xref: /kvm-unit-tests/arm/cstart64.S (revision 8425ac5c37a5462c6b91ff4756ae3ca128a7bb77)
1/*
2 * Boot entry point and assembler functions for aarch64 tests.
3 *
4 * Copyright (C) 2017, Red Hat Inc, Andrew Jones <drjones@redhat.com>
5 *
6 * This work is licensed under the terms of the GNU GPL, version 2.
7 */
8#define __ASSEMBLY__
9#include <auxinfo.h>
10#include <asm/asm-offsets.h>
11#include <asm/assembler.h>
12#include <asm/ptrace.h>
13#include <asm/page.h>
14#include <asm/pgtable-hwdef.h>
15#include <asm/thread_info.h>
16#include <asm/sysreg.h>
17
18.macro zero_range, tmp1, tmp2
199998:	cmp	\tmp1, \tmp2
20	b.eq	9997f
21	stp	xzr, xzr, [\tmp1], #16
22	b	9998b
239997:
24.endm
25
26.section .init
27
28/*
29 * Bootloader params are in x0-x3. See kernel doc
30 * Documentation/arm64/booting.txt
31 */
32.globl start
33start:
34	/* get our base address */
35	adrp	x4, start
36	add     x4, x4, :lo12:start
37
38	/*
39	 * Update all R_AARCH64_RELATIVE relocations using the table
40	 * of Elf64_Rela entries between reloc_start/end. The build
41	 * will not emit other relocation types.
42	 *
43	 * struct Elf64_Rela {
44	 * 	uint64_t r_offset;
45	 * 	uint64_t r_info;
46	 * 	int64_t  r_addend;
47	 * }
48	 */
49	adrp	x5, reloc_start
50	add     x5, x5, :lo12:reloc_start
51	adrp	x6, reloc_end
52	add     x6, x6, :lo12:reloc_end
531:
54	cmp	x5, x6
55	b.hs	1f
56	ldr	x7, [x5]			// r_offset
57	ldr	x8, [x5, #16]			// r_addend
58	add	x8, x8, x4			// val = base + r_addend
59	str	x8, [x4, x7]			// base[r_offset] = val
60	add	x5, x5, #24
61	b	1b
62
631:
64	/* zero BSS */
65	adrp	x4, bss
66	add	x4, x4, :lo12:bss
67	adrp    x5, ebss
68	add     x5, x5, :lo12:ebss
69	zero_range x4, x5
70
71	/* zero and set up stack */
72	adrp    x5, stacktop
73	add     x5, x5, :lo12:stacktop
74	sub	x4, x5, #THREAD_SIZE
75	zero_range x4, x5
76
77	/* set SCTLR_EL1 to a known value */
78	ldr	x4, =INIT_SCTLR_EL1_MMU_OFF
79	msr	sctlr_el1, x4
80	isb
81
82	mov	x4, #1
83	msr	spsel, x4
84	adrp    x4, stackptr
85	add     sp, x4, :lo12:stackptr
86
87	/* enable FP/ASIMD */
88	mov	x4, #(3 << 20)
89	msr	cpacr_el1, x4
90
91	/* set up exception handling */
92	bl	exceptions_init
93
94	/* complete setup */
95	bl	setup				// x0 is the addr of the dtb
96	bl	get_mmu_off
97	cbnz	x0, 1f
98	bl	setup_vm
99
1001:
101	/* run the test */
102	adrp	x0, __argc
103	ldr	x0, [x0, :lo12:__argc]
104	adrp	x1, __argv
105	add	x1, x1, :lo12:__argv
106	adrp	x2, __environ
107	add	x2, x2, :lo12:__environ
108	bl	main
109	bl	exit
110	b	halt
111
112exceptions_init:
113	adrp	x4, vector_table
114	add	x4, x4, :lo12:vector_table
115	msr	vbar_el1, x4
116	isb
117	ret
118
119.text
120
121.globl get_mmu_off
122get_mmu_off:
123	adrp	x0, auxinfo
124	ldr	x0, [x0, :lo12:auxinfo + 8]
125	and	x0, x0, #AUXINFO_MMU_OFF
126	ret
127
128.globl secondary_entry
129secondary_entry:
130	/* Enable FP/ASIMD */
131	mov	x0, #(3 << 20)
132	msr	cpacr_el1, x0
133
