[generic:] preliminary 3.12 support

[openwrt.git] / target / linux / generic / patches-3.12 / 411-mtd-partial_eraseblock_write.patch

diff --git a/target/linux/generic/patches-3.12/411-mtd-partial_eraseblock_write.patch b/target/linux/generic/patches-3.12/411-mtd-partial_eraseblock_write.patch
new file mode 100644 (file)
index 0000000..7ecb331
--- /dev/null
+++ b/target/linux/generic/patches-3.12/411-mtd-partial_eraseblock_write.patch
@@ -0,0 +1,145 @@
+--- a/drivers/mtd/mtdpart.c
++++ b/drivers/mtd/mtdpart.c
+@@ -36,6 +36,8 @@
+ #include "mtdcore.h"
+ #include "mtdsplit.h"
+ 
++#define MTD_ERASE_PARTIAL     0x8000 /* partition only covers parts of an erase block */
++
+ /* Our partition linked list */
+ static LIST_HEAD(mtd_partitions);
+ static DEFINE_MUTEX(mtd_partitions_mutex);
+@@ -232,13 +234,60 @@ static int part_erase(struct mtd_info *m
+       struct mtd_part *part = PART(mtd);
+       int ret;
+ 
++
++      instr->partial_start = false;
++      if (mtd->flags & MTD_ERASE_PARTIAL) {
++              size_t readlen = 0;
++              u64 mtd_ofs;
++
++              instr->erase_buf = kmalloc(part->master->erasesize, GFP_ATOMIC);
++              if (!instr->erase_buf)
++                      return -ENOMEM;
++
++              mtd_ofs = part->offset + instr->addr;
++              instr->erase_buf_ofs = do_div(mtd_ofs, part->master->erasesize);
++
++              if (instr->erase_buf_ofs > 0) {
++                      instr->addr -= instr->erase_buf_ofs;
++                      ret = mtd_read(part->master,
++                              instr->addr + part->offset,
++                              part->master->erasesize,
++                              &readlen, instr->erase_buf);
++
++                      instr->partial_start = true;
++              } else {
++                      mtd_ofs = part->offset + part->mtd.size;
++                      instr->erase_buf_ofs = part->master->erasesize -
++                              do_div(mtd_ofs, part->master->erasesize);
++
++                      if (instr->erase_buf_ofs > 0) {
++                              instr->len += instr->erase_buf_ofs;
++                              ret = mtd_read(part->master,
++                                      part->offset + instr->addr +
++                                      instr->len - part->master->erasesize,
++                                      part->master->erasesize, &readlen,
++                                      instr->erase_buf);
++                      } else {
++                              ret = 0;
++                      }
++              }
++              if (ret < 0) {
++                      kfree(instr->erase_buf);
++                      return ret;
++              }
++
++      }
++
+       instr->addr += part->offset;
+       ret = part->master->_erase(part->master, instr);
+       if (ret) {
+               if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
+                       instr->fail_addr -= part->offset;
+               instr->addr -= part->offset;
++              if (mtd->flags & MTD_ERASE_PARTIAL)
++                      kfree(instr->erase_buf);
+       }
++
+       return ret;
+ }
+ 
+@@ -246,7 +295,25 @@ void mtd_erase_callback(struct erase_inf
+ {
+       if (instr->mtd->_erase == part_erase) {
+               struct mtd_part *part = PART(instr->mtd);
++              size_t wrlen = 0;
+ 
++              if (instr->mtd->flags & MTD_ERASE_PARTIAL) {
++                      if (instr->partial_start) {
++                              part->master->_write(part->master,
++                                      instr->addr, instr->erase_buf_ofs,
++                                      &wrlen, instr->erase_buf);
++                              instr->addr += instr->erase_buf_ofs;
++                      } else {
++                              instr->len -= instr->erase_buf_ofs;
++                              part->master->_write(part->master,
++                                      instr->addr + instr->len,
++                                      instr->erase_buf_ofs, &wrlen,
++                                      instr->erase_buf +
++                                      part->master->erasesize -
++                                      instr->erase_buf_ofs);
++                      }
++                      kfree(instr->erase_buf);
++              }
+               if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
+                       instr->fail_addr -= part->offset;
+               instr->addr -= part->offset;
+@@ -504,18 +571,24 @@ static struct mtd_part *allocate_partiti
+       if ((slave->mtd.flags & MTD_WRITEABLE) &&
+           mtd_mod_by_eb(slave->offset, &slave->mtd)) {
+               /* Doesn't start on a boundary of major erase size */
+-              /* FIXME: Let it be writable if it is on a boundary of
+-               * _minor_ erase size though */
+-              slave->mtd.flags &= ~MTD_WRITEABLE;
+-              printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
+-                      part->name);
++              slave->mtd.flags |= MTD_ERASE_PARTIAL;
++              if (((u32) slave->mtd.size) > master->erasesize)
++                      slave->mtd.flags &= ~MTD_WRITEABLE;
++              else
++                      slave->mtd.erasesize = slave->mtd.size;
+       }
+       if ((slave->mtd.flags & MTD_WRITEABLE) &&
+-          mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
+-              slave->mtd.flags &= ~MTD_WRITEABLE;
+-              printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
+-                      part->name);
++          mtd_mod_by_eb(slave->offset + slave->mtd.size, &slave->mtd)) {
++              slave->mtd.flags |= MTD_ERASE_PARTIAL;
++
++              if ((u32) slave->mtd.size > master->erasesize)
++                      slave->mtd.flags &= ~MTD_WRITEABLE;
++              else
++                      slave->mtd.erasesize = slave->mtd.size;
+       }
++      if ((slave->mtd.flags & (MTD_ERASE_PARTIAL|MTD_WRITEABLE)) == MTD_ERASE_PARTIAL)
++              printk(KERN_WARNING"mtd: partition \"%s\" must either start or end on erase block boundary or be smaller than an erase block -- forcing read-only\n",
++                              part->name);
+ 
+       slave->mtd.ecclayout = master->ecclayout;
+       slave->mtd.ecc_step_size = master->ecc_step_size;
+--- a/include/linux/mtd/mtd.h
++++ b/include/linux/mtd/mtd.h
+@@ -58,6 +58,10 @@ struct erase_info {
+       u_long priv;
+       u_char state;
+       struct erase_info *next;
++
++      u8 *erase_buf;
++      u32 erase_buf_ofs;
++      bool partial_start;
+ };
+ 
+ struct mtd_erase_region_info {