parisc: Add 64-bit eBPF JIT compiler
authorHelge Deller <deller@gmx.de>
Thu, 17 Aug 2023 21:44:59 +0000 (23:44 +0200)
committerHelge Deller <deller@gmx.de>
Tue, 22 Aug 2023 08:24:46 +0000 (10:24 +0200)
Signed-off-by: Helge Deller <deller@gmx.de>
arch/parisc/net/bpf_jit_comp64.c [new file with mode: 0644]

diff --git a/arch/parisc/net/bpf_jit_comp64.c b/arch/parisc/net/bpf_jit_comp64.c
new file mode 100644 (file)
index 0000000..54b0d5e
--- /dev/null
@@ -0,0 +1,1209 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * BPF JIT compiler for PA-RISC (64-bit)
+ *
+ * Copyright(c) 2023 Helge Deller <deller@gmx.de>
+ *
+ * The code is based on the BPF JIT compiler for RV64 by Björn Töpel.
+ *
+ * TODO:
+ * - check if bpf_jit_needs_zext() is needed (currently enabled)
+ * - implement arch_prepare_bpf_trampoline(), poke(), ...
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <linux/libgcc.h>
+#include "bpf_jit.h"
+
+static const int regmap[] = {
+       [BPF_REG_0] =   HPPA_REG_RET0,
+       [BPF_REG_1] =   HPPA_R(5),
+       [BPF_REG_2] =   HPPA_R(6),
+       [BPF_REG_3] =   HPPA_R(7),
+       [BPF_REG_4] =   HPPA_R(8),
+       [BPF_REG_5] =   HPPA_R(9),
+       [BPF_REG_6] =   HPPA_R(10),
+       [BPF_REG_7] =   HPPA_R(11),
+       [BPF_REG_8] =   HPPA_R(12),
+       [BPF_REG_9] =   HPPA_R(13),
+       [BPF_REG_FP] =  HPPA_R(14),
+       [BPF_REG_AX] =  HPPA_R(15),
+};
+
+/*
+ * Stack layout during BPF program execution (note: stack grows up):
+ *
+ *                     high
+ *   HPPA64 sp =>  +----------+ <= HPPA64 fp
+ *                 | saved sp |
+ *                 | saved rp |
+ *                 |   ...    | HPPA64 callee-saved registers
+ *                 | curr args|
+ *                 | local var|
+ *                 +----------+ <= (BPF FP)
+ *                 |          |
+ *                 |   ...    | BPF program stack
+ *                 |          |
+ *                 |   ...    | Function call stack
+ *                 |          |
+ *                 +----------+
+ *                     low
+ */
+
+/* Offset from fp for BPF registers stored on stack. */
+#define STACK_ALIGN    FRAME_SIZE
+
+#define EXIT_PTR_LOAD(reg)     hppa64_ldd_im16(-FRAME_SIZE, HPPA_REG_SP, reg)
+#define EXIT_PTR_STORE(reg)    hppa64_std_im16(reg, -FRAME_SIZE, HPPA_REG_SP)
+#define EXIT_PTR_JUMP(reg, nop)        hppa_bv(HPPA_REG_ZERO, reg, nop)
+
+static u8 bpf_to_hppa_reg(int bpf_reg, struct hppa_jit_context *ctx)
+{
+       u8 reg = regmap[bpf_reg];
+
+       REG_SET_SEEN(ctx, reg);
+       return reg;
+};
+
+static void emit_hppa_copy(const s8 rs, const s8 rd, struct hppa_jit_context *ctx)
+{
+       REG_SET_SEEN(ctx, rd);
+       if (OPTIMIZE_HPPA && (rs == rd))
+               return;
+       REG_SET_SEEN(ctx, rs);
+       emit(hppa_copy(rs, rd), ctx);
+}
+
+static void emit_hppa64_depd(u8 src, u8 pos, u8 len, u8 target, bool no_zero, struct hppa_jit_context *ctx)
+{
+       int c;
+
+       pos &= (BITS_PER_LONG - 1);
+       pos = 63 - pos;
+       len = 64 - len;
+       c =  (len < 32)  ? 0x4 : 0;
+       c |= (pos >= 32) ? 0x2 : 0;
+       c |= (no_zero)   ? 0x1 : 0;
+       emit(hppa_t10_insn(0x3c, target, src, 0, c, pos & 0x1f, len & 0x1f), ctx);
+}
+
+static void emit_hppa64_shld(u8 src, int num, u8 target, struct hppa_jit_context *ctx)
+{
+       emit_hppa64_depd(src, 63-num, 64-num, target, 0, ctx);
+}
+
+static void emit_hppa64_extrd(u8 src, u8 pos, u8 len, u8 target, bool signed_op, struct hppa_jit_context *ctx)
+{
+       int c;
+
+       pos &= (BITS_PER_LONG - 1);
+       len = 64 - len;
+       c =  (len <  32) ? 0x4 : 0;
+       c |= (pos >= 32) ? 0x2 : 0;
+       c |= signed_op   ? 0x1 : 0;
+       emit(hppa_t10_insn(0x36, src, target, 0, c, pos & 0x1f, len & 0x1f), ctx);
+}
+
+static void emit_hppa64_extrw(u8 src, u8 pos, u8 len, u8 target, bool signed_op, struct hppa_jit_context *ctx)
+{
+       int c;
+
+       pos &= (32 - 1);
+       len = 32 - len;
+       c = 0x06 | (signed_op ? 1 : 0);
+       emit(hppa_t10_insn(0x34, src, target, 0, c, pos, len), ctx);
+}
+
+#define emit_hppa64_zext32(r, target, ctx) \
+       emit_hppa64_extrd(r, 63, 32, target, false, ctx)
+#define emit_hppa64_sext32(r, target, ctx) \
+       emit_hppa64_extrd(r, 63, 32, target, true, ctx)
+
+static void emit_hppa64_shrd(u8 src, int num, u8 target, bool signed_op, struct hppa_jit_context *ctx)
+{
+       emit_hppa64_extrd(src, 63-num, 64-num, target, signed_op, ctx);
+}
+
+static void emit_hppa64_shrw(u8 src, int num, u8 target, bool signed_op, struct hppa_jit_context *ctx)
+{
+       emit_hppa64_extrw(src, 31-num, 32-num, target, signed_op, ctx);
+}
+
+/* Emit variable-length instructions for 32-bit imm */
+static void emit_imm32(u8 rd, s32 imm, struct hppa_jit_context *ctx)
+{
+       u32 lower = im11(imm);
+
+       REG_SET_SEEN(ctx, rd);
+       if (OPTIMIZE_HPPA && relative_bits_ok(imm, 14)) {
+               emit(hppa_ldi(imm, rd), ctx);
