xref: /freebsd/sys/arm64/arm64/locore.S (revision ec965063070e5753c166cf592c9336444b74720a)
1/*-
2 * Copyright (c) 2012-2014 Andrew Turner
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29#include "assym.inc"
30#include "opt_kstack_pages.h"
31#include <sys/syscall.h>
32#include <machine/asm.h>
33#include <machine/armreg.h>
34#include <machine/hypervisor.h>
35#include <machine/param.h>
36#include <machine/pte.h>
37#include <machine/vm.h>
38#include <machine/vmparam.h>
39
40#define	VIRT_BITS	48
41
42#if PAGE_SIZE == PAGE_SIZE_16K
43/*
44 * The number of level 3 tables to create. 32 will allow for 1G of address
45 * space, the same as a single level 2 page with 4k pages.
46 */
47#define	L3_PAGE_COUNT	32
48#endif
49
50	.globl	kernbase
51	.set	kernbase, KERNBASE
52
53/*
54 * We assume:
55 *  MMU      on with an identity map, or off
56 *  D-Cache: off
57 *  I-Cache: on or off
58 *  We are loaded at a 2MiB aligned address
59 */
60
61ENTRY(_start)
62	/* Drop to EL1 */
63	bl	drop_to_el1
64
65	/*
66	 * Disable the MMU. We may have entered the kernel with it on and
67	 * will need to update the tables later. If this has been set up
68	 * with anything other than a VA == PA map then this will fail,
69	 * but in this case the code to find where we are running from
70	 * would have also failed.
71	 */
72	dsb	sy
73	mrs	x2, sctlr_el1
74	bic	x2, x2, SCTLR_M
75	msr	sctlr_el1, x2
76	isb
77
78	/* Set the context id */
79	msr	contextidr_el1, xzr
80
81	/* Get the virt -> phys offset */
82	bl	get_virt_delta
83
84	/*
85	 * At this point:
86	 * x29 = PA - VA
87	 * x28 = Our physical load address
88	 */
89
90	/* Create the page tables */
91	bl	create_pagetables
92
93	/*
94	 * At this point:
95	 * x27 = TTBR0 table
96	 * x26 = Kernel L1 table
97	 * x24 = TTBR1 table
98	 */
99
100	/* Enable the mmu */
101	bl	start_mmu
102
103	/* Load the new ttbr0 pagetable */
104	adrp	x27, pagetable_l0_ttbr0
105	add	x27, x27, :lo12:pagetable_l0_ttbr0
106
107	/* Jump to the virtual address space */
108	ldr	x15, .Lvirtdone
109	br	x15
110
111virtdone:
112	/* Set up the stack */
113	adrp	x25, initstack_end
114	add	x25, x25, :lo12:initstack_end
115	mov	sp, x25
116	sub	sp, sp, #PCB_SIZE
117
118	/* Zero the BSS */
119	ldr	x15, .Lbss
120	ldr	x14, .Lend
1211:
122	str	xzr, [x15], #8
123	cmp	x15, x14
124	b.lo	1b
125
126#if defined(PERTHREAD_SSP)
127	/* Set sp_el0 to the boot canary for early per-thread SSP to work */
128	adrp	x15, boot_canary
129	add	x15, x15, :lo12:boot_canary
130	msr	sp_el0, x15
131#endif
132
133	/* Backup the module pointer */
134	mov	x1, x0
135
136	sub	sp, sp, #BOOTPARAMS_SIZE
137	mov	x0, sp
138
139	/* Degate the delda so it is VA -> PA */
140	neg	x29, x29
141
142	str	x1,  [x0, #BP_MODULEP]
143	str	x29, [x0, #BP_KERN_DELTA]
144	adrp	x25, initstack
145	add	x25, x25, :lo12:initstack
146	str	x25, [x0, #BP_KERN_STACK]
147	str	x27, [x0, #BP_KERN_TTBR0]
148	str	x23, [x0, #BP_BOOT_EL]
149
150	/* trace back starts here */
151	mov	fp, #0
152	/* Branch to C code */
153	bl	initarm
154	/* We are done with the boot params */
155	add	sp, sp, #BOOTPARAMS_SIZE
156
157	/*
158	 * Enable pointer authentication in the kernel. We set the keys for
159	 * thread0 in initarm so have to wait until it returns to enable it.
160	 * If we were to enable it in initarm then any authentication when
161	 * returning would fail as it was called with pointer authentication
162	 * disabled.
163	 */
164	bl	ptrauth_start
165
166	bl	mi_startup
167
168	/* We should not get here */
169	brk	0
170
171	.align 3
172.Lvirtdone:
173	.quad	virtdone
174.Lbss:
175	.quad	__bss_start
176.Lend:
177	.quad	__bss_end
178END(_start)
179
180#ifdef SMP
181/*
182 * mpentry(unsigned long)
183 *
184 * Called by a core when it is being brought online.
185 * The data in x0 is passed straight to init_secondary.
186 */
187ENTRY(mpentry)
188	/* Disable interrupts */
189	msr	daifset, #DAIF_INTR
190
191	/* Drop to EL1 */
192	bl	drop_to_el1
193
194	/* Set the context id */
195	msr	contextidr_el1, xzr
196
197	/* Load the kernel page table */
198	adrp	x24, pagetable_l0_ttbr1
199	add	x24, x24, :lo12:pagetable_l0_ttbr1
200	/* Load the identity page table */
201	adrp	x27, pagetable_l0_ttbr0_boostrap
202	add	x27, x27, :lo12:pagetable_l0_ttbr0_boostrap
203
204	/* Enable the mmu */
205	bl	start_mmu
206
207	/* Load the new ttbr0 pagetable */
208	adrp	x27, pagetable_l0_ttbr0
209	add	x27, x27, :lo12:pagetable_l0_ttbr0
210
211	/* Jump to the virtual address space */
212	ldr	x15, =mp_virtdone
213	br	x15
214
215mp_virtdone:
216	/* Start using the AP boot stack */
217	ldr	x4, =bootstack
218	ldr	x4, [x4]
219	mov	sp, x4
220
221#if defined(PERTHREAD_SSP)
222	/* Set sp_el0 to the boot canary for early per-thread SSP to work */
223	adrp	x15, boot_canary
224	add	x15, x15, :lo12:boot_canary
225	msr	sp_el0, x15
226#endif
227
228	/* Load the kernel ttbr0 pagetable */
229	msr	ttbr0_el1, x27
230	isb
231
232	/* Invalidate the TLB */
233	tlbi	vmalle1
234	dsb	sy
235	isb
236
237	b	init_secondary
238END(mpentry)
239#endif
240
241/*
242 * If we are started in EL2, configure the required hypervisor
243 * registers and drop to EL1.
244 */
245LENTRY(drop_to_el1)
246	mrs	x23, CurrentEL
247	lsr	x23, x23, #2
248	cmp	x23, #0x2
249	b.eq	1f
250	ret
2511:
252	/*
253	 * Disable the MMU. If the HCR_EL2.E2H field is set we will clear it
254	 * which may break address translation.
