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 <chenzhou10@xxxxxxxxxx>
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
---
include/linux/memblock.h | 1 +
mm/memblock.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 46 insertions(+)
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 47e3c06..180877c 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -446,6 +446,7 @@ 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_type *regions_to_keep);
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 f315eca..9661807 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -1697,6 +1697,51 @@ void __init memblock_cap_memory_range(phys_addr_t base, phys_addr_t size)
base + size, PHYS_ADDR_MAX);
}
+void __init memblock_cap_memory_ranges(struct memblock_type *regions_to_keep)
+{
+ int start_rgn[INIT_MEMBLOCK_REGIONS], end_rgn[INIT_MEMBLOCK_REGIONS];
+ int i, j, ret, nr = 0;
+ struct memblock_region *regs = regions_to_keep->regions;
+
+ for (i = 0; i < regions_to_keep->cnt; i++) {
+ ret = memblock_isolate_range(&memblock.memory, regs[i].base,
+ regs[i].size, &start_rgn[i], &end_rgn[i]);
+ if (ret)
+ break;
+ nr++;
+ }
+ if (!nr)
+ return;
+
+ /* remove all the MAP regions */
+ for (i = memblock.memory.cnt - 1; i >= end_rgn[nr - 1]; i--)
+ if (!memblock_is_nomap(&memblock.memory.regions[i]))
+ memblock_remove_region(&memblock.memory, i);
+
+ for (i = nr - 1; i > 0; i--)
+ for (j = start_rgn[i] - 1; j >= end_rgn[i - 1]; j--)
+ if (!memblock_is_nomap(&memblock.memory.regions[j]))
+ memblock_remove_region(&memblock.memory, j);
+
+ for (i = start_rgn[0] - 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, regs[0].base);
+
+ for (i = nr - 1; i > 0; i--) {
+ phys_addr_t remove_base = regs[i - 1].base + regs[i - 1].size;
+ phys_addr_t remove_size = regs[i].base - remove_base;
+
+ memblock_remove_range(&memblock.reserved, remove_base,
+ remove_size);
+ }
+
+ memblock_remove_range(&memblock.reserved,
+ regs[nr - 1].base + regs[nr - 1].size, PHYS_ADDR_MAX);
+}
+
void __init memblock_mem_limit_remove_map(phys_addr_t limit)
{
phys_addr_t max_addr;
--
2.7.4
