#include <linux/linkage.h>
#include <asm/assembler.h>
+#include <asm/proc-fns.h>
+#include <asm/cp15.h>
#include "sleep.h"
#include "flowctrl.h"
* should never return
*/
ENTRY(tegra20_hotplug_shutdown)
- /* Turn off SMP coherency */
- exit_smp r4, r5
-
/* Put this CPU down */
cpu_id r0
bl tegra20_cpu_shutdown
ENTRY(tegra20_cpu_shutdown)
cmp r0, #0
moveq pc, lr @ must not be called for CPU 0
+ mov32 r1, TEGRA_PMC_VIRT + PMC_SCRATCH41
+ mov r12, #CPU_RESETTABLE
+ str r12, [r1]
cpu_to_halt_reg r1, r0
ldr r3, =TEGRA_FLOW_CTRL_VIRT
mov pc, lr
ENDPROC(tegra20_cpu_shutdown)
#endif
+
+#ifdef CONFIG_PM_SLEEP
+/*
+ * tegra_pen_lock
+ *
+ * spinlock implementation with no atomic test-and-set and no coherence
+ * using Peterson's algorithm on strongly-ordered registers
+ * used to synchronize a cpu waking up from wfi with entering lp2 on idle
+ *
+ * The reference link of Peterson's algorithm:
+ * http://en.wikipedia.org/wiki/Peterson's_algorithm
+ *
+ * SCRATCH37 = r1 = !turn (inverted from Peterson's algorithm)
+ * on cpu 0:
+ * r2 = flag[0] (in SCRATCH38)
+ * r3 = flag[1] (in SCRATCH39)
+ * on cpu1:
+ * r2 = flag[1] (in SCRATCH39)
+ * r3 = flag[0] (in SCRATCH38)
+ *
+ * must be called with MMU on
+ * corrupts r0-r3, r12
+ */
+ENTRY(tegra_pen_lock)
+ mov32 r3, TEGRA_PMC_VIRT
+ cpu_id r0
+ add r1, r3, #PMC_SCRATCH37
+ cmp r0, #0
+ addeq r2, r3, #PMC_SCRATCH38
+ addeq r3, r3, #PMC_SCRATCH39
+ addne r2, r3, #PMC_SCRATCH39
+ addne r3, r3, #PMC_SCRATCH38
+
+ mov r12, #1
+ str r12, [r2] @ flag[cpu] = 1
+ dsb
+ str r12, [r1] @ !turn = cpu
+1: dsb
+ ldr r12, [r3]
+ cmp r12, #1 @ flag[!cpu] == 1?
+ ldreq r12, [r1]
+ cmpeq r12, r0 @ !turn == cpu?
+ beq 1b @ while !turn == cpu && flag[!cpu] == 1
+
+ mov pc, lr @ locked
+ENDPROC(tegra_pen_lock)
+
+ENTRY(tegra_pen_unlock)
+ dsb
+ mov32 r3, TEGRA_PMC_VIRT
+ cpu_id r0
+ cmp r0, #0
+ addeq r2, r3, #PMC_SCRATCH38
+ addne r2, r3, #PMC_SCRATCH39
+ mov r12, #0
+ str r12, [r2]
+ mov pc, lr
+ENDPROC(tegra_pen_unlock)
+
+/*
+ * tegra20_cpu_clear_resettable(void)
+ *
+ * Called to clear the "resettable soon" flag in PMC_SCRATCH41 when
+ * it is expected that the secondary CPU will be idle soon.
+ */
+ENTRY(tegra20_cpu_clear_resettable)
+ mov32 r1, TEGRA_PMC_VIRT + PMC_SCRATCH41
+ mov r12, #CPU_NOT_RESETTABLE
+ str r12, [r1]
+ mov pc, lr
+ENDPROC(tegra20_cpu_clear_resettable)
+
+/*
+ * tegra20_cpu_set_resettable_soon(void)
+ *
+ * Called to set the "resettable soon" flag in PMC_SCRATCH41 when
+ * it is expected that the secondary CPU will be idle soon.
