powerpc/bpf/jit: Isolate classic BPF JIT specifics into a separate header

Break out classic BPF JIT specifics into a separate header in
preparation for eBPF JIT implementation. Note that ppc32 will still need
the classic BPF JIT.

Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 139 insertions, 0 deletions

diff --git a/arch/powerpc/net/bpf_jit32.h b/arch/powerpc/net/bpf_jit32.h
new file mode 100644
index 000000000000..a8cd7e289ecd
--- /dev/null
+++ b/arch/powerpc/net/bpf_jit32.h
@@ -0,0 +1,139 @@
+/*
+ * bpf_jit32.h: BPF JIT compiler for PPC
+ *
+ * Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation
+ *
+ * Split from bpf_jit.h
+ *
+ * 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.
+ */
+#ifndef _BPF_JIT32_H
+#define _BPF_JIT32_H
+
+#include "bpf_jit.h"
+
+#ifdef CONFIG_PPC64
+#define BPF_PPC_STACK_R3_OFF	48
+#define BPF_PPC_STACK_LOCALS	32
+#define BPF_PPC_STACK_BASIC	(48+64)
+#define BPF_PPC_STACK_SAVE	(18*8)
+#define BPF_PPC_STACKFRAME	(BPF_PPC_STACK_BASIC+BPF_PPC_STACK_LOCALS+ \
+				 BPF_PPC_STACK_SAVE)
+#define BPF_PPC_SLOWPATH_FRAME	(48+64)
+#else
+#define BPF_PPC_STACK_R3_OFF	24
+#define BPF_PPC_STACK_LOCALS	16
+#define BPF_PPC_STACK_BASIC	(24+32)
+#define BPF_PPC_STACK_SAVE	(18*4)
+#define BPF_PPC_STACKFRAME	(BPF_PPC_STACK_BASIC+BPF_PPC_STACK_LOCALS+ \
+				 BPF_PPC_STACK_SAVE)
+#define BPF_PPC_SLOWPATH_FRAME	(24+32)
+#endif
+
+#define REG_SZ         (BITS_PER_LONG/8)
+
+/*
+ * Generated code register usage:
+ *
+ * As normal PPC C ABI (e.g. r1=sp, r2=TOC), with:
+ *
+ * skb		r3	(Entry parameter)
+ * A register	r4
+ * X register	r5
+ * addr param	r6
+ * r7-r10	scratch
+ * skb->data	r14
+ * skb headlen	r15	(skb->len - skb->data_len)
+ * m[0]		r16
+ * m[...]	...
+ * m[15]	r31
+ */
+#define r_skb		3
+#define r_ret		3
+#define r_A		4
+#define r_X		5
+#define r_addr		6
+#define r_scratch1	7
+#define r_scratch2	8
+#define r_D		14
+#define r_HL		15
+#define r_M		16
+
+#ifndef __ASSEMBLY__
+
+/*
+ * Assembly helpers from arch/powerpc/net/bpf_jit.S:
+ */
+#define DECLARE_LOAD_FUNC(func)	\
+	extern u8 func[], func##_negative_offset[], func##_positive_offset[]
+
+DECLARE_LOAD_FUNC(sk_load_word);
+DECLARE_LOAD_FUNC(sk_load_half);
+DECLARE_LOAD_FUNC(sk_load_byte);
+DECLARE_LOAD_FUNC(sk_load_byte_msh);
+
+#define PPC_LBZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LBZ(r, base, i);   \
+		else {	PPC_ADDIS(r, base, IMM_HA(i));			      \
+			PPC_LBZ(r, r, IMM_L(i)); } } while(0)
+
+#define PPC_LD_OFFS(r, base, i) do { if ((i) < 32768) PPC_LD(r, base, i);     \
+		else {	PPC_ADDIS(r, base, IMM_HA(i));			      \
+			PPC_LD(r, r, IMM_L(i)); } } while(0)
+
+#define PPC_LWZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LWZ(r, base, i);   \
+		else {	PPC_ADDIS(r, base, IMM_HA(i));			      \
+			PPC_LWZ(r, r, IMM_L(i)); } } while(0)
+
+#define PPC_LHZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LHZ(r, base, i);   \
+		else {	PPC_ADDIS(r, base, IMM_HA(i));			      \
+			PPC_LHZ(r, r, IMM_L(i)); } } while(0)
+
+#ifdef CONFIG_PPC64
+#define PPC_LL_OFFS(r, base, i) do { PPC_LD_OFFS(r, base, i); } while(0)
+#else
+#define PPC_LL_OFFS(r, base, i) do { PPC_LWZ_OFFS(r, base, i); } while(0)
+#endif
+
+#ifdef CONFIG_SMP
+#ifdef CONFIG_PPC64
+#define PPC_BPF_LOAD_CPU(r)		\
+	do { BUILD_BUG_ON(FIELD_SIZEOF(struct paca_struct, paca_index) != 2);	\
+		PPC_LHZ_OFFS(r, 13, offsetof(struct paca_struct, paca_index));	\
+	} while (0)
+#else
+#define PPC_BPF_LOAD_CPU(r)     \
+	do { BUILD_BUG_ON(FIELD_SIZEOF(struct thread_info, cpu) != 4);		\
+		PPC_LHZ_OFFS(r, (1 & ~(THREAD_SIZE - 1)),			\
+				offsetof(struct thread_info, cpu));		\
+	} while(0)
+#endif
+#else
+#define PPC_BPF_LOAD_CPU(r) do { PPC_LI(r, 0); } while(0)
+#endif
+
+#define PPC_LHBRX_OFFS(r, base, i) \
+		do { PPC_LI32(r, i); PPC_LHBRX(r, r, base); } while(0)
+#ifdef __LITTLE_ENDIAN__
+#define PPC_NTOHS_OFFS(r, base, i)	PPC_LHBRX_OFFS(r, base, i)
+#else
+#define PPC_NTOHS_OFFS(r, base, i)	PPC_LHZ_OFFS(r, base, i)
+#endif
+
+#define SEEN_DATAREF 0x10000 /* might call external helpers */
+#define SEEN_XREG    0x20000 /* X reg is used */
+#define SEEN_MEM     0x40000 /* SEEN_MEM+(1<<n) = use mem[n] for temporary
+			      * storage */
+#define SEEN_MEM_MSK 0x0ffff
+
+struct codegen_context {
+	unsigned int seen;
+	unsigned int idx;
+	int pc_ret0; /* bpf index of first RET #0 instruction (if any) */
+};
+
+#endif
+
+#endif