linux_dsm_epyc7002/include/asm-sparc64/cacheflush.h
David S. Miller dadeafdfc8 [PATCH] sparc64: Reduce ptrace cache flushing
We were flushing the D-cache excessively for ptrace() processing
and this makes debugging threads so slow as to be totally unusable.

All process page accesses via ptrace() go via access_process_vm().
This routine, for each process page, uses get_user_pages().  That
in turn does a flush_dcache_page() on the child pages before we
copy in/out the ptrace request data.

Therefore, all we need to do after the data movement is:

1) Flush the D-cache pages if the kernel maps the page to a different
   color than userspace does.
2) If we wrote to the page, we need to flush the I-cache on older cpus.

Previously we just flushed the entire cache at the end of a ptrace()
request, and that was beyond stupid.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-17 18:03:11 -07:00

79 lines
2.5 KiB
C

#ifndef _SPARC64_CACHEFLUSH_H
#define _SPARC64_CACHEFLUSH_H
#include <linux/config.h>
#include <asm/page.h>
/* Flushing for D-cache alias handling is only needed if
* the page size is smaller than 16K.
*/
#if PAGE_SHIFT < 14
#define DCACHE_ALIASING_POSSIBLE
#endif
#ifndef __ASSEMBLY__
#include <linux/mm.h>
/* Cache flush operations. */
/* These are the same regardless of whether this is an SMP kernel or not. */
#define flush_cache_mm(__mm) \
do { if ((__mm) == current->mm) flushw_user(); } while(0)
#define flush_cache_range(vma, start, end) \
flush_cache_mm((vma)->vm_mm)
#define flush_cache_page(vma, page, pfn) \
flush_cache_mm((vma)->vm_mm)
/*
* On spitfire, the icache doesn't snoop local stores and we don't
* use block commit stores (which invalidate icache lines) during
* module load, so we need this.
*/
extern void flush_icache_range(unsigned long start, unsigned long end);
extern void __flush_icache_page(unsigned long);
extern void __flush_dcache_page(void *addr, int flush_icache);
extern void flush_dcache_page_impl(struct page *page);
#ifdef CONFIG_SMP
extern void smp_flush_dcache_page_impl(struct page *page, int cpu);
extern void flush_dcache_page_all(struct mm_struct *mm, struct page *page);
#else
#define smp_flush_dcache_page_impl(page,cpu) flush_dcache_page_impl(page)
#define flush_dcache_page_all(mm,page) flush_dcache_page_impl(page)
#endif
extern void __flush_dcache_range(unsigned long start, unsigned long end);
extern void flush_dcache_page(struct page *page);
#define flush_icache_page(vma, pg) do { } while(0)
#define flush_icache_user_range(vma,pg,adr,len) do { } while (0)
extern void flush_ptrace_access(struct vm_area_struct *, struct page *,
unsigned long uaddr, void *kaddr,
unsigned long len, int write);
#define copy_to_user_page(vma, page, vaddr, dst, src, len) \
do { \
flush_cache_page(vma, vaddr, page_to_pfn(page)); \
memcpy(dst, src, len); \
flush_ptrace_access(vma, page, vaddr, src, len, 0); \
} while (0)
#define copy_from_user_page(vma, page, vaddr, dst, src, len) \
do { \
flush_cache_page(vma, vaddr, page_to_pfn(page)); \
memcpy(dst, src, len); \
flush_ptrace_access(vma, page, vaddr, dst, len, 1); \
} while (0)
#define flush_dcache_mmap_lock(mapping) do { } while (0)
#define flush_dcache_mmap_unlock(mapping) do { } while (0)
#define flush_cache_vmap(start, end) do { } while (0)
#define flush_cache_vunmap(start, end) do { } while (0)
#endif /* !__ASSEMBLY__ */
#endif /* _SPARC64_CACHEFLUSH_H */