xref: /linux/arch/powerpc/net/bpf_jit_comp64.c (revision be239684b18e1cdcafcf8c7face4a2f562c745ad)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * bpf_jit_comp64.c: eBPF JIT compiler
4  *
5  * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
6  *		  IBM Corporation
7  *
8  * Based on the powerpc classic BPF JIT compiler by Matt Evans
9  */
10 #include <linux/moduleloader.h>
11 #include <asm/cacheflush.h>
12 #include <asm/asm-compat.h>
13 #include <linux/netdevice.h>
14 #include <linux/filter.h>
15 #include <linux/if_vlan.h>
16 #include <asm/kprobes.h>
17 #include <linux/bpf.h>
18 #include <asm/security_features.h>
19 
20 #include "bpf_jit.h"
21 
22 /*
23  * Stack layout:
24  * Ensure the top half (upto local_tmp_var) stays consistent
25  * with our redzone usage.
26  *
27  *		[	prev sp		] <-------------
28  *		[   nv gpr save area	] 5*8		|
29  *		[    tail_call_cnt	] 8		|
30  *		[    local_tmp_var	] 16		|
31  * fp (r31) -->	[   ebpf stack space	] upto 512	|
32  *		[     frame header	] 32/112	|
33  * sp (r1) --->	[    stack pointer	] --------------
34  */
35 
36 /* for gpr non volatile registers BPG_REG_6 to 10 */
37 #define BPF_PPC_STACK_SAVE	(5*8)
38 /* for bpf JIT code internal usage */
39 #define BPF_PPC_STACK_LOCALS	24
40 /* stack frame excluding BPF stack, ensure this is quadword aligned */
41 #define BPF_PPC_STACKFRAME	(STACK_FRAME_MIN_SIZE + \
42 				 BPF_PPC_STACK_LOCALS + BPF_PPC_STACK_SAVE)
43 
44 /* BPF register usage */
45 #define TMP_REG_1	(MAX_BPF_JIT_REG + 0)
46 #define TMP_REG_2	(MAX_BPF_JIT_REG + 1)
47 
48 /* BPF to ppc register mappings */
49 void bpf_jit_init_reg_mapping(struct codegen_context *ctx)
50 {
51 	/* function return value */
52 	ctx->b2p[BPF_REG_0] = _R8;
53 	/* function arguments */
54 	ctx->b2p[BPF_REG_1] = _R3;
55 	ctx->b2p[BPF_REG_2] = _R4;
56 	ctx->b2p[BPF_REG_3] = _R5;
57 	ctx->b2p[BPF_REG_4] = _R6;
58 	ctx->b2p[BPF_REG_5] = _R7;
59 	/* non volatile registers */
60 	ctx->b2p[BPF_REG_6] = _R27;
61 	ctx->b2p[BPF_REG_7] = _R28;
62 	ctx->b2p[BPF_REG_8] = _R29;
63 	ctx->b2p[BPF_REG_9] = _R30;
64 	/* frame pointer aka BPF_REG_10 */
65 	ctx->b2p[BPF_REG_FP] = _R31;
66 	/* eBPF jit internal registers */
67 	ctx->b2p[BPF_REG_AX] = _R12;
68 	ctx->b2p[TMP_REG_1] = _R9;
69 	ctx->b2p[TMP_REG_2] = _R10;
70 }
71 
72 /* PPC NVR range -- update this if we ever use NVRs below r27 */
73 #define BPF_PPC_NVR_MIN		_R27
74 
75 static inline bool bpf_has_stack_frame(struct codegen_context *ctx)
76 {
77 	/*
78 	 * We only need a stack frame if:
79 	 * - we call other functions (kernel helpers), or
80 	 * - the bpf program uses its stack area
81 	 * The latter condition is deduced from the usage of BPF_REG_FP
82 	 */
83 	return ctx->seen & SEEN_FUNC || bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP));
84 }
85 
86 /*
87  * When not setting up our own stackframe, the redzone usage is:
88  *
89  *		[	prev sp		] <-------------
90  *		[	  ...       	] 		|
91  * sp (r1) --->	[    stack pointer	] --------------
92  *		[   nv gpr save area	] 5*8
93  *		[    tail_call_cnt	] 8
94  *		[    local_tmp_var	] 16
95  *		[   unused red zone	] 208 bytes protected
96  */
97 static int bpf_jit_stack_local(struct codegen_context *ctx)
98 {
99 	if (bpf_has_stack_frame(ctx))
100 		return STACK_FRAME_MIN_SIZE + ctx->stack_size;
101 	else
102 		return -(BPF_PPC_STACK_SAVE + 24);
103 }
104 
105 static int bpf_jit_stack_tailcallcnt(struct codegen_context *ctx)
106 {
107 	return bpf_jit_stack_local(ctx) + 16;
108 }
109 
110 static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg)
111 {
112 	if (reg >= BPF_PPC_NVR_MIN && reg < 32)
113 		return (bpf_has_stack_frame(ctx) ?
114 			(BPF_PPC_STACKFRAME + ctx->stack_size) : 0)
115 				- (8 * (32 - reg));
116 
117 	pr_err("BPF JIT is asking about unknown registers");
118 	BUG();
119 }
120 
121 void bpf_jit_realloc_regs(struct codegen_context *ctx)
122 {
123 }
124 
125 void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
126 {
127 	int i;
128 
129 #ifndef CONFIG_PPC_KERNEL_PCREL
130 	if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
131 		EMIT(PPC_RAW_LD(_R2, _R13, offsetof(struct paca_struct, kernel_toc)));
132 #endif
133 
134 	/*
135 	 * Initialize tail_call_cnt if we do tail calls.
136 	 * Otherwise, put in NOPs so that it can be skipped when we are
137 	 * invoked through a tail call.
