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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/x86/mm/iomap_32.c | |
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/x86/mm/iomap_32.c')
-rw-r--r-- | arch/x86/mm/iomap_32.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c new file mode 100644 index 0000000000..9aaa756ddf --- /dev/null +++ b/arch/x86/mm/iomap_32.c @@ -0,0 +1,65 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright © 2008 Ingo Molnar + */ + +#include <asm/iomap.h> +#include <asm/memtype.h> +#include <linux/export.h> +#include <linux/highmem.h> + +static int is_io_mapping_possible(resource_size_t base, unsigned long size) +{ +#if !defined(CONFIG_X86_PAE) && defined(CONFIG_PHYS_ADDR_T_64BIT) + /* There is no way to map greater than 1 << 32 address without PAE */ + if (base + size > 0x100000000ULL) + return 0; +#endif + return 1; +} + +int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot) +{ + enum page_cache_mode pcm = _PAGE_CACHE_MODE_WC; + int ret; + + if (!is_io_mapping_possible(base, size)) + return -EINVAL; + + ret = memtype_reserve_io(base, base + size, &pcm); + if (ret) + return ret; + + *prot = __pgprot(__PAGE_KERNEL | cachemode2protval(pcm)); + /* Filter out unsupported __PAGE_KERNEL* bits: */ + pgprot_val(*prot) &= __default_kernel_pte_mask; + + return 0; +} +EXPORT_SYMBOL_GPL(iomap_create_wc); + +void iomap_free(resource_size_t base, unsigned long size) +{ + memtype_free_io(base, base + size); +} +EXPORT_SYMBOL_GPL(iomap_free); + +void __iomem *__iomap_local_pfn_prot(unsigned long pfn, pgprot_t prot) +{ + /* + * For non-PAT systems, translate non-WB request to UC- just in + * case the caller set the PWT bit to prot directly without using + * pgprot_writecombine(). UC- translates to uncached if the MTRR + * is UC or WC. UC- gets the real intention, of the user, which is + * "WC if the MTRR is WC, UC if you can't do that." + */ + if (!pat_enabled() && pgprot2cachemode(prot) != _PAGE_CACHE_MODE_WB) + prot = __pgprot(__PAGE_KERNEL | + cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS)); + + /* Filter out unsupported __PAGE_KERNEL* bits: */ + pgprot_val(prot) &= __default_kernel_pte_mask; + + return (void __force __iomem *)__kmap_local_pfn_prot(pfn, prot); +} +EXPORT_SYMBOL_GPL(__iomap_local_pfn_prot); |