Merge tag 'mips_5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

Pull MIPS updates from Paul Burton:

 - A set of memblock initialization improvements thanks to Serge Semin,
   tidying up after our conversion from bootmem to memblock back in
   v4.20.

 - Our eBPF JIT the previously supported only MIPS64r2 through MIPS64r5
   is improved to also support MIPS64r6. Support for MIPS32 systems is
   introduced, with the caveat that it only works for programs that
   don't use 64 bit registers or operations - those will bail out & need
   to be interpreted.

 - Improvements to the allocation & configuration of our exception
   vector that should fix issues seen on some platforms using recent
   versions of U-Boot.

 - Some minor improvements to code generated for jump labels, along with
   enabling them by default for generic kernels.

* tag 'mips_5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (27 commits)
  mips: Manually call fdt_init_reserved_mem() method
  mips: Make sure dt memory regions are valid
  mips: Perform early low memory test
  mips: Dump memblock regions for debugging
  mips: Add reserve-nomap memory type support
  mips: Use memblock to reserve the __nosave memory range
  mips: Discard post-CMA-init foreach loop
  mips: Reserve memory for the kernel image resources
  MIPS: Remove duplicate EBase configuration
  MIPS: Sync icache for whole exception vector
  MIPS: Always allocate exception vector for MIPSr2+
  MIPS: Use memblock_phys_alloc() for exception vector
  mips: Combine memblock init and memory reservation loops
  mips: Discard rudiments from bootmem_init
  mips: Make sure kernel .bss exists in boot mem pool
  mips: vdso: drop unnecessary cc-ldoption
  Revert "MIPS: ralink: fix cpu clock of mt7621 and add dt clk devices"
  MIPS: generic: Enable CONFIG_JUMP_LABEL
  MIPS: jump_label: Use compact branches for >= r6
  MIPS: jump_label: Remove redundant nops
  ...

4 files changed, 138 insertions, 1609 deletions

diff --git a/arch/mips/net/Makefile b/arch/mips/net/Makefile
index 47d678416715..72a78462f872 100644
--- a/arch/mips/net/Makefile
+++ b/arch/mips/net/Makefile
@@ -1,4 +1,3 @@
 # MIPS networking code
 
-obj-$(CONFIG_MIPS_CBPF_JIT) += bpf_jit.o bpf_jit_asm.o
 obj-$(CONFIG_MIPS_EBPF_JIT) += ebpf_jit.o
diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c
deleted file mode 100644
index 3a0e34f4e615..000000000000
--- a/arch/mips/net/bpf_jit.c
+++ /dev/null
@@ -1,1270 +0,0 @@
-/*
- * Just-In-Time compiler for BPF filters on MIPS
- *
- * Copyright (c) 2014 Imagination Technologies Ltd.
- * Author: Markos Chandras <markos.chandras@imgtec.com>
- *
- * 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.
- */
-
-#include <linux/bitops.h>
-#include <linux/compiler.h>
-#include <linux/errno.h>
-#include <linux/filter.h>
-#include <linux/if_vlan.h>
-#include <linux/moduleloader.h>
-#include <linux/netdevice.h>
-#include <linux/string.h>
-#include <linux/slab.h>
-#include <linux/types.h>
-#include <asm/asm.h>
-#include <asm/bitops.h>
-#include <asm/cacheflush.h>
-#include <asm/cpu-features.h>
-#include <asm/uasm.h>
-
-#include "bpf_jit.h"
-
-/* ABI
- * r_skb_hl	SKB header length
- * r_data	SKB data pointer
- * r_off	Offset
- * r_A		BPF register A
- * r_X		BPF register X
- * r_skb	*skb
- * r_M		*scratch memory
- * r_skb_len	SKB length
- *
- * On entry (*bpf_func)(*skb, *filter)
- * a0 = MIPS_R_A0 = skb;
- * a1 = MIPS_R_A1 = filter;
- *
- * Stack
- * ...
- * M[15]
- * M[14]
- * M[13]
- * ...
- * M[0] <-- r_M
- * saved reg k-1
- * saved reg k-2
- * ...
