[PATCH] kdump: cleanups for dump file access in linear raw format

[linux-2.6-microblaze.git] / drivers / char / mem.c

diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 257b8ee..b64108d 100644 (file)
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -23,7 +23,10 @@
 #include <linux/devfs_fs_kernel.h>
 #include <linux/ptrace.h>
 #include <linux/device.h>
+#include <linux/highmem.h>
+#include <linux/crash_dump.h>
 #include <linux/backing-dev.h>
+#include <linux/bootmem.h>
 
 #include <asm/uaccess.h>
 #include <asm/io.h>
@@ -273,6 +276,40 @@ static int mmap_kmem(struct file * file, struct vm_area_struct * vma)
        return mmap_mem(file, vma);
 }
 
+#ifdef CONFIG_CRASH_DUMP
+/*
+ * Read memory corresponding to the old kernel.
+ */
+static ssize_t read_oldmem(struct file *file, char __user *buf,
+                               size_t count, loff_t *ppos)
+{
+       unsigned long pfn, offset;
+       size_t read = 0, csize;
+       int rc = 0;
+
+       while(count) {
+               pfn = *ppos / PAGE_SIZE;
+               if (pfn > saved_max_pfn)
+                       return read;
+
+               offset = (unsigned long)(*ppos % PAGE_SIZE);
+               if (count > PAGE_SIZE - offset)
+                       csize = PAGE_SIZE - offset;
+               else
+                       csize = count;
+
+               rc = copy_oldmem_page(pfn, buf, csize, offset, 1);
+               if (rc < 0)
+                       return rc;
+               buf += csize;
+               *ppos += csize;
+               read += csize;
+               count -= csize;
+       }
+       return read;
+}
+#endif
+
 extern long vread(char *buf, char *addr, unsigned long count);
 extern long vwrite(char *buf, char *addr, unsigned long count);
 
@@ -484,7 +521,7 @@ static ssize_t write_kmem(struct file * file, const char __user * buf,
        return virtr + wrote;
 }
 
-#if defined(CONFIG_ISA) || !defined(__mc68000__)
+#if (defined(CONFIG_ISA) || !defined(__mc68000__)) && (!defined(CONFIG_PPC_ISERIES) || defined(CONFIG_PCI))
 static ssize_t read_port(struct file * file, char __user * buf,
                         size_t count, loff_t *ppos)
 {
@@ -721,6 +758,7 @@ static int open_port(struct inode * inode, struct file * filp)
 #define read_full       read_zero
 #define open_mem       open_port
 #define open_kmem      open_mem
+#define open_oldmem    open_mem
 
 static struct file_operations mem_fops = {
        .llseek         = memory_lseek,
@@ -744,7 +782,7 @@ static struct file_operations null_fops = {
        .write          = write_null,
 };
 
-#if defined(CONFIG_ISA) || !defined(__mc68000__)
+#if (defined(CONFIG_ISA) || !defined(__mc68000__)) && (!defined(CONFIG_PPC_ISERIES) || defined(CONFIG_PCI))
 static struct file_operations port_fops = {
        .llseek         = memory_lseek,
        .read           = read_port,
@@ -770,6 +808,13 @@ static struct file_operations full_fops = {
        .write          = write_full,
 };
 
+#ifdef CONFIG_CRASH_DUMP
+static struct file_operations oldmem_fops = {
+       .read   = read_oldmem,
+       .open   = open_oldmem,
+};
+#endif
+
 static ssize_t kmsg_write(struct file * file, const char __user * buf,
                          size_t count, loff_t *ppos)
 {
@@ -804,7 +849,7 @@ static int memory_open(struct inode * inode, struct file * filp)
                case 3:
                        filp->f_op = &null_fops;
                        break;
-#if defined(CONFIG_ISA) || !defined(__mc68000__)
+#if (defined(CONFIG_ISA) || !defined(__mc68000__)) && (!defined(CONFIG_PPC_ISERIES) || defined(CONFIG_PCI))
                case 4:
                        filp->f_op = &port_fops;
                        break;
@@ -825,6 +870,11 @@ static int memory_open(struct inode * inode, struct file * filp)
                case 11:
                        filp->f_op = &kmsg_fops;
                        break;
+#ifdef CONFIG_CRASH_DUMP
+               case 12:
+                       filp->f_op = &oldmem_fops;
+                       break;
+#endif
                default:
                        return -ENXIO;
        }
@@ -846,7 +896,7 @@ static const struct {
        {1, "mem",     S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops},
        {2, "kmem",    S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops},
        {3, "null",    S_IRUGO | S_IWUGO,           &null_fops},
-#if defined(CONFIG_ISA) || !defined(__mc68000__)
+#if (defined(CONFIG_ISA) || !defined(__mc68000__)) && (!defined(CONFIG_PPC_ISERIES) || defined(CONFIG_PCI))
        {4, "port",    S_IRUSR | S_IWUSR | S_IRGRP, &port_fops},
 #endif
        {5, "zero",    S_IRUGO | S_IWUGO,           &zero_fops},
@@ -854,6 +904,9 @@ static const struct {
        {8, "random",  S_IRUGO | S_IWUSR,           &random_fops},
        {9, "urandom", S_IRUGO | S_IWUSR,           &urandom_fops},
        {11,"kmsg",    S_IRUGO | S_IWUSR,           &kmsg_fops},
+#ifdef CONFIG_CRASH_DUMP
+       {12,"oldmem",    S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops},
+#endif
 };
 
 static struct class *mem_class;