xref: /freebsd/sys/arm64/arm64/locore.S (revision 4d3fc8b0570b29fb0d6ee9525f104d52176ff0d4)
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	str	x4,  [x0, #BP_HCR_EL2]
150
151	/* trace back starts here */
152	mov	fp, #0
153	/* Branch to C code */
154	bl	initarm
155	/* We are done with the boot params */
156	add	sp, sp, #BOOTPARAMS_SIZE
157
158	/*
159	 * Enable pointer authentication in the kernel. We set the keys for
160	 * thread0 in initarm so have to wait until it returns to enable it.
161	 * If we were to enable it in initarm then any authentication when
162	 * returning would fail as it was called with pointer authentication
163	 * disabled.
164	 */
165	bl	ptrauth_start
166
167	bl	mi_startup
168
169	/* We should not get here */
170	brk	0
171
172	.align 3
173.Lvirtdone:
174	.quad	virtdone
175.Lbss:
176	.quad	__bss_start
177.Lend:
178	.quad	__bss_end
179END(_start)
180
181#ifdef SMP
182/*
183 * mpentry(unsigned long)
184 *
185 * Called by a core when it is being brought online.
186 * The data in x0 is passed straight to init_secondary.
187 */
188ENTRY(mpentry)
189	/* Disable interrupts */
190	msr	daifset, #DAIF_INTR
191
192	/* Drop to EL1 */
193	bl	drop_to_el1
194
195	/* Set the context id */
196	msr	contextidr_el1, xzr
197
198	/* Load the kernel page table */
199	adrp	x24, pagetable_l0_ttbr1
200	add	x24, x24, :lo12:pagetable_l0_ttbr1
201	/* Load the identity page table */
202	adrp	x27, pagetable_l0_ttbr0_boostrap
203	add	x27, x27, :lo12:pagetable_l0_ttbr0_boostrap
204
205	/* Enable the mmu */
206	bl	start_mmu
207
208	/* Load the new ttbr0 pagetable */
209	adrp	x27, pagetable_l0_ttbr0
210	add	x27, x27, :lo12:pagetable_l0_ttbr0
211
212	/* Jump to the virtual address space */
213	ldr	x15, =mp_virtdone
214	br	x15
215
216mp_virtdone:
217	/* Start using the AP boot stack */
218	ldr	x4, =bootstack
219	ldr	x4, [x4]
220	mov	sp, x4
221
222#if defined(PERTHREAD_SSP)
223	/* Set sp_el0 to the boot canary for early per-thread SSP to work */
224	adrp	x15, boot_canary
225	add	x15, x15, :lo12:boot_canary
226	msr	sp_el0, x15
227#endif
228
229	/* Load the kernel ttbr0 pagetable */
230	msr	ttbr0_el1, x27
231	isb
232
233	/* Invalidate the TLB */
234	tlbi	vmalle1
235	dsb	sy
236	isb
237
238	b	init_secondary
239END(mpentry)
240#endif
241
242/*
243 * If we are started in EL2, configure the required hypervisor
244 * registers and drop to EL1.
245 */
246LENTRY(drop_to_el1)
247	mrs	x23, CurrentEL
248	lsr	x23, x23, #2
249	cmp	x23, #0x2
250	b.eq	1f
251	ret
2521:
253	/*
254	 * Disable the MMU. If the HCR_EL2.E2H field is set we will clear it
255	 * which may break address translation.
256	 */
257	dsb	sy
258	mrs	x2, sctlr_el2
259	bic	x2, x2, SCTLR_M
260	msr	sctlr_el2, x2
261	isb
262
263	/* Configure the Hypervisor */
264	ldr	x2, =(HCR_RW | HCR_APK | HCR_API)
265	msr	hcr_el2, x2
266
267	/* Stash value of HCR_EL2 for later */
268	isb
269	mrs	x4, hcr_el2
270
271	/* Load the Virtualization Process ID Register */
272	mrs	x2, midr_el1
273	msr	vpidr_el2, x2
274
275	/* Load the Virtualization Multiprocess ID Register */
276	mrs	x2, mpidr_el1
277	msr	vmpidr_el2, x2
278
279	/* Set the bits that need to be 1 in sctlr_el1 */
280	ldr	x2, .Lsctlr_res1
281	msr	sctlr_el1, x2
282
283	/*
284	 * On some hardware, e.g., Apple M1, we can't clear E2H, so make sure we
285	 * don't trap to EL2 for SIMD register usage to have at least a
286	 * minimally usable system.