+               return;
+       }
+       if (OPTIMIZE_HPPA && lower == imm) {
+               emit(hppa_ldo(lower, HPPA_REG_ZERO, rd), ctx);
+               return;
+       }
+       emit(hppa_ldil(imm, rd), ctx);
+       if (OPTIMIZE_HPPA && (lower == 0))
+               return;
+       emit(hppa_ldo(lower, rd, rd), ctx);
+}
+
+static bool is_32b_int(s64 val)
+{
+       return val == (s32) val;
+}
+
+/* Emit variable-length instructions for 64-bit imm */
+static void emit_imm(u8 rd, s64 imm, u8 tmpreg, struct hppa_jit_context *ctx)
+{
+       u32 upper32;
+
+       /* get lower 32-bits into rd, sign extended */
+       emit_imm32(rd, imm, ctx);
+
+       /* do we have upper 32-bits too ? */
+       if (OPTIMIZE_HPPA && is_32b_int(imm))
+               return;
+
+       /* load upper 32-bits into lower tmpreg and deposit into rd */
+       upper32 = imm >> 32;
+       if (upper32 || !OPTIMIZE_HPPA) {
+               emit_imm32(tmpreg, upper32, ctx);
+               emit_hppa64_depd(tmpreg, 31, 32, rd, 1, ctx);
+       } else
+               emit_hppa64_depd(HPPA_REG_ZERO, 31, 32, rd, 1, ctx);
+
+}
+
+static int emit_jump(signed long paoff, bool force_far,
+                              struct hppa_jit_context *ctx)
+{
+       unsigned long pc, addr;
+
+       /* Note: Use 2 instructions for jumps if force_far is set. */
+       if (relative_bits_ok(paoff - HPPA_BRANCH_DISPLACEMENT, 22)) {
+               /* use BL,long branch followed by nop() */
+               emit(hppa64_bl_long(paoff - HPPA_BRANCH_DISPLACEMENT), ctx);
+               if (force_far)
+                       emit(hppa_nop(), ctx);
+               return 0;
+       }
+
+       pc = (uintptr_t) &ctx->insns[ctx->ninsns];
+       addr = pc + (paoff * HPPA_INSN_SIZE);
+       /* even the 64-bit kernel runs in memory below 4GB */
+       if (WARN_ON_ONCE(addr >> 32))
+               return -E2BIG;
+       emit(hppa_ldil(addr, HPPA_REG_R31), ctx);
+       emit(hppa_be_l(im11(addr) >> 2, HPPA_REG_R31, NOP_NEXT_INSTR), ctx);
+       return 0;
+}
+
+static void __build_epilogue(bool is_tail_call, struct hppa_jit_context *ctx)
+{
+       int i;
+
+       if (is_tail_call) {
+               /*
+                * goto *(t0 + 4);
+                * Skips first instruction of prologue which initializes tail
+                * call counter. Assumes t0 contains address of target program,
+                * see emit_bpf_tail_call.
+                */
+               emit(hppa_ldo(1 * HPPA_INSN_SIZE, HPPA_REG_T0, HPPA_REG_T0), ctx);
+               emit(hppa_bv(HPPA_REG_ZERO, HPPA_REG_T0, EXEC_NEXT_INSTR), ctx);
+               /* in delay slot: */
+               emit(hppa_copy(HPPA_REG_TCC, HPPA_REG_TCC_IN_INIT), ctx);
+
+               return;
+       }
+
+       /* load epilogue function pointer and jump to it. */
+       /* exit point is either at next instruction, or the outest TCC exit function */
+       emit(EXIT_PTR_LOAD(HPPA_REG_RP), ctx);
+       emit(EXIT_PTR_JUMP(HPPA_REG_RP, NOP_NEXT_INSTR), ctx);
+
+       /* NOTE: we are 64-bit and big-endian, so return lower sign-extended 32-bit value */
+       emit_hppa64_sext32(regmap[BPF_REG_0], HPPA_REG_RET0, ctx);
+
+       /* Restore callee-saved registers. */
+       for (i = 3; i <= 15; i++) {
+               if (OPTIMIZE_HPPA && !REG_WAS_SEEN(ctx, HPPA_R(i)))
+                       continue;
+               emit(hppa64_ldd_im16(-REG_SIZE * i, HPPA_REG_SP, HPPA_R(i)), ctx);
+       }
+
+       /* load original return pointer (stored by outest TCC function) */
+       emit(hppa64_ldd_im16(-2*REG_SIZE, HPPA_REG_SP, HPPA_REG_RP), ctx);
+       emit(hppa_bv(HPPA_REG_ZERO, HPPA_REG_RP, EXEC_NEXT_INSTR), ctx);
+       /* in delay slot: */
+       emit(hppa64_ldd_im5(-REG_SIZE, HPPA_REG_SP, HPPA_REG_SP), ctx);
+
+       emit(hppa_nop(), ctx); // XXX WARUM einer zu wenig ??
+}
+
+static int emit_branch(u8 op, u8 rd, u8 rs, signed long paoff,
+                       struct hppa_jit_context *ctx)
+{
+       int e, s;
+       bool far = false;
+       int off;
+
+       if (op == BPF_JSET) {
+               /*
+                * BPF_JSET is a special case: it has no inverse so translate
+                * to and() function and compare against zero
+                */
+               emit(hppa_and(rd, rs, HPPA_REG_T0), ctx);
+               paoff -= 1; /* reduce offset due to hppa_and() above */
+               rd = HPPA_REG_T0;
+               rs = HPPA_REG_ZERO;
+               op = BPF_JNE;
+       }
+
+       /* set start after BPF_JSET */
+       s = ctx->ninsns;
+
+       if (!relative_branch_ok(paoff - HPPA_BRANCH_DISPLACEMENT + 1, 12)) {
+               op = invert_bpf_cond(op);
+               far = true;
+       }
+
+       /*
+        * For a far branch, the condition is negated and we jump over the
+        * branch itself, and the two instructions from emit_jump.
+        * For a near branch, just use paoff.
