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Subject[PATCH v6 09/36] nds32: MMU initialization
Date
From: Greentime Hu <greentime@andestech.com>

This patch includes memory initializations and highmem supporting.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
---
arch/nds32/mm/highmem.c | 79 +++++++++++++
arch/nds32/mm/init.c | 277 ++++++++++++++++++++++++++++++++++++++++++++++
arch/nds32/mm/mm-nds32.c | 90 +++++++++++++++
3 files changed, 446 insertions(+)
create mode 100644 arch/nds32/mm/highmem.c
create mode 100644 arch/nds32/mm/init.c
create mode 100644 arch/nds32/mm/mm-nds32.c

diff --git a/arch/nds32/mm/highmem.c b/arch/nds32/mm/highmem.c
new file mode 100644
index 0000000..e17cb8a
--- /dev/null
+++ b/arch/nds32/mm/highmem.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/export.h>
+#include <linux/highmem.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/bootmem.h>
+#include <asm/fixmap.h>
+#include <asm/tlbflush.h>
+
+void *kmap(struct page *page)
+{
+ unsigned long vaddr;
+ might_sleep();
+ if (!PageHighMem(page))
+ return page_address(page);
+ vaddr = (unsigned long)kmap_high(page);
+ return (void *)vaddr;
+}
+
+EXPORT_SYMBOL(kmap);
+
+void kunmap(struct page *page)
+{
+ BUG_ON(in_interrupt());
+ if (!PageHighMem(page))
+ return;
+ kunmap_high(page);
+}
+
+EXPORT_SYMBOL(kunmap);
+
+void *kmap_atomic(struct page *page)
+{
+ unsigned int idx;
+ unsigned long vaddr, pte;
+ int type;
+ pte_t *ptep;
+
+ preempt_disable();
+ pagefault_disable();
+ if (!PageHighMem(page))
+ return page_address(page);
+
+ type = kmap_atomic_idx_push();
+
+ idx = type + KM_TYPE_NR * smp_processor_id();
+ vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+ pte = (page_to_pfn(page) << PAGE_SHIFT) | (PAGE_KERNEL);
+ ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
+ set_pte(ptep, pte);
+
+ __nds32__tlbop_inv(vaddr);
+ __nds32__mtsr_dsb(vaddr, NDS32_SR_TLB_VPN);
+ __nds32__tlbop_rwr(pte);
+ __nds32__isb();
+ return (void *)vaddr;
+}
+
+EXPORT_SYMBOL(kmap_atomic);
+
+void __kunmap_atomic(void *kvaddr)
+{
+ if (kvaddr >= (void *)FIXADDR_START) {
+ unsigned long vaddr = (unsigned long)kvaddr;
+ pte_t *ptep;
+ kmap_atomic_idx_pop();
+ __nds32__tlbop_inv(vaddr);
+ __nds32__isb();
+ ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
+ set_pte(ptep, 0);
+ }
+ pagefault_enable();
+ preempt_enable();
+}
+
+EXPORT_SYMBOL(__kunmap_atomic);
diff --git a/arch/nds32/mm/init.c b/arch/nds32/mm/init.c
new file mode 100644
index 0000000..93ee016
--- /dev/null
+++ b/arch/nds32/mm/init.c
@@ -0,0 +1,277 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 1995-2005 Russell King
+// Copyright (C) 2012 ARM Ltd.
+// Copyright (C) 2013-2017 Andes Technology Corporation
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/swap.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/mman.h>
+#include <linux/nodemask.h>
+#include <linux/initrd.h>
+#include <linux/highmem.h>
+#include <linux/memblock.h>
+
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/tlb.h>
+#include <asm/page.h>
+
+DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
+DEFINE_SPINLOCK(anon_alias_lock);
+extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
+extern unsigned long phys_initrd_start;
+extern unsigned long phys_initrd_size;
+
+/*
+ * empty_zero_page is a special page that is used for
+ * zero-initialized data and COW.
