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.
Signed-off-by: Min Zhou <zhoumin@xxxxxxxxxxx>
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
arch/loongarch/Kconfig | 1 +
arch/loongarch/include/asm/pgtable.h | 5 +-
arch/loongarch/include/asm/sparsemem.h | 8 ++
arch/loongarch/mm/init.c | 184 ++++++++++++++++++++++++-
4 files changed, 196 insertions(+), 2 deletions(-)
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index dc19cf3071ea..55ab84fd70e5 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -422,6 +422,7 @@ 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)
diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h
index 5dc84d8f18d6..3b8725fc6693 100644
--- a/arch/loongarch/include/asm/pgtable.h
+++ b/arch/loongarch/include/asm/pgtable.h
@@ -92,7 +92,10 @@ 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))
diff --git a/arch/loongarch/include/asm/sparsemem.h b/arch/loongarch/include/asm/sparsemem.h
index 3d18cdf1b069..a1e440f6bec7 100644
--- a/arch/loongarch/include/asm/sparsemem.h
+++ b/arch/loongarch/include/asm/sparsemem.h
@@ -11,6 +11,14 @@
#define SECTION_SIZE_BITS 29 /* 2^29 = Largest Huge Page Size */
#define MAX_PHYSMEM_BITS 48
+#ifndef CONFIG_SPARSEMEM_VMEMMAP
+#define VMEMMAP_SIZE 0
+#else
+#define VMEMMAP_SIZE (sizeof(struct page) * (1UL << (cpu_pabits + 1 - PAGE_SHIFT)))
+#endif
+
+#include <linux/mm_types.h>
+
#endif /* CONFIG_SPARSEMEM */
#ifdef CONFIG_MEMORY_HOTPLUG
diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c
index 7094a68c9b83..9b65deab6f14 100644
--- a/arch/loongarch/mm/init.c
+++ b/arch/loongarch/mm/init.c
@@ -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>
@@ -157,6 +157,188 @@ void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
#endif
#endif
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+void __meminit arch_vmemmap_verify(pte_t *pte, int node,
+ unsigned long start, unsigned long end)
+{
+ unsigned long pfn = pte_pfn(*pte);
+ int actual_node = early_pfn_to_nid(pfn);
+
+ if (node_distance(actual_node, node) > LOCAL_DISTANCE)
+ pr_warn("[%lx-%lx] potential offnode page_structs\n",
+ start, end - 1);
+}
+
+void * __meminit arch_vmemmap_alloc_block_zero(unsigned long size, int node)
+{
+ void *p = vmemmap_alloc_block(size, node);
+
+ if (!p)
+ return NULL;
+ memset(p, 0, size);
+
+ return p;
+}
+
+pte_t * __meminit arch_vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node)
+{
+ pte_t *pte = pte_offset_kernel(pmd, addr);
+ if (pte_none(*pte)) {
+ pte_t entry;
+ void *p = arch_vmemmap_alloc_block_zero(PAGE_SIZE, node);
+ if (!p)
+ return NULL;
+ entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
+ set_pte_at(&init_mm, addr, pte, entry);
+ }
+ return pte;
+}
+
+pmd_t * __meminit arch_vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
+{
+ pmd_t *pmd = pmd_offset(pud, addr);
+ if (pmd_none(*pmd)) {
+ void *p = arch_vmemmap_alloc_block_zero(PAGE_SIZE, node);
+ if (!p)
+ return NULL;
+ pmd_populate_kernel(&init_mm, pmd, p);
+ }
+ return pmd;
+}
+