+        */
+       off = far ? (2 - HPPA_BRANCH_DISPLACEMENT) : paoff - HPPA_BRANCH_DISPLACEMENT;
+
+       switch (op) {
+       /* IF (dst COND src) JUMP off */
+       case BPF_JEQ:
+               emit(hppa_beq(rd, rs, off), ctx);
+               break;
+       case BPF_JGT:
+               emit(hppa_bgtu(rd, rs, off), ctx);
+               break;
+       case BPF_JLT:
+               emit(hppa_bltu(rd, rs, off), ctx);
+               break;
+       case BPF_JGE:
+               emit(hppa_bgeu(rd, rs, off), ctx);
+               break;
+       case BPF_JLE:
+               emit(hppa_bleu(rd, rs, off), ctx);
+               break;
+       case BPF_JNE:
+               emit(hppa_bne(rd, rs, off), ctx);
+               break;
+       case BPF_JSGT:
+               emit(hppa_bgt(rd, rs, off), ctx);
+               break;
+       case BPF_JSLT:
+               emit(hppa_blt(rd, rs, off), ctx);
+               break;
+       case BPF_JSGE:
+               emit(hppa_bge(rd, rs, off), ctx);
+               break;
+       case BPF_JSLE:
+               emit(hppa_ble(rd, rs, off), ctx);
+               break;
+       default:
+               WARN_ON(1);
+       }
+
+       if (far) {
+               int ret;
+               e = ctx->ninsns;
+               /* Adjust for extra insns. */
+               paoff -= (e - s);
+               ret = emit_jump(paoff, true, ctx);
+               if (ret)
+                       return ret;
+       } else {
+               /*
+                * always allocate 2 nops instead of the far branch to
+                * reduce translation loops
+                */
+               emit(hppa_nop(), ctx);
+               emit(hppa_nop(), ctx);
+       }
+       return 0;
+}
+
+static void emit_zext_32(u8 reg, struct hppa_jit_context *ctx)
+{
+       emit_hppa64_zext32(reg, reg, ctx);
+}
+
+static void emit_bpf_tail_call(int insn, struct hppa_jit_context *ctx)
+{
+       /*
+        * R1 -> &ctx
+        * R2 -> &array
+        * R3 -> index
+        */
+       int off;
+       const s8 arr_reg = regmap[BPF_REG_2];
+       const s8 idx_reg = regmap[BPF_REG_3];
+       struct bpf_array bpfa;
+       struct bpf_prog bpfp;
+
+       /* if there is any tail call, we need to save & restore all registers */
+       REG_SET_SEEN_ALL(ctx);
+
+       /* get address of TCC main exit function for error case into rp */
+       emit(EXIT_PTR_LOAD(HPPA_REG_RP), ctx);
+
+       /* max_entries = array->map.max_entries; */
+       off = offsetof(struct bpf_array, map.max_entries);
+       BUILD_BUG_ON(sizeof(bpfa.map.max_entries) != 4);
+       emit(hppa_ldw(off, arr_reg, HPPA_REG_T1), ctx);
+
+       /*
+        * if (index >= max_entries)
+        *   goto out;
+        */
+       emit(hppa_bltu(idx_reg, HPPA_REG_T1, 2 - HPPA_BRANCH_DISPLACEMENT), ctx);
+       emit(EXIT_PTR_JUMP(HPPA_REG_RP, NOP_NEXT_INSTR), ctx);
+
+       /*
+        * if (--tcc < 0)
+        *   goto out;
+        */
+       REG_FORCE_SEEN(ctx, HPPA_REG_TCC);
+       emit(hppa_ldo(-1, HPPA_REG_TCC, HPPA_REG_TCC), ctx);
+       emit(hppa_bge(HPPA_REG_TCC, HPPA_REG_ZERO, 2 - HPPA_BRANCH_DISPLACEMENT), ctx);
+       emit(EXIT_PTR_JUMP(HPPA_REG_RP, NOP_NEXT_INSTR), ctx);
+
+       /*
+        * prog = array->ptrs[index];
+        * if (!prog)
+        *   goto out;
+        */
+       BUILD_BUG_ON(sizeof(bpfa.ptrs[0]) != 8);
+       emit(hppa64_shladd(idx_reg, 3, arr_reg, HPPA_REG_T0), ctx);
+       off = offsetof(struct bpf_array, ptrs);
+       BUILD_BUG_ON(off < 16);
+       emit(hppa64_ldd_im16(off, HPPA_REG_T0, HPPA_REG_T0), ctx);
+       emit(hppa_bne(HPPA_REG_T0, HPPA_REG_ZERO, 2 - HPPA_BRANCH_DISPLACEMENT), ctx);
+       emit(EXIT_PTR_JUMP(HPPA_REG_RP, NOP_NEXT_INSTR), ctx);
+
+       /*
+        * tcc = temp_tcc;
+        * goto *(prog->bpf_func + 4);
+        */
+       off = offsetof(struct bpf_prog, bpf_func);
+       BUILD_BUG_ON(off < 16);
+       BUILD_BUG_ON(sizeof(bpfp.bpf_func) != 8);
+       emit(hppa64_ldd_im16(off, HPPA_REG_T0, HPPA_REG_T0), ctx);
+       /* Epilogue jumps to *(t0 + 4). */
+       __build_epilogue(true, ctx);
+}
+
+static void init_regs(u8 *rd, u8 *rs, const struct bpf_insn *insn,
+                     struct hppa_jit_context *ctx)
+{
+       u8 code = insn->code;
+
+       switch (code) {
+       case BPF_JMP | BPF_JA:
+       case BPF_JMP | BPF_CALL:
+       case BPF_JMP | BPF_EXIT:
+       case BPF_JMP | BPF_TAIL_CALL:
+               break;
+       default:
+               *rd = bpf_to_hppa_reg(insn->dst_reg, ctx);
+       }
+
+       if (code & (BPF_ALU | BPF_X) || code & (BPF_ALU64 | BPF_X) ||
+           code & (BPF_JMP | BPF_X) || code & (BPF_JMP32 | BPF_X) ||
+           code & BPF_LDX || code & BPF_STX)
+               *rs = bpf_to_hppa_reg(insn->src_reg, ctx);
+}
+
+static void emit_zext_32_rd_rs(u8 *rd, u8 *rs, struct hppa_jit_context *ctx)
+{
+       emit_hppa64_zext32(*rd, HPPA_REG_T2, ctx);
+       *rd = HPPA_REG_T2;
+       emit_hppa64_zext32(*rs, HPPA_REG_T1, ctx);
+       *rs = HPPA_REG_T1;
+}
+
+static void emit_sext_32_rd_rs(u8 *rd, u8 *rs, struct hppa_jit_context *ctx)
+{
+       emit_hppa64_sext32(*rd, HPPA_REG_T2, ctx);
+       *rd = HPPA_REG_T2;
+       emit_hppa64_sext32(*rs, HPPA_REG_T1, ctx);
+       *rs = HPPA_REG_T1;
+}
+
+static void emit_zext_32_rd_t1(u8 *rd, struct hppa_jit_context *ctx)
+{
+       emit_hppa64_zext32(*rd, HPPA_REG_T2, ctx);
+       *rd = HPPA_REG_T2;
+       emit_zext_32(HPPA_REG_T1, ctx);
+}
+
+static void emit_sext_32_rd(u8 *rd, struct hppa_jit_context *ctx)
+{
+       emit_hppa64_sext32(*rd, HPPA_REG_T2, ctx);
+       *rd = HPPA_REG_T2;
+}
+
+static bool is_signed_bpf_cond(u8 cond)
+{
+       return cond == BPF_JSGT || cond == BPF_JSLT ||
+               cond == BPF_JSGE || cond == BPF_JSLE;
+}
+
+static void emit_call(u64 addr, bool fixed, struct hppa_jit_context *ctx)
+{
+       const int offset_sp = 2*FRAME_SIZE;
+
+       emit(hppa_ldo(offset_sp, HPPA_REG_SP, HPPA_REG_SP), ctx);
+
+       emit_hppa_copy(regmap[BPF_REG_1], HPPA_REG_ARG0, ctx);
+       emit_hppa_copy(regmap[BPF_REG_2], HPPA_REG_ARG1, ctx);
+       emit_hppa_copy(regmap[BPF_REG_3], HPPA_REG_ARG2, ctx);
+       emit_hppa_copy(regmap[BPF_REG_4], HPPA_REG_ARG3, ctx);
+       emit_hppa_copy(regmap[BPF_REG_5], HPPA_REG_ARG4, ctx);
+
+       /* Backup TCC. */
+       REG_FORCE_SEEN(ctx, HPPA_REG_TCC_SAVED);
+       if (REG_WAS_SEEN(ctx, HPPA_REG_TCC))
+               emit(hppa_copy(HPPA_REG_TCC, HPPA_REG_TCC_SAVED), ctx);
+
+       /*
+        * Use ldil() to load absolute address. Don't use emit_imm as the
+        * number of emitted instructions should not depend on the value of
+        * addr.
