diff options
author | Olof Johansson <olof@lixom.net> | 2012-09-16 21:33:23 -0400 |
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committer | Olof Johansson <olof@lixom.net> | 2012-09-16 21:33:23 -0400 |
commit | cccc277ba840f32d252a785ab1df686fdc0f49f5 (patch) | |
tree | b6eb71f0ec444d6982bfcb8748d3e570633c7a37 /arch/arm/mach-tegra/sleep-t30.S | |
parent | ea2abb670b712380adf0aa6945dc651711ac2b92 (diff) | |
parent | 453689e407f2b7c0a72a2e6fb2ef84c20475773b (diff) |
Merge tag 'tegra-for-3.7-cpu-hotplug' of git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-tegra into next/soc
From Stephen Warren:
ARM: tegra: implement CPU hotplug
This branch implements CPU hot-plugging support for both Tegra20 and
Tegra30. Portions of the implementation are contained in the clock
driver, hence this branch is based on the common clock conversion in
order to avoid duplicating work.
By Joseph Lo
via Stephen Warren
* tag 'tegra-for-3.7-cpu-hotplug' of git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-tegra:
ARM: tegra20: add CPU hotplug support
ARM: tegra30: add CPU hotplug support
ARM: tegra: clean up the common assembly macros into sleep.h
ARM: tegra: replace the CPU CAR access code by tegra_cpu_car_ops
ARM: tegra: introduce tegra_cpu_car_ops structures
Diffstat (limited to 'arch/arm/mach-tegra/sleep-t30.S')
-rw-r--r-- | arch/arm/mach-tegra/sleep-t30.S | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/sleep-t30.S b/arch/arm/mach-tegra/sleep-t30.S new file mode 100644 index 000000000000..777d9cee8b90 --- /dev/null +++ b/arch/arm/mach-tegra/sleep-t30.S | |||
@@ -0,0 +1,107 @@ | |||
1 | /* | ||
2 | * Copyright (c) 2012, NVIDIA Corporation. All rights reserved. | ||
3 | * | ||
4 | * This program is free software; you can redistribute it and/or modify it | ||
5 | * under the terms and conditions of the GNU General Public License, | ||
6 | * version 2, as published by the Free Software Foundation. | ||
7 | * | ||
8 | * This program is distributed in the hope it will be useful, but WITHOUT | ||
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | ||
11 | * more details. | ||
12 | * | ||
13 | * You should have received a copy of the GNU General Public License | ||
14 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | ||
15 | */ | ||
16 | |||
17 | #include <linux/linkage.h> | ||
18 | |||
19 | #include <asm/assembler.h> | ||
20 | |||
21 | #include <mach/iomap.h> | ||
22 | |||
23 | #include "sleep.h" | ||
24 | #include "flowctrl.h" | ||
25 | |||
26 | #define TEGRA30_POWER_HOTPLUG_SHUTDOWN (1 << 27) /* Hotplug shutdown */ | ||
27 | |||
28 | #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PM_SLEEP) | ||
29 | /* | ||
30 | * tegra30_hotplug_shutdown(void) | ||
31 | * | ||
32 | * Powergates the current CPU. | ||
33 | * Should never return. | ||
34 | */ | ||
35 | ENTRY(tegra30_hotplug_shutdown) | ||
36 | /* Turn off SMP coherency */ | ||
37 | exit_smp r4, r5 | ||
38 | |||
39 | /* Powergate this CPU */ | ||
40 | mov r0, #TEGRA30_POWER_HOTPLUG_SHUTDOWN | ||
41 | bl tegra30_cpu_shutdown | ||
42 | mov pc, lr @ should never get here | ||
43 | ENDPROC(tegra30_hotplug_shutdown) | ||
44 | |||
45 | /* | ||
46 | * tegra30_cpu_shutdown(unsigned long flags) | ||
47 | * | ||
48 | * Puts the current CPU in wait-for-event mode on the flow controller | ||
49 | * and powergates it -- flags (in R0) indicate the request type. | ||
50 | * Must never be called for CPU 0. | ||
51 | * | ||
52 | * corrupts r0-r4, r12 | ||
53 | */ | ||
54 | ENTRY(tegra30_cpu_shutdown) | ||
55 | cpu_id r3 | ||
56 | cmp r3, #0 | ||
57 | moveq pc, lr @ Must never be called for CPU 0 | ||
58 | |||
59 | ldr r12, =TEGRA_FLOW_CTRL_VIRT | ||
60 | cpu_to_csr_reg r1, r3 | ||
61 | add r1, r1, r12 @ virtual CSR address for this CPU | ||
62 | cpu_to_halt_reg r2, r3 | ||
63 | add r2, r2, r12 @ virtual HALT_EVENTS address for this CPU | ||
64 | |||
65 | /* | ||
66 | * Clear this CPU's "event" and "interrupt" flags and power gate | ||
67 | * it when halting but not before it is in the "WFE" state. | ||
68 | */ | ||
69 | movw r12, \ | ||
70 | FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG | \ | ||
71 | FLOW_CTRL_CSR_ENABLE | ||
72 | mov r4, #(1 << 4) | ||
73 | orr r12, r12, r4, lsl r3 | ||
74 | str r12, [r1] | ||
75 | |||
76 | /* Halt this CPU. */ | ||
77 | mov r3, #0x400 | ||
78 | delay_1: | ||
79 | subs r3, r3, #1 @ delay as a part of wfe war. | ||
80 | bge delay_1; | ||
81 | cpsid a @ disable imprecise aborts. | ||
82 | ldr r3, [r1] @ read CSR | ||
83 | str r3, [r1] @ clear CSR | ||
84 | tst r0, #TEGRA30_POWER_HOTPLUG_SHUTDOWN | ||
85 | movne r3, #FLOW_CTRL_WAITEVENT @ For hotplug | ||
86 | str r3, [r2] | ||
87 | ldr r0, [r2] | ||
88 | b wfe_war | ||
89 | |||
90 | __cpu_reset_again: | ||
91 | dsb | ||
92 | .align 5 | ||
93 | wfe @ CPU should be power gated here | ||
94 | wfe_war: | ||
95 | b __cpu_reset_again | ||
96 | |||
97 | /* | ||
98 | * 38 nop's, which fills reset of wfe cache line and | ||
99 | * 4 more cachelines with nop | ||
100 | */ | ||
101 | .rept 38 | ||
102 | nop | ||
103 | .endr | ||
104 | b . @ should never get here | ||
105 | |||
106 | ENDPROC(tegra30_cpu_shutdown) | ||
107 | #endif | ||