- * saved reg 0 <-- r_sp
- * <no argument area>
- *
- *                     Packet layout
- *
- * <--------------------- len ------------------------>
- * <--skb-len(r_skb_hl)-->< ----- skb->data_len ------>
- * ----------------------------------------------------
- * |                  skb->data                       |
- * ----------------------------------------------------
- */
-
-#define ptr typeof(unsigned long)
-
-#define SCRATCH_OFF(k)		(4 * (k))
-
-/* JIT flags */
-#define SEEN_CALL		(1 << BPF_MEMWORDS)
-#define SEEN_SREG_SFT		(BPF_MEMWORDS + 1)
-#define SEEN_SREG_BASE		(1 << SEEN_SREG_SFT)
-#define SEEN_SREG(x)		(SEEN_SREG_BASE << (x))
-#define SEEN_OFF		SEEN_SREG(2)
-#define SEEN_A			SEEN_SREG(3)
-#define SEEN_X			SEEN_SREG(4)
-#define SEEN_SKB		SEEN_SREG(5)
-#define SEEN_MEM		SEEN_SREG(6)
-/* SEEN_SK_DATA also implies skb_hl an skb_len */
-#define SEEN_SKB_DATA		(SEEN_SREG(7) | SEEN_SREG(1) | SEEN_SREG(0))
-
-/* Arguments used by JIT */
-#define ARGS_USED_BY_JIT	2 /* only applicable to 64-bit */
-
-#define SBIT(x)			(1 << (x)) /* Signed version of BIT() */
-
-/**
- * struct jit_ctx - JIT context
- * @skf:		The sk_filter
- * @prologue_bytes:	Number of bytes for prologue
- * @idx:		Instruction index
- * @flags:		JIT flags
- * @offsets:		Instruction offsets
- * @target:		Memory location for the compiled filter
- */
-struct jit_ctx {
-	const struct bpf_prog *skf;
-	unsigned int prologue_bytes;
-	u32 idx;
-	u32 flags;
-	u32 *offsets;
-	u32 *target;
-};
-
-
-static inline int optimize_div(u32 *k)
-{
-	/* power of 2 divides can be implemented with right shift */
-	if (!(*k & (*k-1))) {
-		*k = ilog2(*k);
-		return 1;
-	}
-
-	return 0;
-}
-
-static inline void emit_jit_reg_move(ptr dst, ptr src, struct jit_ctx *ctx);
-
-/* Simply emit the instruction if the JIT memory space has been allocated */
-#define emit_instr(ctx, func, ...)			\
-do {							\
-	if ((ctx)->target != NULL) {			\
-		u32 *p = &(ctx)->target[ctx->idx];	\
-		uasm_i_##func(&p, ##__VA_ARGS__);	\
-	}						\
-	(ctx)->idx++;					\
-} while (0)
-
-/*
- * Similar to emit_instr but it must be used when we need to emit
- * 32-bit or 64-bit instructions
- */
-#define emit_long_instr(ctx, func, ...)			\
-do {							\
-	if ((ctx)->target != NULL) {			\
-		u32 *p = &(ctx)->target[ctx->idx];	\
-		UASM_i_##func(&p, ##__VA_ARGS__);	\
-	}						\
-	(ctx)->idx++;					\
-} while (0)
-
-/* Determine if immediate is within the 16-bit signed range */
-static inline bool is_range16(s32 imm)
-{
-	return !(imm >= SBIT(15) || imm < -SBIT(15));
-}
-
-static inline void emit_addu(unsigned int dst, unsigned int src1,
-			     unsigned int src2, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, addu, dst, src1, src2);
-}
-
-static inline void emit_nop(struct jit_ctx *ctx)
-{
-	emit_instr(ctx, nop);
-}
-
-/* Load a u32 immediate to a register */
-static inline void emit_load_imm(unsigned int dst, u32 imm, struct jit_ctx *ctx)
-{
-	if (ctx->target != NULL) {
-		/* addiu can only handle s16 */
-		if (!is_range16(imm)) {
-			u32 *p = &ctx->target[ctx->idx];
-			uasm_i_lui(&p, r_tmp_imm, (s32)imm >> 16);
-			p = &ctx->target[ctx->idx + 1];
-			uasm_i_ori(&p, dst, r_tmp_imm, imm & 0xffff);
-		} else {
-			u32 *p = &ctx->target[ctx->idx];
-			uasm_i_addiu(&p, dst, r_zero, imm);
-		}
-	}
-	ctx->idx++;
-
-	if (!is_range16(imm))
-		ctx->idx++;
-}
-
-static inline void emit_or(unsigned int dst, unsigned int src1,
-			   unsigned int src2, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, or, dst, src1, src2);
-}
-
-static inline void emit_ori(unsigned int dst, unsigned src, u32 imm,
-			    struct jit_ctx *ctx)
-{
-	if (imm >= BIT(16)) {
-		emit_load_imm(r_tmp, imm, ctx);
-		emit_or(dst, src, r_tmp, ctx);
-	} else {
-		emit_instr(ctx, ori, dst, src, imm);
-	}
-}
-
-static inline void emit_daddiu(unsigned int dst, unsigned int src,
-			       int imm, struct jit_ctx *ctx)
-{
-	/*
-	 * Only used for stack, so the imm is relatively small
-	 * and it fits in 15-bits
-	 */
-	emit_instr(ctx, daddiu, dst, src, imm);
-}
-
-static inline void emit_addiu(unsigned int dst, unsigned int src,
-			      u32 imm, struct jit_ctx *ctx)
-{
-	if (!is_range16(imm)) {
-		emit_load_imm(r_tmp, imm, ctx);
-		emit_addu(dst, r_tmp, src, ctx);
-	} else {
-		emit_instr(ctx, addiu, dst, src, imm);
-	}
-}
-
-static inline void emit_and(unsigned int dst, unsigned int src1,
-			    unsigned int src2, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, and, dst, src1, src2);
-}
-
-static inline void emit_andi(unsigned int dst, unsigned int src,
-			     u32 imm, struct jit_ctx *ctx)
-{
-	/* If imm does not fit in u16 then load it to register */
-	if (imm >= BIT(16)) {
-		emit_load_imm(r_tmp, imm, ctx);
-		emit_and(dst, src, r_tmp, ctx);
-	} else {
-		emit_instr(ctx, andi, dst, src, imm);
-	}
-}
-
-static inline void emit_xor(unsigned int dst, unsigned int src1,
-			    unsigned int src2, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, xor, dst, src1, src2);
-}
-
-static inline void emit_xori(ptr dst, ptr src, u32 imm, struct jit_ctx *ctx)
-{
-	/* If imm does not fit in u16 then load it to register */
-	if (imm >= BIT(16)) {
-		emit_load_imm(r_tmp, imm, ctx);
-		emit_xor(dst, src, r_tmp, ctx);
-	} else {
-		emit_instr(ctx, xori, dst, src, imm);
-	}
-}
-
-static inline void emit_stack_offset(int offset, struct jit_ctx *ctx)
-{
-	emit_long_instr(ctx, ADDIU, r_sp, r_sp, offset);
-}
-
-static inline void emit_subu(unsigned int dst, unsigned int src1,
-			     unsigned int src2, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, subu, dst, src1, src2);
-}
-
-static inline void emit_neg(unsigned int reg, struct jit_ctx *ctx)
