On Mon, Aug 02, 2021 at 04:23:59PM +0100, Lorenzo Pieralisi wrote: > The memory attributes attached to memory regions depend on architecture > specific mappings. > > For some memory regions, the attributes specified by firmware (eg > uncached) are not sufficient to determine how a memory region should be > mapped by an OS (for instance a region that is define as uncached in > firmware can be mapped as Normal or Device memory on arm64) and > therefore the OS must be given control on how to map the region to match > the expected mapping behaviour (eg if a mapping is requested with memory > semantics, it must allow unaligned accesses). > > Rework acpi_os_map_memory() and acpi_os_ioremap() back-end to split > them into two separate code paths: > > acpi_os_memmap() -> memory semantics > acpi_os_ioremap() -> MMIO semantics > > The split allows the architectural implementation back-ends to detect > the default memory attributes required by the mapping in question > (ie the mapping API defines the semantics memory vs MMIO) and map the > memory accordingly. > > Link: https://lore.kernel.org/linux-arm-kernel/31ffe8fc-f5ee-2858-26c5-0fd8bdd68702@xxxxxxx > Tested-by: Hanjun Guo <guohanjun@xxxxxxxxxx> > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx> > Cc: Ard Biesheuvel <ardb@xxxxxxxxxx> > Cc: Will Deacon <will@xxxxxxxxxx> > Cc: Hanjun Guo <guohanjun@xxxxxxxxxx> > Cc: Sudeep Holla <sudeep.holla@xxxxxxx> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> For the arm64 bits: Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx> I presume this will get merged via the ACPI tree? -- Catalin