138 	 */
139 	if (ctx->seen & SEEN_TAILCALL) {
140 		EMIT(PPC_RAW_LI(bpf_to_ppc(TMP_REG_1), 0));
141 		/* this goes in the redzone */
142 		EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, -(BPF_PPC_STACK_SAVE + 8)));
143 	} else {
144 		EMIT(PPC_RAW_NOP());
145 		EMIT(PPC_RAW_NOP());
146 	}
147 
148 	if (bpf_has_stack_frame(ctx)) {
149 		/*
150 		 * We need a stack frame, but we don't necessarily need to
151 		 * save/restore LR unless we call other functions
152 		 */
153 		if (ctx->seen & SEEN_FUNC) {
154 			EMIT(PPC_RAW_MFLR(_R0));
155 			EMIT(PPC_RAW_STD(_R0, _R1, PPC_LR_STKOFF));
156 		}
157 
158 		EMIT(PPC_RAW_STDU(_R1, _R1, -(BPF_PPC_STACKFRAME + ctx->stack_size)));
159 	}
160 
161 	/*
162 	 * Back up non-volatile regs -- BPF registers 6-10
163 	 * If we haven't created our own stack frame, we save these
164 	 * in the protected zone below the previous stack frame
165 	 */
166 	for (i = BPF_REG_6; i <= BPF_REG_10; i++)
167 		if (bpf_is_seen_register(ctx, bpf_to_ppc(i)))
168 			EMIT(PPC_RAW_STD(bpf_to_ppc(i), _R1, bpf_jit_stack_offsetof(ctx, bpf_to_ppc(i))));
169 
170 	/* Setup frame pointer to point to the bpf stack area */
171 	if (bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP)))
172 		EMIT(PPC_RAW_ADDI(bpf_to_ppc(BPF_REG_FP), _R1,
173 				STACK_FRAME_MIN_SIZE + ctx->stack_size));
174 }
175 
176 static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx)
177 {
178 	int i;
179 
180 	/* Restore NVRs */
181 	for (i = BPF_REG_6; i <= BPF_REG_10; i++)
182 		if (bpf_is_seen_register(ctx, bpf_to_ppc(i)))
183 			EMIT(PPC_RAW_LD(bpf_to_ppc(i), _R1, bpf_jit_stack_offsetof(ctx, bpf_to_ppc(i))));
184 
185 	/* Tear down our stack frame */
186 	if (bpf_has_stack_frame(ctx)) {
187 		EMIT(PPC_RAW_ADDI(_R1, _R1, BPF_PPC_STACKFRAME + ctx->stack_size));
188 		if (ctx->seen & SEEN_FUNC) {
189 			EMIT(PPC_RAW_LD(_R0, _R1, PPC_LR_STKOFF));
190 			EMIT(PPC_RAW_MTLR(_R0));
191 		}
192 	}
193 }
194 
195 void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx)
196 {
197 	bpf_jit_emit_common_epilogue(image, ctx);
198 
199 	/* Move result to r3 */
200 	EMIT(PPC_RAW_MR(_R3, bpf_to_ppc(BPF_REG_0)));
201 
202 	EMIT(PPC_RAW_BLR());
203 }
204 
205 static int bpf_jit_emit_func_call_hlp(u32 *image, struct codegen_context *ctx, u64 func)
206 {
207 	unsigned long func_addr = func ? ppc_function_entry((void *)func) : 0;
208 	long reladdr;
209 
210 	if (WARN_ON_ONCE(!core_kernel_text(func_addr)))
211 		return -EINVAL;
212 
213 	if (IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) {
214 		reladdr = func_addr - CTX_NIA(ctx);
215 
216 		if (reladdr >= (long)SZ_8G || reladdr < -(long)SZ_8G) {
217 			pr_err("eBPF: address of %ps out of range of pcrel address.\n",
218 				(void *)func);
219 			return -ERANGE;
220 		}
221 		/* pla r12,addr */
222 		EMIT(PPC_PREFIX_MLS | __PPC_PRFX_R(1) | IMM_H18(reladdr));
223 		EMIT(PPC_INST_PADDI | ___PPC_RT(_R12) | IMM_L(reladdr));
224 		EMIT(PPC_RAW_MTCTR(_R12));
225 		EMIT(PPC_RAW_BCTR());
226 
227 	} else {
228 		reladdr = func_addr - kernel_toc_addr();
229 		if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
230 			pr_err("eBPF: address of %ps out of range of kernel_toc.\n", (void *)func);
231 			return -ERANGE;
232 		}
233 
234 		EMIT(PPC_RAW_ADDIS(_R12, _R2, PPC_HA(reladdr)));
235 		EMIT(PPC_RAW_ADDI(_R12, _R12, PPC_LO(reladdr)));
236 		EMIT(PPC_RAW_MTCTR(_R12));
237 		EMIT(PPC_RAW_BCTRL());
238 	}
239 
240 	return 0;
241 }
242 
243 int bpf_jit_emit_func_call_rel(u32 *image, u32 *fimage, struct codegen_context *ctx, u64 func)
244 {
245 	unsigned int i, ctx_idx = ctx->idx;
246 
247 	if (WARN_ON_ONCE(func && is_module_text_address(func)))
248 		return -EINVAL;
249 
250 	/* skip past descriptor if elf v1 */
251 	func += FUNCTION_DESCR_SIZE;
252 
253 	/* Load function address into r12 */
254 	PPC_LI64(_R12, func);
255 
256 	/* For bpf-to-bpf function calls, the callee's address is unknown
257 	 * until the last extra pass. As seen above, we use PPC_LI64() to
258 	 * load the callee's address, but this may optimize the number of
259 	 * instructions required based on the nature of the address.
260 	 *
261 	 * Since we don't want the number of instructions emitted to increase,
262 	 * we pad the optimized PPC_LI64() call with NOPs to guarantee that
263 	 * we always have a five-instruction sequence, which is the maximum
264 	 * that PPC_LI64() can emit.
265 	 */
266 	if (!image)
267 		for (i = ctx->idx - ctx_idx; i < 5; i++)
268 			EMIT(PPC_RAW_NOP());
269 
270 	EMIT(PPC_RAW_MTCTR(_R12));
271 	EMIT(PPC_RAW_BCTRL());
272 
273 	return 0;
274 }
275 
276 static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out)
277 {
278 	/*
279 	 * By now, the eBPF program has already setup parameters in r3, r4 and r5
280 	 * r3/BPF_REG_1 - pointer to ctx -- passed as is to the next bpf program
281 	 * r4/BPF_REG_2 - pointer to bpf_array
282 	 * r5/BPF_REG_3 - index in bpf_array
283 	 */
284 	int b2p_bpf_array = bpf_to_ppc(BPF_REG_2);
285 	int b2p_index = bpf_to_ppc(BPF_REG_3);
286 	int bpf_tailcall_prologue_size = 8;
287 
288 	if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
289 		bpf_tailcall_prologue_size += 4; /* skip past the toc load */
290 
291 	/*
292 	 * if (index >= array->map.max_entries)
293 	 *   goto out;
294 	 */
295 	EMIT(PPC_RAW_LWZ(bpf_to_ppc(TMP_REG_1), b2p_bpf_array, offsetof(struct bpf_array, map.max_entries)));
296 	EMIT(PPC_RAW_RLWINM(b2p_index, b2p_index, 0, 0, 31));
297 	EMIT(PPC_RAW_CMPLW(b2p_index, bpf_to_ppc(TMP_REG_1)));
298 	PPC_BCC_SHORT(COND_GE, out);
299 
300 	/*
301 	 * if (tail_call_cnt >= MAX_TAIL_CALL_CNT)
302 	 *   goto out;
303 	 */
304 	EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), _R1, bpf_jit_stack_tailcallcnt(ctx)));
305 	EMIT(PPC_RAW_CMPLWI(bpf_to_ppc(TMP_REG_1), MAX_TAIL_CALL_CNT));
306 	PPC_BCC_SHORT(COND_GE, out);
307 
308 	/*
309 	 * tail_call_cnt++;
310 	 */
311 	EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), 1));
312 	EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, bpf_jit_stack_tailcallcnt(ctx)));
313 
314 	/* prog = array->ptrs[index]; */
315 	EMIT(PPC_RAW_MULI(bpf_to_ppc(TMP_REG_1), b2p_index, 8));
316 	EMIT(PPC_RAW_ADD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), b2p_bpf_array));
317 	EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), offsetof(struct bpf_array, ptrs)));
318 
319 	/*
320 	 * if (prog == NULL)
321 	 *   goto out;
322 	 */
323 	EMIT(PPC_RAW_CMPLDI(bpf_to_ppc(TMP_REG_1), 0));
324 	PPC_BCC_SHORT(COND_EQ, out);
325 
326 	/* goto *(prog->bpf_func + prologue_size); */
327 	EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), offsetof(struct bpf_prog, bpf_func)));
328 	EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1),
329 			FUNCTION_DESCR_SIZE + bpf_tailcall_prologue_size));
330 	EMIT(PPC_RAW_MTCTR(bpf_to_ppc(TMP_REG_1)));
331 
332 	/* tear down stack, restore NVRs, ... */
333 	bpf_jit_emit_common_epilogue(image, ctx);
334 
335 	EMIT(PPC_RAW_BCTR());
336 
337 	/* out: */
338 	return 0;
339 }
340 
341 /*
342  * We spill into the redzone always, even if the bpf program has its own stackframe.
