xref: /rk3399_ARM-atf/lib/cpus/aarch32/cpu_helpers.S (revision 51faada71a219a8b94cd8d8e423f0f22e9da4d8f)
1/*
2 * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * Redistributions of source code must retain the above copyright notice, this
8 * list of conditions and the following disclaimer.
9 *
10 * Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 *
14 * Neither the name of ARM nor the names of its contributors may be used
15 * to endorse or promote products derived from this software without specific
16 * prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <arch.h>
32#include <asm_macros.S>
33#include <assert_macros.S>
34#include <cpu_data.h>
35#include <cpu_macros.S>
36
37#if defined(IMAGE_BL1) || defined(IMAGE_BL32)
38	/*
39	 * The reset handler common to all platforms.  After a matching
40	 * cpu_ops structure entry is found, the correponding reset_handler
41	 * in the cpu_ops is invoked. The reset handler is invoked very early
42	 * in the boot sequence and it is assumed that we can clobber r0 - r10
43	 * without the need to follow AAPCS.
44	 * Clobbers: r0 - r10
45	 */
46	.globl	reset_handler
47func reset_handler
48	mov	r10, lr
49
50	/* The plat_reset_handler can clobber r0 - r9 */
51	bl	plat_reset_handler
52
53	/* Get the matching cpu_ops pointer (clobbers: r0 - r5) */
54	bl	get_cpu_ops_ptr
55
56#if ASM_ASSERTION
57	cmp	r0, #0
58	ASM_ASSERT(ne)
59#endif
60
61	/* Get the cpu_ops reset handler */
62	ldr	r1, [r0, #CPU_RESET_FUNC]
63	cmp	r1, #0
64	mov	lr, r10
65	bxne	r1
66	bx	lr
67endfunc reset_handler
68
69#endif /* IMAGE_BL1 || IMAGE_BL32 */
70
71#ifdef IMAGE_BL32 /* The power down core and cluster is needed only in  BL32 */
72	/*
73	 * void prepare_cpu_pwr_dwn(unsigned int power_level)
74	 *
75	 * Prepare CPU power down function for all platforms. The function takes
76	 * a domain level to be powered down as its parameter. After the cpu_ops
77	 * pointer is retrieved from cpu_data, the handler for requested power
78	 * level is called.
79	 */
80	.globl	prepare_cpu_pwr_dwn
81func prepare_cpu_pwr_dwn
82	/*
83	 * If the given power level exceeds CPU_MAX_PWR_DWN_OPS, we call the
84	 * power down handler for the last power level
85	 */
86	mov	r2, #(CPU_MAX_PWR_DWN_OPS - 1)
87	cmp	r0, r2
88	movhi	r0, r2
89
90	push	{r0, lr}
91	bl	_cpu_data
92	pop	{r2, lr}
93
94	ldr	r0, [r0, #CPU_DATA_CPU_OPS_PTR]
95#if ASM_ASSERTION
96	cmp	r0, #0
97	ASM_ASSERT(ne)
98#endif
99
100	/* Get the appropriate power down handler */
101	mov	r1, #CPU_PWR_DWN_OPS
102	add	r1, r1, r2, lsl #2
103	ldr	r1, [r0, r1]
104	bx	r1
105endfunc prepare_cpu_pwr_dwn
106
107	/*
108	 * Initializes the cpu_ops_ptr if not already initialized
109	 * in cpu_data. This must only be called after the data cache
110	 * is enabled. AAPCS is followed.
111	 */
112	.globl	init_cpu_ops
113func init_cpu_ops
114	push	{r4 - r6, lr}
115	bl	_cpu_data
116	mov	r6, r0
117	ldr	r1, [r0, #CPU_DATA_CPU_OPS_PTR]
118	cmp	r1, #0
119	bne	1f
120	bl	get_cpu_ops_ptr
121#if ASM_ASSERTION
122	cmp	r0, #0
123	ASM_ASSERT(ne)
124#endif
125	str	r0, [r6, #CPU_DATA_CPU_OPS_PTR]!
1261:
127	pop	{r4 - r6, pc}
128endfunc init_cpu_ops
129
130#endif /* IMAGE_BL32 */
131
132	/*
133	 * The below function returns the cpu_ops structure matching the
134	 * midr of the core. It reads the MIDR and finds the matching
135	 * entry in cpu_ops entries. Only the implementation and part number
136	 * are used to match the entries.
137	 * Return :
138	 *     r0 - The matching cpu_ops pointer on Success
139	 *     r0 - 0 on failure.
140	 * Clobbers: r0 - r5
141	 */
142	.globl	get_cpu_ops_ptr
143func get_cpu_ops_ptr
144	/* Get the cpu_ops start and end locations */
145	ldr	r4, =(__CPU_OPS_START__ + CPU_MIDR)
146	ldr	r5, =(__CPU_OPS_END__ + CPU_MIDR)
147
148	/* Initialize the return parameter */
149	mov	r0, #0
150
151	/* Read the MIDR_EL1 */
152	ldcopr	r2, MIDR
153	ldr	r3, =CPU_IMPL_PN_MASK
154
155	/* Retain only the implementation and part number using mask */
156	and	r2, r2, r3
1571:
158	/* Check if we have reached end of list */
159	cmp	r4, r5
160	bhs	error_exit
161
162	/* load the midr from the cpu_ops */
163	ldr	r1, [r4], #CPU_OPS_SIZE
164	and	r1, r1, r3
165
166	/* Check if midr matches to midr of this core */
167	cmp	r1, r2
168	bne	1b
169
170	/* Subtract the increment and offset to get the cpu-ops pointer */
171	sub	r0, r4, #(CPU_OPS_SIZE + CPU_MIDR)
172error_exit:
173	bx	lr
174endfunc get_cpu_ops_ptr
175
176/*
177 * Extract CPU revision and variant, and combine them into a single numeric for
178 * easier comparison.
179 */
180	.globl	cpu_get_rev_var
181func cpu_get_rev_var
182	ldcopr	r1, MIDR
183
184	/*
185	 * Extract the variant[23:20] and revision[3:0] from r1 and pack it in
186	 * r0[0:7] as variant[7:4] and revision[3:0]:
187	 *
188	 * First extract r1[23:16] to r0[7:0] and zero fill the rest. Then
189	 * extract r1[3:0] into r0[3:0] retaining other bits.
190	 */
191	ubfx	r0, r1, #(MIDR_VAR_SHIFT - MIDR_REV_BITS), #(MIDR_REV_BITS + MIDR_VAR_BITS)
192	bfi	r0, r1, #MIDR_REV_SHIFT, #MIDR_REV_BITS
193	bx	lr
194endfunc cpu_get_rev_var
195
196/*
197 * Compare the CPU's revision-variant (r0) with a given value (r1), for errata
198 * application purposes. If the revision-variant is less than or same as a given
199 * value, indicates that errata applies; otherwise not.
200 */
201	.globl	cpu_rev_var_ls
202func cpu_rev_var_ls
203	cmp	r0, r1
204	movls	r0, #ERRATA_APPLIES
205	movhi	r0, #ERRATA_NOT_APPLIES
206	bx	lr
207endfunc cpu_rev_var_ls
208
209#if REPORT_ERRATA
210/*
211 * void print_errata_status(void);
212 *
213 * Function to print errata status for CPUs of its class. Must be called only:
214 *
215 *   - with MMU and data caches are enabled;
216 *   - after cpu_ops have been initialized in per-CPU data.
217 */
218	.globl print_errata_status
219func print_errata_status
220	push	{r4, lr}
221#ifdef IMAGE_BL1
222	/*
223	 * BL1 doesn't have per-CPU data. So retrieve the CPU operations
224	 * directly.
225	 */
226	bl	get_cpu_ops_ptr
227	ldr	r0, [r0, #CPU_ERRATA_FUNC]
228	cmp	r0, #0
229	blxne	r0
230#else
231	/*
232	 * Retrieve pointer to cpu_ops, and further, the errata printing
233	 * function. If it's non-NULL, jump to the function in turn.
234	 */
235	bl	_cpu_data
236	ldr	r1, [r0, #CPU_DATA_CPU_OPS_PTR]
237	ldr	r0, [r1, #CPU_ERRATA_FUNC]
238	cmp	r0, #0
239	beq	1f
240
241	mov	r4, r0
242
243	/*
244	 * Load pointers to errata lock and printed flag. Call
245	 * errata_needs_reporting to check whether this CPU needs to report
246	 * errata status pertaining to its class.
247	 */
248	ldr	r0, [r1, #CPU_ERRATA_LOCK]
249	ldr	r1, [r1, #CPU_ERRATA_PRINTED]
250	bl	errata_needs_reporting
251	cmp	r0, #0
252	blxne	r4
2531:
254#endif
255	pop	{r4, pc}
256endfunc print_errata_status
257#endif
258