csky: MMU and page table management
This patch adds files related to memory management and here is our memory-layout: Fixmap : 0xffc02000 – 0xfffff000 (4 MB - 12KB) Pkmap : 0xff800000 – 0xffc00000 (4 MB) Vmalloc : 0xf0200000 – 0xff000000 (238 MB) Lowmem : 0x80000000 – 0xc0000000 (1GB) abiv1 CPU (CK610) is VIPT cache and it doesn't support highmem. abiv2 CPUs are all PIPT cache and they could support highmem. Lowmem is directly mapped by msa0 & msa1 reg, and we needn't setup memory page table for it. Link:https://lore.kernel.org/lkml/20180518215548.GH17671@n2100.armlinux.org.uk/ Signed-off-by: Guo Ren <ren_guo@c-sky.com> Cc: Christoph Hellwig <hch@infradead.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Guo Ren
198
arch/csky/mm/highmem.c
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198
arch/csky/mm/highmem.c
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// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
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#include <linux/module.h>
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#include <linux/highmem.h>
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#include <linux/smp.h>
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#include <linux/bootmem.h>
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#include <asm/fixmap.h>
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#include <asm/tlbflush.h>
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#include <asm/cacheflush.h>
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static pte_t *kmap_pte;
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unsigned long highstart_pfn, highend_pfn;
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void *kmap(struct page *page)
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{
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void *addr;
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might_sleep();
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if (!PageHighMem(page))
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return page_address(page);
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addr = kmap_high(page);
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flush_tlb_one((unsigned long)addr);
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return addr;
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}
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EXPORT_SYMBOL(kmap);
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void kunmap(struct page *page)
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{
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BUG_ON(in_interrupt());
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if (!PageHighMem(page))
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return;
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kunmap_high(page);
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}
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EXPORT_SYMBOL(kunmap);
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void *kmap_atomic(struct page *page)
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{
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unsigned long vaddr;
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int idx, type;
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preempt_disable();
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pagefault_disable();
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if (!PageHighMem(page))
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return page_address(page);
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type = kmap_atomic_idx_push();
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idx = type + KM_TYPE_NR*smp_processor_id();
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vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
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#ifdef CONFIG_DEBUG_HIGHMEM
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BUG_ON(!pte_none(*(kmap_pte - idx)));
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#endif
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set_pte(kmap_pte-idx, mk_pte(page, PAGE_KERNEL));
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flush_tlb_one((unsigned long)vaddr);
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return (void *)vaddr;
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}
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EXPORT_SYMBOL(kmap_atomic);
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void __kunmap_atomic(void *kvaddr)
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{
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unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
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int idx;
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if (vaddr < FIXADDR_START)
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goto out;
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#ifdef CONFIG_DEBUG_HIGHMEM
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idx = KM_TYPE_NR*smp_processor_id() + kmap_atomic_idx();
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BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
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pte_clear(&init_mm, vaddr, kmap_pte - idx);
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flush_tlb_one(vaddr);
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#else
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(void) idx; /* to kill a warning */
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#endif
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kmap_atomic_idx_pop();
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out:
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pagefault_enable();
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preempt_enable();
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}
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EXPORT_SYMBOL(__kunmap_atomic);
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/*
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* This is the same as kmap_atomic() but can map memory that doesn't
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* have a struct page associated with it.
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*/
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void *kmap_atomic_pfn(unsigned long pfn)
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{
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unsigned long vaddr;
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int idx, type;
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pagefault_disable();
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type = kmap_atomic_idx_push();
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idx = type + KM_TYPE_NR*smp_processor_id();
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vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
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set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
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flush_tlb_one(vaddr);
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return (void *) vaddr;
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}
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struct page *kmap_atomic_to_page(void *ptr)
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{
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unsigned long idx, vaddr = (unsigned long)ptr;
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pte_t *pte;
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if (vaddr < FIXADDR_START)
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return virt_to_page(ptr);
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idx = virt_to_fix(vaddr);
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pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
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return pte_page(*pte);
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}
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static void __init fixrange_init(unsigned long start, unsigned long end,
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pgd_t *pgd_base)
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{
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#ifdef CONFIG_HIGHMEM
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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pte_t *pte;
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int i, j, k;
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unsigned long vaddr;
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vaddr = start;
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i = __pgd_offset(vaddr);
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j = __pud_offset(vaddr);
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k = __pmd_offset(vaddr);
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pgd = pgd_base + i;
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for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
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pud = (pud_t *)pgd;
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for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
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pmd = (pmd_t *)pud;
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for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
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if (pmd_none(*pmd)) {
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pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
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set_pmd(pmd, __pmd(__pa(pte)));
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BUG_ON(pte != pte_offset_kernel(pmd, 0));
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}
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vaddr += PMD_SIZE;
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}
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k = 0;
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}
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j = 0;
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}
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#endif
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}
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void __init fixaddr_kmap_pages_init(void)
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{
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unsigned long vaddr;
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pgd_t *pgd_base;
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#ifdef CONFIG_HIGHMEM
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pgd_t *pgd;
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pmd_t *pmd;
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pud_t *pud;
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pte_t *pte;
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#endif
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pgd_base = swapper_pg_dir;
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/*
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* Fixed mappings:
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*/
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vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
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fixrange_init(vaddr, 0, pgd_base);
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#ifdef CONFIG_HIGHMEM
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/*
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* Permanent kmaps:
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*/
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vaddr = PKMAP_BASE;
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fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
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pgd = swapper_pg_dir + __pgd_offset(vaddr);
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pud = (pud_t *)pgd;
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pmd = pmd_offset(pud, vaddr);
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pte = pte_offset_kernel(pmd, vaddr);
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pkmap_page_table = pte;
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#endif
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}
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void __init kmap_init(void)
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{
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unsigned long vaddr;
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fixaddr_kmap_pages_init();
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vaddr = __fix_to_virt(FIX_KMAP_BEGIN);
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kmap_pte = pte_offset_kernel((pmd_t *)pgd_offset_k(vaddr), vaddr);
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}
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