Author: markj
Date: Mon Jan 28 16:14:53 2019
New Revision: 343527
URL: https://svnweb.freebsd.org/changeset/base/343527
Log:
MFC r343274, r343275:
Optimize RISC-V copyin(9)/copyout(9) routines.
Modified:
stable/12/sys/riscv/include/riscvreg.h
stable/12/sys/riscv/riscv/copyinout.S
Directory Properties:
stable/12/ (props changed)
Modified: stable/12/sys/riscv/include/riscvreg.h
==============================================================================
--- stable/12/sys/riscv/include/riscvreg.h Mon Jan 28 14:34:59 2019
(r343526)
+++ stable/12/sys/riscv/include/riscvreg.h Mon Jan 28 16:14:53 2019
(r343527)
@@ -155,7 +155,8 @@
#define SATP_MODE_SV39 (8ULL << SATP_MODE_S)
#define SATP_MODE_SV48 (9ULL << SATP_MODE_S)
-#define XLEN 8
+#define XLEN __riscv_xlen
+#define XLEN_BYTES (XLEN / 8)
#define INSN_SIZE 4
#define INSN_C_SIZE 2
Modified: stable/12/sys/riscv/riscv/copyinout.S
==============================================================================
--- stable/12/sys/riscv/riscv/copyinout.S Mon Jan 28 14:34:59 2019
(r343526)
+++ stable/12/sys/riscv/riscv/copyinout.S Mon Jan 28 16:14:53 2019
(r343527)
@@ -1,5 +1,6 @@
/*-
* Copyright (c) 2015-2018 Ruslan Bukin <b...@bsdpad.com>
+ * Copyright (c) 2019 Mitchell Horne
* All rights reserved.
*
* Portions of this software were developed by SRI International and the
@@ -52,60 +53,94 @@ copyio_fault_nopcb:
END(copyio_fault)
/*
+ * copycommon - common copy routine
+ *
+ * a0 - Source address
+ * a1 - Destination address
+ * a2 - Size of copy
+ */
+ .macro copycommon
+ la a6, copyio_fault /* Get the handler address */
+ SET_FAULT_HANDLER(a6, a7) /* Set the handler */
+ ENTER_USER_ACCESS(a7)
+
+ li t2, XLEN_BYTES
+ blt a2, t2, 3f /* Byte-copy if len < XLEN_BYTES */
+
+ /*
+ * Compare lower bits of src and dest.
+ * If they are aligned with each other, we can do word copy.
+ */
+ andi t0, a0, (XLEN_BYTES-1) /* Low bits of src */
+ andi t1, a1, (XLEN_BYTES-1) /* Low bits of dest */
+ bne t0, t1, 3f /* Misaligned. Go to byte copy */
+ beqz t0, 2f /* Already word-aligned, skip ahead */
+
+ /* Byte copy until the first word-aligned address */
+1: lb a4, 0(a0) /* Load byte from src */
+ addi a0, a0, 1
+ sb a4, 0(a1) /* Store byte in dest */
+ addi a1, a1, 1
+ addi a2, a2, -1 /* len-- */
+ andi t0, a0, (XLEN_BYTES-1)
+ bnez t0, 1b
+
+ /* Copy words */
+2: ld a4, 0(a0) /* Load word from src */
+ addi a0, a0, XLEN_BYTES
+ sd a4, 0(a1) /* Store word in dest */
+ addi a1, a1, XLEN_BYTES
+ addi a2, a2, -XLEN_BYTES /* len -= XLEN_BYTES */
+ bgeu a2, t2, 2b /* Again if len >= XLEN_BYTES */
+
+ /* Check if we're finished */
+ beqz a2, 4f
+
+ /* Copy any remaining bytes */
+3: lb a4, 0(a0) /* Load byte from src */
+ addi a0, a0, 1
+ sb a4, 0(a1) /* Store byte in dest */
+ addi a1, a1, 1
+ addi a2, a2, -1 /* len-- */
+ bnez a2, 3b
+
+4: EXIT_USER_ACCESS(a7)
+ SET_FAULT_HANDLER(x0, a7) /* Clear the handler */
+ .endm
+
+/*
* Copies from a kernel to user address
*
* int copyout(const void *kaddr, void *udaddr, size_t len)
*/
ENTRY(copyout)
- beqz a2, 2f /* If len == 0 then skip loop */
+ beqz a2, copyout_end /* If len == 0 then skip loop */
add a3, a1, a2
li a4, VM_MAXUSER_ADDRESS
bgt a3, a4, copyio_fault_nopcb
- la a6, copyio_fault /* Get the handler address */
- SET_FAULT_HANDLER(a6, a7) /* Set the handler */
- ENTER_USER_ACCESS(a7)
+ copycommon
-1: lb a4, 0(a0) /* Load from kaddr */
- addi a0, a0, 1
- sb a4, 0(a1) /* Store in uaddr */
- addi a1, a1, 1
- addi a2, a2, -1 /* len-- */
- bnez a2, 1b
-
- EXIT_USER_ACCESS(a7)
- SET_FAULT_HANDLER(x0, a7) /* Clear the handler */
-
-2: li a0, 0 /* return 0 */
+copyout_end:
+ li a0, 0 /* return 0 */
ret
END(copyout)
/*
* Copies from a user to kernel address
*
- * int copyin(const void *uaddr, void *kdaddr, size_t len)
+ * int copyin(const void *uaddr, void *kaddr, size_t len)
*/
ENTRY(copyin)
- beqz a2, 2f /* If len == 0 then skip loop */
+ beqz a2, copyin_end /* If len == 0 then skip loop */
add a3, a0, a2
li a4, VM_MAXUSER_ADDRESS
bgt a3, a4, copyio_fault_nopcb
- la a6, copyio_fault /* Get the handler address */
- SET_FAULT_HANDLER(a6, a7) /* Set the handler */
- ENTER_USER_ACCESS(a7)
+ copycommon
-1: lb a4, 0(a0) /* Load from uaddr */
- addi a0, a0, 1
- sb a4, 0(a1) /* Store in kaddr */
- addi a1, a1, 1
- addi a2, a2, -1 /* len-- */
- bnez a2, 1b
-
- EXIT_USER_ACCESS(a7)
- SET_FAULT_HANDLER(x0, a7) /* Clear the handler */
-
-2: li a0, 0 /* return 0 */
+copyin_end:
+ li a0, 0 /* return 0 */
ret
END(copyin)
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