xref: /kvm-unit-tests/arm/cstart64.S (revision 1dd3501a9a81daf08762028efcfd9b508d3df2cb)
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	mov	x4, #1
77	msr	spsel, x4
78	adrp    x4, stackptr
79	add     sp, x4, :lo12:stackptr
80
81	/* enable FP/ASIMD */
82	mov	x4, #(3 << 20)
83	msr	cpacr_el1, x4
84
85	/* set up exception handling */
86	bl	exceptions_init
87
88	/* complete setup */
89	bl	setup				// x0 is the addr of the dtb
90	bl	get_mmu_off
91	cbnz	x0, 1f
92	bl	setup_vm
93
941:
95	/* run the test */
96	adrp	x0, __argc
97	ldr	x0, [x0, :lo12:__argc]
98	adrp	x1, __argv
99	add	x1, x1, :lo12:__argv
100	adrp	x2, __environ
101	add	x2, x2, :lo12:__environ
102	bl	main
103	bl	exit
104	b	halt
105
106exceptions_init:
107	adrp	x4, vector_table
108	add	x4, x4, :lo12:vector_table
109	msr	vbar_el1, x4
110	isb
111	ret
112
113.text
114
115.globl get_mmu_off
116get_mmu_off:
117	adrp	x0, auxinfo
118	ldr	x0, [x0, :lo12:auxinfo + 8]
119	and	x0, x0, #AUXINFO_MMU_OFF
120	ret
121
122.globl secondary_entry
123secondary_entry:
124	/* Enable FP/ASIMD */
125	mov	x0, #(3 << 20)
126	msr	cpacr_el1, x0
127
128	/* set up exception handling */
129	bl	exceptions_init
130
131	/* enable the MMU unless requested off */
132	bl	get_mmu_off
133	cbnz	x0, 1f
134	adrp	x0, mmu_idmap
135	ldr	x0, [x0, :lo12:mmu_idmap]
136	bl	asm_mmu_enable
137
1381:
139	/* set the stack */
140	adrp	x0, secondary_data
141	ldr	x0, [x0, :lo12:secondary_data]
142	mov	sp, x0
143
144	/* finish init in C code */
145	bl	secondary_cinit
146
147	/* x0 is now the entry function, run it */
148	blr	x0
149	b	do_idle
150
151.globl halt
152halt:
1531:	wfi
154	b	1b
155
156/*
157 * asm_mmu_enable
158 *   Inputs:
159 *     x0 is the base address of the translation table
160 *   Outputs: none
161 *
162 * Adapted from
163 *   arch/arm64/kernel/head.S
164 *   arch/arm64/mm/proc.S
165 */
166
167/*
168 * Memory region attributes for LPAE:
169 *
170 *   n = AttrIndx[2:0]
171 *                      n       MAIR
172 *   DEVICE_nGnRnE      000     00000000
173 *   DEVICE_nGnRE       001     00000100
174 *   DEVICE_GRE         010     00001100
175 *   NORMAL_NC          011     01000100
176 *   NORMAL             100     11111111
177 *   NORMAL_WT          101     10111011
178 *   DEVICE_nGRE        110     00001000
179 */
180#define MAIR(attr, mt) ((attr) << ((mt) * 8))
181
182#if PAGE_SIZE == SZ_64K
183#define TCR_TG_FLAGS	TCR_TG0_64K | TCR_TG1_64K
184#elif PAGE_SIZE == SZ_16K
185#define TCR_TG_FLAGS	TCR_TG0_16K | TCR_TG1_16K
186#elif PAGE_SIZE == SZ_4K
187#define TCR_TG_FLAGS	TCR_TG0_4K | TCR_TG1_4K
188#endif
189
190.globl asm_mmu_enable
191asm_mmu_enable:
192	tlbi	vmalle1			// invalidate I + D TLBs
193	dsb	nsh
194
195	/* TCR */
196	ldr	x1, =TCR_TxSZ(VA_BITS) |		\
197		     TCR_TG_FLAGS  |			\
198		     TCR_IRGN_WBWA | TCR_ORGN_WBWA |	\
199		     TCR_SHARED
200	mrs	x2, id_aa64mmfr0_el1
201	bfi	x1, x2, #32, #3
202	msr	tcr_el1, x1
203
204	/* MAIR */
205	ldr	x1, =MAIR(0x00, MT_DEVICE_nGnRnE) |	\
206		     MAIR(0x04, MT_DEVICE_nGnRE) |	\
207		     MAIR(0x0c, MT_DEVICE_GRE) |	\
208		     MAIR(0x44, MT_NORMAL_NC) |		\
209		     MAIR(0xff, MT_NORMAL) |	        \
210		     MAIR(0xbb, MT_NORMAL_WT) |         \
211		     MAIR(0x08, MT_DEVICE_nGRE)
212	msr	mair_el1, x1
213
214	/* TTBR0 */
215	msr	ttbr0_el1, x0
216	isb
217
218	/* SCTLR */
219	mrs	x1, sctlr_el1
220	orr	x1, x1, SCTLR_EL1_C
221	orr	x1, x1, SCTLR_EL1_I
222	orr	x1, x1, SCTLR_EL1_M
223	msr	sctlr_el1, x1
224	isb
225
226	ret
227
228.globl asm_mmu_disable
229asm_mmu_disable:
230	mrs	x0, sctlr_el1
231	bic	x0, x0, SCTLR_EL1_M
232	msr	sctlr_el1, x0
233	isb
234
235	/* Clean + invalidate the entire memory */
236	adrp	x0, __phys_offset
237	ldr	x0, [x0, :lo12:__phys_offset]
238	adrp	x1, __phys_end
239	ldr	x1, [x1, :lo12:__phys_end]
240	sub	x1, x1, x0
241	dcache_by_line_op civac, sy, x0, x1, x2, x3
242
243	ret
244
245/*
246 * Vectors
247 * Adapted from arch/arm64/kernel/entry.S
248 */
249.macro vector_stub, name, vec
250\name:
251	stp	 x0,  x1, [sp, #-S_FRAME_SIZE]!
