Message ID | 20240605093006.145492-7-steven.price@arm.com (mailing list archive) |
---|---|
State | New |
Headers | show |
Series | arm64: Support for running as a guest in Arm CCA | expand |
On Wed, Jun 05, 2024 at 10:29:58AM +0100, Steven Price wrote: > +void set_fixmap_io(enum fixed_addresses idx, phys_addr_t phys) > +{ > + pgprot_t prot = FIXMAP_PAGE_IO; > + > + /* > + * For now we consider all I/O as non-secure. For future > + * filter the I/O base for setting appropriate permissions. > + */ > + prot = __pgprot(pgprot_val(prot) | PROT_NS_SHARED); > + > + return __set_fixmap(idx, phys, prot); > +} In v2, Suzuki said that we want to keep this as a function rather than just adding PROT_NS_SHARED to FIXMAP_PAGE_IO in case we want to change this function in the future to allow protected MMIO. https://lore.kernel.org/linux-arm-kernel/6ba1fd72-3bad-44ca-810d-572b70050772@arm.com/ What I don't understand is that all the other MMIO cases just statically assume unprotected/shard MMIO. Should we drop this patch here as well, adjust FIXMAP_PAGE_IO and think about protected MMIO later when we actually have to do device assignment?
diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h index 87e307804b99..f765943b088c 100644 --- a/arch/arm64/include/asm/fixmap.h +++ b/arch/arm64/include/asm/fixmap.h @@ -107,7 +107,9 @@ void __init early_fixmap_init(void); #define __late_set_fixmap __set_fixmap #define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR) -extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot); +#define set_fixmap_io set_fixmap_io +void set_fixmap_io(enum fixed_addresses idx, phys_addr_t phys); +void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot); #include <asm-generic/fixmap.h> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index c927e9312f10..9123df312842 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1192,6 +1192,19 @@ void vmemmap_free(unsigned long start, unsigned long end, } #endif /* CONFIG_MEMORY_HOTPLUG */ +void set_fixmap_io(enum fixed_addresses idx, phys_addr_t phys) +{ + pgprot_t prot = FIXMAP_PAGE_IO; + + /* + * For now we consider all I/O as non-secure. For future + * filter the I/O base for setting appropriate permissions. + */ + prot = __pgprot(pgprot_val(prot) | PROT_NS_SHARED); + + return __set_fixmap(idx, phys, prot); +} + int pud_set_huge(pud_t *pudp, phys_addr_t phys, pgprot_t prot) { pud_t new_pud = pfn_pud(__phys_to_pfn(phys), mk_pud_sect_prot(prot));