-{
-	emit_subu(reg, r_zero, reg, ctx);
-}
-
-static inline void emit_sllv(unsigned int dst, unsigned int src,
-			     unsigned int sa, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, sllv, dst, src, sa);
-}
-
-static inline void emit_sll(unsigned int dst, unsigned int src,
-			    unsigned int sa, struct jit_ctx *ctx)
-{
-	/* sa is 5-bits long */
-	if (sa >= BIT(5))
-		/* Shifting >= 32 results in zero */
-		emit_jit_reg_move(dst, r_zero, ctx);
-	else
-		emit_instr(ctx, sll, dst, src, sa);
-}
-
-static inline void emit_srlv(unsigned int dst, unsigned int src,
-			     unsigned int sa, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, srlv, dst, src, sa);
-}
-
-static inline void emit_srl(unsigned int dst, unsigned int src,
-			    unsigned int sa, struct jit_ctx *ctx)
-{
-	/* sa is 5-bits long */
-	if (sa >= BIT(5))
-		/* Shifting >= 32 results in zero */
-		emit_jit_reg_move(dst, r_zero, ctx);
-	else
-		emit_instr(ctx, srl, dst, src, sa);
-}
-
-static inline void emit_slt(unsigned int dst, unsigned int src1,
-			    unsigned int src2, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, slt, dst, src1, src2);
-}
-
-static inline void emit_sltu(unsigned int dst, unsigned int src1,
-			     unsigned int src2, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, sltu, dst, src1, src2);
-}
-
-static inline void emit_sltiu(unsigned dst, unsigned int src,
-			      unsigned int imm, struct jit_ctx *ctx)
-{
-	/* 16 bit immediate */
-	if (!is_range16((s32)imm)) {
-		emit_load_imm(r_tmp, imm, ctx);
-		emit_sltu(dst, src, r_tmp, ctx);
-	} else {
-		emit_instr(ctx, sltiu, dst, src, imm);
-	}
-
-}
-
-/* Store register on the stack */
-static inline void emit_store_stack_reg(ptr reg, ptr base,
-					unsigned int offset,
-					struct jit_ctx *ctx)
-{
-	emit_long_instr(ctx, SW, reg, offset, base);
-}
-
-static inline void emit_store(ptr reg, ptr base, unsigned int offset,
-			      struct jit_ctx *ctx)
-{
-	emit_instr(ctx, sw, reg, offset, base);
-}
-
-static inline void emit_load_stack_reg(ptr reg, ptr base,
-				       unsigned int offset,
-				       struct jit_ctx *ctx)
-{
-	emit_long_instr(ctx, LW, reg, offset, base);
-}
-
-static inline void emit_load(unsigned int reg, unsigned int base,
-			     unsigned int offset, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, lw, reg, offset, base);
-}
-
-static inline void emit_load_byte(unsigned int reg, unsigned int base,
-				  unsigned int offset, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, lb, reg, offset, base);
-}
-
-static inline void emit_half_load(unsigned int reg, unsigned int base,
-				  unsigned int offset, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, lh, reg, offset, base);
-}
-
-static inline void emit_half_load_unsigned(unsigned int reg, unsigned int base,
-					   unsigned int offset, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, lhu, reg, offset, base);
-}
-
-static inline void emit_mul(unsigned int dst, unsigned int src1,
-			    unsigned int src2, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, mul, dst, src1, src2);
-}
-
-static inline void emit_div(unsigned int dst, unsigned int src,
-			    struct jit_ctx *ctx)
-{
-	if (ctx->target != NULL) {
-		u32 *p = &ctx->target[ctx->idx];
-		uasm_i_divu(&p, dst, src);
-		p = &ctx->target[ctx->idx + 1];
-		uasm_i_mflo(&p, dst);
-	}
-	ctx->idx += 2; /* 2 insts */
-}
-
-static inline void emit_mod(unsigned int dst, unsigned int src,
-			    struct jit_ctx *ctx)
-{
-	if (ctx->target != NULL) {
-		u32 *p = &ctx->target[ctx->idx];
-		uasm_i_divu(&p, dst, src);
-		p = &ctx->target[ctx->idx + 1];
-		uasm_i_mfhi(&p, dst);
-	}
-	ctx->idx += 2; /* 2 insts */
-}
-
-static inline void emit_dsll(unsigned int dst, unsigned int src,
-			     unsigned int sa, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, dsll, dst, src, sa);
-}
-
-static inline void emit_dsrl32(unsigned int dst, unsigned int src,
-			       unsigned int sa, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, dsrl32, dst, src, sa);
-}
-
-static inline void emit_wsbh(unsigned int dst, unsigned int src,
-			     struct jit_ctx *ctx)
-{
-	emit_instr(ctx, wsbh, dst, src);
-}
-
-/* load pointer to register */
-static inline void emit_load_ptr(unsigned int dst, unsigned int src,
-				     int imm, struct jit_ctx *ctx)
-{
-	/* src contains the base addr of the 32/64-pointer */
-	emit_long_instr(ctx, LW, dst, imm, src);
-}
-
-/* load a function pointer to register */
-static inline void emit_load_func(unsigned int reg, ptr imm,
-				  struct jit_ctx *ctx)
-{
-	if (IS_ENABLED(CONFIG_64BIT)) {
-		/* At this point imm is always 64-bit */
-		emit_load_imm(r_tmp, (u64)imm >> 32, ctx);
-		emit_dsll(r_tmp_imm, r_tmp, 16, ctx); /* left shift by 16 */
-		emit_ori(r_tmp, r_tmp_imm, (imm >> 16) & 0xffff, ctx);
-		emit_dsll(r_tmp_imm, r_tmp, 16, ctx); /* left shift by 16 */
-		emit_ori(reg, r_tmp_imm, imm & 0xffff, ctx);
-	} else {
-		emit_load_imm(reg, imm, ctx);
-	}
-}
-
-/* Move to real MIPS register */
-static inline void emit_reg_move(ptr dst, ptr src, struct jit_ctx *ctx)
-{
-	emit_long_instr(ctx, ADDU, dst, src, r_zero);
-}
-
-/* Move to JIT (32-bit) register */
-static inline void emit_jit_reg_move(ptr dst, ptr src, struct jit_ctx *ctx)
-{
-	emit_addu(dst, src, r_zero, ctx);
-}
-
-/* Compute the immediate value for PC-relative branches. */
-static inline u32 b_imm(unsigned int tgt, struct jit_ctx *ctx)
-{
-	if (ctx->target == NULL)
-		return 0;
-
-	/*
-	 * We want a pc-relative branch. We only do forward branches
-	 * so tgt is always after pc. tgt is the instruction offset
-	 * we want to jump to.
