powerpc/bpf: Move common functions into bpf_jit_comp.c

Move into bpf_jit_comp.c the functions that will remain common to
PPC64 and PPC32 when we add support of EBPF for PPC32.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2c339d77fb168ef12b213ccddfee3cb6c8ce8ae1.1616430991.git.christophe.leroy@csgroup.eu

1 files changed, 5 insertions, 258 deletions

diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index 111451bc5cc0..8a1f9fb00e78 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -18,11 +18,6 @@
 
 #include "bpf_jit64.h"
 
-static void bpf_jit_fill_ill_insns(void *area, unsigned int size)
-{
-	memset32(area, BREAKPOINT_INSTRUCTION, size/4);
-}
-
 static inline bool bpf_has_stack_frame(struct codegen_context *ctx)
 {
 	/*
@@ -69,7 +64,7 @@ static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg)
 	BUG();
 }
 
-static void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
+void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
 {
 	int i;
 
@@ -136,7 +131,7 @@ static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx
 	}
 }
 
-static void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx)
+void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx)
 {
 	bpf_jit_emit_common_epilogue(image, ctx);
 
@@ -171,8 +166,7 @@ static void bpf_jit_emit_func_call_hlp(u32 *image, struct codegen_context *ctx,
 	EMIT(PPC_RAW_BLRL());
 }
 
-static void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx,
-				       u64 func)
+void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func)
 {
 	unsigned int i, ctx_idx = ctx->idx;
 
@@ -273,9 +267,8 @@ static void bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32
 }
 
 /* Assemble the body code between the prologue & epilogue */
-static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
-			      struct codegen_context *ctx,
-			      u32 *addrs, bool extra_pass)
+int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx,
+		       u32 *addrs, bool extra_pass)
 {
 	const struct bpf_insn *insn = fp->insnsi;
 	int flen = fp->len;
@@ -1010,249 +1003,3 @@ cond_branch:
 
