Re: [PATCH v2] memblock: make memblock_find_in_range method private

From: Nick Kossifidis
Date: Sat Aug 07 2021 - 19:41:05 EST


Στις 2021-08-02 09:37, Mike Rapoport έγραψε:
From: Mike Rapoport <rppt@xxxxxxxxxxxxx>

There are a lot of uses of memblock_find_in_range() along with
memblock_reserve() from the times memblock allocation APIs did not exist.

memblock_find_in_range() is the very core of memblock allocations, so any
future changes to its internal behaviour would mandate updates of all the
users outside memblock.

Replace the calls to memblock_find_in_range() with an equivalent calls to
memblock_phys_alloc() and memblock_phys_alloc_range() and make
memblock_find_in_range() private method of memblock.

This simplifies the callers, ensures that (unlikely) errors in
memblock_reserve() are handled and improves maintainability of
memblock_find_in_range().

Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
---
v2: don't change error message in arm::reserve_crashkernel(), per Russell
v1: https://lore.kernel.org/lkml/20210730104039.7047-1-rppt@xxxxxxxxxx

arch/arm/kernel/setup.c | 18 +++++--------
arch/arm64/kvm/hyp/reserved_mem.c | 9 +++----
arch/arm64/mm/init.c | 36 ++++++++-----------------
arch/mips/kernel/setup.c | 14 +++++-----
arch/riscv/mm/init.c | 44 ++++++++++---------------------
arch/s390/kernel/setup.c | 10 ++++---
arch/x86/kernel/aperture_64.c | 5 ++--
arch/x86/mm/init.c | 21 +++++++++------
arch/x86/mm/numa.c | 5 ++--
arch/x86/mm/numa_emulation.c | 5 ++--
arch/x86/realmode/init.c | 2 +-
drivers/acpi/tables.c | 5 ++--
drivers/base/arch_numa.c | 5 +---
drivers/of/of_reserved_mem.c | 12 ++++++---
include/linux/memblock.h | 2 --
mm/memblock.c | 2 +-
16 files changed, 78 insertions(+), 117 deletions(-)

diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index f97eb2371672..67f5421b2af7 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -1012,31 +1012,25 @@ static void __init reserve_crashkernel(void)
unsigned long long lowmem_max = __pa(high_memory - 1) + 1;
if (crash_max > lowmem_max)
crash_max = lowmem_max;
- crash_base = memblock_find_in_range(CRASH_ALIGN, crash_max,
- crash_size, CRASH_ALIGN);
+
+ crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
+ CRASH_ALIGN, crash_max);
if (!crash_base) {
pr_err("crashkernel reservation failed - No suitable area found.\n");
return;
}
} else {
+ unsigned long long crash_max = crash_base + crash_size;
unsigned long long start;

- start = memblock_find_in_range(crash_base,
- crash_base + crash_size,
- crash_size, SECTION_SIZE);
+ start = memblock_phys_alloc_range(crash_size, SECTION_SIZE,
+ crash_base, crash_max);
if (start != crash_base) {
pr_err("crashkernel reservation failed - memory is in use.\n");
return;
}
}

- ret = memblock_reserve(crash_base, crash_size);
- if (ret < 0) {
- pr_warn("crashkernel reservation failed - memory is in use (0x%lx)\n",
- (unsigned long)crash_base);
- return;
- }
-
pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System
RAM: %ldMB)\n",
(unsigned long)(crash_size >> 20),
(unsigned long)(crash_base >> 20),
diff --git a/arch/arm64/kvm/hyp/reserved_mem.c
b/arch/arm64/kvm/hyp/reserved_mem.c
index d654921dd09b..578670e3f608 100644
--- a/arch/arm64/kvm/hyp/reserved_mem.c
+++ b/arch/arm64/kvm/hyp/reserved_mem.c
@@ -92,12 +92,10 @@ void __init kvm_hyp_reserve(void)
* this is unmapped from the host stage-2, and fallback to PAGE_SIZE.
*/
hyp_mem_size = hyp_mem_pages << PAGE_SHIFT;
- hyp_mem_base = memblock_find_in_range(0, memblock_end_of_DRAM(),
- ALIGN(hyp_mem_size, PMD_SIZE),
- PMD_SIZE);
+ hyp_mem_base = memblock_phys_alloc(ALIGN(hyp_mem_size, PMD_SIZE),
+ PMD_SIZE);
if (!hyp_mem_base)
- hyp_mem_base = memblock_find_in_range(0, memblock_end_of_DRAM(),
- hyp_mem_size, PAGE_SIZE);
+ hyp_mem_base = memblock_phys_alloc(hyp_mem_size, PAGE_SIZE);
else
hyp_mem_size = ALIGN(hyp_mem_size, PMD_SIZE);

