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

Rafael J. Wysocki
2021-08-06T13:03:31Z

On Mon, Aug 2, 2021 at 8:37 AM Mike Rapoport <rppt@kernel.org> wrote:
>
> From: Mike Rapoport <rppt@linux.ibm.com>
>
> 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@linux.ibm.com>

For the ACPI part:

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

> ---
> v2: don't change error message in arm::reserve_crashkernel(), per Russell
> v1: https://lore.kernel.org/lkml/20210730104039.7047-1-rppt@kernel.org
>
> 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);
> diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
> index ff0f9e838916..3d9efee0f43c 100644
> --- a/arch/s390/kernel/setup.c
> +++ b/arch/s390/kernel/setup.c
> @@ -626,8 +626,9 @@ static void __init reserve_crashkernel(void)
> return;
> }
> low = crash_base ?: low;
> - crash_base = memblock_find_in_range(low, high, crash_size,
> - KEXEC_CRASH_MEM_ALIGN);
> + crash_base = memblock_phys_alloc_range(crash_size,
> + KEXEC_CRASH_MEM_ALIGN,
> + low, high);
> }
>
> if (!crash_base) {
> @@ -636,14 +637,15 @@ static void __init reserve_crashkernel(void)
> return;
> }
>
> - if (register_memory_notifier(&kdump_mem_nb))
> + if (register_memory_notifier(&kdump_mem_nb)) {
> + memblock_free(crash_base, crash_size);
> return;
> + }
>
> if (!OLDMEM_BASE && MACHINE_IS_VM)
> diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
> crashk_res.start = crash_base;
> crashk_res.end = crash_base + crash_size - 1;
> - memblock_remove(crash_base, crash_size);
> pr_info("Reserving %lluMB of memory at %lluMB "
> "for crashkernel (System RAM: %luMB)\n",
> crash_size >> 20, crash_base >> 20,
> diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
> index 294ed4392a0e..10562885f5fc 100644
> --- a/arch/x86/kernel/aperture_64.c
> +++ b/arch/x86/kernel/aperture_64.c
> @@ -109,14 +109,13 @@ static u32 __init allocate_aperture(void)
> * memory. Unfortunately we cannot move it up because that would
> * make the IOMMU useless.
> */
> - addr = memblock_find_in_range(GART_MIN_ADDR, GART_MAX_ADDR,
> - aper_size, aper_size);
> + addr = memblock_phys_alloc_range(aper_size, aper_size,
> + GART_MIN_ADDR, GART_MAX_ADDR);
> if (!addr) {
> pr_err("Cannot allocate aperture memory hole [mem %#010lx-%#010lx] (%uKB)\n",
> addr, addr + aper_size - 1, aper_size >> 10);
> return 0;
> }
> - memblock_reserve(addr, aper_size);
> pr_info("Mapping aperture over RAM [mem %#010lx-%#010lx] (%uKB)\n",
> addr, addr + aper_size - 1, aper_size >> 10);
> register_nosave_region(addr >> PAGE_SHIFT,
> diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
> index 75ef19aa8903..1152a29ce109 100644
> --- a/arch/x86/mm/init.c
> +++ b/arch/x86/mm/init.c
> @@ -26,6 +26,7 @@
> #include <asm/pti.h>
> #include <asm/text-patching.h>
> #include <asm/memtype.h>
> +#include <xen/xen.h>
>
> /*
> * We need to define the tracepoints somewhere, and tlb.c
> @@ -127,14 +128,12 @@ __ref void *alloc_low_pages(unsigned int num)
> unsigned long ret = 0;
>
> if (min_pfn_mapped < max_pfn_mapped) {
> - ret = memblock_find_in_range(
> + ret = memblock_phys_alloc_range(
> + PAGE_SIZE * num, PAGE_SIZE,
> min_pfn_mapped << PAGE_SHIFT,
> - max_pfn_mapped << PAGE_SHIFT,
> - PAGE_SIZE * num , PAGE_SIZE);
> + max_pfn_mapped << PAGE_SHIFT);
> }
> - if (ret)
> - memblock_reserve(ret, PAGE_SIZE * num);
> - else if (can_use_brk_pgt)
> + if (!ret && can_use_brk_pgt)
> ret = __pa(extend_brk(PAGE_SIZE * num, PAGE_SIZE));
>
> if (!ret)
> @@ -610,9 +609,15 @@ static void __init memory_map_top_down(unsigned long map_start,
> unsigned long addr;
> unsigned long mapped_ram_size = 0;
>
> + real_end = ALIGN_DOWN(map_end, PMD_SIZE);
> +
> /* xen has big range in reserved near end of ram, skip it at first.*/
> - addr = memblock_find_in_range(map_start, map_end, PMD_SIZE, PMD_SIZE);
> - real_end = addr + PMD_SIZE;
> + if (xen_domain()) {
> + addr = memblock_phys_alloc_range(PMD_SIZE, PMD_SIZE,
> + map_start, map_end);
> + memblock_free(addr, PMD_SIZE);
> + real_end = addr + PMD_SIZE;
> + }
>
> /* step_size need to be small so pgt_buf from BRK could cover it */
> step_size = PMD_SIZE;
> diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
> index e94da744386f..a1b5c71099e6 100644
> --- a/arch/x86/mm/numa.c
> +++ b/arch/x86/mm/numa.c
> @@ -376,15 +376,14 @@ static int __init numa_alloc_distance(void)
> cnt++;
> size = cnt * cnt * sizeof(numa_distance[0]);
>
> - phys = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
> - size, PAGE_SIZE);
> + phys = memblock_phys_alloc_range(size, PAGE_SIZE, 0,
> + PFN_PHYS(max_pfn_mapped));
> if (!phys) {
> pr_warn("Warning: can't allocate distance table!\n");
> /* don't retry until explicitly reset */
> numa_distance = (void *)1LU;