+        */
+       WARN_ON(addr >> 32);
+       /* load function address and gp from Elf64_Fdesc descriptor */
+       emit(hppa_ldil(addr, HPPA_REG_R31), ctx);
+       emit(hppa_ldo(im11(addr), HPPA_REG_R31, HPPA_REG_R31), ctx);
+       emit(hppa64_ldd_im16(offsetof(struct elf64_fdesc, addr),
+                            HPPA_REG_R31, HPPA_REG_RP), ctx);
+       emit(hppa64_bve_l_rp(HPPA_REG_RP), ctx);
+       emit(hppa64_ldd_im16(offsetof(struct elf64_fdesc, gp),
+                            HPPA_REG_R31, HPPA_REG_GP), ctx);
+
+       /* Restore TCC. */
+       if (REG_WAS_SEEN(ctx, HPPA_REG_TCC))
+               emit(hppa_copy(HPPA_REG_TCC_SAVED, HPPA_REG_TCC), ctx);
+
+       emit(hppa_ldo(-offset_sp, HPPA_REG_SP, HPPA_REG_SP), ctx);
+
+       /* Set return value. */
+       emit_hppa_copy(HPPA_REG_RET0, regmap[BPF_REG_0], ctx);
+}
+
+static void emit_call_libgcc_ll(void *func, const s8 arg0,
+               const s8 arg1, u8 opcode, struct hppa_jit_context *ctx)
+{
+       u64 func_addr;
+
+       if (BPF_CLASS(opcode) == BPF_ALU) {
+               emit_hppa64_zext32(arg0, HPPA_REG_ARG0, ctx);
+               emit_hppa64_zext32(arg1, HPPA_REG_ARG1, ctx);
+       } else {
+               emit_hppa_copy(arg0, HPPA_REG_ARG0, ctx);
+               emit_hppa_copy(arg1, HPPA_REG_ARG1, ctx);
+       }
+
+       /* libcgcc overwrites HPPA_REG_RET0, so keep copy in HPPA_REG_TCC_SAVED */
+       if (arg0 != HPPA_REG_RET0) {
+               REG_SET_SEEN(ctx, HPPA_REG_TCC_SAVED);
+               emit(hppa_copy(HPPA_REG_RET0, HPPA_REG_TCC_SAVED), ctx);
+       }
+
+       /* set up stack */
+       emit(hppa_ldo(FRAME_SIZE, HPPA_REG_SP, HPPA_REG_SP), ctx);
+
+       func_addr = (uintptr_t) func;
+       /* load function func_address and gp from Elf64_Fdesc descriptor */
+       emit_imm(HPPA_REG_R31, func_addr, arg0, ctx);
+       emit(hppa64_ldd_im16(offsetof(struct elf64_fdesc, addr),
+                            HPPA_REG_R31, HPPA_REG_RP), ctx);
+        /* skip the following bve_l instruction if divisor is 0. */
+        if (BPF_OP(opcode) == BPF_DIV || BPF_OP(opcode) == BPF_MOD) {
+               if (BPF_OP(opcode) == BPF_DIV)
+                       emit_hppa_copy(HPPA_REG_ZERO, HPPA_REG_RET0, ctx);
+               else {
+                       emit_hppa_copy(HPPA_REG_ARG0, HPPA_REG_RET0, ctx);
+               }
+               emit(hppa_beq(HPPA_REG_ARG1, HPPA_REG_ZERO, 2 - HPPA_BRANCH_DISPLACEMENT), ctx);
+       }
+       emit(hppa64_bve_l_rp(HPPA_REG_RP), ctx);
+       emit(hppa64_ldd_im16(offsetof(struct elf64_fdesc, gp),
+                            HPPA_REG_R31, HPPA_REG_GP), ctx);
+
+       emit(hppa_ldo(-FRAME_SIZE, HPPA_REG_SP, HPPA_REG_SP), ctx);
+
+       emit_hppa_copy(HPPA_REG_RET0, arg0, ctx);
+
+       /* restore HPPA_REG_RET0 */
+       if (arg0 != HPPA_REG_RET0)
+               emit(hppa_copy(HPPA_REG_TCC_SAVED, HPPA_REG_RET0), ctx);
+}
+
+static void emit_store(const s8 rd, const s8 rs, s16 off,
+                         struct hppa_jit_context *ctx, const u8 size,
+                         const u8 mode)
+{
+       s8 dstreg;
+
+       /* need to calculate address since offset does not fit in 14 bits? */
+       if (relative_bits_ok(off, 14))
+               dstreg = rd;
+       else {
+               /* need to use R1 here, since addil puts result into R1 */
+               dstreg = HPPA_REG_R1;
+               emit(hppa_addil(off, rd), ctx);
+               off = im11(off);
+       }
+
+       switch (size) {
+       case BPF_B:
+               emit(hppa_stb(rs, off, dstreg), ctx);
+               break;
+       case BPF_H:
+               emit(hppa_sth(rs, off, dstreg), ctx);
+               break;
+       case BPF_W:
+               emit(hppa_stw(rs, off, dstreg), ctx);
+               break;
+       case BPF_DW:
+               if (off & 7) {
+                       emit(hppa_ldo(off, dstreg, HPPA_REG_R1), ctx);
+                       emit(hppa64_std_im5(rs, 0, HPPA_REG_R1), ctx);
+               } else if (off >= -16 && off <= 15)
+                       emit(hppa64_std_im5(rs, off, dstreg), ctx);
+               else
+                       emit(hppa64_std_im16(rs, off, dstreg), ctx);
+               break;
+       }
+}
+
+int bpf_jit_emit_insn(const struct bpf_insn *insn, struct hppa_jit_context *ctx,
+                     bool extra_pass)
+{
+       bool is64 = BPF_CLASS(insn->code) == BPF_ALU64 ||
+                   BPF_CLASS(insn->code) == BPF_JMP;
+       int s, e, ret, i = insn - ctx->prog->insnsi;
+       s64 paoff;
+       struct bpf_prog_aux *aux = ctx->prog->aux;
+       u8 rd = -1, rs = -1, code = insn->code;
+       s16 off = insn->off;
+       s32 imm = insn->imm;
+
+       init_regs(&rd, &rs, insn, ctx);
+
+       switch (code) {
+       /* dst = src */
+       case BPF_ALU | BPF_MOV | BPF_X:
+       case BPF_ALU64 | BPF_MOV | BPF_X:
+               if (imm == 1) {
+                       /* Special mov32 for zext */
+                       emit_zext_32(rd, ctx);
+                       break;
+               }
+               if (!is64 && !aux->verifier_zext)
+                       emit_hppa64_zext32(rs, rd, ctx);
+               else
+                       emit_hppa_copy(rs, rd, ctx);
+               break;
+
+       /* dst = dst OP src */
+       case BPF_ALU | BPF_ADD | BPF_X:
+       case BPF_ALU64 | BPF_ADD | BPF_X:
+                emit(hppa_add(rd, rs, rd), ctx);
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_SUB | BPF_X:
+       case BPF_ALU64 | BPF_SUB | BPF_X:
+                emit(hppa_sub(rd, rs, rd), ctx);
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_AND | BPF_X:
+       case BPF_ALU64 | BPF_AND | BPF_X:
+                emit(hppa_and(rd, rs, rd), ctx);
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_OR | BPF_X:
+       case BPF_ALU64 | BPF_OR | BPF_X:
+                emit(hppa_or(rd, rs, rd), ctx);