252	stp	 x2,  x3, [sp,  #16]
253	stp	 x4,  x5, [sp,  #32]
254	stp	 x6,  x7, [sp,  #48]
255	stp	 x8,  x9, [sp,  #64]
256	stp	x10, x11, [sp,  #80]
257	stp	x12, x13, [sp,  #96]
258	stp	x14, x15, [sp, #112]
259	stp	x16, x17, [sp, #128]
260	stp	x18, x19, [sp, #144]
261	stp	x20, x21, [sp, #160]
262	stp	x22, x23, [sp, #176]
263	stp	x24, x25, [sp, #192]
264	stp	x26, x27, [sp, #208]
265	stp	x28, x29, [sp, #224]
266
267	str	x30, [sp, #S_LR]
268
269	.if \vec >= 8
270	mrs	x1, sp_el0
271	.else
272	add	x1, sp, #S_FRAME_SIZE
273	.endif
274	str	x1, [sp, #S_SP]
275
276	mrs	x1, elr_el1
277	mrs	x2, spsr_el1
278	stp	x1, x2, [sp, #S_PC]
279
280	mov	x0, \vec
281	mov	x1, sp
282	mrs	x2, esr_el1
283	bl	do_handle_exception
284
285	ldp	x1, x2, [sp, #S_PC]
286	msr	spsr_el1, x2
287	msr	elr_el1, x1
288
289	.if \vec >= 8
290	ldr	x1, [sp, #S_SP]
291	msr	sp_el0, x1
292	.endif
293
294	ldr	x30, [sp, #S_LR]
295
296	ldp	x28, x29, [sp, #224]
297	ldp	x26, x27, [sp, #208]
298	ldp	x24, x25, [sp, #192]
299	ldp	x22, x23, [sp, #176]
300	ldp	x20, x21, [sp, #160]
301	ldp	x18, x19, [sp, #144]
302	ldp	x16, x17, [sp, #128]
303	ldp	x14, x15, [sp, #112]
304	ldp	x12, x13, [sp,  #96]
305	ldp	x10, x11, [sp,  #80]
306	ldp	 x8,  x9, [sp,  #64]
307	ldp	 x6,  x7, [sp,  #48]
308	ldp	 x4,  x5, [sp,  #32]
309	ldp	 x2,  x3, [sp,  #16]
310	ldp	 x0,  x1, [sp], #S_FRAME_SIZE
311
312	eret
313.endm
314
315vector_stub	el1t_sync,     0
316vector_stub	el1t_irq,      1
317vector_stub	el1t_fiq,      2
318vector_stub	el1t_error,    3
319
320vector_stub	el1h_sync,     4
321vector_stub	el1h_irq,      5
322vector_stub	el1h_fiq,      6
323vector_stub	el1h_error,    7
324
325vector_stub	el0_sync_64,   8
326vector_stub	el0_irq_64,    9
327vector_stub	el0_fiq_64,   10
328vector_stub	el0_error_64, 11
329
330vector_stub	el0_sync_32,  12
331vector_stub	el0_irq_32,   13
332vector_stub	el0_fiq_32,   14
333vector_stub	el0_error_32, 15
334
335.section .text.ex
336
337.macro ventry, label
338.align 7
339	b	\label
340.endm
341
342.align 11
343vector_table:
344	ventry	el1t_sync			// Synchronous EL1t
345	ventry	el1t_irq			// IRQ EL1t
346	ventry	el1t_fiq			// FIQ EL1t
347	ventry	el1t_error			// Error EL1t
348
349	ventry	el1h_sync			// Synchronous EL1h
350	ventry	el1h_irq			// IRQ EL1h
351	ventry	el1h_fiq			// FIQ EL1h
352	ventry	el1h_error			// Error EL1h
353
354	ventry	el0_sync_64			// Synchronous 64-bit EL0
355	ventry	el0_irq_64			// IRQ 64-bit EL0
356	ventry	el0_fiq_64			// FIQ 64-bit EL0
357	ventry	el0_error_64			// Error 64-bit EL0
358
359	ventry	el0_sync_32			// Synchronous 32-bit EL0
360	ventry	el0_irq_32			// IRQ 32-bit EL0
361	ventry	el0_fiq_32			// FIQ 32-bit EL0
362	ventry	el0_error_32			// Error 32-bit EL0
363