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1/*
2 * Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7#include <arch.h>
8#include <asm_macros.S>
9#include <common/bl_common.h>
10#include <common/runtime_svc.h>
11#include <context.h>
12#include <el3_common_macros.S>
13#include <lib/el3_runtime/cpu_data.h>
14#include <lib/pmf/aarch32/pmf_asm_macros.S>
15#include <lib/runtime_instr.h>
16#include <lib/xlat_tables/xlat_tables_defs.h>
17#include <smccc_helpers.h>
18#include <smccc_macros.S>
19
20	.globl	sp_min_vector_table
21	.globl	sp_min_entrypoint
22	.globl	sp_min_warm_entrypoint
23	.globl	sp_min_handle_smc
24	.globl	sp_min_handle_fiq
25
26	.macro route_fiq_to_sp_min reg
27		/* -----------------------------------------------------
28		 * FIQs are secure interrupts trapped by Monitor and non
29		 * secure is not allowed to mask the FIQs.
30		 * -----------------------------------------------------
31		 */
32		ldcopr	\reg, SCR
33		orr	\reg, \reg, #SCR_FIQ_BIT
34		bic	\reg, \reg, #SCR_FW_BIT
35		stcopr	\reg, SCR
36	.endm
37
38	.macro clrex_on_monitor_entry
39#if (ARM_ARCH_MAJOR == 7)
40	/*
41	 * ARMv7 architectures need to clear the exclusive access when
42	 * entering Monitor mode.
43	 */
44	clrex
45#endif
46	.endm
47
48vector_base sp_min_vector_table
49	b	sp_min_entrypoint
50	b	plat_panic_handler	/* Undef */
51	b	sp_min_handle_smc	/* Syscall */
52	b	plat_panic_handler	/* Prefetch abort */
53	b	plat_panic_handler	/* Data abort */
54	b	plat_panic_handler	/* Reserved */
55	b	plat_panic_handler	/* IRQ */
56	b	sp_min_handle_fiq	/* FIQ */
57
58
59/*
60 * The Cold boot/Reset entrypoint for SP_MIN
61 */
62func sp_min_entrypoint
63#if !RESET_TO_SP_MIN
64	/* ---------------------------------------------------------------
65	 * Preceding bootloader has populated r0 with a pointer to a
66	 * 'bl_params_t' structure & r1 with a pointer to platform
67	 * specific structure
68	 * ---------------------------------------------------------------
69	 */
70	mov	r9, r0
71	mov	r10, r1
72	mov	r11, r2
73	mov	r12, r3
74
75	/* ---------------------------------------------------------------------
76	 * For !RESET_TO_SP_MIN systems, only the primary CPU ever reaches
77	 * sp_min_entrypoint() during the cold boot flow, so the cold/warm boot
78	 * and primary/secondary CPU logic should not be executed in this case.
79	 *
80	 * Also, assume that the previous bootloader has already initialised the
81	 * SCTLR, including the CPU endianness, and has initialised the memory.
82	 * ---------------------------------------------------------------------
83	 */
84	el3_entrypoint_common					\
85		_init_sctlr=0					\
86		_warm_boot_mailbox=0				\
87		_secondary_cold_boot=0				\
88		_init_memory=0					\
89		_init_c_runtime=1				\
90		_exception_vectors=sp_min_vector_table
91
92	/* ---------------------------------------------------------------------
93	 * Relay the previous bootloader's arguments to the platform layer
94	 * ---------------------------------------------------------------------
95	 */
96#else
97	/* ---------------------------------------------------------------------
98	 * For RESET_TO_SP_MIN systems which have a programmable reset address,
99	 * sp_min_entrypoint() is executed only on the cold boot path so we can
100	 * skip the warm boot mailbox mechanism.
101	 * ---------------------------------------------------------------------
102	 */
103	el3_entrypoint_common					\
104		_init_sctlr=1					\
105		_warm_boot_mailbox=!PROGRAMMABLE_RESET_ADDRESS	\
106		_secondary_cold_boot=!COLD_BOOT_SINGLE_CPU	\
107		_init_memory=1					\
108		_init_c_runtime=1				\
109		_exception_vectors=sp_min_vector_table
110
111	/* ---------------------------------------------------------------------
112	 * For RESET_TO_SP_MIN systems, BL32 (SP_MIN) is the first bootloader
113	 * to run so there's no argument to relay from a previous bootloader.
114	 * Zero the arguments passed to the platform layer to reflect that.
