diff options
Diffstat (limited to 'arch/arm/net')
| -rw-r--r-- | arch/arm/net/bpf_jit_32.c | 50 |
1 files changed, 49 insertions, 1 deletions
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index 753b5b2b2e3d..2cc66aa44dfe 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -237,9 +237,55 @@ static inline void emit(u32 inst, struct jit_ctx *ctx) } /* + * This is rather horrid, but necessary to convert an integer constant + * to an immediate operand for the opcodes, and be able to detect at + * build time whether the constant can't be converted (iow, usable in + * BUILD_BUG_ON()). + */ +#define imm12val(v, s) (rol32(v, (s)) | (s) << 7) +#define const_imm8m(x) \ + ({ int r; \ + u32 v = (x); \ + if (!(v & ~0x000000ff)) \ + r = imm12val(v, 0); \ + else if (!(v & ~0xc000003f)) \ + r = imm12val(v, 2); \ + else if (!(v & ~0xf000000f)) \ + r = imm12val(v, 4); \ + else if (!(v & ~0xfc000003)) \ + r = imm12val(v, 6); \ + else if (!(v & ~0xff000000)) \ + r = imm12val(v, 8); \ + else if (!(v & ~0x3fc00000)) \ + r = imm12val(v, 10); \ + else if (!(v & ~0x0ff00000)) \ + r = imm12val(v, 12); \ + else if (!(v & ~0x03fc0000)) \ + r = imm12val(v, 14); \ + else if (!(v & ~0x00ff0000)) \ + r = imm12val(v, 16); \ + else if (!(v & ~0x003fc000)) \ + r = imm12val(v, 18); \ + else if (!(v & ~0x000ff000)) \ + r = imm12val(v, 20); \ + else if (!(v & ~0x0003fc00)) \ + r = imm12val(v, 22); \ + else if (!(v & ~0x0000ff00)) \ + r = imm12val(v, 24); \ + else if (!(v & ~0x00003fc0)) \ + r = imm12val(v, 26); \ + else if (!(v & ~0x00000ff0)) \ + r = imm12val(v, 28); \ + else if (!(v & ~0x000003fc)) \ + r = imm12val(v, 30); \ + else \ + r = -1; \ + r; }) + +/* * Checks if immediate value can be converted to imm12(12 bits) value. */ -static int16_t imm8m(u32 x) +static int imm8m(u32 x) { u32 rot; @@ -249,6 +295,8 @@ static int16_t imm8m(u32 x) return -1; } +#define imm8m(x) (__builtin_constant_p(x) ? const_imm8m(x) : imm8m(x)) + static u32 arm_bpf_ldst_imm12(u32 op, u8 rt, u8 rn, s16 imm12) { op |= rt << 12 | rn << 16; |