-
-	 * Branch on MIPS:
-	 * I: target_offset <- sign_extend(offset)
-	 * I+1: PC += target_offset (delay slot)
-	 *
-	 * ctx->idx currently points to the branch instruction
-	 * but the offset is added to the delay slot so we need
-	 * to subtract 4.
-	 */
-	return ctx->offsets[tgt] -
-		(ctx->idx * 4 - ctx->prologue_bytes) - 4;
-}
-
-static inline void emit_bcond(int cond, unsigned int reg1, unsigned int reg2,
-			     unsigned int imm, struct jit_ctx *ctx)
-{
-	if (ctx->target != NULL) {
-		u32 *p = &ctx->target[ctx->idx];
-
-		switch (cond) {
-		case MIPS_COND_EQ:
-			uasm_i_beq(&p, reg1, reg2, imm);
-			break;
-		case MIPS_COND_NE:
-			uasm_i_bne(&p, reg1, reg2, imm);
-			break;
-		case MIPS_COND_ALL:
-			uasm_i_b(&p, imm);
-			break;
-		default:
-			pr_warn("%s: Unhandled branch conditional: %d\n",
-				__func__, cond);
-		}
-	}
-	ctx->idx++;
-}
-
-static inline void emit_b(unsigned int imm, struct jit_ctx *ctx)
-{
-	emit_bcond(MIPS_COND_ALL, r_zero, r_zero, imm, ctx);
-}
-
-static inline void emit_jalr(unsigned int link, unsigned int reg,
-			     struct jit_ctx *ctx)
-{
-	emit_instr(ctx, jalr, link, reg);
-}
-
-static inline void emit_jr(unsigned int reg, struct jit_ctx *ctx)
-{
-	emit_instr(ctx, jr, reg);
-}
-
-static inline u16 align_sp(unsigned int num)
-{
-	/* Double word alignment for 32-bit, quadword for 64-bit */
-	unsigned int align = IS_ENABLED(CONFIG_64BIT) ? 16 : 8;
-	num = (num + (align - 1)) & -align;
-	return num;
-}
-
-static void save_bpf_jit_regs(struct jit_ctx *ctx, unsigned offset)
-{
-	int i = 0, real_off = 0;
-	u32 sflags, tmp_flags;
-
-	/* Adjust the stack pointer */
-	if (offset)
-		emit_stack_offset(-align_sp(offset), ctx);
-
-	tmp_flags = sflags = ctx->flags >> SEEN_SREG_SFT;
-	/* sflags is essentially a bitmap */
-	while (tmp_flags) {
-		if ((sflags >> i) & 0x1) {
-			emit_store_stack_reg(MIPS_R_S0 + i, r_sp, real_off,
-					     ctx);
-			real_off += SZREG;
-		}
-		i++;
-		tmp_flags >>= 1;
-	}
-
-	/* save return address */
-	if (ctx->flags & SEEN_CALL) {
-		emit_store_stack_reg(r_ra, r_sp, real_off, ctx);
-		real_off += SZREG;
-	}
-
-	/* Setup r_M leaving the alignment gap if necessary */
-	if (ctx->flags & SEEN_MEM) {
-		if (real_off % (SZREG * 2))
-			real_off += SZREG;
-		emit_long_instr(ctx, ADDIU, r_M, r_sp, real_off);
-	}
-}
-
-static void restore_bpf_jit_regs(struct jit_ctx *ctx,
-				 unsigned int offset)
-{
-	int i, real_off = 0;
-	u32 sflags, tmp_flags;
-
-	tmp_flags = sflags = ctx->flags >> SEEN_SREG_SFT;
-	/* sflags is a bitmap */
-	i = 0;
-	while (tmp_flags) {
-		if ((sflags >> i) & 0x1) {
-			emit_load_stack_reg(MIPS_R_S0 + i, r_sp, real_off,
-					    ctx);
-			real_off += SZREG;
-		}
-		i++;
-		tmp_flags >>= 1;
-	}
-
-	/* restore return address */
-	if (ctx->flags & SEEN_CALL)
-		emit_load_stack_reg(r_ra, r_sp, real_off, ctx);
-
-	/* Restore the sp and discard the scrach memory */
-	if (offset)
-		emit_stack_offset(align_sp(offset), ctx);
-}
-
-static unsigned int get_stack_depth(struct jit_ctx *ctx)
-{
-	int sp_off = 0;
-
-
-	/* How may s* regs do we need to preserved? */
-	sp_off += hweight32(ctx->flags >> SEEN_SREG_SFT) * SZREG;
-
-	if (ctx->flags & SEEN_MEM)
-		sp_off += 4 * BPF_MEMWORDS; /* BPF_MEMWORDS are 32-bit */
-
-	if (ctx->flags & SEEN_CALL)
-		sp_off += SZREG; /* Space for our ra register */
-
-	return sp_off;
-}
-
-static void build_prologue(struct jit_ctx *ctx)
-{
-	int sp_off;
-
-	/* Calculate the total offset for the stack pointer */