115	 * ---------------------------------------------------------------------
116	 */
117	mov	r9, #0
118	mov	r10, #0
119	mov	r11, #0
120	mov	r12, #0
121
122#endif /* RESET_TO_SP_MIN */
123
124#if SP_MIN_WITH_SECURE_FIQ
125	route_fiq_to_sp_min r4
126#endif
127
128	mov	r0, r9
129	mov	r1, r10
130	mov	r2, r11
131	mov	r3, r12
132	bl	sp_min_early_platform_setup2
133	bl	sp_min_plat_arch_setup
134
135	/* Jump to the main function */
136	bl	sp_min_main
137
138	/* -------------------------------------------------------------
139	 * Clean the .data & .bss sections to main memory. This ensures
140	 * that any global data which was initialised by the primary CPU
141	 * is visible to secondary CPUs before they enable their data
142	 * caches and participate in coherency.
143	 * -------------------------------------------------------------
144	 */
145	ldr	r0, =__DATA_START__
146	ldr	r1, =__DATA_END__
147	sub	r1, r1, r0
148	bl	clean_dcache_range
149
150	ldr	r0, =__BSS_START__
151	ldr	r1, =__BSS_END__
152	sub	r1, r1, r0
153	bl	clean_dcache_range
154
155	bl	smc_get_next_ctx
156
157	/* r0 points to `smc_ctx_t` */
158	/* The PSCI cpu_context registers have been copied to `smc_ctx_t` */
159	b	sp_min_exit
160endfunc sp_min_entrypoint
161
162
163/*
164 * SMC handling function for SP_MIN.
165 */
166func sp_min_handle_smc
167	/* On SMC entry, `sp` points to `smc_ctx_t`. Save `lr`. */
168	str	lr, [sp, #SMC_CTX_LR_MON]
169
170#if ENABLE_RUNTIME_INSTRUMENTATION
171	/*
172	 * Read the timestamp value and store it on top of the C runtime stack.
173	 * The value will be saved to the per-cpu data once the C stack is
174	 * available, as a valid stack is needed to call _cpu_data()
175	 */
176	strd	r0, r1, [sp, #SMC_CTX_GPREG_R0]
177	ldcopr16 r0, r1, CNTPCT_64
178	ldr	lr, [sp, #SMC_CTX_SP_MON]
179	strd	r0, r1, [lr, #-8]!
180	str	lr, [sp, #SMC_CTX_SP_MON]
181	ldrd	r0, r1, [sp, #SMC_CTX_GPREG_R0]
182#endif
183
184	smccc_save_gp_mode_regs
185
186	clrex_on_monitor_entry
187
188	/*
189	 * `sp` still points to `smc_ctx_t`. Save it to a register
190	 * and restore the C runtime stack pointer to `sp`.
191	 */
192	mov	r2, sp				/* handle */
193	ldr	sp, [r2, #SMC_CTX_SP_MON]
194
195#if ENABLE_RUNTIME_INSTRUMENTATION
196	/* Save handle to a callee saved register */
197	mov	r6, r2
198
199	/*
200	 * Restore the timestamp value and store it in per-cpu data. The value
201	 * will be extracted from per-cpu data by the C level SMC handler and
202	 * saved to the PMF timestamp region.
203	 */
204	ldrd	r4, r5, [sp], #8
205	bl	_cpu_data
206	strd	r4, r5, [r0, #CPU_DATA_PMF_TS0_OFFSET]
207
208	/* Restore handle */
209	mov	r2, r6
210#endif
211
212	ldr	r0, [r2, #SMC_CTX_SCR]
213	and	r3, r0, #SCR_NS_BIT		/* flags */
214
215	/* Switch to Secure Mode*/
216	bic	r0, #SCR_NS_BIT
217	stcopr	r0, SCR
218	isb
219
220	ldr	r0, [r2, #SMC_CTX_GPREG_R0]	/* smc_fid */
221	/* Check whether an SMC64 is issued */
222	tst	r0, #(FUNCID_CC_MASK << FUNCID_CC_SHIFT)
223	beq	1f
224	/* SMC32 is not detected. Return error back to caller */
225	mov	r0, #SMC_UNK
226	str	r0, [r2, #SMC_CTX_GPREG_R0]
227	mov	r0, r2
228	b	sp_min_exit
2291:
230	/* SMC32 is detected */
231	mov	r1, #0				/* cookie */
232	bl	handle_runtime_svc
233
234	/* `r0` points to `smc_ctx_t` */
235	b	sp_min_exit
236endfunc sp_min_handle_smc
237
238/*
239 * Secure Interrupts handling function for SP_MIN.
240 */
241func sp_min_handle_fiq
242#if !SP_MIN_WITH_SECURE_FIQ
243	b plat_panic_handler
244#else
245	/* FIQ has a +4 offset for lr compared to preferred return address */
246	sub	lr, lr, #4
247	/* On SMC entry, `sp` points to `smc_ctx_t`. Save `lr`. */
248	str	lr, [sp, #SMC_CTX_LR_MON]
249
250	smccc_save_gp_mode_regs
251
252	clrex_on_monitor_entry
253
254	/* load run-time stack */
255	mov	r2, sp
256	ldr	sp, [r2, #SMC_CTX_SP_MON]
257
258	/* Switch to Secure Mode */
259	ldr	r0, [r2, #SMC_CTX_SCR]
260	bic	r0, #SCR_NS_BIT
261	stcopr	r0, SCR
262	isb
263
264	push	{r2, r3}
265	bl	sp_min_fiq
266	pop	{r0, r3}
267
268	b	sp_min_exit
269#endif
270endfunc sp_min_handle_fiq
271
272/*
273 * The Warm boot entrypoint for SP_MIN.
274 */
275func sp_min_warm_entrypoint
276#if ENABLE_RUNTIME_INSTRUMENTATION
277	/*
278	 * This timestamp update happens with cache off.  The next
279	 * timestamp collection will need to do cache maintenance prior
280	 * to timestamp update.
281	 */
282	pmf_calc_timestamp_addr rt_instr_svc, RT_INSTR_EXIT_HW_LOW_PWR
283	ldcopr16 r2, r3, CNTPCT_64
284	strd	r2, r3, [r0]
285#endif
286	/*
287	 * On the warm boot path, most of the EL3 initialisations performed by
288	 * 'el3_entrypoint_common' must be skipped:
289	 *
290	 *  - Only when the platform bypasses the BL1/BL32 (SP_MIN) entrypoint by
291	 *    programming the reset address do we need to initialied the SCTLR.
292	 *    In other cases, we assume this has been taken care by the
293	 *    entrypoint code.
294	 *
295	 *  - No need to determine the type of boot, we know it is a warm boot.
296	 *
297	 *  - Do not try to distinguish between primary and secondary CPUs, this
298	 *    notion only exists for a cold boot.
299	 *
300	 *  - No need to initialise the memory or the C runtime environment,
301	 *    it has been done once and for all on the cold boot path.
302	 */
303	el3_entrypoint_common					\
304		_init_sctlr=PROGRAMMABLE_RESET_ADDRESS		\
305		_warm_boot_mailbox=0				\
306		_secondary_cold_boot=0				\
307		_init_memory=0					\
308		_init_c_runtime=0				\
309		_exception_vectors=sp_min_vector_table
310
311	/*
312	 * We're about to enable MMU and participate in PSCI state coordination.
313	 *
314	 * The PSCI implementation invokes platform routines that enable CPUs to
315	 * participate in coherency. On a system where CPUs are not
316	 * cache-coherent without appropriate platform specific programming,
317	 * having caches enabled until such time might lead to coherency issues
318	 * (resulting from stale data getting speculatively fetched, among
319	 * others). Therefore we keep data caches disabled even after enabling
320	 * the MMU for such platforms.
321	 *
322	 * On systems with hardware-assisted coherency, or on single cluster
323	 * platforms, such platform specific programming is not required to
324	 * enter coherency (as CPUs already are); and there's no reason to have
325	 * caches disabled either.
326	 */
327#if HW_ASSISTED_COHERENCY || WARMBOOT_ENABLE_DCACHE_EARLY
328	mov	r0, #0
329#else
330	mov	r0, #DISABLE_DCACHE
331#endif
332	bl	bl32_plat_enable_mmu
333
334#if SP_MIN_WITH_SECURE_FIQ
335	route_fiq_to_sp_min r0
336#endif
337
338	bl	sp_min_warm_boot
339	bl	smc_get_next_ctx
340	/* r0 points to `smc_ctx_t` */
341	/* The PSCI cpu_context registers have been copied to `smc_ctx_t` */
342
343#if ENABLE_RUNTIME_INSTRUMENTATION
344	/* Save smc_ctx_t */
345	mov	r5, r0
346
347	pmf_calc_timestamp_addr rt_instr_svc, RT_INSTR_EXIT_PSCI
348	mov	r4, r0
349
350	/*
351	 * Invalidate before updating timestamp to ensure previous timestamp
352	 * updates on the same cache line with caches disabled are properly
353	 * seen by the same core. Without the cache invalidate, the core might
354	 * write into a stale cache line.
355	 */
356	mov	r1, #PMF_TS_SIZE
357	bl	inv_dcache_range
358
359	ldcopr16 r0, r1, CNTPCT_64
360	strd	r0, r1, [r4]
361
362	/* Restore smc_ctx_t */
363	mov	r0, r5
364#endif
365
366	b	sp_min_exit
367endfunc sp_min_warm_entrypoint
368
369/*
370 * The function to restore the registers from SMC context and return
371 * to the mode restored to SPSR.
372 *
373 * Arguments : r0 must point to the SMC context to restore from.
374 */
375func sp_min_exit
376	monitor_exit
377endfunc sp_min_exit
378