![Michal Simek](/assets/img/avatar_default.png)
MMU contains invalid mapping which wasn't flushed and new mapping is using the same addresses as previous one. That's why TLB miss is not happening to get new correct TLB entry and MMU points to incorrect area. This is replicatable when large files(256MB and more) are copied and checked. Signed-off-by: Michal Simek <michal.simek@xilinx.com>
89 lines
2.2 KiB
C
89 lines
2.2 KiB
C
/*
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* highmem.c: virtual kernel memory mappings for high memory
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*
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* PowerPC version, stolen from the i386 version.
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*
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* Used in CONFIG_HIGHMEM systems for memory pages which
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* are not addressable by direct kernel virtual addresses.
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*
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* Copyright (C) 1999 Gerhard Wichert, Siemens AG
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* Gerhard.Wichert@pdb.siemens.de
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*
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*
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* Redesigned the x86 32-bit VM architecture to deal with
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* up to 16 Terrabyte physical memory. With current x86 CPUs
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* we now support up to 64 Gigabytes physical RAM.
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*
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* Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
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*
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* Reworked for PowerPC by various contributors. Moved from
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* highmem.h by Benjamin Herrenschmidt (c) 2009 IBM Corp.
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*/
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#include <linux/export.h>
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#include <linux/highmem.h>
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/*
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* The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
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* gives a more generic (and caching) interface. But kmap_atomic can
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* be used in IRQ contexts, so in some (very limited) cases we need
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* it.
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*/
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#include <asm/tlbflush.h>
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void *kmap_atomic_prot(struct page *page, pgprot_t prot)
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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_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot));
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local_flush_tlb_page(NULL, vaddr);
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return (void *) vaddr;
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}
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EXPORT_SYMBOL(kmap_atomic_prot);
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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 type;
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unsigned int idx;
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if (vaddr < __fix_to_virt(FIX_KMAP_END)) {
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pagefault_enable();
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preempt_enable();
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return;
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}
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type = kmap_atomic_idx();
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idx = type + KM_TYPE_NR * smp_processor_id();
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#ifdef CONFIG_DEBUG_HIGHMEM
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BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
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#endif
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/*
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* force other mappings to Oops if they'll try to access
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* this pte without first remap it
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*/
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pte_clear(&init_mm, vaddr, kmap_pte-idx);
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local_flush_tlb_page(NULL, vaddr);
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kmap_atomic_idx_pop();
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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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