[U-Boot] [PATCH 2/2] fs/fat: Optimizes memory size with single global variable instead of 3
Tien Fong Chee
tfchee at altera.com
Thu Jul 28 08:11:08 CEST 2016
Single 64KB get_contents_vfatname_block global variable would be used for
all FAT implementation instead of allocating additional two global variables
which are get_denfromdir_block and do_fat_read_at_block. This implementation
can help in saving up 128KB memory space.
Signed-off-by: Tien Fong Chee <tfchee at altera.com>
---
Changes for V2:
- Renaming all references to get_dentfromdir_block and removing redundant
Cc: Dinh Nguyen <dinguyen at opensource.altera.com>
Cc: Dinh Nguyen <dinh.linux at gmail.com>
Cc: ChinLiang <clsee at altera.com>
Cc: Vagrant Cascadian <vagrant at debian.org>
Cc: Simon Glass <sjg at chromium.org>
Cc: Stephen Warren <swarren at nvidia.com>
Cc: Benoît Thébaudeau <benoit at wsystem.com>
---
fs/fat/fat.c | 23 +++++++++--------------
fs/fat/fat_write.c | 20 ++++++--------------
2 files changed, 15 insertions(+), 28 deletions(-)
diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index 826bd85..7f42af7 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -327,7 +327,7 @@ get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
* into 'buffer'.
* Update the number of bytes read in *gotsize or return -1 on fatal errors.
*/
-__u8 get_contents_vfatname_block[MAX_CLUSTSIZE]
+__u8 get_dentfromdir_block[MAX_CLUSTSIZE]
__aligned(ARCH_DMA_MINALIGN);
static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
@@ -373,14 +373,14 @@ static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
/* align to beginning of next cluster if any */
if (pos) {
actsize = min(filesize, (loff_t)bytesperclust);
- if (get_cluster(mydata, curclust, get_contents_vfatname_block,
+ if (get_cluster(mydata, curclust, get_dentfromdir_block,
(int)actsize) != 0) {
printf("Error reading cluster\n");
return -1;
}
filesize -= actsize;
actsize -= pos;
- memcpy(buffer, get_contents_vfatname_block + pos, actsize);
+ memcpy(buffer, get_dentfromdir_block + pos, actsize);
*gotsize += actsize;
if (!filesize)
return 0;
@@ -515,13 +515,13 @@ get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
return -1;
}
- if (get_cluster(mydata, curclust, get_contents_vfatname_block,
+ if (get_cluster(mydata, curclust, get_dentfromdir_block,
mydata->clust_size * mydata->sect_size) != 0) {
debug("Error: reading directory block\n");
return -1;
}
- slotptr2 = (dir_slot *)get_contents_vfatname_block;
+ slotptr2 = (dir_slot *)get_dentfromdir_block;
while (counter > 0) {
if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
& 0xff) != counter)
@@ -532,7 +532,7 @@ get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
/* Save the real directory entry */
realdent = (dir_entry *)slotptr2;
- while ((__u8 *)slotptr2 > get_contents_vfatname_block) {
+ while ((__u8 *)slotptr2 > get_dentfromdir_block) {
slotptr2--;
slot2str(slotptr2, l_name, &idx);
}
@@ -579,8 +579,6 @@ static __u8 mkcksum(const char name[8], const char ext[3])
* Get the directory entry associated with 'filename' from the directory
* starting at 'startsect'
*/
-__u8 get_dentfromdir_block[MAX_CLUSTSIZE]
- __aligned(ARCH_DMA_MINALIGN);
static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
char *filename, dir_entry *retdent,
@@ -811,9 +809,6 @@ exit:
return ret;
}
-__u8 do_fat_read_at_block[MAX_CLUSTSIZE]
- __aligned(ARCH_DMA_MINALIGN);
-
int do_fat_read_at(const char *filename, loff_t pos, void *buffer,
loff_t maxsize, int dols, int dogetsize, loff_t *size)
{
@@ -927,7 +922,7 @@ root_reparse:
int i;
if (mydata->fatsize == 32 || firsttime) {
- dir_ptr = do_fat_read_at_block;
+ dir_ptr = get_dentfromdir_block;
firsttime = 0;
} else {
/**
@@ -947,8 +942,8 @@ root_reparse:
* 0 | sector n+1 | sector n+2 | sector n+3 |
* 1 | sector n+3 | ...