+ */
+struct page *empty_zero_page;
+
+static void __init zone_sizes_init(void)
+{
+ unsigned long zones_size[MAX_NR_ZONES];
+
+ /* Clear the zone sizes */
+ memset(zones_size, 0, sizeof(zones_size));
+
+ zones_size[ZONE_NORMAL] = max_low_pfn;
+#ifdef CONFIG_HIGHMEM
+ zones_size[ZONE_HIGHMEM] = max_pfn;
+#endif
+ free_area_init(zones_size);
+
+}
+
+/*
+ * Map all physical memory under high_memory into kernel's address space.
+ *
+ * This is explicitly coded for two-level page tables, so if you need
+ * something else then this needs to change.
+ */
+static void __init map_ram(void)
+{
+ unsigned long v, p, e;
+ pgd_t *pge;
+ pud_t *pue;
+ pmd_t *pme;
+ pte_t *pte;
+ /* These mark extents of read-only kernel pages...
+ * ...from vmlinux.lds.S
+ */
+
+ p = (u32) memblock_start_of_DRAM() & PAGE_MASK;
+ e = min((u32) memblock_end_of_DRAM(), (u32) __pa(high_memory));
+
+ v = (u32) __va(p);
+ pge = pgd_offset_k(v);
+
+ while (p < e) {
+ int j;
+ pue = pud_offset(pge, v);
+ pme = pmd_offset(pue, v);
+
+ if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) {
+ panic("%s: Kernel hardcoded for "
+ "two-level page tables", __func__);
+ }
+
+ /* Alloc one page for holding PTE's... */
+ pte = (pte_t *) __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
+ memset(pte, 0, PAGE_SIZE);
+ set_pmd(pme, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
+
+ /* Fill the newly allocated page with PTE'S */
+ for (j = 0; p < e && j < PTRS_PER_PTE;
+ v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) {
+ /* Create mapping between p and v. */
+ /* TODO: more fine grant for page access permission */
+ set_pte(pte, __pte(p + pgprot_val(PAGE_KERNEL)));
+ }
+
+ pge++;
+ }
+}
+static pmd_t *fixmap_pmd_p;
+static void __init fixedrange_init(void)
+{
+ unsigned long vaddr;
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+#ifdef CONFIG_HIGHMEM
+ pte_t *pte;
+#endif /* CONFIG_HIGHMEM */
+
+ /*
+ * Fixed mappings:
+ */
+ vaddr = __fix_to_virt(__end_of_fixed_addresses - 1);
+ pgd = swapper_pg_dir + pgd_index(vaddr);
+ pud = pud_offset(pgd, vaddr);
+ pmd = pmd_offset(pud, vaddr);
+ fixmap_pmd_p = (pmd_t *) __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
+ memset(fixmap_pmd_p, 0, PAGE_SIZE);
+ set_pmd(pmd, __pmd(__pa(fixmap_pmd_p) + _PAGE_KERNEL_TABLE));
+
+#ifdef CONFIG_HIGHMEM
+ /*
+ * Permanent kmaps:
+ */
+ vaddr = PKMAP_BASE;
+
+ pgd = swapper_pg_dir + pgd_index(vaddr);
+ pud = pud_offset(pgd, vaddr);
+ pmd = pmd_offset(pud, vaddr);
+ pte = (pte_t *) __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
+ memset(pte, 0, PAGE_SIZE);
+ set_pmd(pmd, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
+ pkmap_page_table = pte;
+#endif /* CONFIG_HIGHMEM */
+}
+
+/*
+ * paging_init() sets up the page tables, initialises the zone memory
+ * maps, and sets up the zero page, bad page and bad page tables.
