mtd: introduce mtd_erase interface

This patch is part of a patch-set which changes the MTD interface
from 'mtd->func()' form to 'mtd_func()' form. We need this because
we want to add common code to to all drivers in the mtd core level,
which is impossible with the current interface when MTD clients
call driver functions like 'read()' or 'write()' directly.

At this point we just introduce a new inline wrapper function, but
later some of them are expected to gain more code. E.g., the input
parameters check should be moved to the wrappers rather than be
duplicated at many drivers.

This particular patch introduced the 'mtd_erase()' interface. The
following patches add all the other interfaces one by one.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

22 files changed, 37 insertions, 28 deletions

diff --git a/drivers/mtd/ftl.c b/drivers/mtd/ftl.c
index c7382bb686c6..a982889277c8 100644
--- a/drivers/mtd/ftl.c
+++ b/drivers/mtd/ftl.c
@@ -355,7 +355,7 @@ static int erase_xfer(partition_t *part,
     erase->len = 1 << part->header.EraseUnitSize;
     erase->priv = (u_long)part;
 
-    ret = part->mbd.mtd->erase(part->mbd.mtd, erase);
+    ret = mtd_erase(part->mbd.mtd, erase);
 
     if (!ret)
             xfer->EraseCount++;
diff --git a/drivers/mtd/inftlmount.c b/drivers/mtd/inftlmount.c
index 2ff601f816ce..0d946f10a682 100644
--- a/drivers/mtd/inftlmount.c
+++ b/drivers/mtd/inftlmount.c
@@ -220,7 +220,7 @@ static int find_boot_record(struct INFTLrecord *inftl)
                                  */
                                 instr->addr = ip->Reserved0 * inftl->EraseSize;
                                 instr->len = inftl->EraseSize;
-                                mtd->erase(mtd, instr);
+                                mtd_erase(mtd, instr);
                         }
                         if ((ip->lastUnit - ip->firstUnit + 1) < ip->virtualUnits) {
                                 printk(KERN_WARNING "INFTL: Media Header "
@@ -393,7 +393,7 @@ int INFTL_formatblock(struct INFTLrecord *inftl, int block)
            mark only the failed block in the bbt. */
         for (physblock = 0; physblock < inftl->EraseSize;
              physblock += instr->len, instr->addr += instr->len) {
-                mtd->erase(inftl->mbd.mtd, instr);
+                mtd_erase(inftl->mbd.mtd, instr);
 
                 if (instr->state == MTD_ERASE_FAILED) {
                         printk(KERN_WARNING "INFTL: error while formatting block %d\n",
diff --git a/drivers/mtd/mtdblock.c b/drivers/mtd/mtdblock.c
index 7c1dc908a174..9b01cb0266e4 100644
--- a/drivers/mtd/mtdblock.c
+++ b/drivers/mtd/mtdblock.c
@@ -85,7 +85,7 @@ static int erase_write (struct mtd_info *mtd, unsigned long pos,
         set_current_state(TASK_INTERRUPTIBLE);
         add_wait_queue(&wait_q, &wait);
 
-        ret = mtd->erase(mtd, &erase);
+        ret = mtd_erase(mtd, &erase);
         if (ret) {
                 set_current_state(TASK_RUNNING);
                 remove_wait_queue(&wait_q, &wait);
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 00423cc85807..41d64ff4c252 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -731,7 +731,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
                           wq_head is no longer there when the
                           callback routine tries to wake us up.
                         */
-                        ret = mtd->erase(mtd, erase);
+                        ret = mtd_erase(mtd, erase);
                         if (!ret) {
                                 set_current_state(TASK_UNINTERRUPTIBLE);
                                 add_wait_queue(&waitq, &wait);
diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c
index 6df4d4d4eb92..76123bd49314 100644
--- a/drivers/mtd/mtdconcat.c
+++ b/drivers/mtd/mtdconcat.c
@@ -379,7 +379,7 @@ static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase)
          * FIXME: Allow INTERRUPTIBLE. Which means
          * not having the wait_queue head on the stack.
          */
-        err = mtd->erase(mtd, erase);
+        err = mtd_erase(mtd, erase);
         if (!err) {
                 set_current_state(TASK_UNINTERRUPTIBLE);
                 add_wait_queue(&waitq, &wait);
diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c
index f3cdce9a85a6..9b2d86323169 100644
--- a/drivers/mtd/mtdoops.c
+++ b/drivers/mtd/mtdoops.c
@@ -112,7 +112,7 @@ static int mtdoops_erase_block(struct mtdoops_context *cxt, int offset)
         set_current_state(TASK_INTERRUPTIBLE);
         add_wait_queue(&wait_q, &wait);
 
