summaryrefslogtreecommitdiff
path: root/arch/powerpc/net/bpf_jit.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/net/bpf_jit.h')
-rw-r--r--arch/powerpc/net/bpf_jit.h227
1 files changed, 227 insertions, 0 deletions
diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h
new file mode 100644
index 0000000..af1ab5e
--- /dev/null
+++ b/arch/powerpc/net/bpf_jit.h
@@ -0,0 +1,227 @@
+/* bpf_jit.h: BPF JIT compiler for PPC64
+ *
+ * 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.
+ */
+#ifndef _BPF_JIT_H
+#define _BPF_JIT_H
+
+#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)
+
+/*
+ * 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_D 14
+#define r_HL 15
+#define r_M 16
+
+#ifndef __ASSEMBLY__
+
+/*
+ * Assembly helpers from arch/powerpc/net/bpf_jit.S:
+ */
+extern u8 sk_load_word[], sk_load_half[], sk_load_byte[], sk_load_byte_msh[];
+
+#define FUNCTION_DESCR_SIZE 24
+
+/*
+ * 16-bit immediate helper macros: HA() is for use with sign-extending instrs
+ * (e.g. LD, ADDI). If the bottom 16 bits is "-ve", add another bit into the
+ * top half to negate the effect (i.e. 0xffff + 1 = 0x(1)0000).
+ */
+#define IMM_H(i) ((uintptr_t)(i)>>16)
+#define IMM_HA(i) (((uintptr_t)(i)>>16) + \
+ (((uintptr_t)(i) & 0x8000) >> 15))
+#define IMM_L(i) ((uintptr_t)(i) & 0xffff)
+
+#define PLANT_INSTR(d, idx, instr) \
+ do { if (d) { (d)[idx] = instr; } idx++; } while (0)
+#define EMIT(instr) PLANT_INSTR(image, ctx->idx, instr)
+
+#define PPC_NOP() EMIT(PPC_INST_NOP)
+#define PPC_BLR() EMIT(PPC_INST_BLR)
+#define PPC_BLRL() EMIT(PPC_INST_BLRL)
+#define PPC_MTLR(r) EMIT(PPC_INST_MTLR | __PPC_RT(r))
+#define PPC_ADDI(d, a, i) EMIT(PPC_INST_ADDI | __PPC_RT(d) | \
+ __PPC_RA(a) | IMM_L(i))
+#define PPC_MR(d, a) PPC_OR(d, a, a)
+#define PPC_LI(r, i) PPC_ADDI(r, 0, i)
+#define PPC_ADDIS(d, a, i) EMIT(PPC_INST_ADDIS | \
+ __PPC_RS(d) | __PPC_RA(a) | IMM_L(i))
+#define PPC_LIS(r, i) PPC_ADDIS(r, 0, i)
+#define PPC_STD(r, base, i) EMIT(PPC_INST_STD | __PPC_RS(r) | \
+ __PPC_RA(base) | ((i) & 0xfffc))
+
+#define PPC_LD(r, base, i) EMIT(PPC_INST_LD | __PPC_RT(r) | \
+ __PPC_RA(base) | IMM_L(i))
+#define PPC_LWZ(r, base, i) EMIT(PPC_INST_LWZ | __PPC_RT(r) | \
+ __PPC_RA(base) | IMM_L(i))
+#define PPC_LHZ(r, base, i) EMIT(PPC_INST_LHZ | __PPC_RT(r) | \
+ __PPC_RA(base) | IMM_L(i))
+/* Convenience helpers for the above with 'far' offsets: */
+#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)
+
+#define PPC_CMPWI(a, i) EMIT(PPC_INST_CMPWI | __PPC_RA(a) | IMM_L(i))
+#define PPC_CMPDI(a, i) EMIT(PPC_INST_CMPDI | __PPC_RA(a) | IMM_L(i))
+#define PPC_CMPLWI(a, i) EMIT(PPC_INST_CMPLWI | __PPC_RA(a) | IMM_L(i))
+#define PPC_CMPLW(a, b) EMIT(PPC_INST_CMPLW | __PPC_RA(a) | __PPC_RB(b))
+
+#define PPC_SUB(d, a, b) EMIT(PPC_INST_SUB | __PPC_RT(d) | \
+ __PPC_RB(a) | __PPC_RA(b))
+#define PPC_ADD(d, a, b) EMIT(PPC_INST_ADD | __PPC_RT(d) | \
+ __PPC_RA(a) | __PPC_RB(b))
+#define PPC_MUL(d, a, b) EMIT(PPC_INST_MULLW | __PPC_RT(d) | \
+ __PPC_RA(a) | __PPC_RB(b))
+#define PPC_MULHWU(d, a, b) EMIT(PPC_INST_MULHWU | __PPC_RT(d) | \
+ __PPC_RA(a) | __PPC_RB(b))
+#define PPC_MULI(d, a, i) EMIT(PPC_INST_MULLI | __PPC_RT(d) | \
+ __PPC_RA(a) | IMM_L(i))
+#define PPC_DIVWU(d, a, b) EMIT(PPC_INST_DIVWU | __PPC_RT(d) | \
+ __PPC_RA(a) | __PPC_RB(b))
+#define PPC_AND(d, a, b) EMIT(PPC_INST_AND | __PPC_RA(d) | \
+ __PPC_RS(a) | __PPC_RB(b))
+#define PPC_ANDI(d, a, i) EMIT(PPC_INST_ANDI | __PPC_RA(d) | \
