unimore/kernel-hacking-2024-linux-steffo
unimore/kernel-hacking-2024-linux-steffo
1
Fork 0
Code Pull requests 5 Wiki Activity

LoongArch: add sparse memory vmemmap support

Browse source 
Add sparse memory vmemmap support for LoongArch.  SPARSEMEM_VMEMMAP uses a
virtually mapped memmap to optimise pfn_to_page and page_to_pfn
operations.  This is the most efficient option when sufficient kernel
resources are available.

Link: https://lkml.kernel.org/r/20221027125253.3458989-3-chenhuacai@loongson.cn
Signed-off-by: Min Zhou <zhoumin@loongson.cn>
Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Philippe Mathieu-Daudé <philmd@linaro.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Will Deacon <will@kernel.org>
Cc: Xuefeng Li <lixuefeng@loongson.cn>
Cc: Xuerui Wang <kernel@xen0n.name>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Feiyang Chen 2022-10-27 20:52:51 +08:00 committed by Andrew Morton
parent 22c4e80466
commit 7b09f5af01
6 changed files with 96 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
arch/loongarch/Kconfig
View file

@ -487,6 +487,7 @@ config ARCH_FLATMEM_ENABLE
config ARCH_SPARSEMEM_ENABLE
def_bool y
select SPARSEMEM_VMEMMAP_ENABLE
help
Say Y to support efficient handling of sparse physical memory,
for architectures which are either NUMA (Non-Uniform Memory Access)

7
arch/loongarch/include/asm/pgtable.h
View file

@ -11,6 +11,7 @@
#include <linux/compiler.h>
#include <asm/addrspace.h>
#include <asm/page.h>
#include <asm/pgtable-bits.h>
#if CONFIG_PGTABLE_LEVELS == 2
@ -59,6 +60,7 @@
#include <linux/mm_types.h>
#include <linux/mmzone.h>
#include <asm/fixmap.h>
#include <asm/sparsemem.h>
struct mm_struct;
struct vm_area_struct;
@ -86,7 +88,10 @@ extern unsigned long zero_page_mask;
#define VMALLOC_START MODULES_END
#define VMALLOC_END \
(vm_map_base + \
min(PTRS_PER_PGD * PTRS_PER_PUD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, (1UL << cpu_vabits)) - PMD_SIZE)
min(PTRS_PER_PGD * PTRS_PER_PUD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, (1UL << cpu_vabits)) - PMD_SIZE - VMEMMAP_SIZE)
#define vmemmap ((struct page *)((VMALLOC_END + PMD_SIZE) & PMD_MASK))
#define VMEMMAP_END ((unsigned long)vmemmap + VMEMMAP_SIZE - 1)
#define pte_ERROR(e) \
pr_err("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))

8
arch/loongarch/include/asm/sparsemem.h
View file

@ -11,8 +11,16 @@
#define SECTION_SIZE_BITS 29 /* 2^29 = Largest Huge Page Size */
#define MAX_PHYSMEM_BITS 48
#ifdef CONFIG_SPARSEMEM_VMEMMAP
#define VMEMMAP_SIZE (sizeof(struct page) * (1UL << (cpu_pabits + 1 - PAGE_SHIFT)))
#endif
#endif /* CONFIG_SPARSEMEM */
#ifndef VMEMMAP_SIZE
#define VMEMMAP_SIZE 0 /* 1, For FLATMEM; 2, For SPARSEMEM without VMEMMAP. */
#endif
#ifdef CONFIG_MEMORY_HOTPLUG
int memory_add_physaddr_to_nid(u64 addr);
#define memory_add_physaddr_to_nid memory_add_physaddr_to_nid

