diff options
| author | Julius Werner <jwerner@chromium.org> | 2013-08-27 15:48:32 -0700 |
|---|---|---|
| committer | Isaac Christensen <isaac.christensen@se-eng.com> | 2014-08-13 00:04:14 +0200 |
| commit | b8fad3d02986222fa162d455eca2ffe807b6a15a (patch) | |
| tree | f6beaf474faa9f4a9a4a611abb52774e7d0906ed /src/include | |
| parent | 4498f6a6e57aa3bc1ed9449e3ad153b1a60c4eb6 (diff) | |
| download | coreboot-b8fad3d02986222fa162d455eca2ffe807b6a15a.tar.xz | |
arm: libpayload: Add cache coherent DMA memory definition and management
This patch adds a mechanism to set aside a region of cache-coherent
(i.e. usually uncached) virtual memory, which can be used to communicate
with DMA devices without automatic cache snooping (common on ARM)
without the need of explicit flush/invalidation instructions in the
driver code.
This works by setting aside said region in the (board-specific) page
table setup, as exemplary done in this patch for the Snow and Pit
boards. It uses a new mechanism for adding board-specific Coreboot table
entries to describe this region in an entry with the LB_DMA tag.
Libpayload's memory allocator is enhanced to be able to operate on
distinct types/regions of memory. It provides dma_malloc() and
dma_memalign() functions for use in drivers, which by default just
operate on the same heap as their traditional counterparts. However, if
the Coreboot table parsing code finds a CB_DMA section, further requests
through the dma_xxx() functions will return memory from the region
described therein instead.
Change-Id: Ia9c249249e936bbc3eb76e7b4822af2230ffb186
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/167155
(cherry picked from commit d142ccdcd902a9d6ab4d495fbe6cbe85c61a5f01)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6622
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/boot/coreboot_tables.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/include/boot/coreboot_tables.h b/src/include/boot/coreboot_tables.h index 3c569a132d..db3c508285 100644 --- a/src/include/boot/coreboot_tables.h +++ b/src/include/boot/coreboot_tables.h @@ -218,6 +218,7 @@ struct lb_gpios { #define LB_TAG_VDAT 0x0015 #define LB_TAG_VBNV 0x0019 #define LB_TAB_VBOOT_HANDOFF 0x0020 +#define LB_TAB_DMA 0x0022 struct lb_range { uint32_t tag; uint32_t size; @@ -332,4 +333,9 @@ void uart_fill_lb(void *data); void lb_add_serial(struct lb_serial *serial, void *data); void lb_add_console(uint16_t consoletype, void *data); +/* Define this in mainboard.c to add board-specific table entries. */ +void lb_board(struct lb_header *header); + +struct lb_record *lb_new_record(struct lb_header *header); + #endif /* COREBOOT_TABLES_H */ |