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https://github.com/rd-stuffs/msm-4.14.git
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836a241832
With commit a05e54c103b0 ("ARM: 8031/2: change fixmap mapping region to
support 32 CPUs"), the fixmap region was expanded to 2MB, but it
precluded any other uses of the fixmap region. In order to support other
uses the fixmap region needs to be expanded beyond 2MB. Fortunately, the
adjacent 1MB range 0xffe00000-0xfff00000 is availabe.
Remove fixmap_page_table ptr and lookup the page table via the virtual
address so that the fixmap region can span more that one pmd. The 2nd
pmd is already created since it is shared with the vector page.
Signed-off-by: Rob Herring <robh@kernel.org>
[kees: fixed CONFIG_DEBUG_HIGHMEM get_fixmap() calls]
[kees: moved pte allocation outside of CONFIG_HIGHMEM]
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
154 lines
3.4 KiB
C
154 lines
3.4 KiB
C
/*
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* arch/arm/mm/highmem.c -- ARM highmem support
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*
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* Author: Nicolas Pitre
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* Created: september 8, 2008
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* Copyright: Marvell Semiconductors Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/highmem.h>
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#include <linux/interrupt.h>
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#include <asm/fixmap.h>
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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#include "mm.h"
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static inline void set_fixmap_pte(int idx, pte_t pte)
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{
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unsigned long vaddr = __fix_to_virt(idx);
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pte_t *ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
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set_pte_ext(ptep, pte, 0);
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local_flush_tlb_kernel_page(vaddr);
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}
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static inline pte_t get_fixmap_pte(unsigned long vaddr)
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{
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pte_t *ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
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return *ptep;
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}
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void *kmap(struct page *page)
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{
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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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return kmap_high(page);
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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 int idx;
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unsigned long vaddr;
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void *kmap;
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int type;
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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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#ifdef CONFIG_DEBUG_HIGHMEM
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/*
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* There is no cache coherency issue when non VIVT, so force the
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* dedicated kmap usage for better debugging purposes in that case.
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*/
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if (!cache_is_vivt())
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kmap = NULL;
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else
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#endif
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kmap = kmap_high_get(page);
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if (kmap)
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return kmap;
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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(idx);
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#ifdef CONFIG_DEBUG_HIGHMEM
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/*
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* With debugging enabled, kunmap_atomic forces that entry to 0.
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* Make sure it was indeed properly unmapped.
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*/
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BUG_ON(!pte_none(get_fixmap_pte(vaddr)));
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#endif
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/*
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* When debugging is off, kunmap_atomic leaves the previous mapping
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* in place, so the contained TLB flush ensures the TLB is updated
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* with the new mapping.
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*/
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set_fixmap_pte(idx, mk_pte(page, kmap_prot));
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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, type;
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if (kvaddr >= (void *)FIXADDR_START) {
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type = kmap_atomic_idx();
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idx = type + KM_TYPE_NR * smp_processor_id();
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if (cache_is_vivt())
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__cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);
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#ifdef CONFIG_DEBUG_HIGHMEM
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BUG_ON(vaddr != __fix_to_virt(idx));
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set_fixmap_pte(idx, __pte(0));
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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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} else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
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/* this address was obtained through kmap_high_get() */
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kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
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}
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pagefault_enable();
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}
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EXPORT_SYMBOL(__kunmap_atomic);
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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(idx);
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#ifdef CONFIG_DEBUG_HIGHMEM
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BUG_ON(!pte_none(get_fixmap_pte(vaddr)));
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#endif
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set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot));
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return (void *)vaddr;
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}
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struct page *kmap_atomic_to_page(const void *ptr)
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{
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unsigned long vaddr = (unsigned long)ptr;
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if (vaddr < FIXADDR_START)
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return virt_to_page(ptr);
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return pte_page(get_fixmap_pte(vaddr));
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}
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