343  * Offsets hardcoded based on BPF_PPC_STACK_SAVE -- see bpf_jit_stack_local()
344  */
345 void bpf_stf_barrier(void);
346 
347 asm (
348 "		.global bpf_stf_barrier		;"
349 "	bpf_stf_barrier:			;"
350 "		std	21,-64(1)		;"
351 "		std	22,-56(1)		;"
352 "		sync				;"
353 "		ld	21,-64(1)		;"
354 "		ld	22,-56(1)		;"
355 "		ori	31,31,0			;"
356 "		.rept 14			;"
357 "		b	1f			;"
358 "	1:					;"
359 "		.endr				;"
360 "		blr				;"
361 );
362 
363 /* Assemble the body code between the prologue & epilogue */
364 int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct codegen_context *ctx,
365 		       u32 *addrs, int pass, bool extra_pass)
366 {
367 	enum stf_barrier_type stf_barrier = stf_barrier_type_get();
368 	const struct bpf_insn *insn = fp->insnsi;
369 	int flen = fp->len;
370 	int i, ret;
371 
372 	/* Start of epilogue code - will only be valid 2nd pass onwards */
373 	u32 exit_addr = addrs[flen];
374 
375 	for (i = 0; i < flen; i++) {
376 		u32 code = insn[i].code;
377 		u32 dst_reg = bpf_to_ppc(insn[i].dst_reg);
378 		u32 src_reg = bpf_to_ppc(insn[i].src_reg);
379 		u32 size = BPF_SIZE(code);
380 		u32 tmp1_reg = bpf_to_ppc(TMP_REG_1);
381 		u32 tmp2_reg = bpf_to_ppc(TMP_REG_2);
382 		u32 save_reg, ret_reg;
383 		s16 off = insn[i].off;
384 		s32 imm = insn[i].imm;
385 		bool func_addr_fixed;
386 		u64 func_addr;
387 		u64 imm64;
388 		u32 true_cond;
389 		u32 tmp_idx;
390 		int j;
391 
392 		/*
393 		 * addrs[] maps a BPF bytecode address into a real offset from
394 		 * the start of the body code.
395 		 */
396 		addrs[i] = ctx->idx * 4;
397 
398 		/*
399 		 * As an optimization, we note down which non-volatile registers
400 		 * are used so that we can only save/restore those in our
401 		 * prologue and epilogue. We do this here regardless of whether
402 		 * the actual BPF instruction uses src/dst registers or not
403 		 * (for instance, BPF_CALL does not use them). The expectation
404 		 * is that those instructions will have src_reg/dst_reg set to
405 		 * 0. Even otherwise, we just lose some prologue/epilogue
406 		 * optimization but everything else should work without
407 		 * any issues.
408 		 */
409 		if (dst_reg >= BPF_PPC_NVR_MIN && dst_reg < 32)
410 			bpf_set_seen_register(ctx, dst_reg);
411 		if (src_reg >= BPF_PPC_NVR_MIN && src_reg < 32)
412 			bpf_set_seen_register(ctx, src_reg);
413 
414 		switch (code) {
415 		/*
416 		 * Arithmetic operations: ADD/SUB/MUL/DIV/MOD/NEG
417 		 */
418 		case BPF_ALU | BPF_ADD | BPF_X: /* (u32) dst += (u32) src */
419 		case BPF_ALU64 | BPF_ADD | BPF_X: /* dst += src */
420 			EMIT(PPC_RAW_ADD(dst_reg, dst_reg, src_reg));
421 			goto bpf_alu32_trunc;
422 		case BPF_ALU | BPF_SUB | BPF_X: /* (u32) dst -= (u32) src */
423 		case BPF_ALU64 | BPF_SUB | BPF_X: /* dst -= src */
424 			EMIT(PPC_RAW_SUB(dst_reg, dst_reg, src_reg));
425 			goto bpf_alu32_trunc;
426 		case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */
427 		case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */
428 			if (!imm) {
429 				goto bpf_alu32_trunc;
430 			} else if (imm >= -32768 && imm < 32768) {
431 				EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(imm)));
432 			} else {
433 				PPC_LI32(tmp1_reg, imm);
434 				EMIT(PPC_RAW_ADD(dst_reg, dst_reg, tmp1_reg));
435 			}
436 			goto bpf_alu32_trunc;
437 		case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */
438 		case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */
439 			if (!imm) {
440 				goto bpf_alu32_trunc;
441 			} else if (imm > -32768 && imm <= 32768) {
442 				EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(-imm)));
443 			} else {
444 				PPC_LI32(tmp1_reg, imm);
445 				EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
446 			}
447 			goto bpf_alu32_trunc;
448 		case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */
449 		case BPF_ALU64 | BPF_MUL | BPF_X: /* dst *= src */
450 			if (BPF_CLASS(code) == BPF_ALU)
451 				EMIT(PPC_RAW_MULW(dst_reg, dst_reg, src_reg));
452 			else
453 				EMIT(PPC_RAW_MULD(dst_reg, dst_reg, src_reg));
454 			goto bpf_alu32_trunc;
455 		case BPF_ALU | BPF_MUL | BPF_K: /* (u32) dst *= (u32) imm */
456 		case BPF_ALU64 | BPF_MUL | BPF_K: /* dst *= imm */
457 			if (imm >= -32768 && imm < 32768)
458 				EMIT(PPC_RAW_MULI(dst_reg, dst_reg, IMM_L(imm)));
459 			else {
460 				PPC_LI32(tmp1_reg, imm);
461 				if (BPF_CLASS(code) == BPF_ALU)
462 					EMIT(PPC_RAW_MULW(dst_reg, dst_reg, tmp1_reg));
463 				else
464 					EMIT(PPC_RAW_MULD(dst_reg, dst_reg, tmp1_reg));
465 			}
466 			goto bpf_alu32_trunc;
467 		case BPF_ALU | BPF_DIV | BPF_X: /* (u32) dst /= (u32) src */
468 		case BPF_ALU | BPF_MOD | BPF_X: /* (u32) dst %= (u32) src */
469 			if (BPF_OP(code) == BPF_MOD) {
470 				EMIT(PPC_RAW_DIVWU(tmp1_reg, dst_reg, src_reg));
471 				EMIT(PPC_RAW_MULW(tmp1_reg, src_reg, tmp1_reg));
472 				EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
473 			} else
474 				EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, src_reg));
475 			goto bpf_alu32_trunc;
476 		case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */
477 		case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */
478 			if (BPF_OP(code) == BPF_MOD) {
479 				EMIT(PPC_RAW_DIVDU(tmp1_reg, dst_reg, src_reg));