+ */
+void __init paging_init(void)
+{
+ int i;
+ void *zero_page;
+
+ pr_info("Setting up paging and PTEs.\n");
+ /* clear out the init_mm.pgd that will contain the kernel's mappings */
+ for (i = 0; i < PTRS_PER_PGD; i++)
+ swapper_pg_dir[i] = __pgd(1);
+
+ map_ram();
+
+ fixedrange_init();
+
+ /* allocate space for empty_zero_page */
+ zero_page = __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
+ memset(zero_page, 0, PAGE_SIZE);
+ zone_sizes_init();
+
+ empty_zero_page = virt_to_page(zero_page);
+ flush_dcache_page(empty_zero_page);
+}
+
+static inline void __init free_highmem(void)
+{
+#ifdef CONFIG_HIGHMEM
+ unsigned long pfn;
+ for (pfn = PFN_UP(__pa(high_memory)); pfn < max_pfn; pfn++) {
+ phys_addr_t paddr = (phys_addr_t) pfn << PAGE_SHIFT;
+ if (!memblock_is_reserved(paddr))
+ free_highmem_page(pfn_to_page(pfn));
+ }
+#endif
+}
+
+static void __init set_max_mapnr_init(void)
+{
+ max_mapnr = max_pfn;
+}
+
+/*
+ * mem_init() marks the free areas in the mem_map and tells us how much
+ * memory is free. This is done after various parts of the system have
+ * claimed their memory after the kernel image.
+ */
+void __init mem_init(void)
+{
+ phys_addr_t memory_start = memblock_start_of_DRAM();
+ BUG_ON(!mem_map);
+ set_max_mapnr_init();
+
+ free_highmem();
+
+ /* this will put all low memory onto the freelists */
+ free_all_bootmem();
+ mem_init_print_info(NULL);
+
+ pr_info("virtual kernel memory layout:\n"
+ " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
+#ifdef CONFIG_HIGHMEM
+ " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
+#endif
+ " consist : 0x%08lx - 0x%08lx (%4ld MB)\n"
+ " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
+ " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
+ " .init : 0x%08lx - 0x%08lx (%4ld kB)\n"
+ " .data : 0x%08lx - 0x%08lx (%4ld kB)\n"
+ " .text : 0x%08lx - 0x%08lx (%4ld kB)\n",
+ FIXADDR_START, FIXADDR_TOP, (FIXADDR_TOP - FIXADDR_START) >> 10,
+#ifdef CONFIG_HIGHMEM
+ PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
+ (LAST_PKMAP * PAGE_SIZE) >> 10,
+#endif
+ CONSISTENT_BASE, CONSISTENT_END,
+ ((CONSISTENT_END) - (CONSISTENT_BASE)) >> 20, VMALLOC_START,
+ (unsigned long)VMALLOC_END, (VMALLOC_END - VMALLOC_START) >> 20,
+ (unsigned long)__va(memory_start), (unsigned long)high_memory,
+ ((unsigned long)high_memory -
+ (unsigned long)__va(memory_start)) >> 20,
+ (unsigned long)&__init_begin, (unsigned long)&__init_end,
+ ((unsigned long)&__init_end -
+ (unsigned long)&__init_begin) >> 10, (unsigned long)&_etext,
+ (unsigned long)&_edata,
+ ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
+ (unsigned long)&_text, (unsigned long)&_etext,
+ ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
+
+ /*
+ * Check boundaries twice: Some fundamental inconsistencies can
+ * be detected at build time already.
