cfi_flash: Fix unaligned accesses to cfi_qry structure

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.

Since the structure is supposed to replicate the actual data layout
in CFI Flash chips, the alignment issue can't be fixed in the structure.
So, unaligned fields need using of explicit unaligned access macros.

Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Reviewed-By: Albert ARIBAUD <albert.u.boot@aribaud.net>
Signed-off-by: Stefan Roese <sr@denx.de>

diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
index 22d8440..f6759a8 100644 (file)
--- a/drivers/mtd/cfi_flash.c
+++ b/drivers/mtd/cfi_flash.c
@@ -38,6 +38,7 @@
 #include <asm/processor.h>
 #include <asm/io.h>
 #include <asm/byteorder.h>
+#include <asm/unaligned.h>
 #include <environment.h>
 #include <mtd/cfi_flash.h>
 #include <watchdog.h>
@@ -1640,9 +1641,10 @@ static void cfi_reverse_geometry(struct cfi_qry *qry)
        u32 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;
+               tmp = get_unaligned(&(qry->erase_region_info[i]));
+               put_unaligned(get_unaligned(&(qry->erase_region_info[j])),
+                             &(qry->erase_region_info[i]));
+               put_unaligned(tmp, &(qry->erase_region_info[j]));
        }
 }
 
@@ -2073,8 +2075,8 @@ 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 = le16_to_cpu(get_unaligned(&(qry.p_id)));
+               info->ext_addr = le16_to_cpu(get_unaligned(&(qry.p_adr)));
                num_erase_regions = qry.num_erase_regions;
 
                if (info->ext_addr) {
@@ -2163,7 +2165,8 @@ ulong flash_get_size (phys_addr_t base, int banknum)
                                break;
                        }
 
-                       tmp = le32_to_cpu(qry.erase_region_info[i]);
+                       tmp = le32_to_cpu(get_unaligned(
+                                               &(qry.erase_region_info[i])));
                        debug("erase region %u: 0x%08lx\n", i, tmp);
 
                        erase_region_count = (tmp & 0xffff) + 1;

diff --git a/include/mtd/cfi_flash.h b/include/mtd/cfi_flash.h
index 966b5e0..b644b91 100644 (file)
--- a/include/mtd/cfi_flash.h
+++ b/include/mtd/cfi_flash.h
@@ -129,12 +129,16 @@ typedef union {
 } cfiword_t;
 
 /* CFI standard query structure */
+/* The offsets and sizes of this packed structure members correspond
+ * to the actual layout in CFI Flash chips. Some 16- and 32-bit members
+ * are unaligned and must be accessed with explicit unaligned access macros.
+ */
 struct cfi_qry {
        u8      qry[3];
-       u16     p_id;
-       u16     p_adr;
-       u16     a_id;
-       u16     a_adr;
+       u16     p_id;                   /* unaligned */
+       u16     p_adr;                  /* unaligned */
+       u16     a_id;                   /* unaligned */
+       u16     a_adr;                  /* unaligned */
        u8      vcc_min;
        u8      vcc_max;
        u8      vpp_min;
@@ -148,10 +152,10 @@ struct cfi_qry {
        u8      block_erase_timeout_max;
        u8      chip_erase_timeout_max;
        u8      dev_size;
-       u16     interface_desc;
-       u16     max_buf_write_size;
+       u16     interface_desc;         /* aligned */
+       u16     max_buf_write_size;     /* aligned */
        u8      num_erase_regions;
-       u32     erase_region_info[NUM_ERASE_REGIONS];
+       u32     erase_region_info[NUM_ERASE_REGIONS];   /* unaligned */
 } __attribute__((packed));
 
 struct cfi_pri_hdr {