480 				EMIT(PPC_RAW_MULD(tmp1_reg, src_reg, tmp1_reg));
481 				EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
482 			} else
483 				EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, src_reg));
484 			break;
485 		case BPF_ALU | BPF_MOD | BPF_K: /* (u32) dst %= (u32) imm */
486 		case BPF_ALU | BPF_DIV | BPF_K: /* (u32) dst /= (u32) imm */
487 		case BPF_ALU64 | BPF_MOD | BPF_K: /* dst %= imm */
488 		case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */
489 			if (imm == 0)
490 				return -EINVAL;
491 			if (imm == 1) {
492 				if (BPF_OP(code) == BPF_DIV) {
493 					goto bpf_alu32_trunc;
494 				} else {
495 					EMIT(PPC_RAW_LI(dst_reg, 0));
496 					break;
497 				}
498 			}
499 
500 			PPC_LI32(tmp1_reg, imm);
501 			switch (BPF_CLASS(code)) {
502 			case BPF_ALU:
503 				if (BPF_OP(code) == BPF_MOD) {
504 					EMIT(PPC_RAW_DIVWU(tmp2_reg, dst_reg, tmp1_reg));
505 					EMIT(PPC_RAW_MULW(tmp1_reg, tmp1_reg, tmp2_reg));
506 					EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
507 				} else
508 					EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, tmp1_reg));
509 				break;
510 			case BPF_ALU64:
511 				if (BPF_OP(code) == BPF_MOD) {
512 					EMIT(PPC_RAW_DIVDU(tmp2_reg, dst_reg, tmp1_reg));
513 					EMIT(PPC_RAW_MULD(tmp1_reg, tmp1_reg, tmp2_reg));
514 					EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
515 				} else
516 					EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, tmp1_reg));
517 				break;
518 			}
519 			goto bpf_alu32_trunc;
520 		case BPF_ALU | BPF_NEG: /* (u32) dst = -dst */
521 		case BPF_ALU64 | BPF_NEG: /* dst = -dst */
522 			EMIT(PPC_RAW_NEG(dst_reg, dst_reg));
523 			goto bpf_alu32_trunc;
524 
525 		/*
526 		 * Logical operations: AND/OR/XOR/[A]LSH/[A]RSH
527 		 */
528 		case BPF_ALU | BPF_AND | BPF_X: /* (u32) dst = dst & src */
529 		case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
530 			EMIT(PPC_RAW_AND(dst_reg, dst_reg, src_reg));
531 			goto bpf_alu32_trunc;
532 		case BPF_ALU | BPF_AND | BPF_K: /* (u32) dst = dst & imm */
533 		case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
534 			if (!IMM_H(imm))
535 				EMIT(PPC_RAW_ANDI(dst_reg, dst_reg, IMM_L(imm)));
536 			else {
537 				/* Sign-extended */
538 				PPC_LI32(tmp1_reg, imm);
539 				EMIT(PPC_RAW_AND(dst_reg, dst_reg, tmp1_reg));
540 			}
541 			goto bpf_alu32_trunc;
542 		case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
543 		case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
544 			EMIT(PPC_RAW_OR(dst_reg, dst_reg, src_reg));
545 			goto bpf_alu32_trunc;
546 		case BPF_ALU | BPF_OR | BPF_K:/* dst = (u32) dst | (u32) imm */
547 		case BPF_ALU64 | BPF_OR | BPF_K:/* dst = dst | imm */
548 			if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) {
549 				/* Sign-extended */
550 				PPC_LI32(tmp1_reg, imm);
551 				EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp1_reg));
552 			} else {
553 				if (IMM_L(imm))
554 					EMIT(PPC_RAW_ORI(dst_reg, dst_reg, IMM_L(imm)));
555 				if (IMM_H(imm))
556 					EMIT(PPC_RAW_ORIS(dst_reg, dst_reg, IMM_H(imm)));
557 			}
558 			goto bpf_alu32_trunc;
559 		case BPF_ALU | BPF_XOR | BPF_X: /* (u32) dst ^= src */
560 		case BPF_ALU64 | BPF_XOR | BPF_X: /* dst ^= src */
561 			EMIT(PPC_RAW_XOR(dst_reg, dst_reg, src_reg));
562 			goto bpf_alu32_trunc;
563 		case BPF_ALU | BPF_XOR | BPF_K: /* (u32) dst ^= (u32) imm */
564 		case BPF_ALU64 | BPF_XOR | BPF_K: /* dst ^= imm */
565 			if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) {
566 				/* Sign-extended */
567 				PPC_LI32(tmp1_reg, imm);
568 				EMIT(PPC_RAW_XOR(dst_reg, dst_reg, tmp1_reg));
569 			} else {
570 				if (IMM_L(imm))
571 					EMIT(PPC_RAW_XORI(dst_reg, dst_reg, IMM_L(imm)));
572 				if (IMM_H(imm))
573 					EMIT(PPC_RAW_XORIS(dst_reg, dst_reg, IMM_H(imm)));
574 			}
575 			goto bpf_alu32_trunc;
576 		case BPF_ALU | BPF_LSH | BPF_X: /* (u32) dst <<= (u32) src */
577 			/* slw clears top 32 bits */
578 			EMIT(PPC_RAW_SLW(dst_reg, dst_reg, src_reg));
579 			/* skip zero extension move, but set address map. */
580 			if (insn_is_zext(&insn[i + 1]))
581 				addrs[++i] = ctx->idx * 4;
582 			break;
583 		case BPF_ALU64 | BPF_LSH | BPF_X: /* dst <<= src; */
584 			EMIT(PPC_RAW_SLD(dst_reg, dst_reg, src_reg));
585 			break;
586 		case BPF_ALU | BPF_LSH | BPF_K: /* (u32) dst <<== (u32) imm */
587 			/* with imm 0, we still need to clear top 32 bits */
588 			EMIT(PPC_RAW_SLWI(dst_reg, dst_reg, imm));
589 			if (insn_is_zext(&insn[i + 1]))
590 				addrs[++i] = ctx->idx * 4;
591 			break;
592 		case BPF_ALU64 | BPF_LSH | BPF_K: /* dst <<== imm */
593 			if (imm != 0)
594 				EMIT(PPC_RAW_SLDI(dst_reg, dst_reg, imm));
595 			break;
596 		case BPF_ALU | BPF_RSH | BPF_X: /* (u32) dst >>= (u32) src */
597 			EMIT(PPC_RAW_SRW(dst_reg, dst_reg, src_reg));
598 			if (insn_is_zext(&insn[i + 1]))
599 				addrs[++i] = ctx->idx * 4;
600 			break;
601 		case BPF_ALU64 | BPF_RSH | BPF_X: /* dst >>= src */
602 			EMIT(PPC_RAW_SRD(dst_reg, dst_reg, src_reg));
603 			break;
604 		case BPF_ALU | BPF_RSH | BPF_K: /* (u32) dst >>= (u32) imm */
605 			EMIT(PPC_RAW_SRWI(dst_reg, dst_reg, imm));
606 			if (insn_is_zext(&insn[i + 1]))
607 				addrs[++i] = ctx->idx * 4;