+ */
+#ifdef CONFIG_HIGHMEM
+ BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
+ BUILD_BUG_ON((CONSISTENT_END) > PKMAP_BASE);
+#endif
+ BUILD_BUG_ON(VMALLOC_END > CONSISTENT_BASE);
+ BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END);
+
+#ifdef CONFIG_HIGHMEM
+ BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
+ BUG_ON(CONSISTENT_END > PKMAP_BASE);
+#endif
+ BUG_ON(VMALLOC_END > CONSISTENT_BASE);
+ BUG_ON(VMALLOC_START >= VMALLOC_END);
+ BUG_ON((unsigned long)high_memory > VMALLOC_START);
+
+ return;
+}
+
+void free_initmem(void)
+{
+ free_initmem_default(-1);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+ free_reserved_area((void *)start, (void *)end, -1, "initrd");
+}
+#endif
+
+void __set_fixmap(enum fixed_addresses idx,
+ phys_addr_t phys, pgprot_t flags)
+{
+ unsigned long addr = __fix_to_virt(idx);
+ pte_t *pte;
+
+ BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
+
+ pte = (pte_t *)&fixmap_pmd_p[pte_index(addr)];;
+
+ if (pgprot_val(flags)) {
+ set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
+ } else {
+ pte_clear(&init_mm, addr, pte);
+ flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
+ }
+}
diff --git a/arch/nds32/mm/mm-nds32.c b/arch/nds32/mm/mm-nds32.c
new file mode 100644
index 0000000..7f7d4b36
--- /dev/null
+++ b/arch/nds32/mm/mm-nds32.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/init_task.h>
+#include <asm/pgalloc.h>
+
+#define FIRST_KERNEL_PGD_NR (USER_PTRS_PER_PGD)
+
+/*
+ * need to get a page for level 1
+ */
+
+pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+ pgd_t *new_pgd, *init_pgd;
+ int i;
+
+ new_pgd = (pgd_t *) __get_free_pages(GFP_KERNEL, 0);
+ if (!new_pgd)
+ return NULL;
+ for (i = 0; i < PTRS_PER_PGD; i++) {
+ (*new_pgd) = 1;
+ new_pgd++;
+ }
+ new_pgd -= PTRS_PER_PGD;
+
+ init_pgd = pgd_offset_k(0);
+
+ memcpy(new_pgd + FIRST_KERNEL_PGD_NR, init_pgd + FIRST_KERNEL_PGD_NR,
+ (PTRS_PER_PGD - FIRST_KERNEL_PGD_NR) * sizeof(pgd_t));
+
+ cpu_dcache_wb_range((unsigned long)new_pgd,
+ (unsigned long)new_pgd +
+ PTRS_PER_PGD * sizeof(pgd_t));
+ inc_zone_page_state(virt_to_page((unsigned long *)new_pgd),
+ NR_PAGETABLE);
+
+ return new_pgd;
+}
+
+void pgd_free(struct mm_struct *mm, pgd_t * pgd)
+{
+ pmd_t *pmd;
+ struct page *pte;
+
+ if (!pgd)
+ return;
+
+ pmd = (pmd_t *) pgd;
+ if (pmd_none(*pmd))
+ goto free;
+ if (pmd_bad(*pmd)) {
+ pmd_ERROR(*pmd);
+ pmd_clear(pmd);
+ goto free;
+ }
+
+ pte = pmd_page(*pmd);
+ pmd_clear(pmd);
+ dec_zone_page_state(virt_to_page((unsigned long *)pgd), NR_PAGETABLE);
+ pte_free(mm, pte);
+ atomic_long_dec(&mm->nr_ptes);
+ pmd_free(mm, pmd);
+free:
+ free_pages((unsigned long)pgd, 0);
+}
+
+/*
+ * In order to soft-boot, we need to insert a 1:1 mapping in place of
+ * the user-mode pages. This will then ensure that we have predictable
+ * results when turning the mmu off
+ */
+void setup_mm_for_reboot(char mode)
+{
+ unsigned long pmdval;
+ pgd_t *pgd;
+ pmd_t *pmd;
+ int i;
+
+ if (current->mm && current->mm->pgd)
+ pgd = current->mm->pgd;
+ else
+ pgd = init_mm.pgd;
+
+ for (i = 0; i < USER_PTRS_PER_PGD; i++) {
+ pmdval = (i << PGDIR_SHIFT);
+ pmd = pmd_offset(pgd + i, i << PGDIR_SHIFT);
+ set_pmd(pmd, __pmd(pmdval));
+ }
+}
--
1.7.9.5
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