-        ret = mtd->erase(mtd, &erase);
+        ret = mtd_erase(mtd, &erase);
         if (ret) {
                 set_current_state(TASK_RUNNING);
                 remove_wait_queue(&wait_q, &wait);
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index a0bd2de4752b..d318fee28595 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -257,7 +257,7 @@ static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
         if (instr->addr >= mtd->size)
                 return -EINVAL;
         instr->addr += part->offset;
-        ret = part->master->erase(part->master, instr);
+        ret = mtd_erase(part->master, instr);
         if (ret) {
                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
                         instr->fail_addr -= part->offset;
diff --git a/drivers/mtd/mtdswap.c b/drivers/mtd/mtdswap.c
index bd9590c723e4..4e12875a916c 100644
--- a/drivers/mtd/mtdswap.c
+++ b/drivers/mtd/mtdswap.c
@@ -567,7 +567,7 @@ retry:
         erase.len       = mtd->erasesize;
         erase.priv      = (u_long)&wq;
 
-        ret = mtd->erase(mtd, &erase);
+        ret = mtd_erase(mtd, &erase);
         if (ret) {
                 if (retries++ < MTDSWAP_ERASE_RETRIES) {
                         dev_warn(d->dev,
diff --git a/drivers/mtd/nftlmount.c b/drivers/mtd/nftlmount.c
index ac4092591aea..9164a56fb5c0 100644
--- a/drivers/mtd/nftlmount.c
+++ b/drivers/mtd/nftlmount.c
@@ -326,7 +326,7 @@ int NFTL_formatblock(struct NFTLrecord *nftl, int block)
         instr->mtd = nftl->mbd.mtd;
         instr->addr = block * nftl->EraseSize;
         instr->len = nftl->EraseSize;
-        mtd->erase(mtd, instr);
+        mtd_erase(mtd, instr);
 
         if (instr->state == MTD_ERASE_FAILED) {
                 printk("Error while formatting block %d\n", block);
diff --git a/drivers/mtd/rfd_ftl.c b/drivers/mtd/rfd_ftl.c
index 73ae217a4252..39de8727a524 100644
--- a/drivers/mtd/rfd_ftl.c
+++ b/drivers/mtd/rfd_ftl.c
@@ -342,7 +342,7 @@ static int erase_block(struct partition *part, int block)
         part->blocks[block].state = BLOCK_ERASING;
         part->blocks[block].free_sectors = 0;
 
-        rc = part->mbd.mtd->erase(part->mbd.mtd, erase);
+        rc = mtd_erase(part->mbd.mtd, erase);
 
         if (rc) {
                 printk(KERN_ERR PREFIX "erase of region %llx,%llx on '%s' "
diff --git a/drivers/mtd/sm_ftl.c b/drivers/mtd/sm_ftl.c
index 1c9f307ae0a1..2f1acb1ab5e8 100644
--- a/drivers/mtd/sm_ftl.c
+++ b/drivers/mtd/sm_ftl.c
@@ -479,7 +479,7 @@ static int sm_erase_block(struct sm_ftl *ftl, int zone_num, uint16_t block,
                 return -EIO;
         }
 
-        if (mtd->erase(mtd, &erase)) {
+        if (mtd_erase(mtd, &erase)) {
                 sm_printk("erase of block %d in zone %d failed",
                                                         block, zone_num);
                 goto error;
diff --git a/drivers/mtd/tests/mtd_oobtest.c b/drivers/mtd/tests/mtd_oobtest.c
index 933f7e5f32d3..7d52854c16dd 100644
--- a/drivers/mtd/tests/mtd_oobtest.c
+++ b/drivers/mtd/tests/mtd_oobtest.c
@@ -78,7 +78,7 @@ static int erase_eraseblock(int ebnum)
         ei.addr = addr;
         ei.len  = mtd->erasesize;
 
