Hi Mike, On 2019/4/16 3:09, Mike Rapoport wrote: > Hi, > > On Mon, Apr 15, 2019 at 06:57:23PM +0800, Chen Zhou wrote: >> The memblock_cap_memory_range() removes all the memory except the >> range passed to it. Extend this function to receive memblock_type >> with the regions that should be kept. >> >> Enable this function in arm64 for reservation of multiple regions >> for the crash kernel. >> >> Signed-off-by: Chen Zhou <chenzho...@huawei.com> >> Signed-off-by: Mike Rapoport <r...@linux.ibm.com> > > I didn't work on this version, please drop the signed-off.
Sorry about this. I should ask you firstly before doing it this way. I will drop it. remove_size); >> + } >> + >> + memblock_remove_range(&memblock.reserved, >> + regs[nr - 1].base + regs[nr - 1].size, PHYS_ADDR_MAX); >> +} >> + > > I've double-checked and I see no problem with using > for_each_mem_range_rev() iterators for removing some ranges. And with them > this functions becomes much clearer and more efficient. > > Can you please check if the below patch works for you? > >>From e25e6c9cd94a01abac124deacc66e5d258fdbf7c Mon Sep 17 00:00:00 2001 > From: Mike Rapoport <r...@linux.ibm.com> > Date: Wed, 10 Apr 2019 16:02:32 +0300 > Subject: [PATCH] memblock: extend memblock_cap_memory_range to multiple ranges > > The memblock_cap_memory_range() removes all the memory except the range > passed to it. Extend this function to receive an array of memblock_regions > that should be kept. This allows switching to simple iteration over > memblock arrays with 'for_each_mem_range_rev' to remove the unneeded memory. > > Enable use of this function in arm64 for reservation of multiple regions for > the crash kernel. > > Signed-off-by: Mike Rapoport <r...@linux.ibm.com> > --- > arch/arm64/mm/init.c | 34 ++++++++++++++++++++++++---------- > include/linux/memblock.h | 2 +- > mm/memblock.c | 44 ++++++++++++++++++++------------------------ > 3 files changed, 45 insertions(+), 35 deletions(-) > > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index 6bc1350..8665d29 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -64,6 +64,10 @@ EXPORT_SYMBOL(memstart_addr); > phys_addr_t arm64_dma_phys_limit __ro_after_init; > > #ifdef CONFIG_KEXEC_CORE > + > +/* at most two crash kernel regions, low_region and high_region */ > +#define CRASH_MAX_USABLE_RANGES 2 > + > /* > * reserve_crashkernel() - reserves memory for crash kernel > * > @@ -280,9 +284,9 @@ early_param("mem", early_mem); > static int __init early_init_dt_scan_usablemem(unsigned long node, > const char *uname, int depth, void *data) > { > - struct memblock_region *usablemem = data; > - const __be32 *reg; > - int len; > + struct memblock_type *usablemem = data; > + const __be32 *reg, *endp; > + int len, nr = 0; > > if (depth != 1 || strcmp(uname, "chosen") != 0) > return 0; > @@ -291,22 +295,32 @@ static int __init early_init_dt_scan_usablemem(unsigned > long node, > if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells))) > return 1; > > - usablemem->base = dt_mem_next_cell(dt_root_addr_cells, ®); > - usablemem->size = dt_mem_next_cell(dt_root_size_cells, ®); > + endp = reg + (len / sizeof(__be32)); > + while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) { > + unsigned long base = dt_mem_next_cell(dt_root_addr_cells, ®); > + unsigned long size = dt_mem_next_cell(dt_root_size_cells, ®); > > + if (memblock_add_range(usablemem, base, size, NUMA_NO_NODE, > + MEMBLOCK_NONE)) > + return 0; > + if (++nr >= CRASH_MAX_USABLE_RANGES) > + break; > + } > return 1; > } > > static void __init fdt_enforce_memory_region(void) > { > - struct memblock_region reg = { > - .size = 0, > + struct memblock_region usable_regions[CRASH_MAX_USABLE_RANGES]; > + struct memblock_type usablemem = { > + .max = CRASH_MAX_USABLE_RANGES, > + .regions = usable_regions, > }; > > - of_scan_flat_dt(early_init_dt_scan_usablemem, ®); > + of_scan_flat_dt(early_init_dt_scan_usablemem, &usablemem); > > - if (reg.size) > - memblock_cap_memory_range(reg.base, reg.size); > + if (usablemem.cnt) > + memblock_cap_memory_ranges(usablemem.regions, usablemem.cnt); > } > > void __init arm64_memblock_init(void) > diff --git a/include/linux/memblock.h b/include/linux/memblock.h > index 294d5d8..f5c029b 100644 > --- a/include/linux/memblock.h > +++ b/include/linux/memblock.h > @@ -404,7 +404,7 @@ 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_cap_memory_ranges(struct memblock_region *regions, int count); > void memblock_mem_limit_remove_map(phys_addr_t limit); > bool memblock_is_memory(phys_addr_t addr); > bool memblock_is_map_memory(phys_addr_t addr); > diff --git a/mm/memblock.c b/mm/memblock.c > index e7665cf..8d4d060 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -1605,36 +1605,31 @@ void __init memblock_enforce_memory_limit(phys_addr_t > limit) > PHYS_ADDR_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); > +void __init memblock_cap_memory_ranges(struct memblock_region *regions, > + int count) > +{ > + struct memblock_type regions_to_keep = { > + .max = count, > + .cnt = count, > + .regions = regions, > + }; > + phys_addr_t start, end; > + u64 i; > > - for (i = start_rgn - 1; i >= 0; i--) > - if (!memblock_is_nomap(&memblock.memory.regions[i])) > - memblock_remove_region(&memblock.memory, i); > + /* truncate memory while skipping NOMAP regions */ > + for_each_mem_range_rev(i, &memblock.memory, ®ions_to_keep, > + NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end, NULL) > + memblock_remove(start, end); Yes, this works well. A minor issue, replace memblock_remove(start, end) with memblock_remove(start, end - start). > > /* truncate the reserved regions */ > - memblock_remove_range(&memblock.reserved, 0, base); > - memblock_remove_range(&memblock.reserved, > - base + size, PHYS_ADDR_MAX); > + for_each_mem_range_rev(i, &memblock.reserved, ®ions_to_keep, > + NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end, NULL) > + memblock_remove_range(&memblock.reserved, start, end); The same as above. Replace memblock_remove_range(&memblock.reserved, start, end) with memblock_remove_range(&memblock.reserved, start, end - start). Thanks, Chen Zhou > } > > void __init memblock_mem_limit_remove_map(phys_addr_t limit) > { > + struct memblock_region region = { 0 }; > phys_addr_t max_addr; > > if (!limit) > @@ -1646,7 +1641,8 @@ void __init memblock_mem_limit_remove_map(phys_addr_t > limit) > if (max_addr == PHYS_ADDR_MAX) > return; > > - memblock_cap_memory_range(0, max_addr); > + region.size = max_addr; > + memblock_cap_memory_ranges(®ion, 1); > } > > static int __init_memblock memblock_search(struct memblock_type *type, > phys_addr_t addr) > _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec