xref: /openbmc/linux/arch/arm/mach-omap2/sleep44xx.S (revision 96de2506) 
1/*
2 * OMAP44xx sleep code.
3 *
4 * Copyright (C) 2011 Texas Instruments, Inc.
5 * 	Santosh Shilimkar <santosh.shilimkar@ti.com>
6 *
7 * This program is free software,you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/linkage.h>
13#include <asm/assembler.h>
14#include <asm/smp_scu.h>
15#include <asm/memory.h>
16#include <asm/hardware/cache-l2x0.h>
17
18#include "omap-secure.h"
19
20#include "common.h"
21#include "omap44xx.h"
22#include "omap4-sar-layout.h"
23
24#if defined(CONFIG_SMP) && defined(CONFIG_PM)
25
26.macro	DO_SMC
27	dsb
28	smc	#0
29	dsb
30.endm
31
32#ifdef CONFIG_ARCH_OMAP4
33
34/*
35 * =============================
36 * == CPU suspend finisher ==
37 * =============================
38 *
39 * void omap4_finish_suspend(unsigned long cpu_state)
40 *
41 * This function code saves the CPU context and performs the CPU
42 * power down sequence. Calling WFI effectively changes the CPU
43 * power domains states to the desired target power state.
44 *
45 * @cpu_state : contains context save state (r0)
46 *	0 - No context lost
47 * 	1 - CPUx L1 and logic lost: MPUSS CSWR
48 * 	2 - CPUx L1 and logic lost + GIC lost: MPUSS OSWR
49 *	3 - CPUx L1 and logic lost + GIC + L2 lost: MPUSS OFF
50 * @return: This function never returns for CPU OFF and DORMANT power states.
51 * Post WFI, CPU transitions to DORMANT or OFF power state and on wake-up
52 * from this follows a full CPU reset path via ROM code to CPU restore code.
53 * The restore function pointer is stored at CPUx_WAKEUP_NS_PA_ADDR_OFFSET.
54 * It returns to the caller for CPU INACTIVE and ON power states or in case
55 * CPU failed to transition to targeted OFF/DORMANT state.
56 *
57 * omap4_finish_suspend() calls v7_flush_dcache_all() which doesn't save
58 * stack frame and it expects the caller to take care of it. Hence the entire
59 * stack frame is saved to avoid possible stack corruption.
60 */
61ENTRY(omap4_finish_suspend)
62	stmfd	sp!, {r4-r12, lr}
63	cmp	r0, #0x0
64	beq	do_WFI				@ No lowpower state, jump to WFI
65
66	/*
67	 * Flush all data from the L1 data cache before disabling
68	 * SCTLR.C bit.
69	 */
70	bl	omap4_get_sar_ram_base
71	ldr	r9, [r0, #OMAP_TYPE_OFFSET]
72	cmp	r9, #0x1			@ Check for HS device
73	bne	skip_secure_l1_clean
74	mov	r0, #SCU_PM_NORMAL
75	mov	r1, #0xFF			@ clean seucre L1
76	stmfd   r13!, {r4-r12, r14}
77	ldr	r12, =OMAP4_MON_SCU_PWR_INDEX
78	DO_SMC
79	ldmfd   r13!, {r4-r12, r14}
80skip_secure_l1_clean:
81	bl	v7_flush_dcache_all
82
83	/*
84	 * Clear the SCTLR.C bit to prevent further data cache
85	 * allocation. Clearing SCTLR.C would make all the data accesses
86	 * strongly ordered and would not hit the cache.
87	 */
88	mrc	p15, 0, r0, c1, c0, 0
89	bic	r0, r0, #(1 << 2)		@ Disable the C bit
90	mcr	p15, 0, r0, c1, c0, 0
91	isb
92
93	bl	v7_invalidate_l1
94
95	/*
96	 * Switch the CPU from Symmetric Multiprocessing (SMP) mode
97	 * to AsymmetricMultiprocessing (AMP) mode by programming
98	 * the SCU power status to DORMANT or OFF mode.
99	 * This enables the CPU to be taken out of coherency by
100	 * preventing the CPU from receiving cache, TLB, or BTB
101	 * maintenance operations broadcast by other CPUs in the cluster.