287	 */
288	tst	x4, #HCR_E2H
289	mov	x3, #CPTR_RES1	/* HCR_E2H == 0 */
290	mov	x5, #CPTR_FPEN	/* HCR_E2H == 1 */
291	csel	x2, x3, x5, eq
292	msr	cptr_el2, x2
293
294	/* Don't trap to EL2 for CP15 traps */
295	msr	hstr_el2, xzr
296
297	/* Enable access to the physical timers at EL1 */
298	mrs	x2, cnthctl_el2
299	orr	x2, x2, #(CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN)
300	msr	cnthctl_el2, x2
301
302	/* Set the counter offset to a known value */
303	msr	cntvoff_el2, xzr
304
305	/* Hypervisor trap functions */
306	adrp	x2, hyp_stub_vectors
307	add	x2, x2, :lo12:hyp_stub_vectors
308	msr	vbar_el2, x2
309
310	/* Zero vttbr_el2 so a hypervisor can tell the host and guest apart */
311	msr	vttbr_el2, xzr
312
313	mov	x2, #(PSR_F | PSR_I | PSR_A | PSR_D | PSR_M_EL1h)
314	msr	spsr_el2, x2
315
316	/* Configure GICv3 CPU interface */
317	mrs	x2, id_aa64pfr0_el1
318	/* Extract GIC bits from the register */
319	ubfx	x2, x2, #ID_AA64PFR0_GIC_SHIFT, #ID_AA64PFR0_GIC_BITS
320	/* GIC[3:0] == 0001 - GIC CPU interface via special regs. supported */
321	cmp	x2, #(ID_AA64PFR0_GIC_CPUIF_EN >> ID_AA64PFR0_GIC_SHIFT)
322	b.ne	2f
323
324	mrs	x2, icc_sre_el2
325	orr	x2, x2, #ICC_SRE_EL2_EN	/* Enable access from insecure EL1 */
326	orr	x2, x2, #ICC_SRE_EL2_SRE	/* Enable system registers */
327	msr	icc_sre_el2, x2
3282:
329
330	/* Set the address to return to our return address */
331	msr	elr_el2, x30
332	isb
333
334	eret
335
336	.align 3
337.Lsctlr_res1:
338	.quad SCTLR_RES1
339LEND(drop_to_el1)
340
341/*
342 * Get the delta between the physical address we were loaded to and the
343 * virtual address we expect to run from. This is used when building the
344 * initial page table.
345 */
346LENTRY(get_virt_delta)
347	/* Load the physical address of virt_map */
348	adrp	x29, virt_map
349	add	x29, x29, :lo12:virt_map
350	/* Load the virtual address of virt_map stored in virt_map */
351	ldr	x28, [x29]
352	/* Find PA - VA as PA' = VA' - VA + PA = VA' + (PA - VA) = VA' + x29 */
353	sub	x29, x29, x28
354	/* Find the load address for the kernel */
355	mov	x28, #(KERNBASE)
356	add	x28, x28, x29
357	ret
358
359	.align 3
360virt_map:
361	.quad	virt_map
362LEND(get_virt_delta)
363
364/*
365 * This builds the page tables containing the identity map, and the kernel
366 * virtual map.
367 *
368 * It relys on:
369 *  We were loaded to an address that is on a 2MiB boundary
370 *  All the memory must not cross a 1GiB boundaty
371 *  x28 contains the physical address we were loaded from
372 *
373 * TODO: This is out of date.