-	sp_off = get_stack_depth(ctx);
-	save_bpf_jit_regs(ctx, sp_off);
-
-	if (ctx->flags & SEEN_SKB)
-		emit_reg_move(r_skb, MIPS_R_A0, ctx);
-
-	if (ctx->flags & SEEN_SKB_DATA) {
-		/* Load packet length */
-		emit_load(r_skb_len, r_skb, offsetof(struct sk_buff, len),
-			  ctx);
-		emit_load(r_tmp, r_skb, offsetof(struct sk_buff, data_len),
-			  ctx);
-		/* Load the data pointer */
-		emit_load_ptr(r_skb_data, r_skb,
-			      offsetof(struct sk_buff, data), ctx);
-		/* Load the header length */
-		emit_subu(r_skb_hl, r_skb_len, r_tmp, ctx);
-	}
-
-	if (ctx->flags & SEEN_X)
-		emit_jit_reg_move(r_X, r_zero, ctx);
-
-	/*
-	 * Do not leak kernel data to userspace, we only need to clear
-	 * r_A if it is ever used.  In fact if it is never used, we
-	 * will not save/restore it, so clearing it in this case would
-	 * corrupt the state of the caller.
-	 */
-	if (bpf_needs_clear_a(&ctx->skf->insns[0]) &&
-	    (ctx->flags & SEEN_A))
-		emit_jit_reg_move(r_A, r_zero, ctx);
-}
-
-static void build_epilogue(struct jit_ctx *ctx)
-{
-	unsigned int sp_off;
-
-	/* Calculate the total offset for the stack pointer */
-
-	sp_off = get_stack_depth(ctx);
-	restore_bpf_jit_regs(ctx, sp_off);
-
-	/* Return */
-	emit_jr(r_ra, ctx);
-	emit_nop(ctx);
-}
-
-#define CHOOSE_LOAD_FUNC(K, func) \
-	((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative : func) : \
-	 func##_positive)
-
-static int build_body(struct jit_ctx *ctx)
-{
-	const struct bpf_prog *prog = ctx->skf;
-	const struct sock_filter *inst;
-	unsigned int i, off, condt;
-	u32 k, b_off __maybe_unused;
-	u8 (*sk_load_func)(unsigned long *skb, int offset);
-
-	for (i = 0; i < prog->len; i++) {
-		u16 code;
-
-		inst = &(prog->insns[i]);
-		pr_debug("%s: code->0x%02x, jt->0x%x, jf->0x%x, k->0x%x\n",
-			 __func__, inst->code, inst->jt, inst->jf, inst->k);
-		k = inst->k;
-		code = bpf_anc_helper(inst);
-
-		if (ctx->target == NULL)
-			ctx->offsets[i] = ctx->idx * 4;
-
-		switch (code) {
-		case BPF_LD | BPF_IMM:
-			/* A <- k ==> li r_A, k */
-			ctx->flags |= SEEN_A;
-			emit_load_imm(r_A, k, ctx);
-			break;
-		case BPF_LD | BPF_W | BPF_LEN:
-			BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4);
-			/* A <- len ==> lw r_A, offset(skb) */
-			ctx->flags |= SEEN_SKB | SEEN_A;
-			off = offsetof(struct sk_buff, len);
-			emit_load(r_A, r_skb, off, ctx);
-			break;
-		case BPF_LD | BPF_MEM:
-			/* A <- M[k] ==> lw r_A, offset(M) */
-			ctx->flags |= SEEN_MEM | SEEN_A;
-			emit_load(r_A, r_M, SCRATCH_OFF(k), ctx);
-			break;
-		case BPF_LD | BPF_W | BPF_ABS:
-			/* A <- P[k:4] */
-			sk_load_func = CHOOSE_LOAD_FUNC(k, sk_load_word);
-			goto load;
-		case BPF_LD | BPF_H | BPF_ABS:
-			/* A <- P[k:2] */
-			sk_load_func = CHOOSE_LOAD_FUNC(k, sk_load_half);
-			goto load;
-		case BPF_LD | BPF_B | BPF_ABS:
-			/* A <- P[k:1] */
-			sk_load_func = CHOOSE_LOAD_FUNC(k, sk_load_byte);
-load:
-			emit_load_imm(r_off, k, ctx);
-load_common:
-			ctx->flags |= SEEN_CALL | SEEN_OFF |
-				SEEN_SKB | SEEN_A | SEEN_SKB_DATA;
-
-			emit_load_func(r_s0, (ptr)sk_load_func, ctx);
-			emit_reg_move(MIPS_R_A0, r_skb, ctx);
-			emit_jalr(MIPS_R_RA, r_s0, ctx);
-			/* Load second argument to delay slot */
-			emit_reg_move(MIPS_R_A1, r_off, ctx);
-			/* Check the error value */
-			emit_bcond(MIPS_COND_EQ, r_ret, 0, b_imm(i + 1, ctx),
-				   ctx);
-			/* Load return register on DS for failures */
-			emit_reg_move(r_ret, r_zero, ctx);
-			/* Return with error */