255	 */
256	dsb	sy
257	mrs	x2, sctlr_el2
258	bic	x2, x2, SCTLR_M
259	msr	sctlr_el2, x2
260	isb
261
262	/* Configure the Hypervisor */
263	ldr	x2, =(HCR_RW | HCR_APK | HCR_API)
264	msr	hcr_el2, x2
265
266	/* Load the Virtualization Process ID Register */
267	mrs	x2, midr_el1
268	msr	vpidr_el2, x2
269
270	/* Load the Virtualization Multiprocess ID Register */
271	mrs	x2, mpidr_el1
272	msr	vmpidr_el2, x2
273
274	/* Set the bits that need to be 1 in sctlr_el1 */
275	ldr	x2, .Lsctlr_res1
276	msr	sctlr_el1, x2
277
278	/* Don't trap to EL2 for exceptions */
279	mov	x2, #CPTR_RES1
280	msr	cptr_el2, x2
281
282	/* Don't trap to EL2 for CP15 traps */
283	msr	hstr_el2, xzr
284
285	/* Enable access to the physical timers at EL1 */
286	mrs	x2, cnthctl_el2
287	orr	x2, x2, #(CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN)
288	msr	cnthctl_el2, x2
289
290	/* Set the counter offset to a known value */
291	msr	cntvoff_el2, xzr
292
293	/* Hypervisor trap functions */
294	adrp	x2, hyp_stub_vectors
295	add	x2, x2, :lo12:hyp_stub_vectors
296	msr	vbar_el2, x2
297
298	/* Zero vttbr_el2 so a hypervisor can tell the host and guest apart */
299	msr	vttbr_el2, xzr
300
301	mov	x2, #(PSR_F | PSR_I | PSR_A | PSR_D | PSR_M_EL1h)
302	msr	spsr_el2, x2
303
304	/* Configure GICv3 CPU interface */
305	mrs	x2, id_aa64pfr0_el1
306	/* Extract GIC bits from the register */
307	ubfx	x2, x2, #ID_AA64PFR0_GIC_SHIFT, #ID_AA64PFR0_GIC_BITS
308	/* GIC[3:0] == 0001 - GIC CPU interface via special regs. supported */
309	cmp	x2, #(ID_AA64PFR0_GIC_CPUIF_EN >> ID_AA64PFR0_GIC_SHIFT)
310	b.ne	2f
311
312	mrs	x2, icc_sre_el2
313	orr	x2, x2, #ICC_SRE_EL2_EN	/* Enable access from insecure EL1 */
314	orr	x2, x2, #ICC_SRE_EL2_SRE	/* Enable system registers */
315	msr	icc_sre_el2, x2
3162:
317
318	/* Set the address to return to our return address */
319	msr	elr_el2, x30
320	isb
321
322	eret
323
324	.align 3
325.Lsctlr_res1:
326	.quad SCTLR_RES1
327LEND(drop_to_el1)
328
329/*
330 * Get the delta between the physical address we were loaded to and the
331 * virtual address we expect to run from. This is used when building the
332 * initial page table.
333 */
334LENTRY(get_virt_delta)
335	/* Load the physical address of virt_map */
336	adrp	x29, virt_map
337	add	x29, x29, :lo12:virt_map
338	/* Load the virtual address of virt_map stored in virt_map */
339	ldr	x28, [x29]
340	/* Find PA - VA as PA' = VA' - VA + PA = VA' + (PA - VA) = VA' + x29 */
341	sub	x29, x29, x28
342	/* Find the load address for the kernel */
343	mov	x28, #(KERNBASE)
344	add	x28, x28, x29
345	ret
346
347	.align 3
348virt_map:
349	.quad	virt_map
350LEND(get_virt_delta)
351
352/*
353 * This builds the page tables containing the identity map, and the kernel
354 * virtual map.
355 *
356 * It relys on:
357 *  We were loaded to an address that is on a 2MiB boundary
358 *  All the memory must not cross a 1GiB boundaty
359 *  x28 contains the physical address we were loaded from
360 *
361 * TODO: This is out of date.
362 *  There are at least 5 pages before that address for the page tables
363 *   The pages used are:
364 *    - The Kernel L2 table
365 *    - The Kernel L1 table
366 *    - The Kernel L0 table             (TTBR1)
367 *    - The identity (PA = VA) L1 table
368 *    - The identity (PA = VA) L0 table (TTBR0)
369 */
370LENTRY(create_pagetables)
371	/* Save the Link register */
372	mov	x5, x30
373
374	/* Clean the page table */
375	adrp	x6, pagetable
376	add	x6, x6, :lo12:pagetable
377	mov	x26, x6
378	adrp	x27, pagetable_end
379	add	x27, x27, :lo12:pagetable_end
3801:
381	stp	xzr, xzr, [x6], #16
382	stp	xzr, xzr, [x6], #16
383	stp	xzr, xzr, [x6], #16
384	stp	xzr, xzr, [x6], #16
385	cmp	x6, x27
386	b.lo	1b
387
388	/*
389	 * Build the TTBR1 maps.