-        err = mtd->erase(mtd, &ei);
+        err = mtd_erase(mtd, &ei);
         if (err) {
                 printk(PRINT_PREF "error %d while erasing EB %d\n", err, ebnum);
                 return err;
diff --git a/drivers/mtd/tests/mtd_pagetest.c b/drivers/mtd/tests/mtd_pagetest.c
index afafb6935fd0..271819fabb55 100644
--- a/drivers/mtd/tests/mtd_pagetest.c
+++ b/drivers/mtd/tests/mtd_pagetest.c
@@ -77,7 +77,7 @@ static int erase_eraseblock(int ebnum)
         ei.addr = addr;
         ei.len  = mtd->erasesize;
 
-        err = mtd->erase(mtd, &ei);
+        err = mtd_erase(mtd, &ei);
         if (err) {
                 printk(PRINT_PREF "error %d while erasing EB %d\n", err, ebnum);
                 return err;
diff --git a/drivers/mtd/tests/mtd_speedtest.c b/drivers/mtd/tests/mtd_speedtest.c
index 493b367bdd35..f67a65e21043 100644
--- a/drivers/mtd/tests/mtd_speedtest.c
+++ b/drivers/mtd/tests/mtd_speedtest.c
@@ -79,7 +79,7 @@ static int erase_eraseblock(int ebnum)
         ei.addr = addr;
         ei.len  = mtd->erasesize;
 
-        err = mtd->erase(mtd, &ei);
+        err = mtd_erase(mtd, &ei);
         if (err) {
                 printk(PRINT_PREF "error %d while erasing EB %d\n", err, ebnum);
                 return err;
@@ -105,7 +105,7 @@ static int multiblock_erase(int ebnum, int blocks)
         ei.addr = addr;
         ei.len  = mtd->erasesize * blocks;
 
-        err = mtd->erase(mtd, &ei);
+        err = mtd_erase(mtd, &ei);
         if (err) {
                 printk(PRINT_PREF "error %d while erasing EB %d, blocks %d\n",
                        err, ebnum, blocks);
diff --git a/drivers/mtd/tests/mtd_stresstest.c b/drivers/mtd/tests/mtd_stresstest.c
index 811642fea6b4..a204a9f90524 100644
--- a/drivers/mtd/tests/mtd_stresstest.c
+++ b/drivers/mtd/tests/mtd_stresstest.c
@@ -112,7 +112,7 @@ static int erase_eraseblock(int ebnum)
         ei.addr = addr;
         ei.len  = mtd->erasesize;
 
-        err = mtd->erase(mtd, &ei);
+        err = mtd_erase(mtd, &ei);
         if (unlikely(err)) {
                 printk(PRINT_PREF "error %d while erasing EB %d\n", err, ebnum);
                 return err;
diff --git a/drivers/mtd/tests/mtd_subpagetest.c b/drivers/mtd/tests/mtd_subpagetest.c
index 1a05bfac4eee..16d0c05024d7 100644
--- a/drivers/mtd/tests/mtd_subpagetest.c
+++ b/drivers/mtd/tests/mtd_subpagetest.c
@@ -80,7 +80,7 @@ static int erase_eraseblock(int ebnum)
         ei.addr = addr;
         ei.len  = mtd->erasesize;
 
-        err = mtd->erase(mtd, &ei);
+        err = mtd_erase(mtd, &ei);
         if (err) {
                 printk(PRINT_PREF "error %d while erasing EB %d\n", err, ebnum);
                 return err;
diff --git a/drivers/mtd/tests/mtd_torturetest.c b/drivers/mtd/tests/mtd_torturetest.c
index 03ab649a6964..102c79b7ac66 100644
--- a/drivers/mtd/tests/mtd_torturetest.c
+++ b/drivers/mtd/tests/mtd_torturetest.c
@@ -105,7 +105,7 @@ static inline int erase_eraseblock(int ebnum)
         ei.addr = addr;
         ei.len  = mtd->erasesize;
 
