Messages in this thread | | | Date | Wed, 14 Jan 2015 16:22:08 +0800 | From | Hanjun Guo <> | Subject | Re: [PATCH] arm64: allow late use of early_ioremap |
| |
Hi Mark,
On 2015年01月13日 03:09, Mark Salter wrote: > On Mon, 2015-01-12 at 17:25 +0000, Will Deacon wrote: >> On Mon, Jan 12, 2015 at 04:55:11PM +0000, Mark Salter wrote: >>> Commit 0e63ea48b4d8 (arm64/efi: add missing call to early_ioremap_reset()) >>> added a missing call to early_ioremap_reset(). This triggers a BUG if code >>> tries using early_ioremap() after the early_ioremap_reset(). This is a >>> problem for some ACPI code which needs short-lived temporary mappings >>> after paging_init() but before mm_init(). This patch adds definitions for
Minor update: ... after paging_init() but before acpi_early_init() in start_kernel().
In ACPI, permanent mapping will be used after acpi_gbl_permanent_mmap set to 1 in acpi_early_init(), since GIC init and Arch timer init will be called before acpi_early_init(), early_ioremap() is still needed after mm_init().
>>> the __late_set_fixmap() and __late_clear_fixmap() which avoids the BUG >>> by allowing later use of early_ioremap(). >>> >>> Signed-off-by: Mark Salter <msalter@redhat.com> >>> CC: Leif Lindholm <leif.lindholm@linaro.org> >>> CC: Ard Biesheuvel <ard.biesheuvel@linaro.org> >>> --- >>> arch/arm64/include/asm/fixmap.h | 3 +++ >>> 1 file changed, 3 insertions(+) >> >> Given that we don't support ACPI on arm64 in mainline, I assume this can >> wait until at least 3.20? > > Sure. Just needs it to go in before ACPI code. And tbh, the ACPI code > could change and make this unneeded.
This is the best solution for now, so I need to add this patch as the first one for ACPI core patch set, is it ok for you?
Thanks Hanjun
| |