374 *  There are at least 5 pages before that address for the page tables
375 *   The pages used are:
376 *    - The Kernel L2 table
377 *    - The Kernel L1 table
378 *    - The Kernel L0 table             (TTBR1)
379 *    - The identity (PA = VA) L1 table
380 *    - The identity (PA = VA) L0 table (TTBR0)
381 */
382LENTRY(create_pagetables)
383	/* Save the Link register */
384	mov	x5, x30
385
386	/* Clean the page table */
387	adrp	x6, pagetable
388	add	x6, x6, :lo12:pagetable
389	mov	x26, x6
390	adrp	x27, pagetable_end
391	add	x27, x27, :lo12:pagetable_end
3921:
393	stp	xzr, xzr, [x6], #16
394	stp	xzr, xzr, [x6], #16
395	stp	xzr, xzr, [x6], #16
396	stp	xzr, xzr, [x6], #16
397	cmp	x6, x27
398	b.lo	1b
399
400	/*
401	 * Build the TTBR1 maps.
402	 */
403
404	/* Find the size of the kernel */
405	mov	x6, #(KERNBASE)
406
407#if defined(LINUX_BOOT_ABI)
408	/* X19 is used as 'map FDT data' flag */
409	mov	x19, xzr
410
411	/* No modules or FDT pointer ? */
412	cbz	x0, booti_no_fdt
413
414	/*
415	 * Test if x0 points to modules descriptor(virtual address) or
416	 * to FDT (physical address)
417	 */
418	cmp	x0, x6		/* x6 is #(KERNBASE) */
419	b.lo	booti_fdt
420#endif
421
422	/* Booted with modules pointer */
423	/* Find modulep - begin */
424	sub	x8, x0, x6
425	/*
426	 * Add space for the module data. When PAGE_SIZE is 4k this will
427	 * add at least 2 level 2 blocks (2 * 2MiB). When PAGE_SIZE is
428	 * larger it will be at least as large as we use smaller level 3
429	 * pages.
430	 */
431	ldr	x7, =((6 * 1024 * 1024) - 1)
432	add	x8, x8, x7
433	b	common
434
435#if defined(LINUX_BOOT_ABI)
436booti_fdt:
437	/* Booted by U-Boot booti with FDT data */
438	/* Set 'map FDT data' flag */
439	mov	x19, #1
440
441booti_no_fdt:
442	/* Booted by U-Boot booti without FTD data */
443	/* Find the end - begin */
444	ldr     x7, .Lend
445	sub     x8, x7, x6
446
447	/*
448	 * Add one 2MiB page for copy of FDT data (maximum FDT size),
449	 * one for metadata and round up
450	 */
451	ldr	x7, =(3 * L2_SIZE - 1)
452	add	x8, x8, x7
453#endif
454
455common:
456#if PAGE_SIZE != PAGE_SIZE_4K
457	/*
458	 * Create L3 pages. The kernel will be loaded at a 2M aligned
459	 * address, however L2 blocks are too large when the page size is
460	 * not 4k to map the kernel with such an aligned address. However,
461	 * when the page size is larger than 4k, L2 blocks are too large to
462	 * map the kernel with such an alignment.
463	 */
464
465	/* Get the number of l3 pages to allocate, rounded down */
466	lsr	x10, x8, #(L3_SHIFT)
467
468	/* Create the kernel space L2 table */
469	mov	x6, x26
470	mov	x7, #(ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
471	mov	x8, #(KERNBASE)
472	mov	x9, x28
473	bl	build_l3_page_pagetable
474
475	/* Move to the l2 table */
476	ldr	x9, =(PAGE_SIZE * L3_PAGE_COUNT)
477	add	x26, x26, x9
478
479	/* Link the l2 -> l3 table */
480	mov	x9, x6
481	mov	x6, x26
482	bl	link_l2_pagetable
483#else
484	/* Get the number of l2 pages to allocate, rounded down */
485	lsr	x10, x8, #(L2_SHIFT)
486
487	/* Create the kernel space L2 table */
488	mov	x6, x26
489	mov	x7, #(ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
490	mov	x8, #(KERNBASE)
491	mov	x9, x28
492	bl	build_l2_block_pagetable
493#endif
494
495	/* Move to the l1 table */
496	add	x26, x26, #PAGE_SIZE
497
498	/* Link the l1 -> l2 table */
499	mov	x9, x6
500	mov	x6, x26
501	bl	link_l1_pagetable
502
503	/* Move to the l0 table */
504	add	x24, x26, #PAGE_SIZE
505
506	/* Link the l0 -> l1 table */
507	mov	x9, x6
508	mov	x6, x24
509	mov	x10, #1
510	bl	link_l0_pagetable
511
512	/*
513	 * Build the TTBR0 maps.  As TTBR0 maps, they must specify ATTR_S1_nG.