608 			break;
609 		case BPF_ALU64 | BPF_RSH | BPF_K: /* dst >>= imm */
610 			if (imm != 0)
611 				EMIT(PPC_RAW_SRDI(dst_reg, dst_reg, imm));
612 			break;
613 		case BPF_ALU | BPF_ARSH | BPF_X: /* (s32) dst >>= src */
614 			EMIT(PPC_RAW_SRAW(dst_reg, dst_reg, src_reg));
615 			goto bpf_alu32_trunc;
616 		case BPF_ALU64 | BPF_ARSH | BPF_X: /* (s64) dst >>= src */
617 			EMIT(PPC_RAW_SRAD(dst_reg, dst_reg, src_reg));
618 			break;
619 		case BPF_ALU | BPF_ARSH | BPF_K: /* (s32) dst >>= imm */
620 			EMIT(PPC_RAW_SRAWI(dst_reg, dst_reg, imm));
621 			goto bpf_alu32_trunc;
622 		case BPF_ALU64 | BPF_ARSH | BPF_K: /* (s64) dst >>= imm */
623 			if (imm != 0)
624 				EMIT(PPC_RAW_SRADI(dst_reg, dst_reg, imm));
625 			break;
626 
627 		/*
628 		 * MOV
629 		 */
630 		case BPF_ALU | BPF_MOV | BPF_X: /* (u32) dst = src */
631 		case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
632 			if (imm == 1) {
633 				/* special mov32 for zext */
634 				EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 0, 31));
635 				break;
636 			}
637 			EMIT(PPC_RAW_MR(dst_reg, src_reg));
638 			goto bpf_alu32_trunc;
639 		case BPF_ALU | BPF_MOV | BPF_K: /* (u32) dst = imm */
640 		case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = (s64) imm */
641 			PPC_LI32(dst_reg, imm);
642 			if (imm < 0)
643 				goto bpf_alu32_trunc;
644 			else if (insn_is_zext(&insn[i + 1]))
645 				addrs[++i] = ctx->idx * 4;
646 			break;
647 
648 bpf_alu32_trunc:
649 		/* Truncate to 32-bits */
650 		if (BPF_CLASS(code) == BPF_ALU && !fp->aux->verifier_zext)
651 			EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 0, 31));
652 		break;
653 
654 		/*
655 		 * BPF_FROM_BE/LE
656 		 */
657 		case BPF_ALU | BPF_END | BPF_FROM_LE:
658 		case BPF_ALU | BPF_END | BPF_FROM_BE:
659 #ifdef __BIG_ENDIAN__
660 			if (BPF_SRC(code) == BPF_FROM_BE)
661 				goto emit_clear;
662 #else /* !__BIG_ENDIAN__ */
663 			if (BPF_SRC(code) == BPF_FROM_LE)
664 				goto emit_clear;
665 #endif
666 			switch (imm) {
667 			case 16:
668 				/* Rotate 8 bits left & mask with 0x0000ff00 */
669 				EMIT(PPC_RAW_RLWINM(tmp1_reg, dst_reg, 8, 16, 23));
670 				/* Rotate 8 bits right & insert LSB to reg */
671 				EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 24, 31));
672 				/* Move result back to dst_reg */
673 				EMIT(PPC_RAW_MR(dst_reg, tmp1_reg));
674 				break;
675 			case 32:
676 				/*
677 				 * Rotate word left by 8 bits:
678 				 * 2 bytes are already in their final position
679 				 * -- byte 2 and 4 (of bytes 1, 2, 3 and 4)
680 				 */
681 				EMIT(PPC_RAW_RLWINM(tmp1_reg, dst_reg, 8, 0, 31));
682 				/* Rotate 24 bits and insert byte 1 */
683 				EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 0, 7));
684 				/* Rotate 24 bits and insert byte 3 */
685 				EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 16, 23));
686 				EMIT(PPC_RAW_MR(dst_reg, tmp1_reg));
687 				break;
688 			case 64:
689 				/* Store the value to stack and then use byte-reverse loads */
690 				EMIT(PPC_RAW_STD(dst_reg, _R1, bpf_jit_stack_local(ctx)));
691 				EMIT(PPC_RAW_ADDI(tmp1_reg, _R1, bpf_jit_stack_local(ctx)));
692 				if (cpu_has_feature(CPU_FTR_ARCH_206)) {
693 					EMIT(PPC_RAW_LDBRX(dst_reg, 0, tmp1_reg));
694 				} else {
695 					EMIT(PPC_RAW_LWBRX(dst_reg, 0, tmp1_reg));
696 					if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN))
697 						EMIT(PPC_RAW_SLDI(dst_reg, dst_reg, 32));
698 					EMIT(PPC_RAW_LI(tmp2_reg, 4));
699 					EMIT(PPC_RAW_LWBRX(tmp2_reg, tmp2_reg, tmp1_reg));
700 					if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
701 						EMIT(PPC_RAW_SLDI(tmp2_reg, tmp2_reg, 32));
702 					EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp2_reg));
703 				}
704 				break;
705 			}
706 			break;
707 
708 emit_clear:
709 			switch (imm) {
710 			case 16:
711 				/* zero-extend 16 bits into 64 bits */
712 				EMIT(PPC_RAW_RLDICL(dst_reg, dst_reg, 0, 48));
713 				if (insn_is_zext(&insn[i + 1]))
714 					addrs[++i] = ctx->idx * 4;
715 				break;
716 			case 32:
717 				if (!fp->aux->verifier_zext)
718 					/* zero-extend 32 bits into 64 bits */
719 					EMIT(PPC_RAW_RLDICL(dst_reg, dst_reg, 0, 32));
720 				break;
721 			case 64:
722 				/* nop */
723 				break;
724 			}
725 			break;
726 
727 		/*
728 		 * BPF_ST NOSPEC (speculation barrier)
729 		 */
730 		case BPF_ST | BPF_NOSPEC:
731 			if (!security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) ||
732 					!security_ftr_enabled(SEC_FTR_STF_BARRIER))
733 				break;
734 
735 			switch (stf_barrier) {
736 			case STF_BARRIER_EIEIO:
737 				EMIT(PPC_RAW_EIEIO() | 0x02000000);
738 				break;
739 			case STF_BARRIER_SYNC_ORI:
740 				EMIT(PPC_RAW_SYNC());
741 				EMIT(PPC_RAW_LD(tmp1_reg, _R13, 0));
742 				EMIT(PPC_RAW_ORI(_R31, _R31, 0));
743 				break;
744 			case STF_BARRIER_FALLBACK:
745 				ctx->seen |= SEEN_FUNC;
746 				PPC_LI64(_R12, dereference_kernel_function_descriptor(bpf_stf_barrier));
747 				EMIT(PPC_RAW_MTCTR(_R12));
748 				EMIT(PPC_RAW_BCTRL());
749 				break;
750 			case STF_BARRIER_NONE:
751 				break;
752 			}
753 			break;
754 
755 		/*
756 		 * BPF_ST(X)
757 		 */
758 		case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src */
