[PATCH 11/13] powerpc64/bpf elfv2: Setup kernel TOC in r2 on entry

[Naveen N. Rao]

In preparation for using kernel TOC, load the same in r2 on entry. With
elfv1, the kernel TOC is already setup by our caller so we just emit a
nop. We adjust the number of instructions to skip on a tail call
accordingly.

Signed-off-by: Naveen N. Rao <naveen.n.rao at linux.vnet.ibm.com>
---
 arch/powerpc/net/bpf_jit_comp64.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index ce4fc59bbd6a92..e05b577d95bf11 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -73,6 +73,12 @@ void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
 {
 	int i;
 
+#ifdef PPC64_ELF_ABI_v2
+	PPC_BPF_LL(_R2, _R13, offsetof(struct paca_struct, kernel_toc));
+#else
+	EMIT(PPC_RAW_NOP());
+#endif
+
 	/*
 	 * Initialize tail_call_cnt if we do tail calls.
 	 * Otherwise, put in NOPs so that it can be skipped when we are
@@ -87,7 +93,7 @@ void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
 		EMIT(PPC_RAW_NOP());
 	}
 
-#define BPF_TAILCALL_PROLOGUE_SIZE	8
+#define BPF_TAILCALL_PROLOGUE_SIZE	12
 
 	if (bpf_has_stack_frame(ctx)) {
 		/*
-- 
2.34.1