102	 */
103	bl	omap4_get_sar_ram_base
104	mov	r8, r0
105	ldr	r9, [r8, #OMAP_TYPE_OFFSET]
106	cmp	r9, #0x1			@ Check for HS device
107	bne	scu_gp_set
108	mrc	p15, 0, r0, c0, c0, 5		@ Read MPIDR
109	ands	r0, r0, #0x0f
110	ldreq	r0, [r8, #SCU_OFFSET0]
111	ldrne	r0, [r8, #SCU_OFFSET1]
112	mov	r1, #0x00
113	stmfd   r13!, {r4-r12, r14}
114	ldr	r12, =OMAP4_MON_SCU_PWR_INDEX
115	DO_SMC
116	ldmfd   r13!, {r4-r12, r14}
117	b	skip_scu_gp_set
118scu_gp_set:
119	mrc	p15, 0, r0, c0, c0, 5		@ Read MPIDR
120	ands	r0, r0, #0x0f
121	ldreq	r1, [r8, #SCU_OFFSET0]
122	ldrne	r1, [r8, #SCU_OFFSET1]
123	bl	omap4_get_scu_base
124	bl	scu_power_mode
125skip_scu_gp_set:
126	mrc	p15, 0, r0, c1, c1, 2		@ Read NSACR data
127	tst	r0, #(1 << 18)
128	mrcne	p15, 0, r0, c1, c0, 1
129	bicne	r0, r0, #(1 << 6)		@ Disable SMP bit
130	mcrne	p15, 0, r0, c1, c0, 1
131	isb
132	dsb
133#ifdef CONFIG_CACHE_L2X0
134	/*
135	 * Clean and invalidate the L2 cache.
136	 * Common cache-l2x0.c functions can't be used here since it
137	 * uses spinlocks. We are out of coherency here with data cache
138	 * disabled. The spinlock implementation uses exclusive load/store
139	 * instruction which can fail without data cache being enabled.
140	 * OMAP4 hardware doesn't support exclusive monitor which can
141	 * overcome exclusive access issue. Because of this, CPU can
142	 * lead to deadlock.
143	 */
144	bl	omap4_get_sar_ram_base
145	mov	r8, r0
146	mrc	p15, 0, r5, c0, c0, 5		@ Read MPIDR
147	ands	r5, r5, #0x0f
148	ldreq	r0, [r8, #L2X0_SAVE_OFFSET0]	@ Retrieve L2 state from SAR
149	ldrne	r0, [r8, #L2X0_SAVE_OFFSET1]	@ memory.
150	cmp	r0, #3
151	bne	do_WFI
152#ifdef CONFIG_PL310_ERRATA_727915
153	mov	r0, #0x03
154	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
155	DO_SMC
156#endif
157	bl	omap4_get_l2cache_base
158	mov	r2, r0
159	ldr	r0, =0xffff
160	str	r0, [r2, #L2X0_CLEAN_INV_WAY]
161wait:
162	ldr	r0, [r2, #L2X0_CLEAN_INV_WAY]
163	ldr	r1, =0xffff
164	ands	r0, r0, r1
165	bne	wait
166#ifdef CONFIG_PL310_ERRATA_727915
167	mov	r0, #0x00
168	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
169	DO_SMC
170#endif
171l2x_sync:
172	bl	omap4_get_l2cache_base
173	mov	r2, r0
174	mov	r0, #0x0
175	str	r0, [r2, #L2X0_CACHE_SYNC]
176sync:
177	ldr	r0, [r2, #L2X0_CACHE_SYNC]
178	ands	r0, r0, #0x1
179	bne	sync
180#endif
181
182do_WFI:
183	bl	omap_do_wfi
184
185	/*
186	 * CPU is here when it failed to enter OFF/DORMANT or
187	 * no low power state was attempted.
188	 */
189	mrc	p15, 0, r0, c1, c0, 0
190	tst	r0, #(1 << 2)			@ Check C bit enabled?
191	orreq	r0, r0, #(1 << 2)		@ Enable the C bit
192	mcreq	p15, 0, r0, c1, c0, 0
193	isb
194
195	/*
196	 * Ensure the CPU power state is set to NORMAL in
197	 * SCU power state so that CPU is back in coherency.