*/
- dir_ptr = (do_fat_read_at_block + mydata->sect_size);
- memcpy(do_fat_read_at_block, dir_ptr, mydata->sect_size);
+ dir_ptr = (get_dentfromdir_block + mydata->sect_size);
+ memcpy(get_dentfromdir_block, dir_ptr, mydata->sect_size);
}
do_read = 1;
diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index c1d48c5..62f32bf 100644
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -369,7 +369,6 @@ static __u32 dir_curclust;
* a slot) into 'l_name'. If successful also copy the real directory entry
* into 'retdent'
* If additional adjacent cluster for directory entries is read into memory,
- * then 'get_contents_vfatname_block' is copied into 'get_dentfromdir_block' and
* the location of the real directory entry is returned by 'retdent'
* Return 0 on success, -1 otherwise.
*/
@@ -384,7 +383,7 @@ get_long_file_name(fsdata *mydata, int curclust, __u8 *cluster,
PREFETCH_BLOCKS :
mydata->clust_size);
__u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
- int idx = 0, cur_position = 0;
+ int idx = 0;
if (counter > VFAT_MAXSEQ) {
debug("Error: VFAT name is too long\n");
@@ -412,13 +411,13 @@ get_long_file_name(fsdata *mydata, int curclust, __u8 *cluster,
dir_curclust = curclust;
- if (get_cluster(mydata, curclust, get_contents_vfatname_block,
+ if (get_cluster(mydata, curclust, get_dentfromdir_block,
mydata->clust_size * mydata->sect_size) != 0) {
debug("Error: reading directory block\n");
return -1;
}
- slotptr2 = (dir_slot *)get_contents_vfatname_block;
+ slotptr2 = (dir_slot *)get_dentfromdir_block;
while (counter > 0) {
if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
& 0xff) != counter)
@@ -429,7 +428,7 @@ get_long_file_name(fsdata *mydata, int curclust, __u8 *cluster,
/* Save the real directory entry */
realdent = (dir_entry *)slotptr2;
- while ((__u8 *)slotptr2 > get_contents_vfatname_block) {
+ while ((__u8 *)slotptr2 > get_dentfromdir_block) {
slotptr2--;
slot2str(slotptr2, l_name, &idx);
}
@@ -454,13 +453,6 @@ get_long_file_name(fsdata *mydata, int curclust, __u8 *cluster,
/* Return the real directory entry */
*retdent = realdent;
- if (slotptr2) {
- memcpy(get_dentfromdir_block, get_contents_vfatname_block,
- mydata->clust_size * mydata->sect_size);
- cur_position = (__u8 *)realdent - get_contents_vfatname_block;
- *retdent = (dir_entry *) &get_dentfromdir_block[cur_position];
- }
-
return 0;
}
@@ -1024,11 +1016,11 @@ static int do_fat_write(const char *filename, void *buffer, loff_t size,
if (disk_read(cursect,
(mydata->fatsize == 32) ?
(mydata->clust_size) :
- PREFETCH_BLOCKS, do_fat_read_at_block) < 0) {
+ PREFETCH_BLOCKS, get_dentfromdir_block) < 0) {
debug("Error: reading rootdir block\n");
goto exit;
}
- dentptr = (dir_entry *) do_fat_read_at_block;
+ dentptr = (dir_entry *) get_dentfromdir_block;
name_len = strlen(filename);
if (name_len >= VFAT_MAXLEN_BYTES)
--
1.8.2.1
More information about the U-Boot
mailing list