ppc: bpf: rename bpf_jit_64.S to bpf_jit_asm.S

Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 229 insertions, 0 deletions

diff --git a/arch/powerpc/net/bpf_jit_asm.S b/arch/powerpc/net/bpf_jit_asm.S
new file mode 100644
index 000000000000..8ff5a3b5d1c3
--- /dev/null
+++ b/arch/powerpc/net/bpf_jit_asm.S
@@ -0,0 +1,229 @@
+/* bpf_jit.S: Packet/header access helper functions
+ * for PPC64 BPF compiler.
+ *
+ * Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+
+#include <asm/ppc_asm.h>
+#include "bpf_jit.h"
+
+/*
+ * All of these routines are called directly from generated code,
+ * whose register usage is:
+ *
+ * r3		skb
+ * r4,r5	A,X
+ * r6		*** address parameter to helper ***
+ * r7-r10	scratch
+ * r14		skb->data
+ * r15		skb headlen
+ * r16-31	M[]
+ */
+
+/*
+ * To consider: These helpers are so small it could be better to just
+ * generate them inline.  Inline code can do the simple headlen check
+ * then branch directly to slow_path_XXX if required.  (In fact, could
+ * load a spare GPR with the address of slow_path_generic and pass size
+ * as an argument, making the call site a mtlr, li and bllr.)
+ */
+	.globl	sk_load_word
+sk_load_word:
+	PPC_LCMPI	r_addr, 0
+	blt	bpf_slow_path_word_neg
+	.globl	sk_load_word_positive_offset
+sk_load_word_positive_offset:
+	/* Are we accessing past headlen? */
+	subi	r_scratch1, r_HL, 4
+	PPC_LCMP	r_scratch1, r_addr
+	blt	bpf_slow_path_word
+	/* Nope, just hitting the header.  cr0 here is eq or gt! */
+#ifdef __LITTLE_ENDIAN__
+	lwbrx	r_A, r_D, r_addr
+#else
+	lwzx	r_A, r_D, r_addr
+#endif
+	blr	/* Return success, cr0 != LT */
+
+	.globl	sk_load_half
+sk_load_half:
+	PPC_LCMPI	r_addr, 0
+	blt	bpf_slow_path_half_neg
+	.globl	sk_load_half_positive_offset
+sk_load_half_positive_offset:
+	subi	r_scratch1, r_HL, 2
+	PPC_LCMP	r_scratch1, r_addr
+	blt	bpf_slow_path_half
+#ifdef __LITTLE_ENDIAN__
+	lhbrx	r_A, r_D, r_addr
+#else
+	lhzx	r_A, r_D, r_addr
+#endif
+	blr
+
+	.globl	sk_load_byte
+sk_load_byte:
+	PPC_LCMPI	r_addr, 0
+	blt	bpf_slow_path_byte_neg
+	.globl	sk_load_byte_positive_offset
+sk_load_byte_positive_offset:
+	PPC_LCMP	r_HL, r_addr
+	ble	bpf_slow_path_byte
+	lbzx	r_A, r_D, r_addr
+	blr
+
+/*
+ * BPF_LDX | BPF_B | BPF_MSH: ldxb  4*([offset]&0xf)
+ * r_addr is the offset value
+ */
+	.globl sk_load_byte_msh
+sk_load_byte_msh:
+	PPC_LCMPI	r_addr, 0
+	blt	bpf_slow_path_byte_msh_neg
+	.globl sk_load_byte_msh_positive_offset
+sk_load_byte_msh_positive_offset:
+	PPC_LCMP	r_HL, r_addr
+	ble	bpf_slow_path_byte_msh
+	lbzx	r_X, r_D, r_addr
+	rlwinm	r_X, r_X, 2, 32-4-2, 31-2
+	blr
+
+/* Call out to skb_copy_bits:
+ * We'll need to back up our volatile regs first; we have
+ * local variable space at r1+(BPF_PPC_STACK_BASIC).
+ * Allocate a new stack frame here to remain ABI-compliant in
+ * stashing LR.
+ */
+#define bpf_slow_path_common(SIZE)				\
+	mflr	r0;						\
+	PPC_STL	r0, PPC_LR_STKOFF(r1);					\
+	/* R3 goes in parameter space of caller's frame */	\
+	PPC_STL	r_skb, (BPF_PPC_STACKFRAME+BPF_PPC_STACK_R3_OFF)(r1);		\
+	PPC_STL	r_A, (BPF_PPC_STACK_BASIC+(0*REG_SZ))(r1);		\
+	PPC_STL	r_X, (BPF_PPC_STACK_BASIC+(1*REG_SZ))(r1);		\
+	addi	r5, r1, BPF_PPC_STACK_BASIC+(2*REG_SZ);		\
+	PPC_STLU	r1, -BPF_PPC_SLOWPATH_FRAME(r1);		\
+	/* R3 = r_skb, as passed */				\
+	mr	r4, r_addr;					\
+	li	r6, SIZE;					\
+	bl	skb_copy_bits;					\
+	nop;							\
+	/* R3 = 0 on success */					\
+	addi	r1, r1, BPF_PPC_SLOWPATH_FRAME;			\
+	PPC_LL	r0, PPC_LR_STKOFF(r1);					\
+	PPC_LL	r_A, (BPF_PPC_STACK_BASIC+(0*REG_SZ))(r1);		\
+	PPC_LL	r_X, (BPF_PPC_STACK_BASIC+(1*REG_SZ))(r1);		\
+	mtlr	r0;						\
+	PPC_LCMPI	r3, 0;						\
+	blt	bpf_error;	/* cr0 = LT */			\
+	PPC_LL	r_skb, (BPF_PPC_STACKFRAME+BPF_PPC_STACK_R3_OFF)(r1);		\
+	/* Great success! */
+
+bpf_slow_path_word:
+	bpf_slow_path_common(4)
+	/* Data value is on stack, and cr0 != LT */
+	lwz	r_A, BPF_PPC_STACK_BASIC+(2*REG_SZ)(r1)
+	blr
+
+bpf_slow_path_half:
+	bpf_slow_path_common(2)
+	lhz	r_A, BPF_PPC_STACK_BASIC+(2*8)(r1)
+	blr
+
+bpf_slow_path_byte:
+	bpf_slow_path_common(1)
+	lbz	r_A, BPF_PPC_STACK_BASIC+(2*8)(r1)
+	blr
+
+bpf_slow_path_byte_msh:
+	bpf_slow_path_common(1)
+	lbz	r_X, BPF_PPC_STACK_BASIC+(2*8)(r1)
+	rlwinm	r_X, r_X, 2, 32-4-2, 31-2
+	blr
+
+/* Call out to bpf_internal_load_pointer_neg_helper:
+ * We'll need to back up our volatile regs first; we have
+ * local variable space at r1+(BPF_PPC_STACK_BASIC).
