Messages in this thread | | | From | Ard Biesheuvel <> | Date | Thu, 22 Aug 2019 09:46:50 +0300 | Subject | Re: [PATCH] arm: skip nomap memblocks while finding the lowmem/highmem boundary |
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On Thu, 22 Aug 2019 at 09:44, Mike Rapoport <rppt@linux.ibm.com> wrote: > > On Thu, Aug 22, 2019 at 03:59:42AM +0000, Chester Lin wrote: > > On Thu, Aug 22, 2019 at 11:45:34AM +0800, Chester Lin wrote: > > > adjust_lowmem_bounds() checks every memblocks in order to find the boundary > > > between lowmem and highmem. However some memblocks could be marked as NOMAP > > > so they are not used by kernel, which should be skipped while calculating > > > the boundary. > > > > > > Signed-off-by: Chester Lin <clin@suse.com> > > > --- > > > arch/arm/mm/mmu.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c > > > index 426d9085396b..b86dba44d828 100644 > > > --- a/arch/arm/mm/mmu.c > > > +++ b/arch/arm/mm/mmu.c > > > @@ -1181,6 +1181,9 @@ void __init adjust_lowmem_bounds(void) > > > phys_addr_t block_start = reg->base; > > > phys_addr_t block_end = reg->base + reg->size; > > > > > > + if (memblock_is_nomap(reg)) > > > + continue; > > > + > > > if (reg->base < vmalloc_limit) { > > > if (block_end > lowmem_limit) > > > /* > > > -- > > > 2.22.0 > > > > > > > Hi Russell, Mike and Ard, > > > > Per the discussion in the thread "[PATH] efi/arm: fix allocation failure ...", > > (https://lkml.org/lkml/2019/8/21/163), I presume that the change to disregard > > NOMAP memblocks in adjust_lowmem_bounds() should be separated as a single patch. > > > > Please let me know if any suggestion, thank you. > > Let's add this one to the series: > > From 06a986e79d60c310c804b3e550bd50316597aec5 Mon Sep 17 00:00:00 2001 > From: Mike Rapoport <rppt@linux.ibm.com> > Date: Thu, 22 Aug 2019 09:27:40 +0300 > Subject: [PATCH] arm: ensure that usable memory in bank 0 starts from a > PMD-aligned address > > The calculation of memblock_limit in adjust_lowmem_bounds() assumes that > bank 0 starts from a PMD-aligned address. However, the beginning of the > first bank may be NOMAP memory and the start of usable memory > will be not aligned to PMD boundary. In such case the memblock_limit will > be set to the end of the NOMAP region, which will prevent any memblock > allocations. > > Mark the region between the end of the NOMAP area and the next PMD-aligned > address as NOMAP as well, so that the usable memory will start at > PMD-aligned address. > > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> --- > arch/arm/mm/mmu.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c > index 4495a26..25da9b2 100644 > --- a/arch/arm/mm/mmu.c > +++ b/arch/arm/mm/mmu.c > @@ -1177,6 +1177,22 @@ void __init adjust_lowmem_bounds(void) > */ > vmalloc_limit = (u64)(uintptr_t)vmalloc_min - PAGE_OFFSET + PHYS_OFFSET; > > + /* > + * The first usable region must be PMD aligned. Mark its start > + * as MEMBLOCK_NOMAP if it isn't > + */ > + for_each_memblock(memory, reg) { > + if (!memblock_is_nomap(reg)) { > + if (!IS_ALIGNED(reg->base, PMD_SIZE)) { > + phys_addr_t len; > + > + len = round_up(reg->base, PMD_SIZE) - reg->base; > + memblock_mark_nomap(reg->base, len); > + } > + break; > + } > + } > + > for_each_memblock(memory, reg) { > phys_addr_t block_start = reg->base; > phys_addr_t block_end = reg->base + reg->size; > -- > 2.7.4 > > > -- > Sincerely yours, > Mike. >
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