ref: 567b1b912a91bf56bebacc67b6a467986d5bed6c
dir: /sys/src/9/bcm/cache.v7.s/
/* * cortex arm arch v7 cache flushing and invalidation * shared by l.s and rebootcode.s */ #define BPIALL MCR CpSC, 0, R0, C(CpCACHE), C(5), 6 /* branch predictor invalidate all */ TEXT cacheiinv(SB), $-4 /* I invalidate */ DSB MOVW $0, R0 MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEinvi), CpCACHEall /* ok on cortex */ BPIALL /* redundant? */ DSB ISB RET TEXT cacheiinvse(SB), $0 /* I invalidate SE */ MOVW 4(FP), R1 ADD R0, R1 BIC $(ICACHELINESZ - 1), R0 DSB _iinvse: MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEinvi), CpCACHEse ADD $ICACHELINESZ, R0 CMP.S R0, R1 BGT _iinvse BPIALL DSB ISB RET /* * set/way operators, passed a suitable set/way value in R0. */ TEXT cachedwb_sw(SB), $-4 MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEwb), CpCACHEsi RET TEXT cachedwbinv_sw(SB), $-4 MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEwbi), CpCACHEsi RET TEXT cachedinv_sw(SB), $-4 MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEinvd), CpCACHEsi RET /* set cache size select */ TEXT setcachelvl(SB), $-4 MCR CpSC, CpIDcssel, R0, C(CpID), C(CpIDidct), 0 ISB RET /* return cache sizes */ TEXT getwayssets(SB), $-4 MRC CpSC, CpIDcsize, R0, C(CpID), C(CpIDidct), 0 RET /* * l1 cache operations. * l1 and l2 ops are intended to be called from C, thus need save no * caller's regs, only those we need to preserve across calls. */ TEXT cachedwb(SB), $-4 MOVW.W R14, -8(R13) MOVW $cachedwb_sw(SB), R0 MOVW $1, R8 BL wholecache(SB) MOVW.P 8(R13), R15 TEXT cachedwbinv(SB), $-4 MOVW.W R14, -8(R13) MOVW $cachedwbinv_sw(SB), R0 MOVW $1, R8 BL wholecache(SB) MOVW.P 8(R13), R15 TEXT cachedinv(SB), $-4 MOVW.W R14, -8(R13) MOVW $cachedinv_sw(SB), R0 MOVW $1, R8 BL wholecache(SB) MOVW.P 8(R13), R15 TEXT cacheuwbinv(SB), $-4 MOVM.DB.W [R14], (R13) /* save lr on stack */ MOVW CPSR, R1 CPSID /* splhi */ MOVM.DB.W [R1], (R13) /* save R1 on stack */ BL cachedwbinv(SB) BL cacheiinv(SB) MOVM.IA.W (R13), [R1] /* restore R1 (saved CPSR) */ MOVW R1, CPSR MOVM.IA.W (R13), [R14] /* restore lr */ RET /* * l2 cache operations */ TEXT l2cacheuwb(SB), $-4 MOVW.W R14, -8(R13) MOVW $cachedwb_sw(SB), R0 MOVW $2, R8 BL wholecache(SB) MOVW.P 8(R13), R15 TEXT l2cacheuwbinv(SB), $-4 MOVW.W R14, -8(R13) MOVW CPSR, R1 CPSID /* splhi */ MOVM.DB.W [R1], (R13) /* save R1 on stack */ MOVW $cachedwbinv_sw(SB), R0 MOVW $2, R8 BL wholecache(SB) BL l2cacheuinv(SB) MOVM.IA.W (R13), [R1] /* restore R1 (saved CPSR) */ MOVW R1, CPSR MOVW.P 8(R13), R15 TEXT l2cacheuinv(SB), $-4 MOVW.W R14, -8(R13) MOVW $cachedinv_sw(SB), R0 MOVW $2, R8 BL wholecache(SB) MOVW.P 8(R13), R15 /* * callers are assumed to be the above l1 and l2 ops. * R0 is the function to call in the innermost loop. * R8 is the cache level (one-origin: 1 or 2). * * initial translation by 5c, then massaged by hand. */ TEXT wholecache+0(SB), $-4 MOVW R0, R1 /* save argument for inner loop in R1 */ SUB $1, R8 /* convert cache level to zero origin */ /* we may not have the MMU on yet, so map R1 to PC's space */ BIC $KSEGM, R1 /* strip segment from address */ MOVW PC, R2 /* get PC's segment ... */ AND $KSEGM, R2 ORR R2, R1 /* combine them */ /* drain write buffers */ BARRIERS MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEwb), CpCACHEwait ISB MOVW CPSR, R2 MOVM.DB.W [R2,R14], (SP) /* save regs on stack */ CPSID /* splhi to make entire op atomic */ /* get cache sizes */ SLL $1, R8, R0 /* R0 = (cache - 1) << 1 */ MCR CpSC, CpIDcssel, R0, C(CpID), C(CpIDidct), 0 /* set cache size select */ ISB MRC CpSC, CpIDcsize, R0, C(CpID), C(CpIDidct), 0 /* get cache sizes */ /* compute # of ways and sets for this cache level */ SRA $3, R0, R5 /* R5 (ways) = R0 >> 3 */ AND $1023, R5 /* R5 = (R0 >> 3) & MASK(10) */ ADD $1, R5 /* R5 (ways) = ((R0 >> 3) & MASK(10)) + 1 */ SRA $13, R0, R2 /* R2 = R0 >> 13 */ AND $32767, R2 /* R2 = (R0 >> 13) & MASK(15) */ ADD $1, R2 /* R2 (sets) = ((R0 >> 13) & MASK(15)) + 1 */ /* precompute set/way shifts for inner loop */ MOVW $6, R4 CMP $0, R8 /* cache == 1? */ MOVW.EQ $30, R3 /* l1 */ MOVW.NE $29, R3 /* l2 */ CMP $16, R5 /* armv8 has 16-way l2, adjust shift */ MOVW.EQ $28, R3 /* iterate over ways */ MOVW $0, R7 /* R7: way */ outer: /* iterate over sets */ MOVW $0, R6 /* R6: set */ inner: /* compute set/way register contents */ SLL R3, R7, R0 /* R0 = way << R3 (L?WAYSH) */ ORR R8<<1, R0 /* R0 = way << L?WAYSH | (cache - 1) << 1 */ ORR R6<<R4, R0 /* R0 = way<<L?WAYSH | (cache-1)<<1 |set<<R4 */ BL (R1) /* call set/way operation with R0 */ ADD $1, R6 /* set++ */ CMP R2, R6 /* set >= sets? */ BLT inner /* no, do next set */ ADD $1, R7 /* way++ */ CMP R5, R7 /* way >= ways? */ BLT outer /* no, do next way */ MOVM.IA.W (SP), [R2,R14] /* restore regs */ MOVW R2, CPSR /* splx */ /* drain write buffers */ MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEwb), CpCACHEwait ISB RET