| Message ID | 20170328065033.15966-2-takahiro.akashi@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 28 March 2017 at 07:50, AKASHI Takahiro <takahiro.akashi@linaro.org> wrote: > Add memblock_cap_memory_range() which will remove all the memblock regions > except the memory range specified in the arguments. In addition, rework is > done on memblock_mem_limit_remove_map() to re-implement it using > memblock_cap_memory_range(). > > This function, like memblock_mem_limit_remove_map(), will not remove > memblocks with MEMMAP_NOMAP attribute as they may be mapped and accessed > later as "device memory." > See the commit a571d4eb55d8 ("mm/memblock.c: add new infrastructure to > address the mem limit issue"). > > This function is used, in a succeeding patch in the series of arm64 kdump > suuport, to limit the range of usable memory, or System RAM, on crash dump > kernel. > (Please note that "mem=" parameter is of little use for this purpose.) > > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> > Reviewed-by: Will Deacon <will.deacon@arm.com> > Acked-by: Catalin Marinas <catalin.marinas@arm.com> > Acked-by: Dennis Chen <dennis.chen@arm.com> > Cc: linux-mm@kvack.org > Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > include/linux/memblock.h | 1 + > mm/memblock.c | 44 +++++++++++++++++++++++++++++--------------- > 2 files changed, 30 insertions(+), 15 deletions(-) > > diff --git a/include/linux/memblock.h b/include/linux/memblock.h > index e82daffcfc44..4ce24a376262 100644 > --- a/include/linux/memblock.h > +++ b/include/linux/memblock.h > @@ -336,6 +336,7 @@ phys_addr_t memblock_mem_size(unsigned long limit_pfn); > phys_addr_t memblock_start_of_DRAM(void); > phys_addr_t memblock_end_of_DRAM(void); > void memblock_enforce_memory_limit(phys_addr_t memory_limit); > +void memblock_cap_memory_range(phys_addr_t base, phys_addr_t size); > void memblock_mem_limit_remove_map(phys_addr_t limit); > bool memblock_is_memory(phys_addr_t addr); > int memblock_is_map_memory(phys_addr_t addr); > diff --git a/mm/memblock.c b/mm/memblock.c > index 2f4ca8104ea4..b049c9b2dba8 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -1543,11 +1543,37 @@ void __init memblock_enforce_memory_limit(phys_addr_t limit) > (phys_addr_t)ULLONG_MAX); > } > > +void __init memblock_cap_memory_range(phys_addr_t base, phys_addr_t size) > +{ > + int start_rgn, end_rgn; > + int i, ret; > + > + if (!size) > + return; > + > + ret = memblock_isolate_range(&memblock.memory, base, size, > + &start_rgn, &end_rgn); > + if (ret) > + return; > + > + /* remove all the MAP regions */ > + for (i = memblock.memory.cnt - 1; i >= end_rgn; i--) > + if (!memblock_is_nomap(&memblock.memory.regions[i])) > + memblock_remove_region(&memblock.memory, i); > + > + for (i = start_rgn - 1; i >= 0; i--) > + if (!memblock_is_nomap(&memblock.memory.regions[i])) > + memblock_remove_region(&memblock.memory, i); > + > + /* truncate the reserved regions */ > + memblock_remove_range(&memblock.reserved, 0, base); > + memblock_remove_range(&memblock.reserved, > + base + size, (phys_addr_t)ULLONG_MAX); > +} > + > void __init memblock_mem_limit_remove_map(phys_addr_t limit) > { > - struct memblock_type *type = &memblock.memory; > phys_addr_t max_addr; > - int i, ret, start_rgn, end_rgn; > > if (!limit) > return; > @@ -1558,19 +1584,7 @@ void __init memblock_mem_limit_remove_map(phys_addr_t limit) > if (max_addr == (phys_addr_t)ULLONG_MAX) > return; > > - ret = memblock_isolate_range(type, max_addr, (phys_addr_t)ULLONG_MAX, > - &start_rgn, &end_rgn); > - if (ret) > - return; > - > - /* remove all the MAP regions above the limit */ > - for (i = end_rgn - 1; i >= start_rgn; i--) { > - if (!memblock_is_nomap(&type->regions[i])) > - memblock_remove_region(type, i); > - } > - /* truncate the reserved regions */ > - memblock_remove_range(&memblock.reserved, max_addr, > - (phys_addr_t)ULLONG_MAX); > + memblock_cap_memory_range(0, max_addr); > } > > static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr) > -- > 2.11.1 >