> return -ENOMEM;
> }
> - memblock_reserve(phys, size);
>
> numa_distance = __va(phys);
> numa_distance_cnt = cnt;
> diff --git a/arch/x86/mm/numa_emulation.c b/arch/x86/mm/numa_emulation.c
> index 87d77cc52f86..737491b13728 100644
> --- a/arch/x86/mm/numa_emulation.c
> +++ b/arch/x86/mm/numa_emulation.c
> @@ -447,13 +447,12 @@ void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt)
> if (numa_dist_cnt) {
> u64 phys;
>
> - phys = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
> - phys_size, PAGE_SIZE);
> + phys = memblock_phys_alloc_range(phys_size, PAGE_SIZE, 0,
> + PFN_PHYS(max_pfn_mapped));
> if (!phys) {
> pr_warn("NUMA: Warning: can't allocate copy of distance table, disabling emulation\n");
> goto no_emu;
> }
> - memblock_reserve(phys, phys_size);
> phys_dist = __va(phys);
>
> for (i = 0; i < numa_dist_cnt; i++)
> diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
> index 6534c92d0f83..31b5856010cb 100644
> --- a/arch/x86/realmode/init.c
> +++ b/arch/x86/realmode/init.c
> @@ -28,7 +28,7 @@ void __init reserve_real_mode(void)
> WARN_ON(slab_is_available());
>
> /* Has to be under 1M so we can execute real-mode AP code. */
> - mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE);
> + mem = memblock_phys_alloc_range(size, PAGE_SIZE, 0, 1<<20);
> if (!mem)
> pr_info("No sub-1M memory is available for the trampoline\n");
> else
> diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
> index a37a1532a575..f9383736fa0f 100644
> --- a/drivers/acpi/tables.c
> +++ b/drivers/acpi/tables.c
> @@ -583,8 +583,8 @@ void __init acpi_table_upgrade(void)
> }
>
> acpi_tables_addr =
> - memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS,
> - all_tables_size, PAGE_SIZE);
> + memblock_phys_alloc_range(all_tables_size, PAGE_SIZE,
> + 0, ACPI_TABLE_UPGRADE_MAX_PHYS);
> if (!acpi_tables_addr) {
> WARN_ON(1);
> return;
> @@ -599,7 +599,6 @@ void __init acpi_table_upgrade(void)
> * Both memblock_reserve and e820__range_add (via arch_reserve_mem_area)
> * works fine.
> */
> - memblock_reserve(acpi_tables_addr, all_tables_size);
> arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
>
> /*
> diff --git a/drivers/base/arch_numa.c b/drivers/base/arch_numa.c
> index 4cc4e117727d..46c503486e96 100644
> --- a/drivers/base/arch_numa.c
> +++ b/drivers/base/arch_numa.c
> @@ -279,13 +279,10 @@ static int __init numa_alloc_distance(void)
> int i, j;
>
> size = nr_node_ids * nr_node_ids * sizeof(numa_distance[0]);
> - phys = memblock_find_in_range(0, PFN_PHYS(max_pfn),
> - size, PAGE_SIZE);
> + phys = memblock_phys_alloc_range(size, PAGE_SIZE, 0, PFN_PHYS(max_pfn));
> if (WARN_ON(!phys))
> return -ENOMEM;
>
> - memblock_reserve(phys, size);
> -
> numa_distance = __va(phys);
> numa_distance_cnt = nr_node_ids;
>
> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> index fd3964d24224..59c1390cdf42 100644
> --- a/drivers/of/of_reserved_mem.c
> +++ b/drivers/of/of_reserved_mem.c
> @@ -33,18 +33,22 @@ static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
> phys_addr_t *res_base)
> {
> phys_addr_t base;
> + int err = 0;
>
> end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
> align = !align ? SMP_CACHE_BYTES : align;
> - base = memblock_find_in_range(start, end, size, align);
> + base = memblock_phys_alloc_range(size, align, start, end);
> if (!base)
> return -ENOMEM;
>
> *res_base = base;
> - if (nomap)
> - return memblock_mark_nomap(base, size);
> + if (nomap) {
> + err = memblock_mark_nomap(base, size);
> + if (err)
> + memblock_free(base, size);
> + }
>
> - return memblock_reserve(base, size);
> + return err;
> }
>
> /*
> diff --git a/include/linux/memblock.h b/include/linux/memblock.h
> index 4a53c3ca86bd..b066024c62e3 100644
> --- a/include/linux/memblock.h
> +++ b/include/linux/memblock.h
> @@ -99,8 +99,6 @@ void memblock_discard(void);
> static inline void memblock_discard(void) {}
> #endif
>
> -phys_addr_t memblock_find_in_range(phys_addr_t start, phys_addr_t end,
> - phys_addr_t size, phys_addr_t align);
> void memblock_allow_resize(void);
> int memblock_add_node(phys_addr_t base, phys_addr_t size, int nid);
> int memblock_add(phys_addr_t base, phys_addr_t size);
> diff --git a/mm/memblock.c b/mm/memblock.c
> index de7b553baa50..28a813d9e955 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -315,7 +315,7 @@ static phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t size,
> * Return:
> * Found address on success, 0 on failure.
> */
> -phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start,
> +static phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start,
> phys_addr_t end, phys_addr_t size,
> phys_addr_t align)
> {
>
> base-commit: ff1176468d368232b684f75e82563369208bc371
> --
> 2.28.0
>