-        err = mtd->erase(mtd, &ei);
+        err = mtd_erase(mtd, &ei);
         if (err) {
                 printk(PRINT_PREF "error %d while erasing EB %d\n", err, ebnum);
                 return err;
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index f20b6f22f240..b6c8959e6c7e 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -361,7 +361,7 @@ retry:
         ei.callback = erase_callback;
         ei.priv     = (unsigned long)&wq;
 
-        err = ubi->mtd->erase(ubi->mtd, &ei);
+        err = mtd_erase(ubi->mtd, &ei);
         if (err) {
                 if (retries++ < UBI_IO_RETRIES) {
                         dbg_io("error %d while erasing PEB %d, retry",
diff --git a/drivers/staging/spectra/lld_mtd.c b/drivers/staging/spectra/lld_mtd.c
index a9c309a167c2..d638fafab649 100644
--- a/drivers/staging/spectra/lld_mtd.c
+++ b/drivers/staging/spectra/lld_mtd.c
@@ -188,7 +188,7 @@ u16 mtd_Erase_Block(u32 block_add)
         erase.len = spectra_mtd->erasesize;
         erase.priv = (unsigned long)&comp;
 
-        ret = spectra_mtd->erase(spectra_mtd, &erase);
+        ret = mtd_erase(spectra_mtd, &erase);
         if (!ret) {
                 wait_for_completion(&comp);
                 if (erase.state != MTD_ERASE_DONE)
diff --git a/fs/jffs2/erase.c b/fs/jffs2/erase.c
index e513f1913c15..540e8eca1b49 100644
--- a/fs/jffs2/erase.c
+++ b/fs/jffs2/erase.c
@@ -74,7 +74,7 @@ static void jffs2_erase_block(struct jffs2_sb_info *c,
         ((struct erase_priv_struct *)instr->priv)->jeb = jeb;
         ((struct erase_priv_struct *)instr->priv)->c = c;
 
-        ret = c->mtd->erase(c->mtd, instr);
+        ret = mtd_erase(c->mtd, instr);
         if (!ret)
                 return;
 
diff --git a/fs/logfs/dev_mtd.c b/fs/logfs/dev_mtd.c
index eb423ebcf538..046362894352 100644
--- a/fs/logfs/dev_mtd.c
+++ b/fs/logfs/dev_mtd.c
@@ -105,7 +105,7 @@ static int logfs_mtd_erase(struct super_block *sb, loff_t ofs, size_t len,
         ei.len = len;
         ei.callback = logfs_erase_callback;
         ei.priv = (long)&complete;
-        ret = mtd->erase(mtd, &ei);
+        ret = mtd_erase(mtd, &ei);
         if (ret)
                 return -EIO;
 
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 9f5b312af783..201bad557047 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -171,11 +171,8 @@ struct mtd_info {
         struct mtd_erase_region_info *eraseregions;
 
         /*
-         * Erase is an asynchronous operation.  Device drivers are supposed
-         * to call instr->callback() whenever the operation completes, even
-         * if it completes with a failure.
-         * Callers are supposed to pass a callback function and wait for it
-         * to be called before writing to the block.
+         * Do not call via these pointers, use corresponding mtd_*()
+         * wrappers instead.
          */
         int (*erase) (struct mtd_info *mtd, struct erase_info *instr);
 
@@ -274,6 +271,18 @@ struct mtd_info {
         void (*put_device) (struct mtd_info *mtd);
 };
 
+/*
+ * Erase is an asynchronous operation.  Device drivers are supposed
+ * to call instr->callback() whenever the operation completes, even
+ * if it completes with a failure.
+ * Callers are supposed to pass a callback function and wait for it
+ * to be called before writing to the block.
+ */
+static inline int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+        return mtd->erase(mtd, instr);
+}
+
 static inline struct mtd_info *dev_to_mtd(struct device *dev)
 {
         return dev ? dev_get_drvdata(dev) : NULL;