From b1b8153cf0aeeb7ae6d4f012b8beb2dcfc92c68a Mon Sep 17 00:00:00 2001 From: Vignesh R Date: Wed, 17 Aug 2016 15:22:36 +0530 Subject: spi: Add support to handle kmap'd buffers in spi_map_buf() JFFS2 FS might sometime provide kmap'd buffers as destination buffers to read data from flash. Update spi_map_buf() function to generate sg_list for such buffers, so that SPI controllers drivers can use DMA to read data into such buffers. Signed-off-by: Vignesh R Signed-off-by: Mark Brown --- drivers/spi/spi.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) (limited to 'drivers/spi/spi.c') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 51ad42f..2a5dd22 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -37,6 +37,7 @@ #include #include #include +#include #define CREATE_TRACE_POINTS #include @@ -709,6 +710,13 @@ static int spi_map_buf(struct spi_master *master, struct device *dev, { const bool vmalloced_buf = is_vmalloc_addr(buf); unsigned int max_seg_size = dma_get_max_seg_size(dev); +#ifdef CONFIG_HIGHMEM + const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE && + (unsigned long)buf < (PKMAP_BASE + + (LAST_PKMAP * PAGE_SIZE))); +#else + const bool kmap_buf = false; +#endif int desc_len; int sgs; struct page *vm_page; @@ -716,7 +724,7 @@ static int spi_map_buf(struct spi_master *master, struct device *dev, size_t min; int i, ret; - if (vmalloced_buf) { + if (vmalloced_buf || kmap_buf) { desc_len = min_t(int, max_seg_size, PAGE_SIZE); sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len); } else if (virt_addr_valid(buf)) { @@ -732,10 +740,13 @@ static int spi_map_buf(struct spi_master *master, struct device *dev, for (i = 0; i < sgs; i++) { - if (vmalloced_buf) { + if (vmalloced_buf || kmap_buf) { min = min_t(size_t, len, desc_len - offset_in_page(buf)); - vm_page = vmalloc_to_page(buf); + if (vmalloced_buf) + vm_page = vmalloc_to_page(buf); + else + vm_page = kmap_to_page(buf); if (!vm_page) { sg_free_table(sgt); return -ENOMEM; -- cgit v1.1