From b0206e7d26ebb695421c7c093b13475bed92c54d Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Tue, 21 Apr 2015 07:18:27 +0200 Subject: ARM: Factor out reusable psci_cpu_off_common Move parts of sunxi's psci_cpu_off into psci_cpu_off_common, namely cache disabling and flushing, clrex and the disabling of SMP for the dying CPU. These steps are apparently generic for ARMv7 and will be reused for Tegra124 support. As the way of disabled SMP is not architectural, though commonly done via ACLTR, the related function can be overloaded. CC: Marc Zyngier Signed-off-by: Jan Kiszka Reviewed-by: Tom Rini Reviewed-by: Thierry Reding Tested-by: Thierry Reding Tested-by: Ian Campbell Signed-off-by: Tom Warren --- arch/arm/cpu/armv7/psci.S | 77 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) (limited to 'arch/arm/cpu/armv7/psci.S') diff --git a/arch/arm/cpu/armv7/psci.S b/arch/arm/cpu/armv7/psci.S index 12ad09b96c..cdcdccdc47 100644 --- a/arch/arm/cpu/armv7/psci.S +++ b/arch/arm/cpu/armv7/psci.S @@ -107,4 +107,81 @@ ENTRY(psci_get_cpu_id) ENDPROC(psci_get_cpu_id) .weak psci_get_cpu_id +/* Imported from Linux kernel */ +LENTRY(v7_flush_dcache_all) + dmb @ ensure ordering with previous memory accesses + mrc p15, 1, r0, c0, c0, 1 @ read clidr + ands r3, r0, #0x7000000 @ extract loc from clidr + mov r3, r3, lsr #23 @ left align loc bit field + beq finished @ if loc is 0, then no need to clean + mov r10, #0 @ start clean at cache level 0 +flush_levels: + add r2, r10, r10, lsr #1 @ work out 3x current cache level + mov r1, r0, lsr r2 @ extract cache type bits from clidr + and r1, r1, #7 @ mask of the bits for current cache only + cmp r1, #2 @ see what cache we have at this level + blt skip @ skip if no cache, or just i-cache + mrs r9, cpsr @ make cssr&csidr read atomic + mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr + isb @ isb to sych the new cssr&csidr + mrc p15, 1, r1, c0, c0, 0 @ read the new csidr + msr cpsr_c, r9 + and r2, r1, #7 @ extract the length of the cache lines + add r2, r2, #4 @ add 4 (line length offset) + ldr r4, =0x3ff + ands r4, r4, r1, lsr #3 @ find maximum number on the way size + clz r5, r4 @ find bit position of way size increment + ldr r7, =0x7fff + ands r7, r7, r1, lsr #13 @ extract max number of the index size +loop1: + mov r9, r7 @ create working copy of max index +loop2: + orr r11, r10, r4, lsl r5 @ factor way and cache number into r11 + orr r11, r11, r9, lsl r2 @ factor index number into r11 + mcr p15, 0, r11, c7, c14, 2 @ clean & invalidate by set/way + subs r9, r9, #1 @ decrement the index + bge loop2 + subs r4, r4, #1 @ decrement the way + bge loop1 +skip: + add r10, r10, #2 @ increment cache number + cmp r3, r10 + bgt flush_levels +finished: + mov r10, #0 @ swith back to cache level 0 + mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr + dsb st + isb + bx lr +ENDPROC(v7_flush_dcache_all) + +ENTRY(psci_disable_smp) + mrc p15, 0, r0, c1, c0, 1 @ ACTLR + bic r0, r0, #(1 << 6) @ Clear SMP bit + mcr p15, 0, r0, c1, c0, 1 @ ACTLR + isb + dsb + bx lr +ENDPROC(psci_disable_smp) +.weak psci_disable_smp + +ENTRY(psci_cpu_off_common) + push {lr} + + mrc p15, 0, r0, c1, c0, 0 @ SCTLR + bic r0, r0, #(1 << 2) @ Clear C bit + mcr p15, 0, r0, c1, c0, 0 @ SCTLR + isb + dsb + + bl v7_flush_dcache_all + + clrex @ Why??? + + bl psci_disable_smp + + pop {lr} + bx lr +ENDPROC(psci_cpu_off_common) + .popsection -- cgit v1.2.1