+pud_t * __meminit arch_vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node)
+{
+ pud_t *pud = pud_offset(p4d, addr);
+ if (pud_none(*pud)) {
+ void *p = arch_vmemmap_alloc_block_zero(PAGE_SIZE, node);
+ if (!p)
+ return NULL;
+#ifndef __PAGETABLE_PMD_FOLDED
+ pmd_init((unsigned long)p, (unsigned long)invalid_pte_table);
+#endif
+ pud_populate(&init_mm, pud, p);
+ }
+ return pud;
+}
+
+p4d_t * __meminit arch_vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node)
+{
+ p4d_t *p4d = p4d_offset(pgd, addr);
+ if (p4d_none(*p4d)) {
+ void *p = arch_vmemmap_alloc_block_zero(PAGE_SIZE, node);
+ if (!p)
+ return NULL;
+#ifndef __PAGETABLE_PUD_FOLDED
+ pud_init((unsigned long)p, (unsigned long)invalid_pmd_table);
+#endif
+ p4d_populate(&init_mm, p4d, p);
+ }
+ return p4d;
+}
+
+pgd_t * __meminit arch_vmemmap_pgd_populate(unsigned long addr, int node)
+{
+ pgd_t *pgd = pgd_offset_k(addr);
+ if (pgd_none(*pgd)) {
+ void *p = arch_vmemmap_alloc_block_zero(PAGE_SIZE, node);
+ if (!p)
+ return NULL;
+ pgd_populate(&init_mm, pgd, p);
+ }
+ return pgd;
+}
+
+int __meminit arch_vmemmap_populate_basepages(unsigned long start,
+ unsigned long end, int node)
+{
+ unsigned long addr = start;
+ pgd_t *pgd;
+ p4d_t *p4d;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+
+ for (; addr < end; addr += PAGE_SIZE) {
+ pgd = arch_vmemmap_pgd_populate(addr, node);
+ if (!pgd)
+ return -ENOMEM;
+ p4d = arch_vmemmap_p4d_populate(pgd, addr, node);
+ if (!p4d)
+ return -ENOMEM;
+ pud = arch_vmemmap_pud_populate(p4d, addr, node);
+ if (!pud)
+ return -ENOMEM;
+ pmd = arch_vmemmap_pmd_populate(pud, addr, node);
+ if (!pmd)
+ return -ENOMEM;
+ pte = arch_vmemmap_pte_populate(pmd, addr, node);
+ if (!pte)
+ return -ENOMEM;
+ arch_vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
+ }
+
+ return 0;
+}
+
+int __meminit arch_vmemmap_populate_hugepages(unsigned long start,
+ unsigned long end, int node)
+{
+ 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 = arch_vmemmap_pgd_populate(addr, node);
+ if (!pgd)
+ return -ENOMEM;
+ p4d = arch_vmemmap_p4d_populate(pgd, addr, node);
+ if (!p4d)
+ return -ENOMEM;
+ pud = arch_vmemmap_pud_populate(p4d, addr, node);
+ if (!pud)
+ return -ENOMEM;
+
+ pmd = pmd_offset(pud, addr);
+ if (pmd_none(*pmd)) {
+ void *p = NULL;
+
+ p = arch_vmemmap_alloc_block_zero(PMD_SIZE, node);
+ if (p) {
+ pmd_t entry;
+
+ entry = pfn_pmd(virt_to_pfn(p), PAGE_KERNEL);
+ entry = pmd_mkhuge(entry);
+ set_pmd_at(&init_mm, addr, pmd, entry);
+
+ continue;
+ }
+ } else if (pmd_huge(*pmd)) {
+ arch_vmemmap_verify((pte_t *)pmd, node, addr, next);
+ continue;
+ }
+ if (arch_vmemmap_populate_basepages(addr, next, node))
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
+ struct vmem_altmap *altmap)
+{
+ return arch_vmemmap_populate_hugepages(start, end, node);
+}
+void vmemmap_free(unsigned long start, unsigned long end,
+ struct vmem_altmap *altmap)
+{
+}
+#endif
+
/*
* Align swapper_pg_dir in to 64K, allows its address to be loaded
* with a single LUI instruction in the TLB handlers. If we used
--
2.27.0