-			emit_b(b_imm(prog->len, ctx), ctx);
-			emit_nop(ctx);
-			break;
-		case BPF_LD | BPF_W | BPF_IND:
-			/* A <- P[X + k:4] */
-			sk_load_func = sk_load_word;
-			goto load_ind;
-		case BPF_LD | BPF_H | BPF_IND:
-			/* A <- P[X + k:2] */
-			sk_load_func = sk_load_half;
-			goto load_ind;
-		case BPF_LD | BPF_B | BPF_IND:
-			/* A <- P[X + k:1] */
-			sk_load_func = sk_load_byte;
-load_ind:
-			ctx->flags |= SEEN_OFF | SEEN_X;
-			emit_addiu(r_off, r_X, k, ctx);
-			goto load_common;
-		case BPF_LDX | BPF_IMM:
-			/* X <- k */
-			ctx->flags |= SEEN_X;
-			emit_load_imm(r_X, k, ctx);
-			break;
-		case BPF_LDX | BPF_MEM:
-			/* X <- M[k] */
-			ctx->flags |= SEEN_X | SEEN_MEM;
-			emit_load(r_X, r_M, SCRATCH_OFF(k), ctx);
-			break;
-		case BPF_LDX | BPF_W | BPF_LEN:
-			/* X <- len */
-			ctx->flags |= SEEN_X | SEEN_SKB;
-			off = offsetof(struct sk_buff, len);
-			emit_load(r_X, r_skb, off, ctx);
-			break;
-		case BPF_LDX | BPF_B | BPF_MSH:
-			/* X <- 4 * (P[k:1] & 0xf) */
-			ctx->flags |= SEEN_X | SEEN_CALL | SEEN_SKB;
-			/* Load offset to a1 */
-			emit_load_func(r_s0, (ptr)sk_load_byte, ctx);
-			/*
-			 * This may emit two instructions so it may not fit
-			 * in the delay slot. So use a0 in the delay slot.
-			 */
-			emit_load_imm(MIPS_R_A1, k, ctx);
-			emit_jalr(MIPS_R_RA, r_s0, ctx);
-			emit_reg_move(MIPS_R_A0, r_skb, ctx); /* delay slot */
-			/* Check the error value */
-			emit_bcond(MIPS_COND_NE, r_ret, 0,
-				   b_imm(prog->len, ctx), ctx);
-			emit_reg_move(r_ret, r_zero, ctx);
-			/* We are good */
-			/* X <- P[1:K] & 0xf */
-			emit_andi(r_X, r_A, 0xf, ctx);
-			/* X << 2 */
-			emit_b(b_imm(i + 1, ctx), ctx);
-			emit_sll(r_X, r_X, 2, ctx); /* delay slot */
-			break;
-		case BPF_ST:
-			/* M[k] <- A */
-			ctx->flags |= SEEN_MEM | SEEN_A;
-			emit_store(r_A, r_M, SCRATCH_OFF(k), ctx);
-			break;
-		case BPF_STX:
-			/* M[k] <- X */
-			ctx->flags |= SEEN_MEM | SEEN_X;
-			emit_store(r_X, r_M, SCRATCH_OFF(k), ctx);
-			break;
-		case BPF_ALU | BPF_ADD | BPF_K:
-			/* A += K */
-			ctx->flags |= SEEN_A;
-			emit_addiu(r_A, r_A, k, ctx);
-			break;
-		case BPF_ALU | BPF_ADD | BPF_X:
-			/* A += X */
-			ctx->flags |= SEEN_A | SEEN_X;
-			emit_addu(r_A, r_A, r_X, ctx);
-			break;
-		case BPF_ALU | BPF_SUB | BPF_K:
-			/* A -= K */
-			ctx->flags |= SEEN_A;
-			emit_addiu(r_A, r_A, -k, ctx);
-			break;
-		case BPF_ALU | BPF_SUB | BPF_X:
-			/* A -= X */
-			ctx->flags |= SEEN_A | SEEN_X;
-			emit_subu(r_A, r_A, r_X, ctx);
-			break;
-		case BPF_ALU | BPF_MUL | BPF_K:
-			/* A *= K */
-			/* Load K to scratch register before MUL */
-			ctx->flags |= SEEN_A;
-			emit_load_imm(r_s0, k, ctx);
-			emit_mul(r_A, r_A, r_s0, ctx);
-			break;
-		case BPF_ALU | BPF_MUL | BPF_X:
-			/* A *= X */
-			ctx->flags |= SEEN_A | SEEN_X;
-			emit_mul(r_A, r_A, r_X, ctx);
-			break;
-		case BPF_ALU | BPF_DIV | BPF_K:
-			/* A /= k */
-			if (k == 1)
-				break;
-			if (optimize_div(&k)) {
-				ctx->flags |= SEEN_A;
-				emit_srl(r_A, r_A, k, ctx);
-				break;
-			}
-			ctx->flags |= SEEN_A;
-			emit_load_imm(r_s0, k, ctx);
-			emit_div(r_A, r_s0, ctx);
-			break;
-		case BPF_ALU | BPF_MOD | BPF_K:
-			/* A %= k */
-			if (k == 1) {
-				ctx->flags |= SEEN_A;
-				emit_jit_reg_move(r_A, r_zero, ctx);
-			} else {
-				ctx->flags |= SEEN_A;
-				emit_load_imm(r_s0, k, ctx);
-				emit_mod(r_A, r_s0, ctx);
-			}
-			break;
-		case BPF_ALU | BPF_DIV | BPF_X:
-			/* A /= X */
