From: Jan Kiszka jan.kiszka@siemens.com
Based on the original version by Marc Zyngier. It adds a psci_cpu_off implementation for the A20 SoC. The mechanism works by first preparing the calling CPU to go offline (disable and flush cache, disable SMP), then requesting CPU 0 to pull the plug. The request is sent as FIQ on SGI15.
Signed-off-by: Jan Kiszka jan.kiszka@siemens.com --- arch/arm/cpu/armv7/sunxi/psci.S | 170 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 170 insertions(+)
diff --git a/arch/arm/cpu/armv7/sunxi/psci.S b/arch/arm/cpu/armv7/sunxi/psci.S index a84807d..0aa4007 100644 --- a/arch/arm/cpu/armv7/sunxi/psci.S +++ b/arch/arm/cpu/armv7/sunxi/psci.S @@ -18,6 +18,7 @@ */
#include <config.h> +#include <asm/gic.h> #include <asm/psci.h> #include <asm/arch/cpu.h>
@@ -38,6 +39,8 @@
#define ONE_MS (CONFIG_SYS_CLK_FREQ / 1000) #define TEN_MS (10 * ONE_MS) +#define GICD_BASE 0x1c81000 +#define GICC_BASE 0x1c82000
.macro timer_wait reg, ticks @ Program CNTP_TVAL @@ -61,7 +64,27 @@
.globl psci_arch_init psci_arch_init: + movw r4, #(GICD_BASE & 0xffff) + movt r4, #(GICD_BASE >> 16) + + ldr r5, [r4, #GICD_IGROUPRn] + bic r5, r5, #(1 << 15) @ SGI15 as Group-0 + str r5, [r4, #GICD_IGROUPRn] + + mov r5, #0 @ Set SGI15 priority to 0 + strb r5, [r4, #(GICD_IPRIORITYRn + 15)] + + add r4, r4, #0x1000 @ GICC address + + mov r5, #0xff + str r5, [r4, #GICC_PMR] @ Be cool with non-secure + + ldr r5, [r4, #GICC_CTLR] + orr r5, r5, #(1 << 3) @ Switch FIQEn on + str r5, [r4, #GICC_CTLR] + mrc p15, 0, r5, c1, c1, 0 @ Read SCR + orr r5, r5, #4 @ Enable FIQ in monitor mode bic r5, r5, #1 @ Secure mode mcr p15, 0, r5, c1, c1, 0 @ Write SCR isb @@ -79,6 +102,77 @@ psci_arch_init:
bx lr
+.globl psci_fiq_enter +psci_fiq_enter: + push {r0-r12} + + @ Switch to secure + mrc p15, 0, r7, c1, c1, 0 + bic r8, r7, #1 + mcr p15, 0, r8, c1, c1, 0 + isb + + movw r8, #(GICC_BASE & 0xffff) + movt r8, #(GICC_BASE >> 16) + ldr r9, [r8, #GICC_IAR] + movw r10, #0x3ff + movt r10, #0 + cmp r9, r10 + beq out + movw r10, #0x3fe + cmp r9, r10 + beq out + str r9, [r8, #GICC_EOIR] + dsb + + @ Compute CPU number + lsr r9, r9, #10 + and r9, r9, #0xf + + movw r8, #(SUN7I_CPUCFG_BASE & 0xffff) + movt r8, #(SUN7I_CPUCFG_BASE >> 16) + + @ Wait for the core to enter WFI + lsl r11, r9, #6 @ x64 + add r11, r11, r8 + +1: ldr r10, [r11, #0x48] + tst r10, #(1 << 2) + bne 2f + timer_wait r10, ONE_MS + b 1b + + @ Reset CPU +2: mov r10, #0 + str r10, [r11, #0x40] + + @ Lock CPU + mov r10, #1 + lsl r9, r10, r9 @ r9 is now CPU mask + ldr r10, [r8, #0x1e4] + bic r10, r10, r9 + str r10, [r8, #0x1e4] + + @ Set power gating + ldr r10, [r8, #0x1b4] + orr r10, r10, #1 + str r10, [r8, #0x1b4] + timer_wait r10, ONE_MS + + @ Activate power clamp + mov r10, #1 +1: str r10, [r8, #0x1b0] + lsl r10, r10, #1 + orr r10, r10, #1 + tst r10, #0x100 + beq 1b + + @ Restore security level +out: mcr p15, 0, r7, c1, c1, 0 + + pop {r0-r12} + subs pc, lr, #4 + @ r1 = target CPU @ r2 = target PC .globl psci_cpu_on @@ -144,6 +238,53 @@ psci_cpu_on: _target_pc: .word 0
+/* Imported from Linux kernel */ +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 + _sunxi_cpu_entry: @ Set SMP bit mrc p15, 0, r0, c1, c0, 1 @@ -158,5 +299,34 @@ _sunxi_cpu_entry: ldr r0, [r0] b _do_nonsec_entry
+.globl psci_cpu_off +psci_cpu_off: + 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??? + + 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 + + @ Ask CPU0 to pull the rug... + movw r0, #(GICD_BASE & 0xffff) + movt r0, #(GICD_BASE >> 16) + movw r1, #15 @ SGI15 + movt r1, #1 @ Target is CPU0 + str r1, [r0, #GICD_SGIR] + dsb + +1: wfi + b 1b + text_end: .popsection