From 51c66ad849a703d9bbfd7704c941827aed0fd9fd Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Mon, 22 Mar 2021 16:37:52 +0000 Subject: powerpc/bpf: Implement extended BPF on PPC32 Implement Extended Berkeley Packet Filter on Powerpc 32 Test result with test_bpf module: test_bpf: Summary: 378 PASSED, 0 FAILED, [354/366 JIT'ed] Registers mapping: [BPF_REG_0] = r11-r12 /* function arguments */ [BPF_REG_1] = r3-r4 [BPF_REG_2] = r5-r6 [BPF_REG_3] = r7-r8 [BPF_REG_4] = r9-r10 [BPF_REG_5] = r21-r22 (Args 9 and 10 come in via the stack) /* non volatile registers */ [BPF_REG_6] = r23-r24 [BPF_REG_7] = r25-r26 [BPF_REG_8] = r27-r28 [BPF_REG_9] = r29-r30 /* frame pointer aka BPF_REG_10 */ [BPF_REG_FP] = r17-r18 /* eBPF jit internal registers */ [BPF_REG_AX] = r19-r20 [TMP_REG] = r31 As PPC32 doesn't have a redzone in the stack, a stack frame must always be set in order to host at least the tail count counter. The stack frame remains for tail calls, it is set by the first callee and freed by the last callee. r0 is used as temporary register as much as possible. It is referenced directly in the code in order to avoid misusing it, because some instructions interpret it as value 0 instead of register r0 (ex: addi, addis, stw, lwz, ...) The following operations are not implemented: case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */ case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */ case BPF_STX | BPF_XADD | BPF_DW: /* *(u64 *)(dst + off) += src */ The following operations are only implemented for power of two constants: case BPF_ALU64 | BPF_MOD | BPF_K: /* dst %= imm */ case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */ Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/61d8b149176ddf99e7d5cef0b6dc1598583ca202.1616430991.git.christophe.leroy@csgroup.eu --- Documentation/admin-guide/sysctl/net.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation/admin-guide') diff --git a/Documentation/admin-guide/sysctl/net.rst b/Documentation/admin-guide/sysctl/net.rst index f2ab8a5b6a4b..685cc13f567b 100644 --- a/Documentation/admin-guide/sysctl/net.rst +++ b/Documentation/admin-guide/sysctl/net.rst @@ -64,6 +64,7 @@ two flavors of JITs, the newer eBPF JIT currently supported on: - arm64 - arm32 - ppc64 + - ppc32 - sparc64 - mips64 - s390x @@ -73,7 +74,6 @@ two flavors of JITs, the newer eBPF JIT currently supported on: And the older cBPF JIT supported on the following archs: - mips - - ppc - sparc eBPF JITs are a superset of cBPF JITs, meaning the kernel will -- cgit v1.2.3