390	 */
391
392	/* Find the size of the kernel */
393	mov	x6, #(KERNBASE)
394
395#if defined(LINUX_BOOT_ABI)
396	/* X19 is used as 'map FDT data' flag */
397	mov	x19, xzr
398
399	/* No modules or FDT pointer ? */
400	cbz	x0, booti_no_fdt
401
402	/*
403	 * Test if x0 points to modules descriptor(virtual address) or
404	 * to FDT (physical address)
405	 */
406	cmp	x0, x6		/* x6 is #(KERNBASE) */
407	b.lo	booti_fdt
408#endif
409
410	/* Booted with modules pointer */
411	/* Find modulep - begin */
412	sub	x8, x0, x6
413	/*
414	 * Add space for the module data. When PAGE_SIZE is 4k this will
415	 * add at least 2 level 2 blocks (2 * 2MiB). When PAGE_SIZE is
416	 * larger it will be at least as large as we use smaller level 3
417	 * pages.
418	 */
419	ldr	x7, =((6 * 1024 * 1024) - 1)
420	add	x8, x8, x7
421	b	common
422
423#if defined(LINUX_BOOT_ABI)
424booti_fdt:
425	/* Booted by U-Boot booti with FDT data */
426	/* Set 'map FDT data' flag */
427	mov	x19, #1
428
429booti_no_fdt:
430	/* Booted by U-Boot booti without FTD data */
431	/* Find the end - begin */
432	ldr     x7, .Lend
433	sub     x8, x7, x6
434
435	/*
436	 * Add one 2MiB page for copy of FDT data (maximum FDT size),
437	 * one for metadata and round up
438	 */
439	ldr	x7, =(3 * L2_SIZE - 1)
440	add	x8, x8, x7
441#endif
442
443common:
444#if PAGE_SIZE != PAGE_SIZE_4K
445	/*
446	 * Create L3 pages. The kernel will be loaded at a 2M aligned
447	 * address, however L2 blocks are too large when the page size is
448	 * not 4k to map the kernel with such an aligned address. However,
449	 * when the page size is larger than 4k, L2 blocks are too large to
450	 * map the kernel with such an alignment.
451	 */
452
453	/* Get the number of l3 pages to allocate, rounded down */
454	lsr	x10, x8, #(L3_SHIFT)
455
456	/* Create the kernel space L2 table */
457	mov	x6, x26
458	mov	x7, #(ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
459	mov	x8, #(KERNBASE)
460	mov	x9, x28
461	bl	build_l3_page_pagetable
462
463	/* Move to the l2 table */
464	ldr	x9, =(PAGE_SIZE * L3_PAGE_COUNT)
465	add	x26, x26, x9
466
467	/* Link the l2 -> l3 table */
468	mov	x9, x6
469	mov	x6, x26
470	bl	link_l2_pagetable
471#else
472	/* Get the number of l2 pages to allocate, rounded down */
473	lsr	x10, x8, #(L2_SHIFT)
474
475	/* Create the kernel space L2 table */
476	mov	x6, x26
477	mov	x7, #(ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
478	mov	x8, #(KERNBASE)
479	mov	x9, x28
480	bl	build_l2_block_pagetable
481#endif
482
483	/* Move to the l1 table */
484	add	x26, x26, #PAGE_SIZE
485
486	/* Link the l1 -> l2 table */
487	mov	x9, x6
488	mov	x6, x26
489	bl	link_l1_pagetable
490
491	/* Move to the l0 table */
492	add	x24, x26, #PAGE_SIZE
493
494	/* Link the l0 -> l1 table */
495	mov	x9, x6
496	mov	x6, x24
497	mov	x10, #1
498	bl	link_l0_pagetable
499
500	/*
501	 * Build the TTBR0 maps.  As TTBR0 maps, they must specify ATTR_S1_nG.