+ */
+ENTRY(tegra20_cpu_set_resettable_soon)
+ mov32 r1, TEGRA_PMC_VIRT + PMC_SCRATCH41
+ mov r12, #CPU_RESETTABLE_SOON
+ str r12, [r1]
+ mov pc, lr
+ENDPROC(tegra20_cpu_set_resettable_soon)
+
+/*
+ * tegra20_cpu_is_resettable_soon(void)
+ *
+ * Returns true if the "resettable soon" flag in PMC_SCRATCH41 has been
+ * set because it is expected that the secondary CPU will be idle soon.
+ */
+ENTRY(tegra20_cpu_is_resettable_soon)
+ mov32 r1, TEGRA_PMC_VIRT + PMC_SCRATCH41
+ ldr r12, [r1]
+ cmp r12, #CPU_RESETTABLE_SOON
+ moveq r0, #1
+ movne r0, #0
+ mov pc, lr
+ENDPROC(tegra20_cpu_is_resettable_soon)
+
+/*
+ * tegra20_sleep_cpu_secondary_finish(unsigned long v2p)
+ *
+ * Enters WFI on secondary CPU by exiting coherency.
+ */
+ENTRY(tegra20_sleep_cpu_secondary_finish)
+ stmfd sp!, {r4-r11, lr}
+
+ mrc p15, 0, r11, c1, c0, 1 @ save actlr before exiting coherency
+
+ /* Flush and disable the L1 data cache */
+ bl tegra_disable_clean_inv_dcache
+
+ mov32 r0, TEGRA_PMC_VIRT + PMC_SCRATCH41
+ mov r3, #CPU_RESETTABLE
+ str r3, [r0]
+
+ bl cpu_do_idle
+
+ /*
+ * cpu may be reset while in wfi, which will return through
+ * tegra_resume to cpu_resume
+ * or interrupt may wake wfi, which will return here
+ * cpu state is unchanged - MMU is on, cache is on, coherency
+ * is off, and the data cache is off
+ *
+ * r11 contains the original actlr
+ */
+
+ bl tegra_pen_lock
+
+ mov32 r3, TEGRA_PMC_VIRT
+ add r0, r3, #PMC_SCRATCH41
+ mov r3, #CPU_NOT_RESETTABLE
+ str r3, [r0]
+
+ bl tegra_pen_unlock
+
+ /* Re-enable the data cache */
+ mrc p15, 0, r10, c1, c0, 0
+ orr r10, r10, #CR_C
+ mcr p15, 0, r10, c1, c0, 0
+ isb
+
+ mcr p15, 0, r11, c1, c0, 1 @ reenable coherency
+
+ /* Invalidate the TLBs & BTAC */
+ mov r1, #0
+ mcr p15, 0, r1, c8, c3, 0 @ invalidate shared TLBs
+ mcr p15, 0, r1, c7, c1, 6 @ invalidate shared BTAC
+ dsb
+ isb
+
+ /* the cpu was running with coherency disabled,
+ * caches may be out of date */
+ bl v7_flush_kern_cache_louis
+
+ ldmfd sp!, {r4 - r11, pc}
+ENDPROC(tegra20_sleep_cpu_secondary_finish)
+
+/*
+ * tegra20_tear_down_cpu
+ *
+ * Switches the CPU cluster to PLL-P and enters sleep.
+ */
+ENTRY(tegra20_tear_down_cpu)
+ bl tegra_switch_cpu_to_pllp
+ b tegra20_enter_sleep
+ENDPROC(tegra20_tear_down_cpu)
+
+/*
+ * tegra20_enter_sleep
+ *
+ * uses flow controller to enter sleep state
+ * executes from IRAM with SDRAM in selfrefresh when target state is LP0 or LP1
+ * executes from SDRAM with target state is LP2
+ */
+tegra20_enter_sleep:
+ mov32 r6, TEGRA_FLOW_CTRL_BASE
+
+ mov r0, #FLOW_CTRL_WAIT_FOR_INTERRUPT
+ orr r0, r0, #FLOW_CTRL_HALT_CPU_IRQ | FLOW_CTRL_HALT_CPU_FIQ
+ cpu_id r1
+ cpu_to_halt_reg r1, r1
+ str r0, [r6, r1]
+ dsb
+ ldr r0, [r6, r1] /* memory barrier */
+
+halted:
+ dsb
+ wfe /* CPU should be power gated here */
+ isb
+ b halted
+
+#endif
projects / ~andy / linux / blobdiff