-			ctx->flags |= SEEN_X | SEEN_A;
-			/* Check if r_X is zero */
-			emit_bcond(MIPS_COND_EQ, r_X, r_zero,
-				   b_imm(prog->len, ctx), ctx);
-			emit_load_imm(r_ret, 0, ctx); /* delay slot */
-			emit_div(r_A, r_X, ctx);
-			break;
-		case BPF_ALU | BPF_MOD | BPF_X:
-			/* A %= X */
-			ctx->flags |= SEEN_X | SEEN_A;
-			/* Check if r_X is zero */
-			emit_bcond(MIPS_COND_EQ, r_X, r_zero,
-				   b_imm(prog->len, ctx), ctx);
-			emit_load_imm(r_ret, 0, ctx); /* delay slot */
-			emit_mod(r_A, r_X, ctx);
-			break;
-		case BPF_ALU | BPF_OR | BPF_K:
-			/* A |= K */
-			ctx->flags |= SEEN_A;
-			emit_ori(r_A, r_A, k, ctx);
-			break;
-		case BPF_ALU | BPF_OR | BPF_X:
-			/* A |= X */
-			ctx->flags |= SEEN_A;
-			emit_ori(r_A, r_A, r_X, ctx);
-			break;
-		case BPF_ALU | BPF_XOR | BPF_K:
-			/* A ^= k */
-			ctx->flags |= SEEN_A;
-			emit_xori(r_A, r_A, k, ctx);
-			break;
-		case BPF_ANC | SKF_AD_ALU_XOR_X:
-		case BPF_ALU | BPF_XOR | BPF_X:
-			/* A ^= X */
-			ctx->flags |= SEEN_A;
-			emit_xor(r_A, r_A, r_X, ctx);
-			break;
-		case BPF_ALU | BPF_AND | BPF_K:
-			/* A &= K */
-			ctx->flags |= SEEN_A;
-			emit_andi(r_A, r_A, k, ctx);
-			break;
-		case BPF_ALU | BPF_AND | BPF_X:
-			/* A &= X */
-			ctx->flags |= SEEN_A | SEEN_X;
-			emit_and(r_A, r_A, r_X, ctx);
-			break;
-		case BPF_ALU | BPF_LSH | BPF_K:
-			/* A <<= K */
-			ctx->flags |= SEEN_A;
-			emit_sll(r_A, r_A, k, ctx);
-			break;
-		case BPF_ALU | BPF_LSH | BPF_X:
-			/* A <<= X */
-			ctx->flags |= SEEN_A | SEEN_X;
-			emit_sllv(r_A, r_A, r_X, ctx);
-			break;
-		case BPF_ALU | BPF_RSH | BPF_K:
-			/* A >>= K */
-			ctx->flags |= SEEN_A;
-			emit_srl(r_A, r_A, k, ctx);
-			break;
-		case BPF_ALU | BPF_RSH | BPF_X:
-			ctx->flags |= SEEN_A | SEEN_X;
-			emit_srlv(r_A, r_A, r_X, ctx);
-			break;
-		case BPF_ALU | BPF_NEG:
-			/* A = -A */
-			ctx->flags |= SEEN_A;
-			emit_neg(r_A, ctx);
-			break;
-		case BPF_JMP | BPF_JA:
-			/* pc += K */
-			emit_b(b_imm(i + k + 1, ctx), ctx);
-			emit_nop(ctx);
-			break;
-		case BPF_JMP | BPF_JEQ | BPF_K:
-			/* pc += ( A == K ) ? pc->jt : pc->jf */
-			condt = MIPS_COND_EQ | MIPS_COND_K;
-			goto jmp_cmp;
-		case BPF_JMP | BPF_JEQ | BPF_X:
-			ctx->flags |= SEEN_X;
-			/* pc += ( A == X ) ? pc->jt : pc->jf */
-			condt = MIPS_COND_EQ | MIPS_COND_X;
-			goto jmp_cmp;
-		case BPF_JMP | BPF_JGE | BPF_K:
-			/* pc += ( A >= K ) ? pc->jt : pc->jf */
-			condt = MIPS_COND_GE | MIPS_COND_K;
-			goto jmp_cmp;
-		case BPF_JMP | BPF_JGE | BPF_X:
-			ctx->flags |= SEEN_X;
-			/* pc += ( A >= X ) ? pc->jt : pc->jf */
-			condt = MIPS_COND_GE | MIPS_COND_X;
-			goto jmp_cmp;
-		case BPF_JMP | BPF_JGT | BPF_K:
-			/* pc += ( A > K ) ? pc->jt : pc->jf */
-			condt = MIPS_COND_GT | MIPS_COND_K;
-			goto jmp_cmp;
-		case BPF_JMP | BPF_JGT | BPF_X:
-			ctx->flags |= SEEN_X;
-			/* pc += ( A > X ) ? pc->jt : pc->jf */
-			condt = MIPS_COND_GT | MIPS_COND_X;
-jmp_cmp:
-			/* Greater or Equal */
-			if ((condt & MIPS_COND_GE) ||
-			    (condt & MIPS_COND_GT)) {
-				if (condt & MIPS_COND_K) { /* K */
-					ctx->flags |= SEEN_A;
-					emit_sltiu(r_s0, r_A, k, ctx);
-				} else { /* X */
-					ctx->flags |= SEEN_A |
-						SEEN_X;
-					emit_sltu(r_s0, r_A, r_X, ctx);
-				}
-				/* A < (K|X) ? r_scrach = 1 */
-				b_off = b_imm(i + inst->jf + 1, ctx);
-				emit_bcond(MIPS_COND_NE, r_s0, r_zero, b_off,
-					   ctx);
-				emit_nop(ctx);
-				/* A > (K|X) ? scratch = 0 */
-				if (condt & MIPS_COND_GT) {
