Messages in this thread Patch in this message | | | From | Nicolai Stange <> | Subject | [PATCH v2 2/2] efi: efi_mem_reserve(): don't reserve through memblock after mm_init() | Date | Thu, 22 Dec 2016 11:23:40 +0100 |
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Before invoking the arch specific handler, efi_mem_reserve() reserves the given memory region through memblock.
efi_mem_reserve() can get called after mm_init() though -- through efi_bgrt_init(), for example. After mm_init(), memblock is dead and should not be used anymore.
Let efi_mem_reserve() check whether memblock is dead and not do the reservation if so. Emit a warning from the generic efi_arch mem_reserve() in this case: if the architecture doesn't provide any other means of registering the region as reserved, the operation would be a nop.
Fixes: 4bc9f92e64c8 ("x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data") Signed-off-by: Nicolai Stange <nicstange@gmail.com> --- Changes to v1: Change the if condition from slab_is_available() to !slab_is_available as pointed out by Mika Penttilä at http://lkml.kernel.org/r/c7bf34ba-56f0-8346-36d1-7069f2115dcf@nextfour.com
drivers/firmware/efi/efi.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 92914801e388..158a8df2f4af 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -403,7 +403,10 @@ u64 __init efi_mem_desc_end(efi_memory_desc_t *md) return end; } -void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {} +void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) +{ + WARN(slab_is_available(), "efi_mem_reserve() has no effect"); +} /** * efi_mem_reserve - Reserve an EFI memory region @@ -419,7 +422,7 @@ void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {} */ void __init efi_mem_reserve(phys_addr_t addr, u64 size) { - if (!memblock_is_region_reserved(addr, size)) + if (!slab_is_available() && !memblock_is_region_reserved(addr, size)) memblock_reserve(addr, size); /* -- 2.11.0
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