diff --git a/drivers/net/wireless/intel/iwlwifi/fw/dbg.c b/drivers/net/wireless/intel/iwlwifi/fw/dbg.c index 7fadaec777ce..4c5dbd8248e7 100644 --- a/drivers/net/wireless/intel/iwlwifi/fw/dbg.c +++ b/drivers/net/wireless/intel/iwlwifi/fw/dbg.c @@ -559,41 +559,71 @@ static void iwl_dump_prph(struct iwl_fw_runtime *fwrt, } /* - * alloc_sgtable - allocates scallerlist table in the given size, - * fills it with pages and returns it + * alloc_sgtable - allocates (chained) scatterlist in the given size, + * fills it with pages and returns it * @size: the size (in bytes) of the table -*/ -static struct scatterlist *alloc_sgtable(int size) + */ +static struct scatterlist *alloc_sgtable(ssize_t size) { - int alloc_size, nents, i; - struct page *new_page; - struct scatterlist *iter; - struct scatterlist *table; + struct scatterlist *result = NULL, *prev; + int nents, i, n_prev; nents = DIV_ROUND_UP(size, PAGE_SIZE); - table = kcalloc(nents, sizeof(*table), GFP_KERNEL); - if (!table) - return NULL; - sg_init_table(table, nents); - iter = table; - for_each_sg(table, iter, sg_nents(table), i) { - new_page = alloc_page(GFP_KERNEL); - if (!new_page) { - /* release all previous allocated pages in the table */ - iter = table; - for_each_sg(table, iter, sg_nents(table), i) { - new_page = sg_page(iter); - if (new_page) - __free_page(new_page); - } - kfree(table); + +#define N_ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(*result)) + /* + * We need an additional entry for table chaining, + * this ensures the loop can finish i.e. we can + * fit at least two entries per page (obviously, + * many more really fit.) + */ + BUILD_BUG_ON(N_ENTRIES_PER_PAGE < 2); + + while (nents > 0) { + struct scatterlist *new, *iter; + int n_fill, n_alloc; + + if (nents <= N_ENTRIES_PER_PAGE) { + /* last needed table */ + n_fill = nents; + n_alloc = nents; + nents = 0; + } else { + /* fill a page with entries */ + n_alloc = N_ENTRIES_PER_PAGE; + /* reserve one for chaining */ + n_fill = n_alloc - 1; + nents -= n_fill; + } + + new = kcalloc(n_alloc, sizeof(*new), GFP_KERNEL); + if (!new) { + if (result) + _devcd_free_sgtable(result); return NULL; } - alloc_size = min_t(int, size, PAGE_SIZE); - size -= PAGE_SIZE; - sg_set_page(iter, new_page, alloc_size, 0); + sg_init_table(new, n_alloc); + + if (!result) + result = new; + else + sg_chain(prev, n_prev, new); + prev = new; + n_prev = n_alloc; + + for_each_sg(new, iter, n_fill, i) { + struct page *new_page = alloc_page(GFP_KERNEL); + + if (!new_page) { + _devcd_free_sgtable(result); + return NULL; + } + + sg_set_page(iter, new_page, PAGE_SIZE, 0); + } } - return table; + + return result; } static void iwl_fw_get_prph_len(struct iwl_fw_runtime *fwrt,