1 files changed, 69 insertions, 0 deletions
diff --git a/arch/alpha/include/asm/cacheflush.h b/arch/alpha/include/asm/cacheflush.h
new file mode 100644
index 0000000000..36a7e924c3
--- /dev/null
+++ b/arch/alpha/include/asm/cacheflush.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ALPHA_CACHEFLUSH_H
+#define _ALPHA_CACHEFLUSH_H
+
+#include <linux/mm.h>
+
+/* Note that the following two definitions are _highly_ dependent
+   on the contexts in which they are used in the kernel.  I personally
+   think it is criminal how loosely defined these macros are.  */
+
+/* We need to flush the kernel's icache after loading modules.  The
+   only other use of this macro is in load_aout_interp which is not
+   used on Alpha. 
+
+   Note that this definition should *not* be used for userspace
+   icache flushing.  While functional, it is _way_ overkill.  The
+   icache is tagged with ASNs and it suffices to allocate a new ASN
+   for the process.  */
+#ifndef CONFIG_SMP
+#define flush_icache_range(start, end)		imb()
+#else
+#define flush_icache_range(start, end)		smp_imb()
+extern void smp_imb(void);
+#endif
+
+/* We need to flush the userspace icache after setting breakpoints in
+   ptrace.
+
+   Instead of indiscriminately using imb, take advantage of the fact
+   that icache entries are tagged with the ASN and load a new mm context.  */
+/* ??? Ought to use this in arch/alpha/kernel/signal.c too.  */
+
+#ifndef CONFIG_SMP
+#include <linux/sched.h>
+
+extern void __load_new_mm_context(struct mm_struct *);
+static inline void
+flush_icache_user_page(struct vm_area_struct *vma, struct page *page,
+			unsigned long addr, int len)
+{
+	if (vma->vm_flags & VM_EXEC) {
+		struct mm_struct *mm = vma->vm_mm;
+		if (current->active_mm == mm)
+			__load_new_mm_context(mm);
+		else
+			mm->context[smp_processor_id()] = 0;
+	}
+}
+#define flush_icache_user_page flush_icache_user_page
+#else /* CONFIG_SMP */
+extern void flush_icache_user_page(struct vm_area_struct *vma,
+		struct page *page, unsigned long addr, int len);
+#define flush_icache_user_page flush_icache_user_page
+#endif /* CONFIG_SMP */
+
+/*
+ * Both implementations of flush_icache_user_page flush the entire
+ * address space, so one call, no matter how many pages.
+ */
+static inline void flush_icache_pages(struct vm_area_struct *vma,
+		struct page *page, unsigned int nr)
+{
+	flush_icache_user_page(vma, page, 0, 0);
+}
+#define flush_icache_pages flush_icache_pages
+
+#include <asm-generic/cacheflush.h>
+
+#endif /* _ALPHA_CACHEFLUSH_H */