[U-Boot] [PATCH] ARM: cfi_flash: Fix unaligned accesses to cfi_qry structure

[Andrew Gabbasov]

Packed structure cfi_qry contains unaligned 16- and 32-bits members,
accessing which causes problems when cfi_flash driver is compiled with
-munaligned-access option: flash initialization hangs, probably
due to data error.

This fix converts 16- and 32-bit members to byte arrays and uses special
macros to access such fields. It removes possible unaligned accesses
in cfi_flash driver.

Signed-off-by: Andrew Gabbasov <andrew_gabbasov at mentor.com>
---
 drivers/mtd/cfi_flash.c |   23 +++++++++++++----------
 include/mtd/cfi_flash.h |   18 +++++++++++-------
 2 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
index 60dbb78..2112ffc 100644
--- a/drivers/mtd/cfi_flash.c
+++ b/drivers/mtd/cfi_flash.c
@@ -1636,13 +1636,16 @@ void flash_read_factory_serial (flash_info_t * info, void *buffer, int offset,
  */
 static void cfi_reverse_geometry(struct cfi_qry *qry)
 {
-	unsigned int i, j;
-	u32 tmp;
+	unsigned int i, j, k;
+	u8 tmp;
 
 	for (i = 0, j = qry->num_erase_regions - 1; i < j; i++, j--) {
-		tmp = qry->erase_region_info[i];
-		qry->erase_region_info[i] = qry->erase_region_info[j];
-		qry->erase_region_info[j] = tmp;
+		for (k = 0; k < 4; k++) {
+			tmp = qry->erase_region_info[k][i];
+			qry->erase_region_info[k][i] =
+				qry->erase_region_info[k][j];
+			qry->erase_region_info[k][j] = tmp;
+		}
 	}
 }
 
@@ -1891,7 +1894,7 @@ static int __flash_detect_cfi (flash_info_t * info, struct cfi_qry *qry)
 		    && flash_isequal (info, 0, FLASH_OFFSET_CFI_RESP + 2, 'Y')) {
 			flash_read_cfi(info, qry, FLASH_OFFSET_CFI_RESP,
 					sizeof(struct cfi_qry));
-			info->interface	= le16_to_cpu(qry->interface_desc);
+			info->interface	= cfiqry_get16(qry->interface_desc);
 
 			info->cfi_offset = flash_offset_cfi[cfi_offset];
 			debug ("device interface is %d\n",
@@ -2053,8 +2056,8 @@ ulong flash_get_size (phys_addr_t base, int banknum)
 	info->start[0] = (ulong)map_physmem(base, info->portwidth, MAP_NOCACHE);
 
 	if (flash_detect_cfi (info, &qry)) {
-		info->vendor = le16_to_cpu(qry.p_id);
-		info->ext_addr = le16_to_cpu(qry.p_adr);
+		info->vendor = cfiqry_get16(qry.p_id);
+		info->ext_addr = cfiqry_get16(qry.p_adr);
 		num_erase_regions = qry.num_erase_regions;
 
 		if (info->ext_addr) {
@@ -2140,7 +2143,7 @@ ulong flash_get_size (phys_addr_t base, int banknum)
 				break;
 			}
 
-			tmp = le32_to_cpu(qry.erase_region_info[i]);
+			tmp = cfiqry_get32(qry.erase_region_info[i]);
 			debug("erase region %u: 0x%08lx\n", i, tmp);
 
 			erase_region_count = (tmp & 0xffff) + 1;
@@ -2213,7 +2216,7 @@ ulong flash_get_size (phys_addr_t base, int banknum)
 		}
 
 		info->sector_count = sect_cnt;
-		info->buffer_size = 1 << le16_to_cpu(qry.max_buf_write_size);
+		info->buffer_size = 1 << cfiqry_get16(qry.max_buf_write_size);
 		tmp = 1 << qry.block_erase_timeout_typ;
 		info->erase_blk_tout = tmp *
 			(1 << qry.block_erase_timeout_max);
diff --git a/include/mtd/cfi_flash.h b/include/mtd/cfi_flash.h
index 966b5e0..30d6896 100644
--- a/include/mtd/cfi_flash.h
+++ b/include/mtd/cfi_flash.h
@@ -131,10 +131,10 @@ typedef union {
 /* CFI standard query structure */
 struct cfi_qry {
 	u8	qry[3];
-	u16	p_id;
-	u16	p_adr;
-	u16	a_id;
-	u16	a_adr;
+	u8	p_id[2];
+	u8	p_adr[2];
+	u8	a_id[2];
+	u8	a_adr[2];
 	u8	vcc_min;
 	u8	vcc_max;
 	u8	vpp_min;
@@ -148,10 +148,10 @@ struct cfi_qry {
 	u8	block_erase_timeout_max;
 	u8	chip_erase_timeout_max;
 	u8	dev_size;
-	u16	interface_desc;
-	u16	max_buf_write_size;
+	u8	interface_desc[2];
+	u8	max_buf_write_size[2];
 	u8	num_erase_regions;
-	u32	erase_region_info[NUM_ERASE_REGIONS];
+	u8	erase_region_info[4][NUM_ERASE_REGIONS];
 } __attribute__((packed));
 
 struct cfi_pri_hdr {
@@ -160,6 +160,10 @@ struct cfi_pri_hdr {
 	u8	minor_version;
 } __attribute__((packed));
 
+#define cfiqry_get16(mp) ((u16)((mp)[0]) | ((u16)((mp)[1]) << 8))
+#define cfiqry_get32(mp) ((u32)((mp)[0]) | ((u32)((mp)[1]) << 8) | \
+			  ((u32)((mp)[2]) << 16) | ((u32)((mp)[3]) << 24))
+
 #ifndef CONFIG_SYS_FLASH_BANKS_LIST
 #define CONFIG_SYS_FLASH_BANKS_LIST { CONFIG_SYS_FLASH_BASE }
 #endif
-- 
1.7.10.4