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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/powerpc/net/bpf_jit.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/net/bpf_jit.h')
-rw-r--r--arch/powerpc/net/bpf_jit.h183
1 files changed, 183 insertions, 0 deletions
diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h
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+++ b/arch/powerpc/net/bpf_jit.h
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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * bpf_jit.h: BPF JIT compiler for PPC
+ *
+ * Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation
+ * 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
+ */
+#ifndef _BPF_JIT_H
+#define _BPF_JIT_H
+
+#ifndef __ASSEMBLY__
+
+#include <asm/types.h>
+#include <asm/ppc-opcode.h>
+
+#ifdef CONFIG_PPC64_ELF_ABI_V1
+#define FUNCTION_DESCR_SIZE 24
+#else
+#define FUNCTION_DESCR_SIZE 0
+#endif
+
+#define PLANT_INSTR(d, idx, instr) \
+ do { if (d) { (d)[idx] = instr; } idx++; } while (0)
+#define EMIT(instr) PLANT_INSTR(image, ctx->idx, instr)
+
+/* Long jump; (unconditional 'branch') */
+#define PPC_JMP(dest) \
+ do { \
+ long offset = (long)(dest) - (ctx->idx * 4); \
+ if ((dest) != 0 && !is_offset_in_branch_range(offset)) { \
+ pr_err_ratelimited("Branch offset 0x%lx (@%u) out of range\n", offset, ctx->idx); \
+ return -ERANGE; \
+ } \
+ EMIT(PPC_RAW_BRANCH(offset)); \
+ } while (0)
+
+/* bl (unconditional 'branch' with link) */
+#define PPC_BL(dest) EMIT(PPC_RAW_BL((dest) - (unsigned long)(image + ctx->idx)))
+
+/* "cond" here covers BO:BI fields. */
+#define PPC_BCC_SHORT(cond, dest) \
+ do { \
+ long offset = (long)(dest) - (ctx->idx * 4); \
+ if ((dest) != 0 && !is_offset_in_cond_branch_range(offset)) { \
+ pr_err_ratelimited("Conditional branch offset 0x%lx (@%u) out of range\n", offset, ctx->idx); \
+ return -ERANGE; \
+ } \
+ EMIT(PPC_INST_BRANCH_COND | (((cond) & 0x3ff) << 16) | (offset & 0xfffc)); \
+ } while (0)
+
+/* Sign-extended 32-bit immediate load */
+#define PPC_LI32(d, i) do { \
+ if ((int)(uintptr_t)(i) >= -32768 && \
+ (int)(uintptr_t)(i) < 32768) \
+ EMIT(PPC_RAW_LI(d, i)); \
+ else { \
+ EMIT(PPC_RAW_LIS(d, IMM_H(i))); \
+ if (IMM_L(i)) \
+ EMIT(PPC_RAW_ORI(d, d, IMM_L(i))); \
+ } } while(0)
+
+#ifdef CONFIG_PPC64
+#define PPC_LI64(d, i) do { \
+ if ((long)(i) >= -2147483648 && \
+ (long)(i) < 2147483648) \
+ PPC_LI32(d, i); \
+ else { \
+ if (!((uintptr_t)(i) & 0xffff800000000000ULL)) \
+ EMIT(PPC_RAW_LI(d, ((uintptr_t)(i) >> 32) & \
+ 0xffff)); \
+ else { \
+ EMIT(PPC_RAW_LIS(d, ((uintptr_t)(i) >> 48))); \
+ if ((uintptr_t)(i) & 0x0000ffff00000000ULL) \
+ EMIT(PPC_RAW_ORI(d, d, \
+ ((uintptr_t)(i) >> 32) & 0xffff)); \
+ } \
+ EMIT(PPC_RAW_SLDI(d, d, 32)); \
+ if ((uintptr_t)(i) & 0x00000000ffff0000ULL) \
+ EMIT(PPC_RAW_ORIS(d, d, \
+ ((uintptr_t)(i) >> 16) & 0xffff)); \
+ if ((uintptr_t)(i) & 0x000000000000ffffULL) \
+ EMIT(PPC_RAW_ORI(d, d, (uintptr_t)(i) & \
+ 0xffff)); \
+ } } while (0)
+#endif
+
+/*
+ * 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_offset_in_cond_branch_range((long)(dest) - (ctx->idx * 4))) { \
+ PPC_BCC_SHORT(cond, dest); \
+ EMIT(PPC_RAW_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 COND_LE (CR0_GT | COND_CMP_FALSE)
+
+#define SEEN_FUNC 0x20000000 /* might call external helpers */
+#define SEEN_TAILCALL 0x40000000 /* uses tail calls */
+
+struct codegen_context {
+ /*
+ * This is used to track register usage as well
+ * as calls to external helpers.
+ * - register usage is tracked with corresponding
+ * bits (r3-r31)
+ * - rest of the bits can be used to track other
+ * things -- for now, we use bits 0 to 2
+ * encoded in SEEN_* macros above
+ */
+ unsigned int seen;
+ unsigned int idx;
+ unsigned int stack_size;
+ int b2p[MAX_BPF_JIT_REG + 2];
+ unsigned int exentry_idx;
+ unsigned int alt_exit_addr;
+};
+
+#define bpf_to_ppc(r) (ctx->b2p[r])
+
+#ifdef CONFIG_PPC32
+#define BPF_FIXUP_LEN 3 /* Three instructions => 12 bytes */
+#else
+#define BPF_FIXUP_LEN 2 /* Two instructions => 8 bytes */
+#endif
+
+static inline void bpf_flush_icache(void *start, void *end)
+{
+ smp_wmb(); /* smp write barrier */
+ flush_icache_range((unsigned long)start, (unsigned long)end);
+}
+
+static inline bool bpf_is_seen_register(struct codegen_context *ctx, int i)
+{
+ return ctx->seen & (1 << (31 - i));
+}
+
+static inline void bpf_set_seen_register(struct codegen_context *ctx, int i)
+{
+ ctx->seen |= 1 << (31 - i);
+}
+
+static inline void bpf_clear_seen_register(struct codegen_context *ctx, int i)
+{
+ ctx->seen &= ~(1 << (31 - i));
+}
+
+void bpf_jit_init_reg_mapping(struct codegen_context *ctx);
+int bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func);
+int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx,
+ u32 *addrs, int pass);
+void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx);
+void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx);
+void bpf_jit_realloc_regs(struct codegen_context *ctx);
+int bpf_jit_emit_exit_insn(u32 *image, struct codegen_context *ctx, int tmp_reg, long exit_addr);
+
+int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, int pass, struct codegen_context *ctx,
+ int insn_idx, int jmp_off, int dst_reg);
+
+#endif
+
+#endif