MIPS: OCTEON: Protect accesses to bootbus flash with octeon_bootbus_sem.

Without this, we get bus errors.

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9460/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 41 insertions, 1 deletions

diff --git a/arch/mips/cavium-octeon/flash_setup.c b/arch/mips/cavium-octeon/flash_setup.c
index 237e5b1a72d8..39e26dfe7d8d 100644
--- a/arch/mips/cavium-octeon/flash_setup.c
+++ b/arch/mips/cavium-octeon/flash_setup.c
@@ -9,6 +9,7 @@
  */
 #include <linux/kernel.h>
 #include <linux/export.h>
+#include <linux/semaphore.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/map.h>
 #include <linux/mtd/partitions.h>
@@ -25,6 +26,41 @@ static const char *part_probe_types[] = {
         NULL
 };
 
+static map_word octeon_flash_map_read(struct map_info *map, unsigned long ofs)
+{
+        map_word r;
+
+        down(&octeon_bootbus_sem);
+        r = inline_map_read(map, ofs);
+        up(&octeon_bootbus_sem);
+
+        return r;
+}
+
+static void octeon_flash_map_write(struct map_info *map, const map_word datum,
+                                   unsigned long ofs)
+{
+        down(&octeon_bootbus_sem);
+        inline_map_write(map, datum, ofs);
+        up(&octeon_bootbus_sem);
+}
+
+static void octeon_flash_map_copy_from(struct map_info *map, void *to,
+                                       unsigned long from, ssize_t len)
+{
+        down(&octeon_bootbus_sem);
+        inline_map_copy_from(map, to, from, len);
+        up(&octeon_bootbus_sem);
+}
+
+static void octeon_flash_map_copy_to(struct map_info *map, unsigned long to,
+                                     const void *from, ssize_t len)
+{
+        down(&octeon_bootbus_sem);
+        inline_map_copy_to(map, to, from, len);
+        up(&octeon_bootbus_sem);
+}
+
 /**
  * Module/ driver initialization.
  *
@@ -56,7 +92,11 @@ static int __init flash_init(void)
                 flash_map.virt = ioremap(flash_map.phys, flash_map.size);
                 pr_notice("Bootbus flash: Setting flash for %luMB flash at "
                           "0x%08llx\n", flash_map.size >> 20, flash_map.phys);
-                simple_map_init(&flash_map);
+                WARN_ON(!map_bankwidth_supported(flash_map.bankwidth));
+                flash_map.read = octeon_flash_map_read;
+                flash_map.write = octeon_flash_map_write;
+                flash_map.copy_from = octeon_flash_map_copy_from;
+                flash_map.copy_to = octeon_flash_map_copy_to;
                 mymtd = do_map_probe("cfi_probe", &flash_map);
                 if (mymtd) {
                         mymtd->owner = THIS_MODULE;