[PATCH v2 2/3] MIPS: OCTEON: Protect accesses to bootbus flash with octeon_bootbus_sem.

From: Aleksey Makarov
Date: Thu Mar 05 2015 - 09:39:58 EST


From: David Daney <david.daney@xxxxxxxxxx>

Without this, we get bus errors.

Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
Signed-off-by: Aleksey Makarov <aleksey.makarov@xxxxxxxxxx>
---
arch/mips/Kconfig | 1 +
arch/mips/cavium-octeon/flash_setup.c | 42 ++++++++++++++++++++++++++++++++++-
2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index c7a1690..f7804e9 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -793,6 +793,7 @@ config CAVIUM_OCTEON_SOC
select SYS_SUPPORTS_SMP
select NR_CPUS_DEFAULT_16
select BUILTIN_DTB
+ select MTD_COMPLEX_MAPPINGS
help
This option supports all of the Octeon reference boards from Cavium
Networks. It builds a kernel that dynamically determines the Octeon
diff --git a/arch/mips/cavium-octeon/flash_setup.c b/arch/mips/cavium-octeon/flash_setup.c
index 237e5b1..39e26df 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;
--
2.3.0

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