+ __PPC_RS(a) | IMM_L(i))
+#define PPC_AND_DOT(d, a, b) EMIT(PPC_INST_ANDDOT | __PPC_RA(d) | \
+ __PPC_RS(a) | __PPC_RB(b))
+#define PPC_OR(d, a, b) EMIT(PPC_INST_OR | __PPC_RA(d) | \
+ __PPC_RS(a) | __PPC_RB(b))
+#define PPC_ORI(d, a, i) EMIT(PPC_INST_ORI | __PPC_RA(d) | \
+ __PPC_RS(a) | IMM_L(i))
+#define PPC_ORIS(d, a, i) EMIT(PPC_INST_ORIS | __PPC_RA(d) | \
+ __PPC_RS(a) | IMM_L(i))
+#define PPC_SLW(d, a, s) EMIT(PPC_INST_SLW | __PPC_RA(d) | \
+ __PPC_RS(a) | __PPC_RB(s))
+#define PPC_SRW(d, a, s) EMIT(PPC_INST_SRW | __PPC_RA(d) | \
+ __PPC_RS(a) | __PPC_RB(s))
+/* slwi = rlwinm Rx, Ry, n, 0, 31-n */
+#define PPC_SLWI(d, a, i) EMIT(PPC_INST_RLWINM | __PPC_RA(d) | \
+ __PPC_RS(a) | __PPC_SH(i) | \
+ __PPC_MB(0) | __PPC_ME(31-(i)))
+/* srwi = rlwinm Rx, Ry, 32-n, n, 31 */
+#define PPC_SRWI(d, a, i) EMIT(PPC_INST_RLWINM | __PPC_RA(d) | \
+ __PPC_RS(a) | __PPC_SH(32-(i)) | \
+ __PPC_MB(i) | __PPC_ME(31))
+/* sldi = rldicr Rx, Ry, n, 63-n */
+#define PPC_SLDI(d, a, i) EMIT(PPC_INST_RLDICR | __PPC_RA(d) | \
+ __PPC_RS(a) | __PPC_SH(i) | \
+ __PPC_MB(63-(i)) | (((i) & 0x20) >> 4))
+#define PPC_NEG(d, a) EMIT(PPC_INST_NEG | __PPC_RT(d) | __PPC_RA(a))
+
+/* Long jump; (unconditional 'branch') */
+#define PPC_JMP(dest) EMIT(PPC_INST_BRANCH | \
+ (((dest) - (ctx->idx * 4)) & 0x03fffffc))
+/* "cond" here covers BO:BI fields. */
+#define PPC_BCC_SHORT(cond, dest) EMIT(PPC_INST_BRANCH_COND | \
+ (((cond) & 0x3ff) << 16) | \
+ (((dest) - (ctx->idx * 4)) & \
+ 0xfffc))
+#define PPC_LI32(d, i) do { PPC_LI(d, IMM_L(i)); \
+ if ((u32)(uintptr_t)(i) >= 32768) { \
+ PPC_ADDIS(d, d, IMM_HA(i)); \
+ } } while(0)
+#define PPC_LI64(d, i) do { \
+ if (!((uintptr_t)(i) & 0xffffffff00000000ULL)) \
+ PPC_LI32(d, i); \
+ else { \
+ PPC_LIS(d, ((uintptr_t)(i) >> 48)); \
+ if ((uintptr_t)(i) & 0x0000ffff00000000ULL) \
+ PPC_ORI(d, d, \
+ ((uintptr_t)(i) >> 32) & 0xffff); \
+ PPC_SLDI(d, d, 32); \
+ if ((uintptr_t)(i) & 0x00000000ffff0000ULL) \
+ PPC_ORIS(d, d, \
+ ((uintptr_t)(i) >> 16) & 0xffff); \
+ if ((uintptr_t)(i) & 0x000000000000ffffULL) \
+ PPC_ORI(d, d, (uintptr_t)(i) & 0xffff); \
+ } } while (0);
+
+static inline bool is_nearbranch(int offset)
+{
+ return (offset < 32768) && (offset >= -32768);
+}
+
+/*
+ * The fly in the ointment of code size changing from pass to pass is
+ * avoided by padding the short branch case with a NOP. If code size differs
+ * with different branch reaches we will have the issue of code moving from
+ * one pass to the next and will need a few passes to converge on a stable
+ * state.
+ */
+#define PPC_BCC(cond, dest) do { \
+ if (is_nearbranch((dest) - (ctx->idx * 4))) { \
+ PPC_BCC_SHORT(cond, dest); \
+ PPC_NOP(); \
+ } else { \
+ /* Flip the 'T or F' bit to invert comparison */ \
+ PPC_BCC_SHORT(cond ^ COND_CMP_TRUE, (ctx->idx+2)*4); \
+ PPC_JMP(dest); \
+ } } while(0)
+
+/* To create a branch condition, select a bit of cr0... */
+#define CR0_LT 0
+#define CR0_GT 1
+#define CR0_EQ 2
+/* ...and modify BO[3] */
+#define COND_CMP_TRUE 0x100
+#define COND_CMP_FALSE 0x000
+/* Together, they make all required comparisons: */
+#define COND_GT (CR0_GT | COND_CMP_TRUE)
+#define COND_GE (CR0_LT | COND_CMP_FALSE)
+#define COND_EQ (CR0_EQ | COND_CMP_TRUE)
+#define COND_NE (CR0_EQ | COND_CMP_FALSE)
+#define COND_LT (CR0_LT | COND_CMP_TRUE)
+
+#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
generated by cgit v0.10.2 at 2024-11-06 03:50:42 (GMT)