134	/* set up exception handling */
135	bl	exceptions_init
136
137	/* enable the MMU unless requested off */
138	bl	get_mmu_off
139	cbnz	x0, 1f
140	adrp	x0, mmu_idmap
141	ldr	x0, [x0, :lo12:mmu_idmap]
142	bl	asm_mmu_enable
143
1441:
145	/* set the stack */
146	adrp	x0, secondary_data
147	ldr	x0, [x0, :lo12:secondary_data]
148	mov	sp, x0
149
150	/* finish init in C code */
151	bl	secondary_cinit
152
153	/* x0 is now the entry function, run it */
154	blr	x0
155	b	do_idle
156
157.globl halt
158halt:
1591:	wfi
160	b	1b
161
162/*
163 * asm_mmu_enable
164 *   Inputs:
165 *     x0 is the base address of the translation table
166 *   Outputs: none
167 *
168 * Adapted from
169 *   arch/arm64/kernel/head.S
170 *   arch/arm64/mm/proc.S
171 */
172
173/*
174 * Memory region attributes for LPAE:
175 *
176 *   n = AttrIndx[2:0]
177 *                      n       MAIR
178 *   DEVICE_nGnRnE      000     00000000
179 *   DEVICE_nGnRE       001     00000100
180 *   DEVICE_GRE         010     00001100
181 *   NORMAL_NC          011     01000100
182 *   NORMAL             100     11111111
183 *   NORMAL_WT          101     10111011
184 *   DEVICE_nGRE        110     00001000
185 */
186#define MAIR(attr, mt) ((attr) << ((mt) * 8))
187
188#if PAGE_SIZE == SZ_64K
189#define TCR_TG_FLAGS	TCR_TG0_64K | TCR_TG1_64K
190#elif PAGE_SIZE == SZ_16K
191#define TCR_TG_FLAGS	TCR_TG0_16K | TCR_TG1_16K
192#elif PAGE_SIZE == SZ_4K
193#define TCR_TG_FLAGS	TCR_TG0_4K | TCR_TG1_4K
194#endif
195
196.globl asm_mmu_enable
197asm_mmu_enable:
198	tlbi	vmalle1			// invalidate I + D TLBs
199	dsb	nsh
200
201	/* TCR */
202	ldr	x1, =TCR_TxSZ(VA_BITS) |		\
203		     TCR_TG_FLAGS  |			\
204		     TCR_IRGN_WBWA | TCR_ORGN_WBWA |	\
205		     TCR_SHARED |			\
206		     TCR_EPD1
207	mrs	x2, id_aa64mmfr0_el1
208	bfi	x1, x2, #32, #3
209	msr	tcr_el1, x1
210
211	/* MAIR */
212	ldr	x1, =MAIR(0x00, MT_DEVICE_nGnRnE) |	\
213		     MAIR(0x04, MT_DEVICE_nGnRE) |	\
214		     MAIR(0x0c, MT_DEVICE_GRE) |	\
215		     MAIR(0x44, MT_NORMAL_NC) |		\
216		     MAIR(0xff, MT_NORMAL) |	        \
217		     MAIR(0xbb, MT_NORMAL_WT) |         \
218		     MAIR(0x08, MT_DEVICE_nGRE)
219	msr	mair_el1, x1
220
221	/* TTBR0 */
222	msr	ttbr0_el1, x0
223	isb
224
225	/* SCTLR */
226	mrs	x1, sctlr_el1
227	orr	x1, x1, SCTLR_EL1_C
228	orr	x1, x1, SCTLR_EL1_I
229	orr	x1, x1, SCTLR_EL1_M
230	msr	sctlr_el1, x1
231	isb
232
233	ret
234
235.globl asm_mmu_disable
236asm_mmu_disable:
237	mrs	x0, sctlr_el1
238	bic	x0, x0, SCTLR_EL1_M
239	msr	sctlr_el1, x0
240	isb
241
242	/* Clean + invalidate the entire memory */
243	adrp	x0, __phys_offset
244	ldr	x0, [x0, :lo12:__phys_offset]
245	adrp	x1, __phys_end
246	ldr	x1, [x1, :lo12:__phys_end]
247	sub	x1, x1, x0
248	dcache_by_line_op civac, sy, x0, x1, x2, x3
249
250	ret
251
252/*
253 * Vectors
254 * Adapted from arch/arm64/kernel/entry.S
255 */
256.macro vector_stub, name, vec
257\name:
258	stp	 x0,  x1, [sp, #-S_FRAME_SIZE]!