-					/* Checking for equality */
-					ctx->flags |= SEEN_A | SEEN_X;
-					if (condt & MIPS_COND_K)
-						emit_load_imm(r_s0, k, ctx);
-					else
-						emit_jit_reg_move(r_s0, r_X,
-								  ctx);
-					b_off = b_imm(i + inst->jf + 1, ctx);
-					emit_bcond(MIPS_COND_EQ, r_A, r_s0,
-						   b_off, ctx);
-					emit_nop(ctx);
-					/* Finally, A > K|X */
-					b_off = b_imm(i + inst->jt + 1, ctx);
-					emit_b(b_off, ctx);
-					emit_nop(ctx);
-				} else {
-					/* A >= (K|X) so jump */
-					b_off = b_imm(i + inst->jt + 1, ctx);
-					emit_b(b_off, ctx);
-					emit_nop(ctx);
-				}
-			} else {
-				/* A == K|X */
-				if (condt & MIPS_COND_K) { /* K */
-					ctx->flags |= SEEN_A;
-					emit_load_imm(r_s0, k, ctx);
-					/* jump true */
-					b_off = b_imm(i + inst->jt + 1, ctx);
-					emit_bcond(MIPS_COND_EQ, r_A, r_s0,
-						   b_off, ctx);
-					emit_nop(ctx);
-					/* jump false */
-					b_off = b_imm(i + inst->jf + 1,
-						      ctx);
-					emit_bcond(MIPS_COND_NE, r_A, r_s0,
-						   b_off, ctx);
-					emit_nop(ctx);
-				} else { /* X */
-					/* jump true */
-					ctx->flags |= SEEN_A | SEEN_X;
-					b_off = b_imm(i + inst->jt + 1,
-						      ctx);
-					emit_bcond(MIPS_COND_EQ, r_A, r_X,
-						   b_off, ctx);
-					emit_nop(ctx);
-					/* jump false */
-					b_off = b_imm(i + inst->jf + 1, ctx);
-					emit_bcond(MIPS_COND_NE, r_A, r_X,
-						   b_off, ctx);
-					emit_nop(ctx);
-				}
-			}
-			break;
-		case BPF_JMP | BPF_JSET | BPF_K:
-			ctx->flags |= SEEN_A;
-			/* pc += (A & K) ? pc -> jt : pc -> jf */
-			emit_load_imm(r_s1, k, ctx);
-			emit_and(r_s0, r_A, r_s1, ctx);
-			/* jump true */
-			b_off = b_imm(i + inst->jt + 1, ctx);
-			emit_bcond(MIPS_COND_NE, r_s0, r_zero, b_off, ctx);
-			emit_nop(ctx);
-			/* jump false */
-			b_off = b_imm(i + inst->jf + 1, ctx);
-			emit_b(b_off, ctx);
-			emit_nop(ctx);
-			break;
-		case BPF_JMP | BPF_JSET | BPF_X:
-			ctx->flags |= SEEN_X | SEEN_A;
-			/* pc += (A & X) ? pc -> jt : pc -> jf */
-			emit_and(r_s0, r_A, r_X, ctx);
-			/* jump true */
-			b_off = b_imm(i + inst->jt + 1, ctx);
-			emit_bcond(MIPS_COND_NE, r_s0, r_zero, b_off, ctx);
-			emit_nop(ctx);
-			/* jump false */
-			b_off = b_imm(i + inst->jf + 1, ctx);
-			emit_b(b_off, ctx);
-			emit_nop(ctx);
-			break;
-		case BPF_RET | BPF_A:
-			ctx->flags |= SEEN_A;
-			if (i != prog->len - 1)
-				/*
-				 * If this is not the last instruction
-				 * then jump to the epilogue
-				 */
-				emit_b(b_imm(prog->len, ctx), ctx);
-			emit_reg_move(r_ret, r_A, ctx); /* delay slot */
-			break;
-		case BPF_RET | BPF_K:
-			/*
-			 * It can emit two instructions so it does not fit on
-			 * the delay slot.
-			 */
-			emit_load_imm(r_ret, k, ctx);
-			if (i != prog->len - 1) {
-				/*
-				 * If this is not the last instruction
-				 * then jump to the epilogue
-				 */
-				emit_b(b_imm(prog->len, ctx), ctx);
-				emit_nop(ctx);
-			}
-			break;
-		case BPF_MISC | BPF_TAX:
-			/* X = A */
-			ctx->flags |= SEEN_X | SEEN_A;
-			emit_jit_reg_move(r_X, r_A, ctx);
-			break;
-		case BPF_MISC | BPF_TXA:
-			/* A = X */
-			ctx->flags |= SEEN_A | SEEN_X;
-			emit_jit_reg_move(r_A, r_X, ctx);
-			break;
-		/* AUX */
-		case BPF_ANC | SKF_AD_PROTOCOL:
-			/* A = ntohs(skb->protocol */
-			ctx->flags |= SEEN_SKB | SEEN_OFF | SEEN_A;
-			BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff,
-						  protocol) != 2);
-			off = offsetof(struct sk_buff, protocol);