diff --git a/include/linux/memblock.h b/include/linux/memblock.h index e82daffcfc44..4ce24a376262 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -336,6 +336,7 @@ phys_addr_t memblock_mem_size(unsigned long limit_pfn); phys_addr_t memblock_start_of_DRAM(void); phys_addr_t memblock_end_of_DRAM(void); void memblock_enforce_memory_limit(phys_addr_t memory_limit); +void memblock_cap_memory_range(phys_addr_t base, phys_addr_t size); void memblock_mem_limit_remove_map(phys_addr_t limit); bool memblock_is_memory(phys_addr_t addr); int memblock_is_map_memory(phys_addr_t addr); diff --git a/mm/memblock.c b/mm/memblock.c index 2f4ca8104ea4..b049c9b2dba8 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1543,11 +1543,37 @@ void __init memblock_enforce_memory_limit(phys_addr_t limit) (phys_addr_t)ULLONG_MAX); } +void __init memblock_cap_memory_range(phys_addr_t base, phys_addr_t size) +{ + int start_rgn, end_rgn; + int i, ret; + + if (!size) + return; + + ret = memblock_isolate_range(&memblock.memory, base, size, + &start_rgn, &end_rgn); + if (ret) + return; + + /* remove all the MAP regions */ + for (i = memblock.memory.cnt - 1; i >= end_rgn; i--) + if (!memblock_is_nomap(&memblock.memory.regions[i])) + memblock_remove_region(&memblock.memory, i); + + for (i = start_rgn - 1; i >= 0; i--) + if (!memblock_is_nomap(&memblock.memory.regions[i])) + memblock_remove_region(&memblock.memory, i); + + /* truncate the reserved regions */ + memblock_remove_range(&memblock.reserved, 0, base); + memblock_remove_range(&memblock.reserved, + base + size, (phys_addr_t)ULLONG_MAX); +} + void __init memblock_mem_limit_remove_map(phys_addr_t limit) { - struct memblock_type *type = &memblock.memory; phys_addr_t max_addr; - int i, ret, start_rgn, end_rgn; if (!limit) return; @@ -1558,19 +1584,7 @@ void __init memblock_mem_limit_remove_map(phys_addr_t limit) if (max_addr == (phys_addr_t)ULLONG_MAX) return; - ret = memblock_isolate_range(type, max_addr, (phys_addr_t)ULLONG_MAX, - &start_rgn, &end_rgn); - if (ret) - return; - - /* remove all the MAP regions above the limit */ - for (i = end_rgn - 1; i >= start_rgn; i--) { - if (!memblock_is_nomap(&type->regions[i])) - memblock_remove_region(type, i); - } - /* truncate the reserved regions */ - memblock_remove_range(&memblock.reserved, max_addr, - (phys_addr_t)ULLONG_MAX); + memblock_cap_memory_range(0, max_addr); } static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr)
Add memblock_cap_memory_range() which will remove all the memblock regions except the memory range specified in the arguments. In addition, rework is done on memblock_mem_limit_remove_map() to re-implement it using memblock_cap_memory_range(). This function, like memblock_mem_limit_remove_map(), will not remove memblocks with MEMMAP_NOMAP attribute as they may be mapped and accessed later as "device memory." See the commit a571d4eb55d8 ("mm/memblock.c: add new infrastructure to address the mem limit issue"). This function is used, in a succeeding patch in the series of arm64 kdump suuport, to limit the range of usable memory, or System RAM, on crash dump kernel. (Please note that "mem=" parameter is of little use for this purpose.) Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Dennis Chen <dennis.chen@arm.com> Cc: linux-mm@kvack.org Cc: Andrew Morton <akpm@linux-foundation.org> --- include/linux/memblock.h | 1 + mm/memblock.c | 44 +++++++++++++++++++++++++++++--------------- 2 files changed, 30 insertions(+), 15 deletions(-)