759 		case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
760 			if (BPF_CLASS(code) == BPF_ST) {
761 				EMIT(PPC_RAW_LI(tmp1_reg, imm));
762 				src_reg = tmp1_reg;
763 			}
764 			EMIT(PPC_RAW_STB(src_reg, dst_reg, off));
765 			break;
766 		case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
767 		case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
768 			if (BPF_CLASS(code) == BPF_ST) {
769 				EMIT(PPC_RAW_LI(tmp1_reg, imm));
770 				src_reg = tmp1_reg;
771 			}
772 			EMIT(PPC_RAW_STH(src_reg, dst_reg, off));
773 			break;
774 		case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
775 		case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
776 			if (BPF_CLASS(code) == BPF_ST) {
777 				PPC_LI32(tmp1_reg, imm);
778 				src_reg = tmp1_reg;
779 			}
780 			EMIT(PPC_RAW_STW(src_reg, dst_reg, off));
781 			break;
782 		case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
783 		case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
784 			if (BPF_CLASS(code) == BPF_ST) {
785 				PPC_LI32(tmp1_reg, imm);
786 				src_reg = tmp1_reg;
787 			}
788 			if (off % 4) {
789 				EMIT(PPC_RAW_LI(tmp2_reg, off));
790 				EMIT(PPC_RAW_STDX(src_reg, dst_reg, tmp2_reg));
791 			} else {
792 				EMIT(PPC_RAW_STD(src_reg, dst_reg, off));
793 			}
794 			break;
795 
796 		/*
797 		 * BPF_STX ATOMIC (atomic ops)
798 		 */
799 		case BPF_STX | BPF_ATOMIC | BPF_W:
800 		case BPF_STX | BPF_ATOMIC | BPF_DW:
801 			save_reg = tmp2_reg;
802 			ret_reg = src_reg;
803 
804 			/* Get offset into TMP_REG_1 */
805 			EMIT(PPC_RAW_LI(tmp1_reg, off));
806 			tmp_idx = ctx->idx * 4;
807 			/* load value from memory into TMP_REG_2 */
808 			if (size == BPF_DW)
809 				EMIT(PPC_RAW_LDARX(tmp2_reg, tmp1_reg, dst_reg, 0));
810 			else
811 				EMIT(PPC_RAW_LWARX(tmp2_reg, tmp1_reg, dst_reg, 0));
812 
813 			/* Save old value in _R0 */
814 			if (imm & BPF_FETCH)
815 				EMIT(PPC_RAW_MR(_R0, tmp2_reg));
816 
817 			switch (imm) {
818 			case BPF_ADD:
819 			case BPF_ADD | BPF_FETCH:
820 				EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg));
821 				break;
822 			case BPF_AND:
823 			case BPF_AND | BPF_FETCH:
824 				EMIT(PPC_RAW_AND(tmp2_reg, tmp2_reg, src_reg));
825 				break;
826 			case BPF_OR:
827 			case BPF_OR | BPF_FETCH:
828 				EMIT(PPC_RAW_OR(tmp2_reg, tmp2_reg, src_reg));
829 				break;
830 			case BPF_XOR:
831 			case BPF_XOR | BPF_FETCH:
832 				EMIT(PPC_RAW_XOR(tmp2_reg, tmp2_reg, src_reg));
833 				break;
834 			case BPF_CMPXCHG:
835 				/*
836 				 * Return old value in BPF_REG_0 for BPF_CMPXCHG &
837 				 * in src_reg for other cases.
838 				 */
839 				ret_reg = bpf_to_ppc(BPF_REG_0);
840 
841 				/* Compare with old value in BPF_R0 */
842 				if (size == BPF_DW)
843 					EMIT(PPC_RAW_CMPD(bpf_to_ppc(BPF_REG_0), tmp2_reg));
844 				else
845 					EMIT(PPC_RAW_CMPW(bpf_to_ppc(BPF_REG_0), tmp2_reg));
846 				/* Don't set if different from old value */
847 				PPC_BCC_SHORT(COND_NE, (ctx->idx + 3) * 4);
848 				fallthrough;
849 			case BPF_XCHG:
850 				save_reg = src_reg;
851 				break;
852 			default:
853 				pr_err_ratelimited(
854 					"eBPF filter atomic op code %02x (@%d) unsupported\n",
855 					code, i);
856 				return -EOPNOTSUPP;
857 			}
858 
859 			/* store new value */
860 			if (size == BPF_DW)
861 				EMIT(PPC_RAW_STDCX(save_reg, tmp1_reg, dst_reg));
862 			else
863 				EMIT(PPC_RAW_STWCX(save_reg, tmp1_reg, dst_reg));
864 			/* we're done if this succeeded */
865 			PPC_BCC_SHORT(COND_NE, tmp_idx);
866 
867 			if (imm & BPF_FETCH) {
868 				EMIT(PPC_RAW_MR(ret_reg, _R0));
869 				/*
870 				 * Skip unnecessary zero-extension for 32-bit cmpxchg.
871 				 * For context, see commit 39491867ace5.
872 				 */
873 				if (size != BPF_DW && imm == BPF_CMPXCHG &&
874 				    insn_is_zext(&insn[i + 1]))
875 					addrs[++i] = ctx->idx * 4;
876 			}
877 			break;
878 
879 		/*
880 		 * BPF_LDX
881 		 */
882 		/* dst = *(u8 *)(ul) (src + off) */
883 		case BPF_LDX | BPF_MEM | BPF_B:
884 		case BPF_LDX | BPF_PROBE_MEM | BPF_B:
885 		/* dst = *(u16 *)(ul) (src + off) */
886 		case BPF_LDX | BPF_MEM | BPF_H:
887 		case BPF_LDX | BPF_PROBE_MEM | BPF_H:
888 		/* dst = *(u32 *)(ul) (src + off) */
889 		case BPF_LDX | BPF_MEM | BPF_W:
890 		case BPF_LDX | BPF_PROBE_MEM | BPF_W:
891 		/* dst = *(u64 *)(ul) (src + off) */
892 		case BPF_LDX | BPF_MEM | BPF_DW:
893 		case BPF_LDX | BPF_PROBE_MEM | BPF_DW:
894 			/*
895 			 * As PTR_TO_BTF_ID that uses BPF_PROBE_MEM mode could either be a valid
896 			 * kernel pointer or NULL but not a userspace address, execute BPF_PROBE_MEM
897 			 * load only if addr is kernel address (see is_kernel_addr()), otherwise
898 			 * set dst_reg=0 and move on.
899 			 */
900 			if (BPF_MODE(code) == BPF_PROBE_MEM) {
901 				EMIT(PPC_RAW_ADDI(tmp1_reg, src_reg, off));
902 				if (IS_ENABLED(CONFIG_PPC_BOOK3E_64))
903 					PPC_LI64(tmp2_reg, 0x8000000000000000ul);
904 				else /* BOOK3S_64 */
905 					PPC_LI64(tmp2_reg, PAGE_OFFSET);
906 				EMIT(PPC_RAW_CMPLD(tmp1_reg, tmp2_reg));
907 				PPC_BCC_SHORT(COND_GT, (ctx->idx + 3) * 4);
908 				EMIT(PPC_RAW_LI(dst_reg, 0));
909 				/*
910 				 * Check if 'off' is word aligned for BPF_DW, because
911 				 * we might generate two instructions.