514	 * They are only needed early on, so the VA = PA map is uncached.
515	 */
516	add	x27, x24, #PAGE_SIZE
517
518	mov	x6, x27		/* The initial page table */
519
520	/* Create the VA = PA map */
521	mov	x7, #(ATTR_S1_nG | ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
522	adrp	x16, _start
523	and	x16, x16, #(~L2_OFFSET)
524	mov	x9, x16		/* PA start */
525	mov	x8, x16		/* VA start (== PA start) */
526	mov	x10, #1
527	bl	build_l2_block_pagetable
528
529#if defined(SOCDEV_PA)
530	/* Create a table for the UART */
531	mov	x7, #(ATTR_S1_nG | ATTR_S1_IDX(VM_MEMATTR_DEVICE))
532	ldr	x9, =(L2_SIZE)
533	add	x16, x16, x9	/* VA start */
534	mov	x8, x16
535
536	/* Store the socdev virtual address */
537	add	x17, x8, #(SOCDEV_PA & L2_OFFSET)
538	adrp	x9, socdev_va
539	str	x17, [x9, :lo12:socdev_va]
540
541	mov	x9, #(SOCDEV_PA & ~L2_OFFSET)	/* PA start */
542	mov	x10, #1
543	bl	build_l2_block_pagetable
544#endif
545
546#if defined(LINUX_BOOT_ABI)
547	/* Map FDT data ? */
548	cbz	x19, 1f
549
550	/* Create the mapping for FDT data (2 MiB max) */
551	mov	x7, #(ATTR_S1_nG | ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
552	ldr	x9, =(L2_SIZE)
553	add	x16, x16, x9	/* VA start */
554	mov	x8, x16
555	mov	x9, x0			/* PA start */
556	/* Update the module pointer to point at the allocated memory */
557	and	x0, x0, #(L2_OFFSET)	/* Keep the lower bits */
558	add	x0, x0, x8		/* Add the aligned virtual address */
559
560	mov	x10, #1
561	bl	build_l2_block_pagetable
562
5631:
564#endif
565
566	/* Move to the l1 table */
567	add	x27, x27, #PAGE_SIZE
568
569	/* Link the l1 -> l2 table */
570	mov	x9, x6
571	mov	x6, x27
572	bl	link_l1_pagetable
573
574	/* Move to the l0 table */
575	add	x27, x27, #PAGE_SIZE
576
577	/* Link the l0 -> l1 table */
578	mov	x9, x6
579	mov	x6, x27
580	mov	x10, #1
581	bl	link_l0_pagetable
582
583	/* Restore the Link register */
584	mov	x30, x5
585	ret
586LEND(create_pagetables)
587
588/*
589 * Builds an L0 -> L1 table descriptor
590 *
591 *  x6  = L0 table
592 *  x8  = Virtual Address
593 *  x9  = L1 PA (trashed)
594 *  x10 = Entry count (trashed)
595 *  x11, x12 and x13 are trashed
596 */
597LENTRY(link_l0_pagetable)
598	/*
599	 * Link an L0 -> L1 table entry.
600	 */
601	/* Find the table index */
602	lsr	x11, x8, #L0_SHIFT
603	and	x11, x11, #L0_ADDR_MASK
604
605	/* Build the L0 block entry */
606	mov	x12, #L0_TABLE
607	orr	x12, x12, #(TATTR_UXN_TABLE | TATTR_AP_TABLE_NO_EL0)
608
609	/* Only use the output address bits */
610	lsr	x9, x9, #PAGE_SHIFT
6111:	orr	x13, x12, x9, lsl #PAGE_SHIFT
612
613	/* Store the entry */
614	str	x13, [x6, x11, lsl #3]
615
616	sub	x10, x10, #1
617	add	x11, x11, #1
618	add	x9, x9, #1
619	cbnz	x10, 1b
620
621	ret
622LEND(link_l0_pagetable)
623
624/*
625 * Builds an L1 -> L2 table descriptor
626 *
627 *  x6  = L1 table
628 *  x8  = Virtual Address
629 *  x9  = L2 PA (trashed)
630 *  x11, x12 and x13 are trashed
631 */
632LENTRY(link_l1_pagetable)
633	/*
634	 * Link an L1 -> L2 table entry.