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_XOR | BPF_X:
+       case BPF_ALU64 | BPF_XOR | BPF_X:
+                emit(hppa_xor(rd, rs, rd), ctx);
+               if (!is64 && !aux->verifier_zext && rs != rd)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_MUL | BPF_K:
+       case BPF_ALU64 | BPF_MUL | BPF_K:
+               emit_imm(HPPA_REG_T1, is64 ? (s64)(s32)imm : (u32)imm, HPPA_REG_T2, ctx);
+               rs = HPPA_REG_T1;
+               fallthrough;
+       case BPF_ALU | BPF_MUL | BPF_X:
+       case BPF_ALU64 | BPF_MUL | BPF_X:
+               emit_call_libgcc_ll(__muldi3, rd, rs, code, ctx);
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_DIV | BPF_K:
+       case BPF_ALU64 | BPF_DIV | BPF_K:
+               emit_imm(HPPA_REG_T1, is64 ? (s64)(s32)imm : (u32)imm, HPPA_REG_T2, ctx);
+               rs = HPPA_REG_T1;
+               fallthrough;
+       case BPF_ALU | BPF_DIV | BPF_X:
+       case BPF_ALU64 | BPF_DIV | BPF_X:
+               emit_call_libgcc_ll(&hppa_div64, rd, rs, code, ctx);
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_MOD | BPF_K:
+       case BPF_ALU64 | BPF_MOD | BPF_K:
+               emit_imm(HPPA_REG_T1, is64 ? (s64)(s32)imm : (u32)imm, HPPA_REG_T2, ctx);
+               rs = HPPA_REG_T1;
+               fallthrough;
+       case BPF_ALU | BPF_MOD | BPF_X:
+       case BPF_ALU64 | BPF_MOD | BPF_X:
+               emit_call_libgcc_ll(&hppa_div64_rem, rd, rs, code, ctx);
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+
+       case BPF_ALU | BPF_LSH | BPF_X:
+       case BPF_ALU64 | BPF_LSH | BPF_X:
+               emit_hppa64_sext32(rs, HPPA_REG_T0, ctx);
+               emit(hppa64_mtsarcm(HPPA_REG_T0), ctx);
+               if (is64)
+                       emit(hppa64_depdz_sar(rd, rd), ctx);
+               else
+                       emit(hppa_depwz_sar(rd, rd), ctx);
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_RSH | BPF_X:
+       case BPF_ALU64 | BPF_RSH | BPF_X:
+               emit(hppa_mtsar(rs), ctx);
+               if (is64)
+                       emit(hppa64_shrpd_sar(rd, rd), ctx);
+               else
+                       emit(hppa_shrpw_sar(rd, rd), ctx);
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_ARSH | BPF_X:
+       case BPF_ALU64 | BPF_ARSH | BPF_X:
+               emit_hppa64_sext32(rs, HPPA_REG_T0, ctx);
+                emit(hppa64_mtsarcm(HPPA_REG_T0), ctx);
+               if (is64)
+                       emit(hppa_extrd_sar(rd, rd, 1), ctx);
+               else
+                       emit(hppa_extrws_sar(rd, rd), ctx);
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+
+       /* dst = -dst */
+       case BPF_ALU | BPF_NEG:
+       case BPF_ALU64 | BPF_NEG:
+               emit(hppa_sub(HPPA_REG_ZERO, rd, rd), ctx);
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+
+       /* dst = BSWAP##imm(dst) */
+       case BPF_ALU | BPF_END | BPF_FROM_BE:
+               switch (imm) {
+               case 16:
+                       /* zero-extend 16 bits into 64 bits */
+                       emit_hppa64_depd(HPPA_REG_ZERO, 63-16, 64-16, rd, 1, ctx);
+                       break;
+               case 32:
+                       if (!aux->verifier_zext)
+                               emit_zext_32(rd, ctx);
+                       break;
+               case 64:
+                       /* Do nothing */
+                       break;
+               }
+               break;
+
+       case BPF_ALU | BPF_END | BPF_FROM_LE:
+               switch (imm) {
+               case 16:
+                       emit(hppa_extru(rd, 31 - 8, 8, HPPA_REG_T1), ctx);
+                       emit(hppa_depwz(rd, 23, 8, HPPA_REG_T1), ctx);
+                       emit(hppa_extru(HPPA_REG_T1, 31, 16, rd), ctx);
+                       emit_hppa64_extrd(HPPA_REG_T1, 63, 16, rd, 0, ctx);
+                       break;
+               case 32:
+                       emit(hppa_shrpw(rd, rd, 16, HPPA_REG_T1), ctx);
+                       emit_hppa64_depd(HPPA_REG_T1, 63-16, 8, HPPA_REG_T1, 1, ctx);
+                       emit(hppa_shrpw(rd, HPPA_REG_T1, 8, HPPA_REG_T1), ctx);
+                       emit_hppa64_extrd(HPPA_REG_T1, 63, 32, rd, 0, ctx);
+                       break;
+               case 64:
+                       emit(hppa64_permh_3210(rd, HPPA_REG_T1), ctx);
+                       emit(hppa64_hshl(HPPA_REG_T1, 8, HPPA_REG_T2), ctx);
+                       emit(hppa64_hshr_u(HPPA_REG_T1, 8, HPPA_REG_T1), ctx);
+                       emit(hppa_or(HPPA_REG_T2, HPPA_REG_T1, rd), ctx);
+                       break;
+               default:
+                       pr_err("bpf-jit: BPF_END imm %d invalid\n", imm);
+                       return -1;
+               }
+               break;
+
+       /* dst = imm */
+       case BPF_ALU | BPF_MOV | BPF_K:
+       case BPF_ALU64 | BPF_MOV | BPF_K:
+               emit_imm(rd, imm, HPPA_REG_T2, ctx);
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+
+       /* dst = dst OP imm */
+       case BPF_ALU | BPF_ADD | BPF_K:
+       case BPF_ALU64 | BPF_ADD | BPF_K:
+               if (relative_bits_ok(imm, 14)) {
+                       emit(hppa_ldo(imm, rd, rd), ctx);
+               } else {
+                       emit_imm(HPPA_REG_T1, imm, HPPA_REG_T2, ctx);
+                       emit(hppa_add(rd, HPPA_REG_T1, rd), ctx);
+               }
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_SUB | BPF_K:
+       case BPF_ALU64 | BPF_SUB | BPF_K:
+               if (relative_bits_ok(-imm, 14)) {
+                       emit(hppa_ldo(-imm, rd, rd), ctx);
+               } else {
+                       emit_imm(HPPA_REG_T1, imm, HPPA_REG_T2, ctx);
+                       emit(hppa_sub(rd, HPPA_REG_T1, rd), ctx);
+               }
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_AND | BPF_K:
