diff options
| author | Aaron Durbin <adurbin@chromium.org> | 2018-04-18 01:02:47 -0600 |
|---|---|---|
| committer | Patrick Georgi <pgeorgi@google.com> | 2018-04-26 06:55:59 +0000 |
| commit | 696c642afa8558d7949a13b117066d0a732653fb (patch) | |
| tree | f645e458a5447eeebc07a3a64a3e8ff0035db2c9 /src/include/cpu | |
| parent | d127be102be3744b9b81036e5fa53acbddaae03b (diff) | |
| download | coreboot-696c642afa8558d7949a13b117066d0a732653fb.tar.xz | |
cpu/x86: add limited runtime identity page mapping
When employing PAGING_IN_CACHE_AS_RAM more areas need to be
mapped in at runtime. Therefore, paging_identity_map_addr() is
added to support adding identity mappings. Because there are a
fixed amount of pages in cache-as-ram paging only the existing
paging structures can be used. As such that's a limitation on
what regions and length one can map. Using util/x86/x86_page_tables.go
to generate page tables will always populate all the page directory
pages. Therefore, 2MiB mappings are easy to map in.
BUG=b:72728953
Change-Id: Ibe33aa12972ff678d2e9b80874529380b4ce9fd7
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/25718
Reviewed-by: Justin TerAvest <teravest@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Diffstat (limited to 'src/include/cpu')
| -rw-r--r-- | src/include/cpu/x86/pae.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/src/include/cpu/x86/pae.h b/src/include/cpu/x86/pae.h index a8b5e893fc..51e47e1e85 100644 --- a/src/include/cpu/x86/pae.h +++ b/src/include/cpu/x86/pae.h @@ -32,6 +32,11 @@ void paging_set_default_pat(void); * failure. */ int paging_enable_for_car(const char *pdpt_name, const char *pt_name); +/* Identity map the region indicated by 'base' and 'size'. Both 'base' and + * 'size' need to be 4KiB or 2 MiB aligned. 'pat' should be one of the + * PAT defines above. 0 is returned on success, < 0 on failure. */ +int paging_identity_map_addr(uintptr_t base, size_t size, int pat); + #define MAPPING_ERROR ((void *)0xffffffffUL) void *map_2M_page(unsigned long page); |