635	 */
636	/* Find the table index */
637	lsr	x11, x8, #L1_SHIFT
638	and	x11, x11, #Ln_ADDR_MASK
639
640	/* Build the L1 block entry */
641	mov	x12, #L1_TABLE
642
643	/* Only use the output address bits */
644	lsr	x9, x9, #PAGE_SHIFT
645	orr	x13, x12, x9, lsl #PAGE_SHIFT
646
647	/* Store the entry */
648	str	x13, [x6, x11, lsl #3]
649
650	ret
651LEND(link_l1_pagetable)
652
653/*
654 * Builds count 2 MiB page table entry
655 *  x6  = L2 table
656 *  x7  = Block attributes
657 *  x8  = VA start
658 *  x9  = PA start (trashed)
659 *  x10 = Entry count (trashed)
660 *  x11, x12 and x13 are trashed
661 */
662LENTRY(build_l2_block_pagetable)
663	/*
664	 * Build the L2 table entry.
665	 */
666	/* Find the table index */
667	lsr	x11, x8, #L2_SHIFT
668	and	x11, x11, #Ln_ADDR_MASK
669
670	/* Build the L2 block entry */
671	orr	x12, x7, #L2_BLOCK
672	orr	x12, x12, #(ATTR_DEFAULT)
673	orr	x12, x12, #(ATTR_S1_UXN)
674
675	/* Only use the output address bits */
676	lsr	x9, x9, #L2_SHIFT
677
678	/* Set the physical address for this virtual address */
6791:	orr	x13, x12, x9, lsl #L2_SHIFT
680
681	/* Store the entry */
682	str	x13, [x6, x11, lsl #3]
683
684	sub	x10, x10, #1
685	add	x11, x11, #1
686	add	x9, x9, #1
687	cbnz	x10, 1b
688
689	ret
690LEND(build_l2_block_pagetable)
691
692#if PAGE_SIZE != PAGE_SIZE_4K
693/*
694 * Builds an L2 -> L3 table descriptor
695 *
696 *  x6  = L2 table
697 *  x8  = Virtual Address
698 *  x9  = L3 PA (trashed)
699 *  x11, x12 and x13 are trashed
700 */
701LENTRY(link_l2_pagetable)
702	/*
703	 * Link an L2 -> L3 table entry.
704	 */
705	/* Find the table index */
706	lsr	x11, x8, #L2_SHIFT
707	and	x11, x11, #Ln_ADDR_MASK
708
709	/* Build the L1 block entry */
710	mov	x12, #L2_TABLE
711
712	/* Only use the output address bits */
713	lsr	x9, x9, #PAGE_SHIFT
714	orr	x13, x12, x9, lsl #PAGE_SHIFT
715
716	/* Store the entry */
717	str	x13, [x6, x11, lsl #3]
718
719	ret
720LEND(link_l2_pagetable)
721
722/*
723 * Builds count level 3 page table entries
724 *  x6  = L3 table
725 *  x7  = Block attributes
726 *  x8  = VA start
727 *  x9  = PA start (trashed)
728 *  x10 = Entry count (trashed)
729 *  x11, x12 and x13 are trashed
730 */
731LENTRY(build_l3_page_pagetable)
732	/*
733	 * Build the L3 table entry.