+       case BPF_ALU64 | BPF_AND | BPF_K:
+               emit_imm(HPPA_REG_T1, imm, HPPA_REG_T2, ctx);
+                emit(hppa_and(rd, HPPA_REG_T1, rd), ctx);
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_OR | BPF_K:
+       case BPF_ALU64 | BPF_OR | BPF_K:
+               emit_imm(HPPA_REG_T1, imm, HPPA_REG_T2, ctx);
+                emit(hppa_or(rd, HPPA_REG_T1, rd), ctx);
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_XOR | BPF_K:
+       case BPF_ALU64 | BPF_XOR | BPF_K:
+               emit_imm(HPPA_REG_T1, imm, HPPA_REG_T2, ctx);
+                emit(hppa_xor(rd, HPPA_REG_T1, rd), ctx);
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_LSH | BPF_K:
+       case BPF_ALU64 | BPF_LSH | BPF_K:
+               if (imm != 0) {
+                       emit_hppa64_shld(rd, imm, rd, ctx);
+               }
+
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_RSH | BPF_K:
+       case BPF_ALU64 | BPF_RSH | BPF_K:
+               if (imm != 0) {
+                       if (is64)
+                               emit_hppa64_shrd(rd, imm, rd, false, ctx);
+                       else
+                               emit_hppa64_shrw(rd, imm, rd, false, ctx);
+               }
+
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+       case BPF_ALU | BPF_ARSH | BPF_K:
+       case BPF_ALU64 | BPF_ARSH | BPF_K:
+               if (imm != 0) {
+                       if (is64)
+                               emit_hppa64_shrd(rd, imm, rd, true, ctx);
+                       else
+                               emit_hppa64_shrw(rd, imm, rd, true, ctx);
+               }
+
+               if (!is64 && !aux->verifier_zext)
+                       emit_zext_32(rd, ctx);
+               break;
+
+       /* JUMP off */
+       case BPF_JMP | BPF_JA:
+               paoff = hppa_offset(i, off, ctx);
+               ret = emit_jump(paoff, false, ctx);
+               if (ret)
+                       return ret;
+               break;
+
+       /* IF (dst COND src) JUMP off */
+       case BPF_JMP | BPF_JEQ | BPF_X:
+       case BPF_JMP32 | BPF_JEQ | BPF_X:
+       case BPF_JMP | BPF_JGT | BPF_X:
+       case BPF_JMP32 | BPF_JGT | BPF_X:
+       case BPF_JMP | BPF_JLT | BPF_X:
+       case BPF_JMP32 | BPF_JLT | BPF_X:
+       case BPF_JMP | BPF_JGE | BPF_X:
+       case BPF_JMP32 | BPF_JGE | BPF_X:
+       case BPF_JMP | BPF_JLE | BPF_X:
+       case BPF_JMP32 | BPF_JLE | BPF_X:
+       case BPF_JMP | BPF_JNE | BPF_X:
+       case BPF_JMP32 | BPF_JNE | BPF_X:
+       case BPF_JMP | BPF_JSGT | BPF_X:
+       case BPF_JMP32 | BPF_JSGT | BPF_X:
+       case BPF_JMP | BPF_JSLT | BPF_X:
+       case BPF_JMP32 | BPF_JSLT | BPF_X:
+       case BPF_JMP | BPF_JSGE | BPF_X:
+       case BPF_JMP32 | BPF_JSGE | BPF_X:
+       case BPF_JMP | BPF_JSLE | BPF_X:
+       case BPF_JMP32 | BPF_JSLE | BPF_X:
+       case BPF_JMP | BPF_JSET | BPF_X:
+       case BPF_JMP32 | BPF_JSET | BPF_X:
+               paoff = hppa_offset(i, off, ctx);
+               if (!is64) {
+                       s = ctx->ninsns;
+                       if (is_signed_bpf_cond(BPF_OP(code)))
+                               emit_sext_32_rd_rs(&rd, &rs, ctx);
+                       else
+                               emit_zext_32_rd_rs(&rd, &rs, ctx);
+                       e = ctx->ninsns;
+
+                       /* Adjust for extra insns */
+                       paoff -= (e - s);
+               }
+               if (BPF_OP(code) == BPF_JSET) {
+                       /* Adjust for and */
+                       paoff -= 1;
+                       emit(hppa_and(rs, rd, HPPA_REG_T1), ctx);
+                       emit_branch(BPF_JNE, HPPA_REG_T1, HPPA_REG_ZERO, paoff,
+                                   ctx);
+               } else {
+                       emit_branch(BPF_OP(code), rd, rs, paoff, ctx);
+               }
+               break;
+
+       /* IF (dst COND imm) JUMP off */
+       case BPF_JMP | BPF_JEQ | BPF_K:
+       case BPF_JMP32 | BPF_JEQ | BPF_K:
+       case BPF_JMP | BPF_JGT | BPF_K:
+       case BPF_JMP32 | BPF_JGT | BPF_K:
+       case BPF_JMP | BPF_JLT | BPF_K:
+       case BPF_JMP32 | BPF_JLT | BPF_K:
+       case BPF_JMP | BPF_JGE | BPF_K:
+       case BPF_JMP32 | BPF_JGE | BPF_K:
+       case BPF_JMP | BPF_JLE | BPF_K:
+       case BPF_JMP32 | BPF_JLE | BPF_K:
+       case BPF_JMP | BPF_JNE | BPF_K:
+       case BPF_JMP32 | BPF_JNE | BPF_K:
+       case BPF_JMP | BPF_JSGT | BPF_K:
+       case BPF_JMP32 | BPF_JSGT | BPF_K:
+       case BPF_JMP | BPF_JSLT | BPF_K:
+       case BPF_JMP32 | BPF_JSLT | BPF_K:
+       case BPF_JMP | BPF_JSGE | BPF_K:
+       case BPF_JMP32 | BPF_JSGE | BPF_K:
+       case BPF_JMP | BPF_JSLE | BPF_K:
+       case BPF_JMP32 | BPF_JSLE | BPF_K:
+               paoff = hppa_offset(i, off, ctx);
+               s = ctx->ninsns;
+               if (imm) {
+                       emit_imm(HPPA_REG_T1, imm, HPPA_REG_T2, ctx);
+                       rs = HPPA_REG_T1;
+               } else {
+                       rs = HPPA_REG_ZERO;
+               }
+               if (!is64) {
+                       if (is_signed_bpf_cond(BPF_OP(code)))
+                               emit_sext_32_rd(&rd, ctx);
+                       else
+                               emit_zext_32_rd_t1(&rd, ctx);
+               }
+               e = ctx->ninsns;
+
+               /* Adjust for extra insns */
+               paoff -= (e - s);
+               emit_branch(BPF_OP(code), rd, rs, paoff, ctx);
+               break;
+       case BPF_JMP | BPF_JSET | BPF_K:
+       case BPF_JMP32 | BPF_JSET | BPF_K:
+               paoff = hppa_offset(i, off, ctx);
+               s = ctx->ninsns;
+               emit_imm(HPPA_REG_T1, imm, HPPA_REG_T2, ctx);
+               emit(hppa_and(HPPA_REG_T1, rd, HPPA_REG_T1), ctx);
+               /* For jset32, we should clear the upper 32 bits of t1, but
