diff options
| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
| commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
| tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/parisc/include/asm/shmparam.h | |
| parent | Initial commit. (diff) | |
| download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip | |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/parisc/include/asm/shmparam.h')
| -rw-r--r-- | arch/parisc/include/asm/shmparam.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/parisc/include/asm/shmparam.h b/arch/parisc/include/asm/shmparam.h new file mode 100644 index 0000000000..5a95b0f62b --- /dev/null +++ b/arch/parisc/include/asm/shmparam.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASMPARISC_SHMPARAM_H +#define _ASMPARISC_SHMPARAM_H + +/* + * PA-RISC uses virtually indexed & physically tagged (VIPT) caches + * which has strict requirements when two pages to the same physical + * address are accessed through different mappings. Read the section + * "Address Aliasing" in the arch docs for more detail: + * PA-RISC 1.1 (page 3-6): + * https://parisc.wiki.kernel.org/images-parisc/6/68/Pa11_acd.pdf + * PA-RISC 2.0 (page F-5): + * https://parisc.wiki.kernel.org/images-parisc/7/73/Parisc2.0.pdf + * + * For Linux we allow kernel and userspace to map pages on page size + * granularity (SHMLBA) but have to ensure that, if two pages are + * mapped to the same physical address, the virtual and physical + * addresses modulo SHM_COLOUR are identical. + */ +#define SHMLBA PAGE_SIZE /* attach addr a multiple of this */ +#define SHM_COLOUR 0x00400000 /* shared mappings colouring */ + +#endif /* _ASMPARISC_SHMPARAM_H */ |