259	stp	 x2,  x3, [sp,  #16]
260	stp	 x4,  x5, [sp,  #32]
261	stp	 x6,  x7, [sp,  #48]
262	stp	 x8,  x9, [sp,  #64]
263	stp	x10, x11, [sp,  #80]
264	stp	x12, x13, [sp,  #96]
265	stp	x14, x15, [sp, #112]
266	stp	x16, x17, [sp, #128]
267	stp	x18, x19, [sp, #144]
268	stp	x20, x21, [sp, #160]
269	stp	x22, x23, [sp, #176]
270	stp	x24, x25, [sp, #192]
271	stp	x26, x27, [sp, #208]
272	stp	x28, x29, [sp, #224]
273
274	str	x30, [sp, #S_LR]
275
276	.if \vec >= 8
277	mrs	x1, sp_el0
278	.else
279	add	x1, sp, #S_FRAME_SIZE
280	.endif
281	str	x1, [sp, #S_SP]
282
283	mrs	x1, elr_el1
284	mrs	x2, spsr_el1
285	stp	x1, x2, [sp, #S_PC]
286
287	mov	x0, \vec
288	mov	x1, sp
289	mrs	x2, esr_el1
290	bl	do_handle_exception
291
292	ldp	x1, x2, [sp, #S_PC]
293	msr	spsr_el1, x2
294	msr	elr_el1, x1
295
296	.if \vec >= 8
297	ldr	x1, [sp, #S_SP]
298	msr	sp_el0, x1
299	.endif
300
301	ldr	x30, [sp, #S_LR]
302
303	ldp	x28, x29, [sp, #224]
304	ldp	x26, x27, [sp, #208]
305	ldp	x24, x25, [sp, #192]
306	ldp	x22, x23, [sp, #176]
307	ldp	x20, x21, [sp, #160]
308	ldp	x18, x19, [sp, #144]
309	ldp	x16, x17, [sp, #128]
310	ldp	x14, x15, [sp, #112]
311	ldp	x12, x13, [sp,  #96]
312	ldp	x10, x11, [sp,  #80]
313	ldp	 x8,  x9, [sp,  #64]
314	ldp	 x6,  x7, [sp,  #48]
315	ldp	 x4,  x5, [sp,  #32]
316	ldp	 x2,  x3, [sp,  #16]
317	ldp	 x0,  x1, [sp], #S_FRAME_SIZE
318
319	eret
320.endm
321
322vector_stub	el1t_sync,     0
323vector_stub	el1t_irq,      1
324vector_stub	el1t_fiq,      2
325vector_stub	el1t_error,    3
326
327vector_stub	el1h_sync,     4
328vector_stub	el1h_irq,      5
329vector_stub	el1h_fiq,      6
330vector_stub	el1h_error,    7
331
332vector_stub	el0_sync_64,   8
333vector_stub	el0_irq_64,    9
334vector_stub	el0_fiq_64,   10
335vector_stub	el0_error_64, 11
336
337vector_stub	el0_sync_32,  12
338vector_stub	el0_irq_32,   13
339vector_stub	el0_fiq_32,   14
340vector_stub	el0_error_32, 15
341
342.section .text.ex
343
344.macro ventry, label
345.align 7
346	b	\label
347.endm
348
349.align 11
350vector_table:
351	ventry	el1t_sync			// Synchronous EL1t
352	ventry	el1t_irq			// IRQ EL1t
353	ventry	el1t_fiq			// FIQ EL1t
354	ventry	el1t_error			// Error EL1t
355
356	ventry	el1h_sync			// Synchronous EL1h
357	ventry	el1h_irq			// IRQ EL1h
358	ventry	el1h_fiq			// FIQ EL1h
359	ventry	el1h_error			// Error EL1h
360
361	ventry	el0_sync_64			// Synchronous 64-bit EL0
362	ventry	el0_irq_64			// IRQ 64-bit EL0
363	ventry	el0_fiq_64			// FIQ 64-bit EL0
364	ventry	el0_error_64			// Error 64-bit EL0
365
366	ventry	el0_sync_32			// Synchronous 32-bit EL0
367	ventry	el0_irq_32			// IRQ 32-bit EL0
368	ventry	el0_fiq_32			// FIQ 32-bit EL0
369	ventry	el0_error_32			// Error 32-bit EL0
370