912 				 */
913 				if (BPF_SIZE(code) == BPF_DW && (off & 3))
914 					PPC_JMP((ctx->idx + 3) * 4);
915 				else
916 					PPC_JMP((ctx->idx + 2) * 4);
917 			}
918 
919 			switch (size) {
920 			case BPF_B:
921 				EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off));
922 				break;
923 			case BPF_H:
924 				EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off));
925 				break;
926 			case BPF_W:
927 				EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off));
928 				break;
929 			case BPF_DW:
930 				if (off % 4) {
931 					EMIT(PPC_RAW_LI(tmp1_reg, off));
932 					EMIT(PPC_RAW_LDX(dst_reg, src_reg, tmp1_reg));
933 				} else {
934 					EMIT(PPC_RAW_LD(dst_reg, src_reg, off));
935 				}
936 				break;
937 			}
938 
939 			if (size != BPF_DW && insn_is_zext(&insn[i + 1]))
940 				addrs[++i] = ctx->idx * 4;
941 
942 			if (BPF_MODE(code) == BPF_PROBE_MEM) {
943 				ret = bpf_add_extable_entry(fp, image, fimage, pass, ctx,
944 							    ctx->idx - 1, 4, dst_reg);
945 				if (ret)
946 					return ret;
947 			}
948 			break;
949 
950 		/*
951 		 * Doubleword load
952 		 * 16 byte instruction that uses two 'struct bpf_insn'
953 		 */
954 		case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
955 			imm64 = ((u64)(u32) insn[i].imm) |
956 				    (((u64)(u32) insn[i+1].imm) << 32);
957 			tmp_idx = ctx->idx;
958 			PPC_LI64(dst_reg, imm64);
959 			/* padding to allow full 5 instructions for later patching */
960 			if (!image)
961 				for (j = ctx->idx - tmp_idx; j < 5; j++)
962 					EMIT(PPC_RAW_NOP());
963 			/* Adjust for two bpf instructions */
964 			addrs[++i] = ctx->idx * 4;
965 			break;
966 
967 		/*
968 		 * Return/Exit
969 		 */
970 		case BPF_JMP | BPF_EXIT:
971 			/*
972 			 * If this isn't the very last instruction, branch to
973 			 * the epilogue. If we _are_ the last instruction,
974 			 * we'll just fall through to the epilogue.
975 			 */
976 			if (i != flen - 1) {
977 				ret = bpf_jit_emit_exit_insn(image, ctx, tmp1_reg, exit_addr);
978 				if (ret)
979 					return ret;
980 			}
981 			/* else fall through to the epilogue */
982 			break;
983 
984 		/*
985 		 * Call kernel helper or bpf function
986 		 */
987 		case BPF_JMP | BPF_CALL:
988 			ctx->seen |= SEEN_FUNC;
989 
990 			ret = bpf_jit_get_func_addr(fp, &insn[i], extra_pass,
991 						    &func_addr, &func_addr_fixed);
992 			if (ret < 0)
993 				return ret;
994 
995 			if (func_addr_fixed)
996 				ret = bpf_jit_emit_func_call_hlp(image, ctx, func_addr);
997 			else
998 				ret = bpf_jit_emit_func_call_rel(image, fimage, ctx, func_addr);
999 
1000 			if (ret)
1001 				return ret;
1002 
1003 			/* move return value from r3 to BPF_REG_0 */
1004 			EMIT(PPC_RAW_MR(bpf_to_ppc(BPF_REG_0), _R3));
1005 			break;
1006 
1007 		/*
1008 		 * Jumps and branches
1009 		 */
1010 		case BPF_JMP | BPF_JA:
1011 			PPC_JMP(addrs[i + 1 + off]);
1012 			break;
1013 
1014 		case BPF_JMP | BPF_JGT | BPF_K:
1015 		case BPF_JMP | BPF_JGT | BPF_X:
1016 		case BPF_JMP | BPF_JSGT | BPF_K:
1017 		case BPF_JMP | BPF_JSGT | BPF_X:
1018 		case BPF_JMP32 | BPF_JGT | BPF_K:
1019 		case BPF_JMP32 | BPF_JGT | BPF_X:
1020 		case BPF_JMP32 | BPF_JSGT | BPF_K:
1021 		case BPF_JMP32 | BPF_JSGT | BPF_X:
1022 			true_cond = COND_GT;
1023 			goto cond_branch;
1024 		case BPF_JMP | BPF_JLT | BPF_K:
1025 		case BPF_JMP | BPF_JLT | BPF_X:
1026 		case BPF_JMP | BPF_JSLT | BPF_K:
1027 		case BPF_JMP | BPF_JSLT | BPF_X:
1028 		case BPF_JMP32 | BPF_JLT | BPF_K:
1029 		case BPF_JMP32 | BPF_JLT | BPF_X:
1030 		case BPF_JMP32 | BPF_JSLT | BPF_K:
1031 		case BPF_JMP32 | BPF_JSLT | BPF_X:
1032 			true_cond = COND_LT;
1033 			goto cond_branch;
1034 		case BPF_JMP | BPF_JGE | BPF_K:
1035 		case BPF_JMP | BPF_JGE | BPF_X:
1036 		case BPF_JMP | BPF_JSGE | BPF_K:
1037 		case BPF_JMP | BPF_JSGE | BPF_X:
1038 		case BPF_JMP32 | BPF_JGE | BPF_K:
1039 		case BPF_JMP32 | BPF_JGE | BPF_X:
1040 		case BPF_JMP32 | BPF_JSGE | BPF_K:
1041 		case BPF_JMP32 | BPF_JSGE | BPF_X:
1042 			true_cond = COND_GE;
1043 			goto cond_branch;
1044 		case BPF_JMP | BPF_JLE | BPF_K:
1045 		case BPF_JMP | BPF_JLE | BPF_X:
1046 		case BPF_JMP | BPF_JSLE | BPF_K:
1047 		case BPF_JMP | BPF_JSLE | BPF_X:
1048 		case BPF_JMP32 | BPF_JLE | BPF_K:
1049 		case BPF_JMP32 | BPF_JLE | BPF_X:
1050 		case BPF_JMP32 | BPF_JSLE | BPF_K:
1051 		case BPF_JMP32 | BPF_JSLE | BPF_X:
1052 			true_cond = COND_LE;
1053 			goto cond_branch;
1054 		case BPF_JMP | BPF_JEQ | BPF_K:
1055 		case BPF_JMP | BPF_JEQ | BPF_X:
1056 		case BPF_JMP32 | BPF_JEQ | BPF_K:
1057 		case BPF_JMP32 | BPF_JEQ | BPF_X:
1058 			true_cond = COND_EQ;
1059 			goto cond_branch;
1060 		case BPF_JMP | BPF_JNE | BPF_K:
1061 		case BPF_JMP | BPF_JNE | BPF_X:
1062 		case BPF_JMP32 | BPF_JNE | BPF_K:
1063 		case BPF_JMP32 | BPF_JNE | BPF_X:
1064 			true_cond = COND_NE;
1065 			goto cond_branch;
1066 		case BPF_JMP | BPF_JSET | BPF_K:
1067 		case BPF_JMP | BPF_JSET | BPF_X:
1068 		case BPF_JMP32 | BPF_JSET | BPF_K:
1069 		case BPF_JMP32 | BPF_JSET | BPF_X:
1070 			true_cond = COND_NE;
1071 			/* Fall through */
1072 
1073 cond_branch:
1074 			switch (code) {
