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| author | Vignesh R <vigneshr@ti.com> | 2016-08-17 15:22:36 +0530 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2016-08-17 12:24:01 +0100 |
| commit | b1b8153cf0aeeb7ae6d4f012b8beb2dcfc92c68a (patch) | |
| tree | b9fb07d7e31ff24bc7fb47138129548750d9612f /drivers/spi/spi.c | |
| parent | 29b4817d4018df78086157ea3a55c1d9424a7cfc (diff) | |
| download | op-kernel-dev-b1b8153cf0aeeb7ae6d4f012b8beb2dcfc92c68a.zip op-kernel-dev-b1b8153cf0aeeb7ae6d4f012b8beb2dcfc92c68a.tar.gz | |
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 <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi.c')
| -rw-r--r-- | drivers/spi/spi.c | 17 |
1 files changed, 14 insertions, 3 deletions
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 <linux/kthread.h> #include <linux/ioport.h> #include <linux/acpi.h> +#include <linux/highmem.h> #define CREATE_TRACE_POINTS #include <trace/events/spi.h> @@ -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; |
