arch/alpha/include/asm/cacheflush.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ALPHA_CACHEFLUSH_H
   3 #define _ALPHA_CACHEFLUSH_H
   4
   5 #include <linux/mm.h>
   6
   7 /* Note that the following two definitions are _highly_ dependent
   8    on the contexts in which they are used in the kernel.  I personally
   9    think it is criminal how loosely defined these macros are.  */
  10
  11 /* We need to flush the kernel's icache after loading modules.  The
  12    only other use of this macro is in load_aout_interp which is not
  13    used on Alpha.
  14
  15    Note that this definition should *not* be used for userspace
  16    icache flushing.  While functional, it is _way_ overkill.  The
  17    icache is tagged with ASNs and it suffices to allocate a new ASN
  18    for the process.  */
  19 #ifndef CONFIG_SMP
  20 #define flush_icache_range(start, end)          imb()
  21 #else
  22 #define flush_icache_range(start, end)          smp_imb()
  23 extern void smp_imb(void);
  24 #endif
  25
  26 /* We need to flush the userspace icache after setting breakpoints in
  27    ptrace.
  28
  29    Instead of indiscriminately using imb, take advantage of the fact
  30    that icache entries are tagged with the ASN and load a new mm context.  */
  31 /* ??? Ought to use this in arch/alpha/kernel/signal.c too.  */
  32
  33 #ifndef CONFIG_SMP
  34 #include <linux/sched.h>
  35
  36 extern void __load_new_mm_context(struct mm_struct *);
  37 static inline void
  38 flush_icache_user_page(struct vm_area_struct *vma, struct page *page,
  39                         unsigned long addr, int len)
  40 {
  41         if (vma->vm_flags & VM_EXEC) {
  42                 struct mm_struct *mm = vma->vm_mm;
  43                 if (current->active_mm == mm)
  44                         __load_new_mm_context(mm);
  45                 else
  46                         mm->context[smp_processor_id()] = 0;
  47         }
  48 }
  49 #define flush_icache_user_page flush_icache_user_page
  50 #else /* CONFIG_SMP */
  51 extern void flush_icache_user_page(struct vm_area_struct *vma,
  52                 struct page *page, unsigned long addr, int len);
  53 #define flush_icache_user_page flush_icache_user_page
  54 #endif /* CONFIG_SMP */
  55
  56 /* This is used only in __do_fault and do_swap_page.  */
  57 #define flush_icache_page(vma, page) \
  58         flush_icache_user_page((vma), (page), 0, 0)
  59
  60 #include <asm-generic/cacheflush.h>
  61
  62 #endif /* _ALPHA_CACHEFLUSH_H */