1075 			case BPF_JMP | BPF_JGT | BPF_X:
1076 			case BPF_JMP | BPF_JLT | BPF_X:
1077 			case BPF_JMP | BPF_JGE | BPF_X:
1078 			case BPF_JMP | BPF_JLE | BPF_X:
1079 			case BPF_JMP | BPF_JEQ | BPF_X:
1080 			case BPF_JMP | BPF_JNE | BPF_X:
1081 			case BPF_JMP32 | BPF_JGT | BPF_X:
1082 			case BPF_JMP32 | BPF_JLT | BPF_X:
1083 			case BPF_JMP32 | BPF_JGE | BPF_X:
1084 			case BPF_JMP32 | BPF_JLE | BPF_X:
1085 			case BPF_JMP32 | BPF_JEQ | BPF_X:
1086 			case BPF_JMP32 | BPF_JNE | BPF_X:
1087 				/* unsigned comparison */
1088 				if (BPF_CLASS(code) == BPF_JMP32)
1089 					EMIT(PPC_RAW_CMPLW(dst_reg, src_reg));
1090 				else
1091 					EMIT(PPC_RAW_CMPLD(dst_reg, src_reg));
1092 				break;
1093 			case BPF_JMP | BPF_JSGT | BPF_X:
1094 			case BPF_JMP | BPF_JSLT | BPF_X:
1095 			case BPF_JMP | BPF_JSGE | BPF_X:
1096 			case BPF_JMP | BPF_JSLE | BPF_X:
1097 			case BPF_JMP32 | BPF_JSGT | BPF_X:
1098 			case BPF_JMP32 | BPF_JSLT | BPF_X:
1099 			case BPF_JMP32 | BPF_JSGE | BPF_X:
1100 			case BPF_JMP32 | BPF_JSLE | BPF_X:
1101 				/* signed comparison */
1102 				if (BPF_CLASS(code) == BPF_JMP32)
1103 					EMIT(PPC_RAW_CMPW(dst_reg, src_reg));
1104 				else
1105 					EMIT(PPC_RAW_CMPD(dst_reg, src_reg));
1106 				break;
1107 			case BPF_JMP | BPF_JSET | BPF_X:
1108 			case BPF_JMP32 | BPF_JSET | BPF_X:
1109 				if (BPF_CLASS(code) == BPF_JMP) {
1110 					EMIT(PPC_RAW_AND_DOT(tmp1_reg, dst_reg, src_reg));
1111 				} else {
1112 					EMIT(PPC_RAW_AND(tmp1_reg, dst_reg, src_reg));
1113 					EMIT(PPC_RAW_RLWINM_DOT(tmp1_reg, tmp1_reg, 0, 0, 31));
1114 				}
1115 				break;
1116 			case BPF_JMP | BPF_JNE | BPF_K:
1117 			case BPF_JMP | BPF_JEQ | BPF_K:
1118 			case BPF_JMP | BPF_JGT | BPF_K:
1119 			case BPF_JMP | BPF_JLT | BPF_K:
1120 			case BPF_JMP | BPF_JGE | BPF_K:
1121 			case BPF_JMP | BPF_JLE | BPF_K:
1122 			case BPF_JMP32 | BPF_JNE | BPF_K:
1123 			case BPF_JMP32 | BPF_JEQ | BPF_K:
1124 			case BPF_JMP32 | BPF_JGT | BPF_K:
1125 			case BPF_JMP32 | BPF_JLT | BPF_K:
1126 			case BPF_JMP32 | BPF_JGE | BPF_K:
1127 			case BPF_JMP32 | BPF_JLE | BPF_K:
1128 			{
1129 				bool is_jmp32 = BPF_CLASS(code) == BPF_JMP32;
1130 
1131 				/*
1132 				 * Need sign-extended load, so only positive
1133 				 * values can be used as imm in cmpldi
1134 				 */
1135 				if (imm >= 0 && imm < 32768) {
1136 					if (is_jmp32)
1137 						EMIT(PPC_RAW_CMPLWI(dst_reg, imm));
1138 					else
1139 						EMIT(PPC_RAW_CMPLDI(dst_reg, imm));
1140 				} else {
1141 					/* sign-extending load */
1142 					PPC_LI32(tmp1_reg, imm);
1143 					/* ... but unsigned comparison */
1144 					if (is_jmp32)
1145 						EMIT(PPC_RAW_CMPLW(dst_reg, tmp1_reg));
1146 					else
1147 						EMIT(PPC_RAW_CMPLD(dst_reg, tmp1_reg));
1148 				}
1149 				break;
1150 			}
1151 			case BPF_JMP | BPF_JSGT | BPF_K:
1152 			case BPF_JMP | BPF_JSLT | BPF_K:
1153 			case BPF_JMP | BPF_JSGE | BPF_K:
1154 			case BPF_JMP | BPF_JSLE | BPF_K:
1155 			case BPF_JMP32 | BPF_JSGT | BPF_K:
1156 			case BPF_JMP32 | BPF_JSLT | BPF_K:
1157 			case BPF_JMP32 | BPF_JSGE | BPF_K:
1158 			case BPF_JMP32 | BPF_JSLE | BPF_K:
1159 			{
1160 				bool is_jmp32 = BPF_CLASS(code) == BPF_JMP32;
1161 
1162 				/*
1163 				 * signed comparison, so any 16-bit value
1164 				 * can be used in cmpdi
1165 				 */
1166 				if (imm >= -32768 && imm < 32768) {
1167 					if (is_jmp32)
1168 						EMIT(PPC_RAW_CMPWI(dst_reg, imm));
1169 					else
1170 						EMIT(PPC_RAW_CMPDI(dst_reg, imm));
1171 				} else {
1172 					PPC_LI32(tmp1_reg, imm);
1173 					if (is_jmp32)
1174 						EMIT(PPC_RAW_CMPW(dst_reg, tmp1_reg));
1175 					else
1176 						EMIT(PPC_RAW_CMPD(dst_reg, tmp1_reg));
1177 				}
1178 				break;
1179 			}
1180 			case BPF_JMP | BPF_JSET | BPF_K:
1181 			case BPF_JMP32 | BPF_JSET | BPF_K:
1182 				/* andi does not sign-extend the immediate */
1183 				if (imm >= 0 && imm < 32768)
1184 					/* PPC_ANDI is _only/always_ dot-form */
1185 					EMIT(PPC_RAW_ANDI(tmp1_reg, dst_reg, imm));
1186 				else {
1187 					PPC_LI32(tmp1_reg, imm);
1188 					if (BPF_CLASS(code) == BPF_JMP) {
1189 						EMIT(PPC_RAW_AND_DOT(tmp1_reg, dst_reg,
1190 								     tmp1_reg));
1191 					} else {
1192 						EMIT(PPC_RAW_AND(tmp1_reg, dst_reg, tmp1_reg));
1193 						EMIT(PPC_RAW_RLWINM_DOT(tmp1_reg, tmp1_reg,
1194 									0, 0, 31));
1195 					}
1196 				}
1197 				break;
1198 			}
1199 			PPC_BCC(true_cond, addrs[i + 1 + off]);
1200 			break;
1201 
1202 		/*
1203 		 * Tail call
1204 		 */
1205 		case BPF_JMP | BPF_TAIL_CALL:
1206 			ctx->seen |= SEEN_TAILCALL;
1207 			ret = bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]);
1208 			if (ret < 0)
1209 				return ret;
1210 			break;
1211 
1212 		default:
1213 			/*
1214 			 * The filter contains something cruel & unusual.
1215 			 * We don't handle it, but also there shouldn't be
1216 			 * anything missing from our list.
1217 			 */
1218 			pr_err_ratelimited("eBPF filter opcode %04x (@%d) unsupported\n",
1219 					code, i);
1220 			return -ENOTSUPP;
1221 		}
1222 	}
1223 
1224 	/* Set end-of-body-code address for exit. */
1225 	addrs[i] = ctx->idx * 4;
1226 
1227 	return 0;
1228 }
1229