summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/net/bpf_jit64.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/net/bpf_jit64.h')
-rw-r--r--arch/powerpc/net/bpf_jit64.h102
1 files changed, 102 insertions, 0 deletions
diff --git a/arch/powerpc/net/bpf_jit64.h b/arch/powerpc/net/bpf_jit64.h
new file mode 100644
index 000000000000..5046d6f65c02
--- /dev/null
+++ b/arch/powerpc/net/bpf_jit64.h
@@ -0,0 +1,102 @@
+/*
+ * bpf_jit64.h: BPF JIT compiler for PPC64
+ *
+ * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
+ * 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_JIT64_H
+#define _BPF_JIT64_H
+
+#include "bpf_jit.h"
+
+/*
+ * Stack layout:
+ *
+ * [ prev sp ] <-------------
+ * [ nv gpr save area ] 8*8 |
+ * fp (r31) --> [ ebpf stack space ] 512 |
+ * [ local/tmp var space ] 16 |
+ * [ frame header ] 32/112 |
+ * sp (r1) ---> [ stack pointer ] --------------
+ */
+
+/* for bpf JIT code internal usage */
+#define BPF_PPC_STACK_LOCALS 16
+/* for gpr non volatile registers BPG_REG_6 to 10, plus skb cache registers */
+#define BPF_PPC_STACK_SAVE (8*8)
+/* Ensure this is quadword aligned */
+#define BPF_PPC_STACKFRAME (STACK_FRAME_MIN_SIZE + BPF_PPC_STACK_LOCALS + \
+ MAX_BPF_STACK + BPF_PPC_STACK_SAVE)
+
+#ifndef __ASSEMBLY__
+
+/* BPF register usage */
+#define SKB_HLEN_REG (MAX_BPF_REG + 0)
+#define SKB_DATA_REG (MAX_BPF_REG + 1)
+#define TMP_REG_1 (MAX_BPF_REG + 2)
+#define TMP_REG_2 (MAX_BPF_REG + 3)
+
+/* BPF to ppc register mappings */
+static const int b2p[] = {
+ /* function return value */
+ [BPF_REG_0] = 8,
+ /* function arguments */
+ [BPF_REG_1] = 3,
+ [BPF_REG_2] = 4,
+ [BPF_REG_3] = 5,
+ [BPF_REG_4] = 6,
+ [BPF_REG_5] = 7,
+ /* non volatile registers */
+ [BPF_REG_6] = 27,
+ [BPF_REG_7] = 28,
+ [BPF_REG_8] = 29,
+ [BPF_REG_9] = 30,
+ /* frame pointer aka BPF_REG_10 */
+ [BPF_REG_FP] = 31,
+ /* eBPF jit internal registers */
+ [SKB_HLEN_REG] = 25,
+ [SKB_DATA_REG] = 26,
+ [TMP_REG_1] = 9,
+ [TMP_REG_2] = 10
+};
+
+/* Assembly helpers */
+#define DECLARE_LOAD_FUNC(func) u64 func(u64 r3, u64 r4); \
+ u64 func##_negative_offset(u64 r3, u64 r4); \
+ u64 func##_positive_offset(u64 r3, u64 r4);
+
+DECLARE_LOAD_FUNC(sk_load_word);
+DECLARE_LOAD_FUNC(sk_load_half);
+DECLARE_LOAD_FUNC(sk_load_byte);
+
+#define CHOOSE_LOAD_FUNC(imm, func) \
+ (imm < 0 ? \
+ (imm >= SKF_LL_OFF ? func##_negative_offset : func) : \
+ func##_positive_offset)
+
+#define SEEN_FUNC 0x1000 /* might call external helpers */
+#define SEEN_STACK 0x2000 /* uses BPF stack */
+#define SEEN_SKB 0x4000 /* uses sk_buff */
+
+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-r10 and r25-r31)
+ * - rest of the bits can be used to track other
+ * things -- for now, we use bits 16 to 23
+ * encoded in SEEN_* macros above
+ */
+ unsigned int seen;
+ unsigned int idx;
+};
+
+#endif /* !__ASSEMBLY__ */
+
+#endif