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From: Russell King <rmk+kernel@armlinux.org.uk>
To: netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Cc: Daniel Borkmann <daniel@iogearbox.net>
Subject: [PATCH net-next 12/13] ARM: net: bpf: always use odd/even register pair
Date: Tue, 10 Jul 2018 13:37:05 +0100	[thread overview]
Message-ID: <E1fcrtB-0005Va-8S@rmk-PC.armlinux.org.uk> (raw)
In-Reply-To: <20180710123340.GK17271@n2100.armlinux.org.uk>

Always use an odd/even register pair for our 64-bit registers, so that
we're able to use the double-word load/store instructions in the future.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 arch/arm/net/bpf_jit_32.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index 926e81c15505..ca6534cabfa9 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -47,27 +47,27 @@
  * The callee saved registers depends on whether frame pointers are enabled.
  * With frame pointers (to be compliant with the ABI):
  *
- *                                high
- * original ARM_SP =>     +------------------+ \
- *                        |        pc        | |
- * current ARM_FP =>      +------------------+ } callee saved registers
- *                        |r4-r8,r10,fp,ip,lr| |
- *                        +------------------+ /
- *                                low
+ *                              high
+ * original ARM_SP =>     +--------------+ \
+ *                        |      pc      | |
+ * current ARM_FP =>      +--------------+ } callee saved registers
+ *                        |r4-r9,fp,ip,lr| |
+ *                        +--------------+ /
+ *                              low
  *
  * Without frame pointers:
  *
- *                                high
- * original ARM_SP =>     +------------------+
- *                        | r4-r8,r10,fp,lr  | callee saved registers
- * current ARM_FP =>      +------------------+
- *                                low
+ *                              high
+ * original ARM_SP =>     +--------------+
+ *                        |  r4-r9,fp,lr | callee saved registers
+ * current ARM_FP =>      +--------------+
+ *                              low
  *
  * When popping registers off the stack at the end of a BPF function, we
  * reference them via the current ARM_FP register.
  */
 #define CALLEE_MASK	(1 << ARM_R4 | 1 << ARM_R5 | 1 << ARM_R6 | \
-			 1 << ARM_R7 | 1 << ARM_R8 | 1 << ARM_R10 | \
+			 1 << ARM_R7 | 1 << ARM_R8 | 1 << ARM_R9 | \
 			 1 << ARM_FP)
 #define CALLEE_PUSH_MASK (CALLEE_MASK | 1 << ARM_LR)
 #define CALLEE_POP_MASK  (CALLEE_MASK | 1 << ARM_PC)
@@ -157,7 +157,7 @@ static const s8 bpf2a32[][2] = {
 	 * for constant blindings and others.
 	 */
 	[TMP_REG_1] = {ARM_R7, ARM_R6},
-	[TMP_REG_2] = {ARM_R10, ARM_R8},
+	[TMP_REG_2] = {ARM_R9, ARM_R8},
 	/* Tail call count. Stored on stack scratch space. */
 	[TCALL_CNT] = {STACK_OFFSET(BPF_TC_HI), STACK_OFFSET(BPF_TC_LO)},
 	/* temporary register for blinding constants.
-- 
2.7.4

  parent reply	other threads:[~2018-07-10 12:37 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-10 12:33 [PATCH 00/13] ARM BPF jit compiler improvements Russell King - ARM Linux
2018-07-10 12:36 ` [PATCH net-next 01/13] ARM: net: bpf: enumerate the JIT scratch stack layout Russell King
2018-07-10 18:30   ` Daniel Borkmann
2018-07-10 21:57     ` Russell King - ARM Linux
2018-07-10 12:36 ` [PATCH net-next 02/13] ARM: net: bpf: provide load/store ops with negative immediates Russell King
2018-07-10 12:36 ` [PATCH net-next 03/13] ARM: net: bpf: use negative numbers for stacked registers Russell King
2018-07-10 12:36 ` [PATCH net-next 04/13] ARM: net: bpf: remove is_on_stack() and sstk/dstk Russell King
2018-07-10 12:36 ` [PATCH net-next 05/13] ARM: net: bpf: provide accessor functions for BPF registers Russell King
2018-07-10 12:36 ` [PATCH net-next 06/13] ARM: net: bpf: 64-bit " Russell King
2018-07-10 12:36 ` [PATCH net-next 07/13] ARM: net: bpf: access eBPF scratch space using ARM FP register Russell King
2018-07-10 12:36 ` [PATCH net-next 08/13] ARM: net: bpf: use immediate forms of instructions where possible Russell King
2018-07-10 19:12   ` kbuild test robot
2018-07-10 12:36 ` [PATCH net-next 09/13] ARM: net: bpf: use ldr instructions with shifted rm register Russell King
2018-07-10 12:36 ` [PATCH net-next 10/13] ARM: net: bpf: avoid reloading 'index' Russell King
2018-07-10 12:37 ` [PATCH net-next 11/13] ARM: net: bpf: avoid reloading 'array' Russell King
2018-07-10 12:37 ` Russell King [this message]
2018-07-10 12:37 ` [PATCH net-next 13/13] ARM: net: bpf: use double-word load/stores where available Russell King
2018-07-10 17:03   ` Olof Johansson
2018-07-10 17:14     ` Russell King - ARM Linux

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