198	 * In non-coherent mode CPU can lock-up and lead to
199	 * system deadlock.
200	 */
201	mrc	p15, 0, r0, c1, c0, 1
202	tst	r0, #(1 << 6)			@ Check SMP bit enabled?
203	orreq	r0, r0, #(1 << 6)
204	mcreq	p15, 0, r0, c1, c0, 1
205	isb
206	bl	omap4_get_sar_ram_base
207	mov	r8, r0
208	ldr	r9, [r8, #OMAP_TYPE_OFFSET]
209	cmp	r9, #0x1			@ Check for HS device
210	bne	scu_gp_clear
211	mov	r0, #SCU_PM_NORMAL
212	mov	r1, #0x00
213	stmfd   r13!, {r4-r12, r14}
214	ldr	r12, =OMAP4_MON_SCU_PWR_INDEX
215	DO_SMC
216	ldmfd   r13!, {r4-r12, r14}
217	b	skip_scu_gp_clear
218scu_gp_clear:
219	bl	omap4_get_scu_base
220	mov	r1, #SCU_PM_NORMAL
221	bl	scu_power_mode
222skip_scu_gp_clear:
223	isb
224	dsb
225	ldmfd	sp!, {r4-r12, pc}
226ENDPROC(omap4_finish_suspend)
227
228/*
229 * ============================
230 * == CPU resume entry point ==
231 * ============================
232 *
233 * void omap4_cpu_resume(void)
234 *
235 * ROM code jumps to this function while waking up from CPU
236 * OFF or DORMANT state. Physical address of the function is
237 * stored in the SAR RAM while entering to OFF or DORMANT mode.
238 * The restore function pointer is stored at CPUx_WAKEUP_NS_PA_ADDR_OFFSET.
239 */
240ENTRY(omap4_cpu_resume)
241	/*
242	 * Configure ACTRL and enable NS SMP bit access on CPU1 on HS device.
243	 * OMAP44XX EMU/HS devices - CPU0 SMP bit access is enabled in PPA
244	 * init and for CPU1, a secure PPA API provided. CPU0 must be ON
245	 * while executing NS_SMP API on CPU1 and PPA version must be 1.4.0+.
246	 * OMAP443X GP devices- SMP bit isn't accessible.
247	 * OMAP446X GP devices - SMP bit access is enabled on both CPUs.
248	 */
249	ldr	r8, =OMAP44XX_SAR_RAM_BASE
250	ldr	r9, [r8, #OMAP_TYPE_OFFSET]
251	cmp	r9, #0x1			@ Skip if GP device
252	bne	skip_ns_smp_enable
253	mrc     p15, 0, r0, c0, c0, 5
254	ands    r0, r0, #0x0f
255	beq	skip_ns_smp_enable
256ppa_actrl_retry:
257	mov     r0, #OMAP4_PPA_CPU_ACTRL_SMP_INDEX
258	adr	r1, ppa_zero_params_offset
259	ldr	r3, [r1]
260	add	r3, r3, r1			@ Pointer to ppa_zero_params
261	mov	r1, #0x0			@ Process ID
262	mov	r2, #0x4			@ Flag
263	mov	r6, #0xff
264	mov	r12, #0x00			@ Secure Service ID
265	DO_SMC
266	cmp	r0, #0x0			@ API returns 0 on success.
267	beq	enable_smp_bit
268	b	ppa_actrl_retry
269enable_smp_bit:
270	mrc	p15, 0, r0, c1, c0, 1
271	tst	r0, #(1 << 6)			@ Check SMP bit enabled?
272	orreq	r0, r0, #(1 << 6)
273	mcreq	p15, 0, r0, c1, c0, 1
274	isb
275skip_ns_smp_enable:
276#ifdef CONFIG_CACHE_L2X0
277	/*
278	 * Restore the L2 AUXCTRL and enable the L2 cache.
279	 * OMAP4_MON_L2X0_AUXCTRL_INDEX =  Program the L2X0 AUXCTRL
280	 * OMAP4_MON_L2X0_CTRL_INDEX =  Enable the L2 using L2X0 CTRL
281	 * register r0 contains value to be programmed.
