Avoid excessive scheduling delays under a preemptible kernel by yielding the NEON after every block of input. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> --- arch/arm64/crypto/aes-ce-ccm-core.S | 150 +++++++++++++------- 1 file changed, 95 insertions(+), 55 deletions(-) diff --git a/arch/arm64/crypto/aes-ce-ccm-core.S b/arch/arm64/crypto/aes-ce-ccm-core.S index e3a375c4cb83..22ee196cae00 100644 --- a/arch/arm64/crypto/aes-ce-ccm-core.S +++ b/arch/arm64/crypto/aes-ce-ccm-core.S @@ -19,24 +19,33 @@ * u32 *macp, u8 const rk[], u32 rounds); */ ENTRY(ce_aes_ccm_auth_data) - ldr w8, [x3] /* leftover from prev round? */ + frame_push 7 + + mov x19, x0 + mov x20, x1 + mov x21, x2 + mov x22, x3 + mov x23, x4 + mov x24, x5 + + ldr w25, [x22] /* leftover from prev round? */ ld1 {v0.16b}, [x0] /* load mac */ - cbz w8, 1f - sub w8, w8, #16 + cbz w25, 1f + sub w25, w25, #16 eor v1.16b, v1.16b, v1.16b -0: ldrb w7, [x1], #1 /* get 1 byte of input */ - subs w2, w2, #1 - add w8, w8, #1 +0: ldrb w7, [x20], #1 /* get 1 byte of input */ + subs w21, w21, #1 + add w25, w25, #1 ins v1.b[0], w7 ext v1.16b, v1.16b, v1.16b, #1 /* rotate in the input bytes */ beq 8f /* out of input? */ - cbnz w8, 0b + cbnz w25, 0b eor v0.16b, v0.16b, v1.16b -1: ld1 {v3.4s}, [x4] /* load first round key */ - prfm pldl1strm, [x1] - cmp w5, #12 /* which key size? */ - add x6, x4, #16 - sub w7, w5, #2 /* modified # of rounds */ +1: ld1 {v3.4s}, [x23] /* load first round key */ + prfm pldl1strm, [x20] + cmp w24, #12 /* which key size? */ + add x6, x23, #16 + sub w7, w24, #2 /* modified # of rounds */ bmi 2f bne 5f mov v5.16b, v3.16b @@ -55,33 +64,43 @@ ENTRY(ce_aes_ccm_auth_data) ld1 {v5.4s}, [x6], #16 /* load next round key */ bpl 3b aese v0.16b, v4.16b - subs w2, w2, #16 /* last data? */ + subs w21, w21, #16 /* last data? */ eor v0.16b, v0.16b, v5.16b /* final round */ bmi 6f - ld1 {v1.16b}, [x1], #16 /* load next input block */ + ld1 {v1.16b}, [x20], #16 /* load next input block */ eor v0.16b, v0.16b, v1.16b /* xor with mac */ - bne 1b -6: st1 {v0.16b}, [x0] /* store mac */ + beq 6f + + if_will_cond_yield_neon + st1 {v0.16b}, [x19] /* store mac */ + do_cond_yield_neon + ld1 {v0.16b}, [x19] /* reload mac */ + endif_yield_neon + + b 1b +6: st1 {v0.16b}, [x19] /* store mac */ beq 10f - adds w2, w2, #16 + adds w21, w21, #16 beq 10f - mov w8, w2 -7: ldrb w7, [x1], #1 + mov w25, w21 +7: ldrb w7, [x20], #1 umov w6, v0.b[0] eor w6, w6, w7 - strb w6, [x0], #1 - subs w2, w2, #1 + strb w6, [x19], #1 + subs w21, w21, #1 beq 10f ext v0.16b, v0.16b, v0.16b, #1 /* rotate out the mac bytes */ b 7b -8: mov w7, w8 - add w8, w8, #16 +8: mov w7, w25 + add w25, w25, #16 9: ext v1.16b, v1.16b, v1.16b, #1 adds w7, w7, #1 bne 9b eor v0.16b, v0.16b, v1.16b - st1 {v0.16b}, [x0] -10: str w8, [x3] + st1 {v0.16b}, [x19] +10: str w25, [x22] + + frame_pop 7 ret ENDPROC(ce_aes_ccm_auth_data) @@ -126,19 +145,29 @@ ENTRY(ce_aes_ccm_final) ENDPROC(ce_aes_ccm_final) .macro aes_ccm_do_crypt,enc - ldr x8, [x6, #8] /* load lower ctr */ - ld1 {v0.16b}, [x5] /* load mac */ -CPU_LE( rev x8, x8 ) /* keep swabbed ctr in reg */ + frame_push 8 + + mov x19, x0 + mov x20, x1 + mov x21, x2 + mov x22, x3 + mov x23, x4 + mov x24, x5 + mov x25, x6 + + ldr x26, [x25, #8] /* load lower ctr */ + ld1 {v0.16b}, [x24] /* load mac */ +CPU_LE( rev x26, x26 ) /* keep swabbed ctr in reg */ 0: /* outer loop */ - ld1 {v1.8b}, [x6] /* load upper ctr */ - prfm pldl1strm, [x1] - add x8, x8, #1 - rev x9, x8 - cmp w4, #12 /* which key size? */ - sub w7, w4, #2 /* get modified # of rounds */ + ld1 {v1.8b}, [x25] /* load upper ctr */ + prfm pldl1strm, [x20] + add x26, x26, #1 + rev x9, x26 + cmp w23, #12 /* which key size? */ + sub w7, w23, #2 /* get modified # of rounds */ ins v1.d[1], x9 /* no carry in lower ctr */ - ld1 {v3.4s}, [x3] /* load first round key */ - add x10, x3, #16 + ld1 {v3.4s}, [x22] /* load first round key */ + add x10, x22, #16 bmi 1f bne 4f mov v5.16b, v3.16b @@ -165,9 +194,9 @@ CPU_LE( rev x8, x8 ) /* keep swabbed ctr in reg */ bpl 2b aese v0.16b, v4.16b aese v1.16b, v4.16b - subs w2, w2, #16 - bmi 6f /* partial block? */ - ld1 {v2.16b}, [x1], #16 /* load next input block */ + subs w21, w21, #16 + bmi 7f /* partial block? */ + ld1 {v2.16b}, [x20], #16 /* load next input block */ .if \enc == 1 eor v2.16b, v2.16b, v5.16b /* final round enc+mac */ eor v1.16b, v1.16b, v2.16b /* xor with crypted ctr */ @@ -176,18 +205,29 @@ CPU_LE( rev x8, x8 ) /* keep swabbed ctr in reg */ eor v1.16b, v2.16b, v5.16b /* final round enc */ .endif eor v0.16b, v0.16b, v2.16b /* xor mac with pt ^ rk[last] */ - st1 {v1.16b}, [x0], #16 /* write output block */ - bne 0b -CPU_LE( rev x8, x8 ) - st1 {v0.16b}, [x5] /* store mac */ - str x8, [x6, #8] /* store lsb end of ctr (BE) */ -5: ret - -6: eor v0.16b, v0.16b, v5.16b /* final round mac */ + st1 {v1.16b}, [x19], #16 /* write output block */ + beq 5f + + if_will_cond_yield_neon + st1 {v0.16b}, [x24] /* store mac */ + do_cond_yield_neon + ld1 {v0.16b}, [x24] /* reload mac */ + endif_yield_neon + + b 0b +5: +CPU_LE( rev x26, x26 ) + st1 {v0.16b}, [x24] /* store mac */ + str x26, [x25, #8] /* store lsb end of ctr (BE) */ + +6: frame_pop 8 + ret + +7: eor v0.16b, v0.16b, v5.16b /* final round mac */ eor v1.16b, v1.16b, v5.16b /* final round enc */ - st1 {v0.16b}, [x5] /* store mac */ - add w2, w2, #16 /* process partial tail block */ -7: ldrb w9, [x1], #1 /* get 1 byte of input */ + st1 {v0.16b}, [x24] /* store mac */ + add w21, w21, #16 /* process partial tail block */ +8: ldrb w9, [x20], #1 /* get 1 byte of input */ umov w6, v1.b[0] /* get top crypted ctr byte */ umov w7, v0.b[0] /* get top mac byte */ .if \enc == 1 @@ -197,13 +237,13 @@ CPU_LE( rev x8, x8 ) eor w9, w9, w6 eor w7, w7, w9 .endif - strb w9, [x0], #1 /* store out byte */ - strb w7, [x5], #1 /* store mac byte */ - subs w2, w2, #1 - beq 5b + strb w9, [x19], #1 /* store out byte */ + strb w7, [x24], #1 /* store mac byte */ + subs w21, w21, #1 + beq 6b ext v0.16b, v0.16b, v0.16b, #1 /* shift out mac byte */ ext v1.16b, v1.16b, v1.16b, #1 /* shift out ctr byte */ - b 7b + b 8b .endm /* -- 2.11.0