, 0 },
 #ifdef CONFIG_PRINTK
-       [11] = { "kmsg", 0644, &kmsg_fops, NULL },
+       [11] = { "kmsg", 0644, &kmsg_fops, 0 },
 #endif
 };
 
@@ -816,12 +820,7 @@ static int memory_open(struct inode *inode, struct file *filp)
                return -ENXIO;
 
        filp->f_op = dev->fops;
-       if (dev->dev_info)
-               filp->f_mapping->backing_dev_info = dev->dev_info;
-
-       /* Is /dev/mem or /dev/kmem ? */
-       if (dev->dev_info == &directly_mappable_cdev_bdi)
-               filp->f_mode |= FMODE_UNSIGNED_OFFSET;
+       filp->f_mode |= dev->fmode;
 
        if (dev->fops->open)
                return dev->fops->open(inode, filp);
@@ -846,11 +845,6 @@ static struct class *mem_class;
 static int __init chr_dev_init(void)
 {
        int minor;
-       int err;
-
-       err = bdi_init(&zero_bdi);
-       if (err)
-               return err;
 
        if (register_chrdev(MEM_MAJOR, "mem", &memory_fops))
                printk("unable to get major %d for memory devs\n", MEM_MAJOR);