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https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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2d4dc890b5
Mtdblock driver doesn't call flush_dcache_page for pages in request. So, this causes problems on architectures where the icache doesn't fill from the dcache or with dcache aliases. The patch fixes this. The ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE symbol was introduced to avoid pointless empty cache-thrashing loops on architectures for which flush_dcache_page() is a no-op. Every architecture was provided with this flush pages on architectires where ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE is equal 1 or do nothing otherwise. See "fix mtd_blkdevs problem with caches on some architectures" discussion on LKML for more information. Signed-off-by: Ilya Loginov <isloginov@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Peter Horton <phorton@bitbox.co.uk> Cc: "Ed L. Cashin" <ecashin@coraid.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
76 lines
2.6 KiB
C
76 lines
2.6 KiB
C
#ifndef _ALPHA_CACHEFLUSH_H
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#define _ALPHA_CACHEFLUSH_H
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#include <linux/mm.h>
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/* Caches aren't brain-dead on the Alpha. */
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#define flush_cache_all() do { } while (0)
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#define flush_cache_mm(mm) do { } while (0)
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#define flush_cache_dup_mm(mm) do { } while (0)
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#define flush_cache_range(vma, start, end) do { } while (0)
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#define flush_cache_page(vma, vmaddr, pfn) do { } while (0)
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#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
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#define flush_dcache_page(page) do { } while (0)
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#define flush_dcache_mmap_lock(mapping) do { } while (0)
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#define flush_dcache_mmap_unlock(mapping) do { } while (0)
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#define flush_cache_vmap(start, end) do { } while (0)
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#define flush_cache_vunmap(start, end) do { } while (0)
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/* Note that the following two definitions are _highly_ dependent
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on the contexts in which they are used in the kernel. I personally
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think it is criminal how loosely defined these macros are. */
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/* We need to flush the kernel's icache after loading modules. The
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only other use of this macro is in load_aout_interp which is not
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used on Alpha.
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Note that this definition should *not* be used for userspace
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icache flushing. While functional, it is _way_ overkill. The
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icache is tagged with ASNs and it suffices to allocate a new ASN
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for the process. */
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#ifndef CONFIG_SMP
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#define flush_icache_range(start, end) imb()
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#else
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#define flush_icache_range(start, end) smp_imb()
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extern void smp_imb(void);
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#endif
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/* We need to flush the userspace icache after setting breakpoints in
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ptrace.
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Instead of indiscriminately using imb, take advantage of the fact
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that icache entries are tagged with the ASN and load a new mm context. */
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/* ??? Ought to use this in arch/alpha/kernel/signal.c too. */
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#ifndef CONFIG_SMP
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extern void __load_new_mm_context(struct mm_struct *);
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static inline void
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flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
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unsigned long addr, int len)
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{
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if (vma->vm_flags & VM_EXEC) {
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struct mm_struct *mm = vma->vm_mm;
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if (current->active_mm == mm)
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__load_new_mm_context(mm);
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else
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mm->context[smp_processor_id()] = 0;
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}
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}
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#else
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extern void flush_icache_user_range(struct vm_area_struct *vma,
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struct page *page, unsigned long addr, int len);
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#endif
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/* This is used only in do_no_page and do_swap_page. */
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#define flush_icache_page(vma, page) \
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flush_icache_user_range((vma), (page), 0, 0)
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#define copy_to_user_page(vma, page, vaddr, dst, src, len) \
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do { memcpy(dst, src, len); \
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flush_icache_user_range(vma, page, vaddr, len); \
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} while (0)
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#define copy_from_user_page(vma, page, vaddr, dst, src, len) \
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memcpy(dst, src, len)
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#endif /* _ALPHA_CACHEFLUSH_H */
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