+                * sign-extension is sufficient here and saves one instruction,
+                * as t1 is used only in comparison against zero.
+                */
+               if (!is64 && imm < 0)
+                       emit_hppa64_sext32(HPPA_REG_T1, HPPA_REG_T1, ctx);
+               e = ctx->ninsns;
+               paoff -= (e - s);
+               emit_branch(BPF_JNE, HPPA_REG_T1, HPPA_REG_ZERO, paoff, ctx);
+               break;
+       /* function call */
+       case BPF_JMP | BPF_CALL:
+       {
+               bool fixed_addr;
+               u64 addr;
+
+               ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass,
+                                           &addr, &fixed_addr);
+               if (ret < 0)
+                       return ret;
+
+               REG_SET_SEEN_ALL(ctx);
+               emit_call(addr, fixed_addr, ctx);
+               break;
+       }
+       /* tail call */
+       case BPF_JMP | BPF_TAIL_CALL:
+               emit_bpf_tail_call(i, ctx);
+               break;
+
+       /* function return */
+       case BPF_JMP | BPF_EXIT:
+               if (i == ctx->prog->len - 1)
+                       break;
+
+               paoff = epilogue_offset(ctx);
+               ret = emit_jump(paoff, false, ctx);
+               if (ret)
+                       return ret;
+               break;
+
+       /* dst = imm64 */
+       case BPF_LD | BPF_IMM | BPF_DW:
+       {
+               struct bpf_insn insn1 = insn[1];
+               u64 imm64 = (u64)insn1.imm << 32 | (u32)imm;
+               if (bpf_pseudo_func(insn))
+                       imm64 = (uintptr_t)dereference_function_descriptor((void*)imm64);
+               emit_imm(rd, imm64, HPPA_REG_T2, ctx);
+
+               return 1;
+       }
+
+       /* LDX: dst = *(size *)(src + off) */
+       case BPF_LDX | BPF_MEM | BPF_B:
+       case BPF_LDX | BPF_MEM | BPF_H:
+       case BPF_LDX | BPF_MEM | BPF_W:
+       case BPF_LDX | BPF_MEM | BPF_DW:
+       case BPF_LDX | BPF_PROBE_MEM | BPF_B:
+       case BPF_LDX | BPF_PROBE_MEM | BPF_H:
+       case BPF_LDX | BPF_PROBE_MEM | BPF_W:
+       case BPF_LDX | BPF_PROBE_MEM | BPF_DW:
+       {
+               u8 srcreg;
+
+               /* need to calculate address since offset does not fit in 14 bits? */
+               if (relative_bits_ok(off, 14))
+                       srcreg = rs;
+               else {
+                       /* need to use R1 here, since addil puts result into R1 */
+                       srcreg = HPPA_REG_R1;
+                       BUG_ON(rs == HPPA_REG_R1);
+                       BUG_ON(rd == HPPA_REG_R1);
+                       emit(hppa_addil(off, rs), ctx);
+                       off = im11(off);
+               }
+
+               switch (BPF_SIZE(code)) {
+               case BPF_B:
+                       emit(hppa_ldb(off, srcreg, rd), ctx);
+                       if (insn_is_zext(&insn[1]))
+                               return 1;
+                       break;
+               case BPF_H:
+                       emit(hppa_ldh(off, srcreg, rd), ctx);
+                       if (insn_is_zext(&insn[1]))
+                               return 1;
+                       break;
+               case BPF_W:
+                       emit(hppa_ldw(off, srcreg, rd), ctx);
+                       if (insn_is_zext(&insn[1]))
+                               return 1;
+                       break;
+               case BPF_DW:
+                       if (off & 7) {
+                               emit(hppa_ldo(off, srcreg, HPPA_REG_R1), ctx);
+                               emit(hppa64_ldd_reg(HPPA_REG_ZERO, HPPA_REG_R1, rd), ctx);
+                       } else if (off >= -16 && off <= 15)
+                               emit(hppa64_ldd_im5(off, srcreg, rd), ctx);
+                       else
+                               emit(hppa64_ldd_im16(off, srcreg, rd), ctx);
+                       break;
+               }
+               break;
+       }
+       /* speculation barrier */
+       case BPF_ST | BPF_NOSPEC:
+               break;
+
+       /* ST: *(size *)(dst + off) = imm */
+       /* STX: *(size *)(dst + off) = src */
+       case BPF_ST | BPF_MEM | BPF_B:
+       case BPF_ST | BPF_MEM | BPF_H:
+       case BPF_ST | BPF_MEM | BPF_W:
+       case BPF_ST | BPF_MEM | BPF_DW:
+
+       case BPF_STX | BPF_MEM | BPF_B:
+       case BPF_STX | BPF_MEM | BPF_H:
+       case BPF_STX | BPF_MEM | BPF_W:
+       case BPF_STX | BPF_MEM | BPF_DW:
+               if (BPF_CLASS(code) == BPF_ST) {
+                       emit_imm(HPPA_REG_T2, imm, HPPA_REG_T1, ctx);
+                       rs = HPPA_REG_T2;
+               }
+
+               emit_store(rd, rs, off, ctx, BPF_SIZE(code), BPF_MODE(code));
+               break;
+
+       case BPF_STX | BPF_ATOMIC | BPF_W:
+       case BPF_STX | BPF_ATOMIC | BPF_DW:
+               pr_info_once(
+                       "bpf-jit: not supported: atomic operation %02x ***\n",
+                       insn->imm);
+               return -EFAULT;
+
+       default:
+               pr_err("bpf-jit: unknown opcode %02x\n", code);
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+void bpf_jit_build_prologue(struct hppa_jit_context *ctx)
+{
+       int bpf_stack_adjust, stack_adjust, i;
+       unsigned long addr;
+       s8 reg;
+
+       /*
+        * stack on hppa grows up, so if tail calls are used we need to
+        * allocate the maximum stack size
+        */
+       if (REG_ALL_SEEN(ctx))
+               bpf_stack_adjust = MAX_BPF_STACK;
+       else
+               bpf_stack_adjust = ctx->prog->aux->stack_depth;
+       bpf_stack_adjust = round_up(bpf_stack_adjust, STACK_ALIGN);
+
+       stack_adjust = FRAME_SIZE + bpf_stack_adjust;
+       stack_adjust = round_up(stack_adjust, STACK_ALIGN);
+
+       /*
+        * NOTE: We construct an Elf64_Fdesc descriptor here.