502	 * They are only needed early on, so the VA = PA map is uncached.
503	 */
504	add	x27, x24, #PAGE_SIZE
505
506	mov	x6, x27		/* The initial page table */
507
508	/* Create the VA = PA map */
509	mov	x7, #(ATTR_S1_nG | ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
510	adrp	x16, _start
511	and	x16, x16, #(~L2_OFFSET)
512	mov	x9, x16		/* PA start */
513	mov	x8, x16		/* VA start (== PA start) */
514	mov	x10, #1
515	bl	build_l2_block_pagetable
516
517#if defined(SOCDEV_PA)
518	/* Create a table for the UART */
519	mov	x7, #(ATTR_S1_nG | ATTR_S1_IDX(VM_MEMATTR_DEVICE))
520	ldr	x9, =(L2_SIZE)
521	add	x16, x16, x9	/* VA start */
522	mov	x8, x16
523
524	/* Store the socdev virtual address */
525	add	x17, x8, #(SOCDEV_PA & L2_OFFSET)
526	adrp	x9, socdev_va
527	str	x17, [x9, :lo12:socdev_va]
528
529	mov	x9, #(SOCDEV_PA & ~L2_OFFSET)	/* PA start */
530	mov	x10, #1
531	bl	build_l2_block_pagetable
532#endif
533
534#if defined(LINUX_BOOT_ABI)
535	/* Map FDT data ? */
536	cbz	x19, 1f
537
538	/* Create the mapping for FDT data (2 MiB max) */
539	mov	x7, #(ATTR_S1_nG | ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
540	ldr	x9, =(L2_SIZE)
541	add	x16, x16, x9	/* VA start */
542	mov	x8, x16
543	mov	x9, x0			/* PA start */
544	/* Update the module pointer to point at the allocated memory */
545	and	x0, x0, #(L2_OFFSET)	/* Keep the lower bits */
546	add	x0, x0, x8		/* Add the aligned virtual address */
547
548	mov	x10, #1
549	bl	build_l2_block_pagetable
550
5511:
552#endif
553
554	/* Move to the l1 table */
555	add	x27, x27, #PAGE_SIZE
556
557	/* Link the l1 -> l2 table */
558	mov	x9, x6
559	mov	x6, x27
560	bl	link_l1_pagetable
561
562	/* Move to the l0 table */
563	add	x27, x27, #PAGE_SIZE
564
565	/* Link the l0 -> l1 table */
566	mov	x9, x6
567	mov	x6, x27
568	mov	x10, #1
569	bl	link_l0_pagetable
570
571	/* Restore the Link register */
572	mov	x30, x5
573	ret
574LEND(create_pagetables)
575
576/*
577 * Builds an L0 -> L1 table descriptor
578 *
579 *  x6  = L0 table
580 *  x8  = Virtual Address
581 *  x9  = L1 PA (trashed)
582 *  x10 = Entry count (trashed)
583 *  x11, x12 and x13 are trashed
584 */
585LENTRY(link_l0_pagetable)
586	/*
587	 * Link an L0 -> L1 table entry.
588	 */
589	/* Find the table index */
590	lsr	x11, x8, #L0_SHIFT
591	and	x11, x11, #L0_ADDR_MASK
592
593	/* Build the L0 block entry */
594	mov	x12, #L0_TABLE
595	orr	x12, x12, #(TATTR_UXN_TABLE | TATTR_AP_TABLE_NO_EL0)
596
597	/* Only use the output address bits */
598	lsr	x9, x9, #PAGE_SHIFT
5991:	orr	x13, x12, x9, lsl #PAGE_SHIFT
600
601	/* Store the entry */
602	str	x13, [x6, x11, lsl #3]
603
604	sub	x10, x10, #1
605	add	x11, x11, #1
606	add	x9, x9, #1
607	cbnz	x10, 1b
608
609	ret
610LEND(link_l0_pagetable)
611
612/*
613 * Builds an L1 -> L2 table descriptor
614 *
615 *  x6  = L1 table
616 *  x8  = Virtual Address
617 *  x9  = L2 PA (trashed)
618 *  x11, x12 and x13 are trashed
619 */
620LENTRY(link_l1_pagetable)
621	/*
622	 * Link an L1 -> L2 table entry.
