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Subject[PATCH 10/16 v5] pramfs: xip operations
From: Marco Stornelli <marco.stornelli@gmail.com>

XIP operations.

Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com>
---
diff -Nurp linux-2.6.36-orig/fs/pramfs/xip.c linux-2.6.36/fs/pramfs/xip.c
--- linux-2.6.36-orig/fs/pramfs/xip.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.36/fs/pramfs/xip.c 2010-12-12 18:34:05.000000000 +0100
@@ -0,0 +1,83 @@
+/*
+ * BRIEF DESCRIPTION
+ *
+ * XIP operations.
+ *
+ * Copyright 2009-2010 Marco Stornelli <marco.stornelli@gmail.com>
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/genhd.h>
+#include <linux/buffer_head.h>
+#include "pram.h"
+#include "xip.h"
+
+static int pram_find_and_alloc_blocks(struct inode *inode, sector_t iblock,
+ sector_t *data_block, int create)
+{
+ int err = -EIO;
+ u64 block;
+
+ mutex_lock(&PRAM_I(inode)->truncate_mutex);
+
+ block = pram_find_data_block(inode, iblock);
+
+ if (!block) {
+ if (!create) {
+ err = -ENODATA;
+ goto err;
+ }
+
+ err = pram_alloc_blocks(inode, iblock, 1);
+ if (err)
+ goto err;
+
+ block = pram_find_data_block(inode, iblock);
+ if (!block) {
+ err = -ENODATA;
+ goto err;
+ }
+ }
+
+ *data_block = block;
+ err = 0;
+
+ err:
+ mutex_unlock(&PRAM_I(inode)->truncate_mutex);
+ return err;
+}
+
+static inline int __pram_get_block(struct inode *inode, pgoff_t pgoff, int create,
+ sector_t *result)
+{
+ int rc = 0;
+
+ rc = pram_find_and_alloc_blocks(inode, (sector_t)pgoff, result, create);
+
+ if (rc == -ENODATA)
+ BUG_ON(create);
+
+ return rc;
+}
+
+int pram_get_xip_mem(struct address_space *mapping, pgoff_t pgoff, int create,
+ void **kmem, unsigned long *pfn)
+{
+ int rc;
+ sector_t block;
+
+ /* first, retrieve the block */
+ rc = __pram_get_block(mapping->host, pgoff, create, &block);
+ if (rc)
+ goto exit;
+
+ *kmem = pram_get_block(mapping->host->i_sb, block);
+ *pfn = page_to_pfn(virt_to_page((unsigned long)*kmem));
+
+exit:
+ return rc;
+}
diff -Nurp linux-2.6.36-orig/fs/pramfs/xip.h linux-2.6.36/fs/pramfs/xip.h
--- linux-2.6.36-orig/fs/pramfs/xip.h 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.36/fs/pramfs/xip.h 2010-11-28 12:37:00.000000000 +0100
@@ -0,0 +1,28 @@
+/*
+ * BRIEF DESCRIPTION
+ *
+ * XIP operations.
+ *
+ * Copyright 2009-2010 Marco Stornelli <marco.stornelli@gmail.com>
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifdef CONFIG_PRAMFS_XIP
+int pram_get_xip_mem(struct address_space *, pgoff_t, int, void **,
+ unsigned long *);
+static inline int pram_use_xip(struct super_block *sb)
+{
+ struct pram_sb_info *sbi = (struct pram_sb_info *)sb->s_fs_info;
+ return sbi->s_mount_opt & PRAM_MOUNT_XIP;
+}
+#define mapping_is_xip(map) unlikely(map->a_ops->get_xip_mem)
+
+#else
+
+#define mapping_is_xip(map) 0
+#define pram_use_xip(sb) 0
+#define pram_get_xip_mem NULL
+
+#endif

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