+ * Allocate a new stack frame here to remain ABI-compliant in
+ * stashing LR.
+ */
+#define sk_negative_common(SIZE)				\
+	mflr	r0;						\
+	PPC_STL	r0, PPC_LR_STKOFF(r1);					\
+	/* R3 goes in parameter space of caller's frame */	\
+	PPC_STL	r_skb, (BPF_PPC_STACKFRAME+BPF_PPC_STACK_R3_OFF)(r1);		\
+	PPC_STL	r_A, (BPF_PPC_STACK_BASIC+(0*REG_SZ))(r1);		\
+	PPC_STL	r_X, (BPF_PPC_STACK_BASIC+(1*REG_SZ))(r1);		\
+	PPC_STLU	r1, -BPF_PPC_SLOWPATH_FRAME(r1);		\
+	/* R3 = r_skb, as passed */				\
+	mr	r4, r_addr;					\
+	li	r5, SIZE;					\
+	bl	bpf_internal_load_pointer_neg_helper;		\
+	nop;							\
+	/* R3 != 0 on success */				\
+	addi	r1, r1, BPF_PPC_SLOWPATH_FRAME;			\
+	PPC_LL	r0, PPC_LR_STKOFF(r1);					\
+	PPC_LL	r_A, (BPF_PPC_STACK_BASIC+(0*REG_SZ))(r1);		\
+	PPC_LL	r_X, (BPF_PPC_STACK_BASIC+(1*REG_SZ))(r1);		\
+	mtlr	r0;						\
+	PPC_LCMPLI	r3, 0;						\
+	beq	bpf_error_slow;	/* cr0 = EQ */			\
+	mr	r_addr, r3;					\
+	PPC_LL	r_skb, (BPF_PPC_STACKFRAME+BPF_PPC_STACK_R3_OFF)(r1);		\
+	/* Great success! */
+
+bpf_slow_path_word_neg:
+	lis     r_scratch1,-32	/* SKF_LL_OFF */
+	PPC_LCMP	r_addr, r_scratch1	/* addr < SKF_* */
+	blt	bpf_error	/* cr0 = LT */
+	.globl	sk_load_word_negative_offset
+sk_load_word_negative_offset:
+	sk_negative_common(4)
+	lwz	r_A, 0(r_addr)
+	blr
+
+bpf_slow_path_half_neg:
+	lis     r_scratch1,-32	/* SKF_LL_OFF */
+	PPC_LCMP	r_addr, r_scratch1	/* addr < SKF_* */
+	blt	bpf_error	/* cr0 = LT */
+	.globl	sk_load_half_negative_offset
+sk_load_half_negative_offset:
+	sk_negative_common(2)
+	lhz	r_A, 0(r_addr)
+	blr
+
+bpf_slow_path_byte_neg:
+	lis     r_scratch1,-32	/* SKF_LL_OFF */
+	PPC_LCMP	r_addr, r_scratch1	/* addr < SKF_* */
+	blt	bpf_error	/* cr0 = LT */
+	.globl	sk_load_byte_negative_offset
+sk_load_byte_negative_offset:
+	sk_negative_common(1)
+	lbz	r_A, 0(r_addr)
+	blr
+
+bpf_slow_path_byte_msh_neg:
+	lis     r_scratch1,-32	/* SKF_LL_OFF */
+	PPC_LCMP	r_addr, r_scratch1	/* addr < SKF_* */
+	blt	bpf_error	/* cr0 = LT */
+	.globl	sk_load_byte_msh_negative_offset
+sk_load_byte_msh_negative_offset:
+	sk_negative_common(1)
+	lbz	r_X, 0(r_addr)
+	rlwinm	r_X, r_X, 2, 32-4-2, 31-2
+	blr
+
+bpf_error_slow:
+	/* fabricate a cr0 = lt */
+	li	r_scratch1, -1
+	PPC_LCMPI	r_scratch1, 0
+bpf_error:
+	/* Entered with cr0 = lt */
+	li	r3, 0
+	/* Generated code will 'blt epilogue', returning 0. */
+	blr