623	 */
624	/* Find the table index */
625	lsr	x11, x8, #L1_SHIFT
626	and	x11, x11, #Ln_ADDR_MASK
627
628	/* Build the L1 block entry */
629	mov	x12, #L1_TABLE
630
631	/* Only use the output address bits */
632	lsr	x9, x9, #PAGE_SHIFT
633	orr	x13, x12, x9, lsl #PAGE_SHIFT
634
635	/* Store the entry */
636	str	x13, [x6, x11, lsl #3]
637
638	ret
639LEND(link_l1_pagetable)
640
641/*
642 * Builds count 2 MiB page table entry
643 *  x6  = L2 table
644 *  x7  = Block attributes
645 *  x8  = VA start
646 *  x9  = PA start (trashed)
647 *  x10 = Entry count (trashed)
648 *  x11, x12 and x13 are trashed
649 */
650LENTRY(build_l2_block_pagetable)
651	/*
652	 * Build the L2 table entry.
653	 */
654	/* Find the table index */
655	lsr	x11, x8, #L2_SHIFT
656	and	x11, x11, #Ln_ADDR_MASK
657
658	/* Build the L2 block entry */
659	orr	x12, x7, #L2_BLOCK
660	orr	x12, x12, #(ATTR_DEFAULT)
661	orr	x12, x12, #(ATTR_S1_UXN)
662
663	/* Only use the output address bits */
664	lsr	x9, x9, #L2_SHIFT
665
666	/* Set the physical address for this virtual address */
6671:	orr	x13, x12, x9, lsl #L2_SHIFT
668
669	/* Store the entry */
670	str	x13, [x6, x11, lsl #3]
671
672	sub	x10, x10, #1
673	add	x11, x11, #1
674	add	x9, x9, #1
675	cbnz	x10, 1b
676
677	ret
678LEND(build_l2_block_pagetable)
679
680#if PAGE_SIZE != PAGE_SIZE_4K
681/*
682 * Builds an L2 -> L3 table descriptor
683 *
684 *  x6  = L2 table
685 *  x8  = Virtual Address
686 *  x9  = L3 PA (trashed)
687 *  x11, x12 and x13 are trashed
688 */
689LENTRY(link_l2_pagetable)
690	/*
691	 * Link an L2 -> L3 table entry.
692	 */
693	/* Find the table index */
694	lsr	x11, x8, #L2_SHIFT
695	and	x11, x11, #Ln_ADDR_MASK
696
697	/* Build the L1 block entry */
698	mov	x12, #L2_TABLE
699
700	/* Only use the output address bits */
701	lsr	x9, x9, #PAGE_SHIFT
702	orr	x13, x12, x9, lsl #PAGE_SHIFT
703
704	/* Store the entry */
705	str	x13, [x6, x11, lsl #3]
706
707	ret
708LEND(link_l2_pagetable)
709
710/*
711 * Builds count level 3 page table entries
712 *  x6  = L3 table
713 *  x7  = Block attributes
714 *  x8  = VA start
715 *  x9  = PA start (trashed)
716 *  x10 = Entry count (trashed)
717 *  x11, x12 and x13 are trashed
718 */
719LENTRY(build_l3_page_pagetable)
720	/*
721	 * Build the L3 table entry.