 	return 0;
 }
-
-/* Fix the branch target addresses for subprog calls */
-static int bpf_jit_fixup_subprog_calls(struct bpf_prog *fp, u32 *image,
-				       struct codegen_context *ctx, u32 *addrs)
-{
-	const struct bpf_insn *insn = fp->insnsi;
-	bool func_addr_fixed;
-	u64 func_addr;
-	u32 tmp_idx;
-	int i, ret;
-
-	for (i = 0; i < fp->len; i++) {
-		/*
-		 * During the extra pass, only the branch target addresses for
-		 * the subprog calls need to be fixed. All other instructions
-		 * can left untouched.
-		 *
-		 * The JITed image length does not change because we already
-		 * ensure that the JITed instruction sequence for these calls
-		 * are of fixed length by padding them with NOPs.
-		 */
-		if (insn[i].code == (BPF_JMP | BPF_CALL) &&
-		    insn[i].src_reg == BPF_PSEUDO_CALL) {
-			ret = bpf_jit_get_func_addr(fp, &insn[i], true,
-						    &func_addr,
-						    &func_addr_fixed);
-			if (ret < 0)
-				return ret;
-
-			/*
-			 * Save ctx->idx as this would currently point to the
-			 * end of the JITed image and set it to the offset of
-			 * the instruction sequence corresponding to the
-			 * subprog call temporarily.
-			 */
-			tmp_idx = ctx->idx;
-			ctx->idx = addrs[i] / 4;
-			bpf_jit_emit_func_call_rel(image, ctx, func_addr);
-
-			/*
-			 * Restore ctx->idx here. This is safe as the length
-			 * of the JITed sequence remains unchanged.
-			 */
-			ctx->idx = tmp_idx;
-		}
-	}
-
-	return 0;
-}
-
-struct powerpc64_jit_data {
-	struct bpf_binary_header *header;
-	u32 *addrs;
-	u8 *image;
-	u32 proglen;
-	struct codegen_context ctx;
-};
-
-bool bpf_jit_needs_zext(void)
-{
-	return true;
-}
-
-struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
-{
-	u32 proglen;
-	u32 alloclen;
-	u8 *image = NULL;
-	u32 *code_base;
-	u32 *addrs;
-	struct powerpc64_jit_data *jit_data;
-	struct codegen_context cgctx;
-	int pass;
-	int flen;
-	struct bpf_binary_header *bpf_hdr;
-	struct bpf_prog *org_fp = fp;
-	struct bpf_prog *tmp_fp;
-	bool bpf_blinded = false;
-	bool extra_pass = false;
-
-	if (!fp->jit_requested)
-		return org_fp;
-
-	tmp_fp = bpf_jit_blind_constants(org_fp);
-	if (IS_ERR(tmp_fp))
-		return org_fp;
-
-	if (tmp_fp != org_fp) {
-		bpf_blinded = true;
-		fp = tmp_fp;
-	}
-
-	jit_data = fp->aux->jit_data;
-	if (!jit_data) {
-		jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL);
-		if (!jit_data) {
-			fp = org_fp;
-			goto out;
-		}
-		fp->aux->jit_data = jit_data;
-	}
-
-	flen = fp->len;
-	addrs = jit_data->addrs;
-	if (addrs) {
-		cgctx = jit_data->ctx;
-		image = jit_data->image;
-		bpf_hdr = jit_data->header;
-		proglen = jit_data->proglen;
-		alloclen = proglen + FUNCTION_DESCR_SIZE;
-		extra_pass = true;
-		goto skip_init_ctx;
-	}
-
-	addrs = kcalloc(flen + 1, sizeof(*addrs), GFP_KERNEL);
-	if (addrs == NULL) {
-		fp = org_fp;
-		goto out_addrs;
-	}
-
-	memset(&cgctx, 0, sizeof(struct codegen_context));
-
-	/* Make sure that the stack is quadword aligned. */
-	cgctx.stack_size = round_up(fp->aux->stack_depth, 16);
-
-	/* Scouting faux-generate pass 0 */
-	if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) {
-		/* We hit something illegal or unsupported. */
-		fp = org_fp;
-		goto out_addrs;
-	}
-
-	/*
-	 * If we have seen a tail call, we need a second pass.
-	 * This is because bpf_jit_emit_common_epilogue() is called
-	 * from bpf_jit_emit_tail_call() with a not yet stable ctx->seen.
-	 */
-	if (cgctx.seen & SEEN_TAILCALL) {
-		cgctx.idx = 0;
-		if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) {
-			fp = org_fp;
-			goto out_addrs;
-		}
-	}
-
-	/*
-	 * Pretend to build prologue, given the features we've seen.  This will
-	 * update ctgtx.idx as it pretends to output instructions, then we can
-	 * calculate total size from idx.
-	 */
-	bpf_jit_build_prologue(0, &cgctx);
-	bpf_jit_build_epilogue(0, &cgctx);
-
-	proglen = cgctx.idx * 4;
-	alloclen = proglen + FUNCTION_DESCR_SIZE;
-
-	bpf_hdr = bpf_jit_binary_alloc(alloclen, &image, 4,
-			bpf_jit_fill_ill_insns);
-	if (!bpf_hdr) {
-		fp = org_fp;
-		goto out_addrs;
-	}
-
-skip_init_ctx:
-	code_base = (u32 *)(image + FUNCTION_DESCR_SIZE);
-
-	if (extra_pass) {
-		/*
-		 * Do not touch the prologue and epilogue as they will remain
-		 * unchanged. Only fix the branch target address for subprog
-		 * calls in the body.
-		 *
-		 * This does not change the offsets and lengths of the subprog
-		 * call instruction sequences and hence, the size of the JITed
-		 * image as well.
-		 */
-		bpf_jit_fixup_subprog_calls(fp, code_base, &cgctx, addrs);
-
-		/* There is no need to perform the usual passes. */
-		goto skip_codegen_passes;
-	}
-
-	/* Code generation passes 1-2 */
-	for (pass = 1; pass < 3; pass++) {
-		/* Now build the prologue, body code & epilogue for real. */
-		cgctx.idx = 0;
-		bpf_jit_build_prologue(code_base, &cgctx);
-		bpf_jit_build_body(fp, code_base, &cgctx, addrs, extra_pass);
-		bpf_jit_build_epilogue(code_base, &cgctx);
-
-		if (bpf_jit_enable > 1)
-			pr_info("Pass %d: shrink = %d, seen = 0x%x\n", pass,
-				proglen - (cgctx.idx * 4), cgctx.seen);
-	}
-
-skip_codegen_passes:
-	if (bpf_jit_enable > 1)
-		/*
-		 * Note that we output the base address of the code_base
-		 * rather than image, since opcodes are in code_base.
-		 */
-		bpf_jit_dump(flen, proglen, pass, code_base);
-
-#ifdef PPC64_ELF_ABI_v1
-	/* Function descriptor nastiness: Address + TOC */
-	((u64 *)image)[0] = (u64)code_base;
-	((u64 *)image)[1] = local_paca->kernel_toc;
-#endif
-
-	fp->bpf_func = (void *)image;
-	fp->jited = 1;
-	fp->jited_len = alloclen;
-
-	bpf_flush_icache(bpf_hdr, (u8 *)bpf_hdr + (bpf_hdr->pages * PAGE_SIZE));
-	if (!fp->is_func || extra_pass) {
-		bpf_prog_fill_jited_linfo(fp, addrs);
-out_addrs:
-		kfree(addrs);
-		kfree(jit_data);
-		fp->aux->jit_data = NULL;
-	} else {
-		jit_data->addrs = addrs;
-		jit_data->ctx = cgctx;
-		jit_data->proglen = proglen;
-		jit_data->image = image;
-		jit_data->header = bpf_hdr;
-	}
-
-out:
-	if (bpf_blinded)
-		bpf_jit_prog_release_other(fp, fp == org_fp ? tmp_fp : org_fp);
-
-	return fp;
-}
-
-/* Overriding bpf_jit_free() as we don't set images read-only. */
-void bpf_jit_free(struct bpf_prog *fp)
-{
-	unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK;
-	struct bpf_binary_header *bpf_hdr = (void *)addr;
-
-	if (fp->jited)
-		bpf_jit_binary_free(bpf_hdr);
-
-	bpf_prog_unlock_free(fp);
-}