On Wed, Jul 31, 2019 at 11:38:57AM -0400, Pavel Tatashin wrote: > +/* > + * The following code is adoped from "Bare-metal Boot Code for ARMv8-A > + * Processors Version 1.0, 5.3.1 Cleaning and invalidating the caches". > + * http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dai0527a > + */ > +.macro dcache_invalidate tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, tmp8 > + mov \tmp0, #0x0 /* tmp0 = Cache level */ > + msr CSSELR_EL1, \tmp0 /* 0x0 for L1, 0x2 for L2 */ > + mrs \tmp4, CCSIDR_EL1 /* Read Cache Size ID */ > + and \tmp1, \tmp4, #0x7 > + add \tmp1, \tmp1, #0x4 /* tmp1 Cache Line Size */ > + ldr \tmp3, =0x7fff > + and \tmp2, \tmp3, \tmp4, lsr #13 /* tmp2 Cache Set num - 1 */ > + ldr \tmp3, =0x3ff > + and \tmp3, \tmp3, \tmp4, lsr #3 /* tmp3 Cache Assoc. num - 1 */ > + clz \tmp4, \tmp3 /* tmp4 way pos. in the CISW */ > + mov \tmp5, #0 /* tmp5 way counter way_loop */ > +1: /* way_loop */ > + mov \tmp6, #0 /* tmp6 set counter set_loop */ > +2: /* set_loop */ > + lsl \tmp7, \tmp5, \tmp4 > + orr \tmp7, \tmp0, \tmp7 /* Set way */ > + lsl \tmp8, \tmp6, \tmp1 > + orr \tmp7, \tmp7, \tmp8 /* Set set */ > + dc cisw, \tmp7 /* Clean & Inval. cache line */ > + add \tmp6, \tmp6, #1 /* Increment set counter */ > + cmp \tmp6, \tmp2 /* Last set reached yet? */ > + ble 2b /* If not, iterate set_loop, */ > + add \tmp5, \tmp5, #1 /* else, next way. */ > + cmp \tmp5, \tmp3 /* Last way reached yet? */ > + ble 1b /* If not, iterate way_loop. */ > +.endm > + For various reasons, one cannot safely use Set/Way operations in portable code. They only make sense for low-level platform-specific firmware performing power management operations. If you need to perform D-cache maintenance, you must use the VA operations to do so. Thanks, Mark.