722	 */
723	/* Find the table index */
724	lsr	x11, x8, #L3_SHIFT
725	and	x11, x11, #Ln_ADDR_MASK
726
727	/* Build the L3 page entry */
728	orr	x12, x7, #L3_PAGE
729	orr	x12, x12, #(ATTR_DEFAULT)
730	orr	x12, x12, #(ATTR_S1_UXN)
731
732	/* Only use the output address bits */
733	lsr	x9, x9, #L3_SHIFT
734
735	/* Set the physical address for this virtual address */
7361:	orr	x13, x12, x9, lsl #L3_SHIFT
737
738	/* Store the entry */
739	str	x13, [x6, x11, lsl #3]
740
741	sub	x10, x10, #1
742	add	x11, x11, #1
743	add	x9, x9, #1
744	cbnz	x10, 1b
745
746	ret
747LEND(build_l3_page_pagetable)
748#endif
749
750LENTRY(start_mmu)
751	dsb	sy
752
753	/* Load the exception vectors */
754	ldr	x2, =exception_vectors
755	msr	vbar_el1, x2
756
757	/* Load ttbr0 and ttbr1 */
758	msr	ttbr0_el1, x27
759	msr	ttbr1_el1, x24
760	isb
761
762	/* Clear the Monitor Debug System control register */
763	msr	mdscr_el1, xzr
764
765	/* Invalidate the TLB */
766	tlbi	vmalle1is
767	dsb	ish
768	isb
769
770	ldr	x2, mair
771	msr	mair_el1, x2
772
773	/*
774	 * Setup TCR according to the PARange and ASIDBits fields
775	 * from ID_AA64MMFR0_EL1 and the HAFDBS field from the
776	 * ID_AA64MMFR1_EL1.  More precisely, set TCR_EL1.AS
777	 * to 1 only if the ASIDBits field equals 0b0010.
778	 */
779	ldr	x2, tcr
780	mrs	x3, id_aa64mmfr0_el1
781
782	/* Copy the bottom 3 bits from id_aa64mmfr0_el1 into TCR.IPS */
783	bfi	x2, x3, #(TCR_IPS_SHIFT), #(TCR_IPS_WIDTH)
784	and	x3, x3, #(ID_AA64MMFR0_ASIDBits_MASK)
785
786	/* Check if the HW supports 16 bit ASIDS */
787	cmp	x3, #(ID_AA64MMFR0_ASIDBits_16)
788	/* If so x3 == 1, else x3 == 0 */
789	cset	x3, eq
790	/* Set TCR.AS with x3 */
791	bfi	x2, x3, #(TCR_ASID_SHIFT), #(TCR_ASID_WIDTH)
792
793	/*
794	 * Check if the HW supports access flag and dirty state updates,
795	 * and set TCR_EL1.HA and TCR_EL1.HD accordingly.
796	 */
797	mrs	x3, id_aa64mmfr1_el1
798	and	x3, x3, #(ID_AA64MMFR1_HAFDBS_MASK)
799	cmp	x3, #1
800	b.ne	1f
801	orr 	x2, x2, #(TCR_HA)
802	b	2f
8031:
804	cmp	x3, #2
805	b.ne	2f
806	orr 	x2, x2, #(TCR_HA | TCR_HD)
8072:
808	msr	tcr_el1, x2
809
810	/*
811	 * Setup SCTLR.