282	 * L2 cache is already invalidate by ROM code as part
283	 * of MPUSS OFF wakeup path.
284	 */
285	ldr	r2, =OMAP44XX_L2CACHE_BASE
286	ldr	r0, [r2, #L2X0_CTRL]
287	and	r0, #0x0f
288	cmp	r0, #1
289	beq	skip_l2en			@ Skip if already enabled
290	ldr	r3, =OMAP44XX_SAR_RAM_BASE
291	ldr	r1, [r3, #OMAP_TYPE_OFFSET]
292	cmp	r1, #0x1			@ Check for HS device
293	bne     set_gp_por
294	ldr     r0, =OMAP4_PPA_L2_POR_INDEX
295	ldr     r1, =OMAP44XX_SAR_RAM_BASE
296	ldr     r4, [r1, #L2X0_PREFETCH_CTRL_OFFSET]
297	adr     r1, ppa_por_params_offset
298	ldr	r3, [r1]
299	add	r3, r3, r1			@ Pointer to ppa_por_params
300	str     r4, [r3, #0x04]
301	mov	r1, #0x0			@ Process ID
302	mov	r2, #0x4			@ Flag
303	mov	r6, #0xff
304	mov	r12, #0x00			@ Secure Service ID
305	DO_SMC
306	b	set_aux_ctrl
307set_gp_por:
308	ldr     r1, =OMAP44XX_SAR_RAM_BASE
309	ldr     r0, [r1, #L2X0_PREFETCH_CTRL_OFFSET]
310	ldr	r12, =OMAP4_MON_L2X0_PREFETCH_INDEX	@ Setup L2 PREFETCH
311	DO_SMC
312set_aux_ctrl:
313	ldr     r1, =OMAP44XX_SAR_RAM_BASE
314	ldr	r0, [r1, #L2X0_AUXCTRL_OFFSET]
315	ldr	r12, =OMAP4_MON_L2X0_AUXCTRL_INDEX	@ Setup L2 AUXCTRL
316	DO_SMC
317	mov	r0, #0x1
318	ldr	r12, =OMAP4_MON_L2X0_CTRL_INDEX		@ Enable L2 cache
319	DO_SMC
320skip_l2en:
321#endif
322
323	b	cpu_resume			@ Jump to generic resume
324ppa_por_params_offset:
325	.long	ppa_por_params - .
326ENDPROC(omap4_cpu_resume)
327#endif	/* CONFIG_ARCH_OMAP4 */
328
329#endif	/* defined(CONFIG_SMP) && defined(CONFIG_PM) */
330
331ENTRY(omap_do_wfi)
332	stmfd	sp!, {lr}
333#ifdef CONFIG_OMAP_INTERCONNECT_BARRIER
334	/* Drain interconnect write buffers. */
335	bl	omap_interconnect_sync
336#endif
337
338	/*
339	 * Execute an ISB instruction to ensure that all of the
340	 * CP15 register changes have been committed.
341	 */
342	isb
343
344	/*
345	 * Execute a barrier instruction to ensure that all cache,
346	 * TLB and branch predictor maintenance operations issued
347	 * by any CPU in the cluster have completed.
348	 */
349	dsb
350	dmb
351
352	/*
353	 * Execute a WFI instruction and wait until the
354	 * STANDBYWFI output is asserted to indicate that the
355	 * CPU is in idle and low power state. CPU can specualatively
356	 * prefetch the instructions so add NOPs after WFI. Sixteen
357	 * NOPs as per Cortex-A9 pipeline.
358	 */
359	wfi					@ Wait For Interrupt
360	nop
361	nop
362	nop
363	nop
364	nop
365	nop
366	nop
367	nop
368	nop
369	nop
370	nop
371	nop
372	nop
373	nop
374	nop
375	nop
376
377	ldmfd	sp!, {pc}
378ppa_zero_params_offset:
379	.long	ppa_zero_params - .
380ENDPROC(omap_do_wfi)
381
382	.data
383	.align	2
384ppa_zero_params:
385	.word		0
386
387ppa_por_params:
388	.word		1, 0
389