+        * The first 4 words initialize the TCC and compares them.
+        * Then follows the virtual address of the eBPF function,
+        * and the gp for this function.
+        *
+        * The first instruction sets the tail-call-counter (TCC) register.
+        * This instruction is skipped by tail calls.
+        * Use a temporary register instead of a caller-saved register initially.
+        */
+       REG_FORCE_SEEN(ctx, HPPA_REG_TCC_IN_INIT);
+       emit(hppa_ldi(MAX_TAIL_CALL_CNT, HPPA_REG_TCC_IN_INIT), ctx);
+
+       /*
+        * Skip all initializations when called as BPF TAIL call.
+        */
+       emit(hppa_ldi(MAX_TAIL_CALL_CNT, HPPA_REG_R1), ctx);
+       emit(hppa_beq(HPPA_REG_TCC_IN_INIT, HPPA_REG_R1, 6 - HPPA_BRANCH_DISPLACEMENT), ctx);
+       emit(hppa64_bl_long(ctx->prologue_len - 3 - HPPA_BRANCH_DISPLACEMENT), ctx);
+
+       /* store entry address of this eBPF function */
+       addr = (uintptr_t) &ctx->insns[0];
+       emit(addr >> 32, ctx);
+       emit(addr & 0xffffffff, ctx);
+
+       /* store gp of this eBPF function */
+       asm("copy %%r27,%0" : "=r" (addr) );
+       emit(addr >> 32, ctx);
+       emit(addr & 0xffffffff, ctx);
+
+       /* Set up hppa stack frame. */
+       emit_hppa_copy(HPPA_REG_SP, HPPA_REG_R1, ctx);
+       emit(hppa_ldo(stack_adjust, HPPA_REG_SP, HPPA_REG_SP), ctx);
+       emit(hppa64_std_im5 (HPPA_REG_R1, -REG_SIZE, HPPA_REG_SP), ctx);
+       emit(hppa64_std_im16(HPPA_REG_RP, -2*REG_SIZE, HPPA_REG_SP), ctx);
+
+       /* Save callee-save registers. */
+       for (i = 3; i <= 15; i++) {
+               if (OPTIMIZE_HPPA && !REG_WAS_SEEN(ctx, HPPA_R(i)))
+                       continue;
+               emit(hppa64_std_im16(HPPA_R(i), -REG_SIZE * i, HPPA_REG_SP), ctx);
+       }
+
+       /* load function parameters; load all if we use tail functions */
+       #define LOAD_PARAM(arg, dst) \
+               if (REG_WAS_SEEN(ctx, regmap[dst]) ||   \
+                   REG_WAS_SEEN(ctx, HPPA_REG_TCC))    \
+                       emit_hppa_copy(arg, regmap[dst], ctx)
+       LOAD_PARAM(HPPA_REG_ARG0, BPF_REG_1);
+       LOAD_PARAM(HPPA_REG_ARG1, BPF_REG_2);
+       LOAD_PARAM(HPPA_REG_ARG2, BPF_REG_3);
+       LOAD_PARAM(HPPA_REG_ARG3, BPF_REG_4);
+       LOAD_PARAM(HPPA_REG_ARG4, BPF_REG_5);
+       #undef LOAD_PARAM
+
+       REG_FORCE_SEEN(ctx, HPPA_REG_T0);
+       REG_FORCE_SEEN(ctx, HPPA_REG_T1);
+       REG_FORCE_SEEN(ctx, HPPA_REG_T2);
+
+       /*
+        * Now really set the tail call counter (TCC) register.
+        */
+       if (REG_WAS_SEEN(ctx, HPPA_REG_TCC))
+               emit(hppa_ldi(MAX_TAIL_CALL_CNT, HPPA_REG_TCC), ctx);
+
+       /*
+        * Save epilogue function pointer for outer TCC call chain.
+        * The main TCC call stores the final RP on stack.
+        */
+       addr = (uintptr_t) &ctx->insns[ctx->epilogue_offset];
+       /* skip first two instructions which jump to exit */
+       addr += 2 * HPPA_INSN_SIZE;
+       emit_imm(HPPA_REG_T2, addr, HPPA_REG_T1, ctx);
+       emit(EXIT_PTR_STORE(HPPA_REG_T2), ctx);
+
+       /* Set up BPF frame pointer. */
+       reg = regmap[BPF_REG_FP];       /* -> HPPA_REG_FP */
+       if (REG_WAS_SEEN(ctx, reg)) {
+               emit(hppa_ldo(-FRAME_SIZE, HPPA_REG_SP, reg), ctx);
+       }
+}
+
+void bpf_jit_build_epilogue(struct hppa_jit_context *ctx)
+{
+       __build_epilogue(false, ctx);
+}
+
+bool bpf_jit_supports_kfunc_call(void)
+{
+       return true;
+}