812	 */
813	ldr	x2, sctlr_set
814	ldr	x3, sctlr_clear
815	mrs	x1, sctlr_el1
816	bic	x1, x1, x3	/* Clear the required bits */
817	orr	x1, x1, x2	/* Set the required bits */
818	msr	sctlr_el1, x1
819	isb
820
821	ret
822
823	.align 3
824mair:
825	.quad	MAIR_ATTR(MAIR_DEVICE_nGnRnE, VM_MEMATTR_DEVICE_nGnRnE) | \
826		MAIR_ATTR(MAIR_NORMAL_NC, VM_MEMATTR_UNCACHEABLE)   |	\
827		MAIR_ATTR(MAIR_NORMAL_WB, VM_MEMATTR_WRITE_BACK)    |	\
828		MAIR_ATTR(MAIR_NORMAL_WT, VM_MEMATTR_WRITE_THROUGH) |	\
829		MAIR_ATTR(MAIR_DEVICE_nGnRE, VM_MEMATTR_DEVICE_nGnRE)
830tcr:
831#if PAGE_SIZE == PAGE_SIZE_4K
832#define	TCR_TG	(TCR_TG1_4K | TCR_TG0_4K)
833#elif PAGE_SIZE == PAGE_SIZE_16K
834#define	TCR_TG	(TCR_TG1_16K | TCR_TG0_16K)
835#else
836#error Unsupported page size
837#endif
838
839	.quad (TCR_TxSZ(64 - VIRT_BITS) | TCR_TG | \
840	    TCR_CACHE_ATTRS | TCR_SMP_ATTRS)
841sctlr_set:
842	/* Bits to set */
843	.quad (SCTLR_LSMAOE | SCTLR_nTLSMD | SCTLR_UCI | SCTLR_SPAN | \
844	    SCTLR_nTWE | SCTLR_nTWI | SCTLR_UCT | SCTLR_DZE | \
845	    SCTLR_I | SCTLR_SED | SCTLR_SA0 | SCTLR_SA | SCTLR_C | \
846	    SCTLR_M | SCTLR_CP15BEN)
847sctlr_clear:
848	/* Bits to clear */
849	.quad (SCTLR_EE | SCTLR_E0E | SCTLR_IESB | SCTLR_WXN | SCTLR_UMA | \
850	    SCTLR_ITD | SCTLR_A)
851LEND(start_mmu)
852
853ENTRY(abort)
854	b abort
855END(abort)
856
857	.section .init_pagetable, "aw", %nobits
858	.align PAGE_SHIFT
859	/*
860	 * 6 initial tables (in the following order):
861	 *           L2 for kernel (High addresses)
862	 *           L1 for kernel
863	 *           L0 for kernel
864	 *           L1 bootstrap for user   (Low addresses)
865	 *           L0 bootstrap for user
866	 *           L0 for user
867	 */
868	.globl pagetable_l0_ttbr1
869pagetable:
870#if PAGE_SIZE != PAGE_SIZE_4K
871	.space	(PAGE_SIZE * L3_PAGE_COUNT)
872pagetable_l2_ttbr1:
873#endif
874	.space	PAGE_SIZE
875pagetable_l1_ttbr1:
876	.space	PAGE_SIZE
877pagetable_l0_ttbr1:
878	.space	PAGE_SIZE
879pagetable_l2_ttbr0_bootstrap:
880	.space	PAGE_SIZE
881pagetable_l1_ttbr0_bootstrap:
882	.space	PAGE_SIZE
883pagetable_l0_ttbr0_boostrap:
884	.space	PAGE_SIZE
885pagetable_l0_ttbr0:
886	.space	PAGE_SIZE
887
888pagetable_end:
889
890el2_pagetable:
891	.space	PAGE_SIZE
892
893	.align	4
894initstack:
895	.space	(PAGE_SIZE * KSTACK_PAGES)
896initstack_end:
897
898
899.text
900EENTRY(aarch32_sigcode)
901	.word 0xe1a0000d	// mov r0, sp
902	.word 0xe2800040	// add r0, r0, #SIGF_UC
903	.word 0xe59f700c	// ldr r7, [pc, #12]
904	.word 0xef000000	// swi #0
905	.word 0xe59f7008	// ldr r7, [pc, #8]
906	.word 0xef000000	// swi #0
907	.word 0xeafffffa	// b . - 16
908EEND(aarch32_sigcode)
909	.word SYS_sigreturn
910	.word SYS_exit
911	.align	3
912aarch32_esigcode:
913	.data
914	.global sz_aarch32_sigcode
915sz_aarch32_sigcode:
916	.quad aarch32_esigcode - aarch32_sigcode
917