@@ -105,7 +103,6 @@ void __init kvm_hyp_reserve(void)
kvm_err("Failed to reserve hyp memory\n");
return;
}
- memblock_reserve(hyp_mem_base, hyp_mem_size);

kvm_info("Reserved %lld MiB at 0x%llx\n", hyp_mem_size >> 20,
hyp_mem_base);
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 8490ed2917ff..d566478a06dd 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -74,6 +74,7 @@ phys_addr_t arm64_dma_phys_limit __ro_after_init;
static void __init reserve_crashkernel(void)
{
unsigned long long crash_base, crash_size;
+ unsigned long crash_max = arm64_dma_phys_limit;
int ret;

ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
@@ -84,33 +85,18 @@ static void __init reserve_crashkernel(void)

crash_size = PAGE_ALIGN(crash_size);

- if (crash_base == 0) {
- /* Current arm64 boot protocol requires 2MB alignment */
- crash_base = memblock_find_in_range(0, arm64_dma_phys_limit,
- crash_size, SZ_2M);
- if (crash_base == 0) {
- pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
- crash_size);
- return;
- }
- } else {
- /* User specifies base address explicitly. */
- if (!memblock_is_region_memory(crash_base, crash_size)) {
- pr_warn("cannot reserve crashkernel: region is not memory\n");
- return;
- }
+ /* User specifies base address explicitly. */
+ if (crash_base)
+ crash_max = crash_base + crash_size;

- if (memblock_is_region_reserved(crash_base, crash_size)) {
- pr_warn("cannot reserve crashkernel: region overlaps reserved memory\n");
- return;
- }
-
- if (!IS_ALIGNED(crash_base, SZ_2M)) {
- pr_warn("cannot reserve crashkernel: base address is not 2MB aligned\n");
- return;
- }
+ /* Current arm64 boot protocol requires 2MB alignment */
+ crash_base = memblock_phys_alloc_range(crash_size, SZ_2M,
+ crash_base, crash_max);
+ if (!crash_base) {
+ pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
+ crash_size);
+ return;
}
- memblock_reserve(crash_base, crash_size);

pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n",
crash_base, crash_base + crash_size, crash_size >> 20);
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 23a140327a0b..f979adfd4fc2 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -452,8 +452,9 @@ static void __init mips_parse_crashkernel(void)
return;

if (crash_base <= 0) {
- crash_base = memblock_find_in_range(CRASH_ALIGN, CRASH_ADDR_MAX,
- crash_size, CRASH_ALIGN);
+ crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
+ CRASH_ALIGN,
+ CRASH_ADDR_MAX);
if (!crash_base) {
pr_warn("crashkernel reservation failed - No suitable area found.\n");
return;
@@ -461,8 +462,9 @@ static void __init mips_parse_crashkernel(void)
} else {
unsigned long long start;

- start = memblock_find_in_range(crash_base, crash_base + crash_size,
- crash_size, 1);
+ start = memblock_phys_alloc_range(crash_size, 1,
+ crash_base,
+ crash_base + crash_size);
if (start != crash_base) {
pr_warn("Invalid memory region reserved for crash kernel\n");
return;
@@ -656,10 +658,6 @@ static void __init arch_mem_init(char **cmdline_p)
mips_reserve_vmcore();

mips_parse_crashkernel();
-#ifdef CONFIG_KEXEC
- if (crashk_res.start != crashk_res.end)
- memblock_reserve(crashk_res.start, resource_size(&crashk_res));
-#endif
device_tree_init();

/*
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index a14bf3910eec..88649337c568 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -812,38 +812,22 @@ static void __init reserve_crashkernel(void)

crash_size = PAGE_ALIGN(crash_size);

- if (crash_base == 0) {
- /*
- * Current riscv boot protocol requires 2MB alignment for
- * RV64 and 4MB alignment for RV32 (hugepage size)
- */
- crash_base = memblock_find_in_range(search_start, search_end,
- crash_size, PMD_SIZE);
-
- if (crash_base == 0) {
- pr_warn("crashkernel: couldn't allocate %lldKB\n",
- crash_size >> 10);
- return;
- }
- } else {
- /* User specifies base address explicitly. */
- if (!memblock_is_region_memory(crash_base, crash_size)) {
- pr_warn("crashkernel: requested region is not memory\n");
- return;
- }
-
- if (memblock_is_region_reserved(crash_base, crash_size)) {
- pr_warn("crashkernel: requested region is reserved\n");
- return;
- }
-
+ if (crash_base) {
+ search_start = crash_base;
+ search_end = crash_base + crash_size;
+ }

- if (!IS_ALIGNED(crash_base, PMD_SIZE)) {
- pr_warn("crashkernel: requested region is misaligned\n");
- return;
- }
+ /*
+ * Current riscv boot protocol requires 2MB alignment for
+ * RV64 and 4MB alignment for RV32 (hugepage size)
+ */
+ crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
+ search_start, search_end);
+ if (crash_base == 0) {
+ pr_warn("crashkernel: couldn't allocate %lldKB\n",
+ crash_size >> 10);
+ return;
}
- memblock_reserve(crash_base, crash_size);

pr_info("crashkernel: reserved 0x%016llx - 0x%016llx (%lld MB)\n",
crash_base, crash_base + crash_size, crash_size >> 20);

For the riscv part:

Acked-by: Nick Kossifidis <mick@xxxxxxxxxxxx>