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-rw-r--r--arch/arm64/lib/copy_page.S80
1 files changed, 80 insertions, 0 deletions
diff --git a/arch/arm64/lib/copy_page.S b/arch/arm64/lib/copy_page.S
new file mode 100644
index 0000000000..c336d2ffde
--- /dev/null
+++ b/arch/arm64/lib/copy_page.S
@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/linkage.h>
+#include <linux/const.h>
+#include <asm/assembler.h>
+#include <asm/page.h>
+#include <asm/cpufeature.h>
+#include <asm/alternative.h>
+
+/*
+ * Copy a page from src to dest (both are page aligned)
+ *
+ * Parameters:
+ * x0 - dest
+ * x1 - src
+ */
+SYM_FUNC_START(__pi_copy_page)
+alternative_if ARM64_HAS_NO_HW_PREFETCH
+ // Prefetch three cache lines ahead.
+ prfm pldl1strm, [x1, #128]
+ prfm pldl1strm, [x1, #256]
+ prfm pldl1strm, [x1, #384]
+alternative_else_nop_endif
+
+ ldp x2, x3, [x1]
+ ldp x4, x5, [x1, #16]
+ ldp x6, x7, [x1, #32]
+ ldp x8, x9, [x1, #48]
+ ldp x10, x11, [x1, #64]
+ ldp x12, x13, [x1, #80]
+ ldp x14, x15, [x1, #96]
+ ldp x16, x17, [x1, #112]
+
+ add x0, x0, #256
+ add x1, x1, #128
+1:
+ tst x0, #(PAGE_SIZE - 1)
+
+alternative_if ARM64_HAS_NO_HW_PREFETCH
+ prfm pldl1strm, [x1, #384]
+alternative_else_nop_endif
+
+ stnp x2, x3, [x0, #-256]
+ ldp x2, x3, [x1]
+ stnp x4, x5, [x0, #16 - 256]
+ ldp x4, x5, [x1, #16]
+ stnp x6, x7, [x0, #32 - 256]
+ ldp x6, x7, [x1, #32]
+ stnp x8, x9, [x0, #48 - 256]
+ ldp x8, x9, [x1, #48]
+ stnp x10, x11, [x0, #64 - 256]
+ ldp x10, x11, [x1, #64]
+ stnp x12, x13, [x0, #80 - 256]
+ ldp x12, x13, [x1, #80]
+ stnp x14, x15, [x0, #96 - 256]
+ ldp x14, x15, [x1, #96]
+ stnp x16, x17, [x0, #112 - 256]
+ ldp x16, x17, [x1, #112]
+
+ add x0, x0, #128
+ add x1, x1, #128
+
+ b.ne 1b
+
+ stnp x2, x3, [x0, #-256]
+ stnp x4, x5, [x0, #16 - 256]
+ stnp x6, x7, [x0, #32 - 256]
+ stnp x8, x9, [x0, #48 - 256]
+ stnp x10, x11, [x0, #64 - 256]
+ stnp x12, x13, [x0, #80 - 256]
+ stnp x14, x15, [x0, #96 - 256]
+ stnp x16, x17, [x0, #112 - 256]
+
+ ret
+SYM_FUNC_END(__pi_copy_page)
+SYM_FUNC_ALIAS(copy_page, __pi_copy_page)
+EXPORT_SYMBOL(copy_page)