[PATCH] powerpc: force 4k update_flash block and list sizes
From: John Rose <hidden>
Date: 2006-11-07 23:53:26
The enablement of 64k pages on POWER platforms exposed a quirk in the RTAS mechanism for updating firmware. RTAS assumes 4k for flash block and list sizes, and use of any other sizes results in a failure. This patch changes the rtas_flash module to force the use of 4k memory block and list sizes when preparing and sending a firmware image to RTAS. It also changes rtas_flash to use a slab cache to ensure 4k alignment of flash block data. Such alignment is a documented requirement. Signed-off-by: John Rose <redacted> ___ Intended for inclusion for 2.6.20, if appropriate. Thanks! John --- uf_4k-johnrose/arch/powerpc/kernel/rtas_flash.c | 52 +++++++++++++++++++----- 1 files changed, 42 insertions(+), 10 deletions(-) diff -puN arch/powerpc/kernel/rtas_flash.c~uf_4k_alt2 arch/powerpc/kernel/rtas_flash.c
--- uf_4k/arch/powerpc/kernel/rtas_flash.c~uf_4k_alt2 2006-11-06 16:59:27.000000000 -0600
+++ uf_4k-johnrose/arch/powerpc/kernel/rtas_flash.c 2006-11-06 17:02:31.000000000 -0600@@ -72,6 +72,10 @@ #define VALIDATE_BUF_SIZE 4096 #define RTAS_MSG_MAXLEN 64 +/* Quirk - RTAS requires 4k list length and block size */ +#define RTAS_BLKLIST_LENGTH 4096 +#define RTAS_BLK_SIZE 4096 + struct flash_block { char *data; unsigned long length;
@@ -83,7 +87,7 @@ struct flash_block { * into a version/length and translate the pointers * to absolute. */ -#define FLASH_BLOCKS_PER_NODE ((PAGE_SIZE - 16) / sizeof(struct flash_block)) +#define FLASH_BLOCKS_PER_NODE ((RTAS_BLKLIST_LENGTH - 16) / sizeof(struct flash_block)) struct flash_block_list { unsigned long num_blocks; struct flash_block_list *next;
@@ -96,6 +100,9 @@ struct flash_block_list_header { /* just static struct flash_block_list_header rtas_firmware_flash_list = {0, NULL}; +/* Use slab cache to guarantee 4k alignment */ +static kmem_cache_t *flash_block_cache = NULL; + #define FLASH_BLOCK_LIST_VERSION (1UL) /* Local copy of the flash block list.
@@ -153,7 +160,7 @@ static int flash_list_valid(struct flash return FLASH_IMG_NULL_DATA; } block_size = f->blocks[i].length; - if (block_size <= 0 || block_size > PAGE_SIZE) { + if (block_size <= 0 || block_size > RTAS_BLK_SIZE) { return FLASH_IMG_BAD_LEN; } image_size += block_size;
@@ -177,9 +184,9 @@ static void free_flash_list(struct flash while (f) { for (i = 0; i < f->num_blocks; i++) - free_page((unsigned long)(f->blocks[i].data)); + kmem_cache_free(flash_block_cache, f->blocks[i].data); next = f->next; - free_page((unsigned long)f); + kmem_cache_free(flash_block_cache, f); f = next; } }
@@ -278,6 +285,12 @@ static ssize_t rtas_flash_read(struct fi return msglen; } +/* constructor for flash_block_cache */ +void rtas_block_ctor(void *ptr, kmem_cache_t *cache, unsigned long flags) +{ + memset(ptr, 0, RTAS_BLK_SIZE); +} + /* We could be much more efficient here. But to keep this function * simple we allocate a page to the block list no matter how small the * count is. If the system is low on memory it will be just as well
@@ -302,7 +315,7 @@ static ssize_t rtas_flash_write(struct f * proc file */ if (uf->flist == NULL) { - uf->flist = (struct flash_block_list *) get_zeroed_page(GFP_KERNEL); + uf->flist = kmem_cache_alloc(flash_block_cache, GFP_KERNEL); if (!uf->flist) return -ENOMEM; }
@@ -313,21 +326,21 @@ static ssize_t rtas_flash_write(struct f next_free = fl->num_blocks; if (next_free == FLASH_BLOCKS_PER_NODE) { /* Need to allocate another block_list */ - fl->next = (struct flash_block_list *)get_zeroed_page(GFP_KERNEL); + fl->next = kmem_cache_alloc(flash_block_cache, GFP_KERNEL); if (!fl->next) return -ENOMEM; fl = fl->next; next_free = 0; } - if (count > PAGE_SIZE) - count = PAGE_SIZE; - p = (char *)get_zeroed_page(GFP_KERNEL); + if (count > RTAS_BLK_SIZE) + count = RTAS_BLK_SIZE; + p = kmem_cache_alloc(flash_block_cache, GFP_KERNEL); if (!p) return -ENOMEM; if(copy_from_user(p, buffer, count)) { - free_page((unsigned long)p); + kmem_cache_free(flash_block_cache, p); return -EFAULT; } fl->blocks[next_free].data = p;
@@ -791,6 +804,16 @@ int __init rtas_flash_init(void) goto cleanup; rtas_flash_term_hook = rtas_flash_firmware; + + flash_block_cache = kmem_cache_create("rtas_flash_cache", + RTAS_BLK_SIZE, RTAS_BLK_SIZE, 0, + rtas_block_ctor, NULL); + if (!flash_block_cache) { + printk(KERN_ERR "%s: failed to create block cache\n", + __FUNCTION__); + rc = -ENOMEM; + goto cleanup; + } return 0; cleanup:
@@ -804,7 +827,16 @@ cleanup: void __exit rtas_flash_cleanup(void) { + int rc; + rtas_flash_term_hook = NULL; + + if (flash_block_cache) { + rc = kmem_cache_destroy(flash_block_cache); + if (rc) + printk(KERN_WARNING "%s: cache memory leak\n", + __FUNCTION__); + } remove_flash_pde(firmware_flash_pde); remove_flash_pde(firmware_update_pde); remove_flash_pde(validate_pde);
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