72
arch/loongarch/mm/init.c
View file

@ -22,7 +22,7 @@
#include <linux/pfn.h>
#include <linux/hardirq.h>
#include <linux/gfp.h>
#include <linux/initrd.h>
#include <linux/hugetlb.h>
#include <linux/mmzone.h>
#include <asm/asm-offsets.h>
@ -152,6 +152,72 @@ EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
#endif
#endif
#ifdef CONFIG_SPARSEMEM_VMEMMAP
static int __meminit vmemmap_populate_hugepages(unsigned long start, unsigned long end,
int node, struct vmem_altmap *altmap)
{
unsigned long addr = start;
unsigned long next;
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
for (addr = start; addr < end; addr = next) {
next = pmd_addr_end(addr, end);
pgd = vmemmap_pgd_populate(addr, node);
if (!pgd)
return -ENOMEM;
p4d = vmemmap_p4d_populate(pgd, addr, node);
if (!p4d)
return -ENOMEM;
pud = vmemmap_pud_populate(p4d, addr, node);
if (!pud)
return -ENOMEM;
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd)) {
void *p = NULL;
p = vmemmap_alloc_block_buf(PMD_SIZE, node, NULL);
if (p) {
pmd_t entry;
entry = pfn_pmd(virt_to_pfn(p), PAGE_KERNEL);
pmd_val(entry) |= _PAGE_HUGE | _PAGE_HGLOBAL;
set_pmd_at(&init_mm, addr, pmd, entry);
continue;
}
} else if (pmd_val(*pmd) & _PAGE_HUGE) {
vmemmap_verify((pte_t *)pmd, node, addr, next);
continue;
}
if (vmemmap_populate_basepages(addr, next, node, NULL))
return -ENOMEM;
}
return 0;
}
int __meminit vmemmap_populate(unsigned long start, unsigned long end,
int node, struct vmem_altmap *altmap)
{
#if CONFIG_PGTABLE_LEVELS == 2
return vmemmap_populate_basepages(start, end, node, NULL);
#else
return vmemmap_populate_hugepages(start, end, node, NULL);
#endif
}
#ifdef CONFIG_MEMORY_HOTPLUG
void vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *altmap)
{
}
#endif
#endif
static pte_t *fixmap_pte(unsigned long addr)
{
pgd_t *pgd;
@ -168,7 +234,7 @@ static pte_t *fixmap_pte(unsigned long addr)
new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
pgd_populate(&init_mm, pgd, new);
#ifndef __PAGETABLE_PUD_FOLDED
pud_init((unsigned long)new, (unsigned long)invalid_pmd_table);
pud_init(new);
#endif
}
@ -179,7 +245,7 @@ static pte_t *fixmap_pte(unsigned long addr)
new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
pud_populate(&init_mm, pud, new);
#ifndef __PAGETABLE_PMD_FOLDED
pmd_init((unsigned long)new, (unsigned long)invalid_pte_table);
pmd_init(new);
#endif
}

2
include/linux/mm.h
View file

@ -3360,6 +3360,8 @@ void *sparse_buffer_alloc(unsigned long size);
struct page * __populate_section_memmap(unsigned long pfn,
unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
struct dev_pagemap *pgmap);
void pmd_init(void *addr);
void pud_init(void *addr);
pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
p4d_t *vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node);
pud_t *vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node);

10
mm/sparse-vmemmap.c
View file

@ -196,6 +196,10 @@ pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
return pmd;
}
void __weak __meminit pmd_init(void *addr)
{
}
pud_t * __meminit vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node)
{
pud_t *pud = pud_offset(p4d, addr);
@ -203,11 +207,16 @@ pud_t * __meminit vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node)
void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
if (!p)
return NULL;
pmd_init(p);
pud_populate(&init_mm, pud, p);
}
return pud;
}
void __weak __meminit pud_init(void *addr)
{
}
p4d_t * __meminit vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node)
{
p4d_t *p4d = p4d_offset(pgd, addr);
@ -215,6 +224,7 @@ p4d_t * __meminit vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node)
void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
if (!p)
return NULL;
pud_init(p);
p4d_populate(&init_mm, p4d, p);
}
return p4d;