734	 */
735	/* Find the table index */
736	lsr	x11, x8, #L3_SHIFT
737	and	x11, x11, #Ln_ADDR_MASK
738
739	/* Build the L3 page entry */
740	orr	x12, x7, #L3_PAGE
741	orr	x12, x12, #(ATTR_DEFAULT)
742	orr	x12, x12, #(ATTR_S1_UXN)
743
744	/* Only use the output address bits */
745	lsr	x9, x9, #L3_SHIFT
746
747	/* Set the physical address for this virtual address */
7481:	orr	x13, x12, x9, lsl #L3_SHIFT
749
750	/* Store the entry */
751	str	x13, [x6, x11, lsl #3]
752
753	sub	x10, x10, #1
754	add	x11, x11, #1
755	add	x9, x9, #1
756	cbnz	x10, 1b
757
758	ret
759LEND(build_l3_page_pagetable)
760#endif
761
762LENTRY(start_mmu)
763	dsb	sy
764
765	/* Load the exception vectors */
766	ldr	x2, =exception_vectors
767	msr	vbar_el1, x2
768
769	/* Load ttbr0 and ttbr1 */
770	msr	ttbr0_el1, x27
771	msr	ttbr1_el1, x24
772	isb
773
774	/* Clear the Monitor Debug System control register */
775	msr	mdscr_el1, xzr
776
777	/* Invalidate the TLB */
778	tlbi	vmalle1is
779	dsb	ish
780	isb
781
782	ldr	x2, mair
783	msr	mair_el1, x2
784
785	/*
786	 * Setup TCR according to the PARange and ASIDBits fields
787	 * from ID_AA64MMFR0_EL1 and the HAFDBS field from the
788	 * ID_AA64MMFR1_EL1.  More precisely, set TCR_EL1.AS
789	 * to 1 only if the ASIDBits field equals 0b0010.
790	 */
791	ldr	x2, tcr
792	mrs	x3, id_aa64mmfr0_el1
793
794	/* Copy the bottom 3 bits from id_aa64mmfr0_el1 into TCR.IPS */
795	bfi	x2, x3, #(TCR_IPS_SHIFT), #(TCR_IPS_WIDTH)
796	and	x3, x3, #(ID_AA64MMFR0_ASIDBits_MASK)
797
798	/* Check if the HW supports 16 bit ASIDS */
799	cmp	x3, #(ID_AA64MMFR0_ASIDBits_16)
800	/* If so x3 == 1, else x3 == 0 */
801	cset	x3, eq
802	/* Set TCR.AS with x3 */
803	bfi	x2, x3, #(TCR_ASID_SHIFT), #(TCR_ASID_WIDTH)
804
805	/*
806	 * Check if the HW supports access flag and dirty state updates,
807	 * and set TCR_EL1.HA and TCR_EL1.HD accordingly.
808	 */
809	mrs	x3, id_aa64mmfr1_el1
810	and	x3, x3, #(ID_AA64MMFR1_HAFDBS_MASK)
811	cmp	x3, #1
812	b.ne	1f
813	orr 	x2, x2, #(TCR_HA)
814	b	2f
8151:
816	cmp	x3, #2
817	b.ne	2f
818	orr 	x2, x2, #(TCR_HA | TCR_HD)
8192:
820	msr	tcr_el1, x2
821
822	/*
823	 * Setup SCTLR.
824	 */
825	ldr	x2, sctlr_set
826	ldr	x3, sctlr_clear
827	mrs	x1, sctlr_el1
828	bic	x1, x1, x3	/* Clear the required bits */
829	orr	x1, x1, x2	/* Set the required bits */
830	msr	sctlr_el1, x1
831	isb
832
833	ret
834
835	.align 3
836mair:
837	.quad	MAIR_ATTR(MAIR_DEVICE_nGnRnE, VM_MEMATTR_DEVICE_nGnRnE) | \
838		MAIR_ATTR(MAIR_NORMAL_NC, VM_MEMATTR_UNCACHEABLE)   |	\
839		MAIR_ATTR(MAIR_NORMAL_WB, VM_MEMATTR_WRITE_BACK)    |	\
840		MAIR_ATTR(MAIR_NORMAL_WT, VM_MEMATTR_WRITE_THROUGH) |	\
841		MAIR_ATTR(MAIR_DEVICE_nGnRE, VM_MEMATTR_DEVICE_nGnRE)
842tcr:
843#if PAGE_SIZE == PAGE_SIZE_4K
844#define	TCR_TG	(TCR_TG1_4K | TCR_TG0_4K)
845#elif PAGE_SIZE == PAGE_SIZE_16K
846#define	TCR_TG	(TCR_TG1_16K | TCR_TG0_16K)
847#else
848#error Unsupported page size
849#endif
850
851	.quad (TCR_TxSZ(64 - VIRT_BITS) | TCR_TG | \
852	    TCR_CACHE_ATTRS | TCR_SMP_ATTRS)
853sctlr_set:
854	/* Bits to set */
855	.quad (SCTLR_LSMAOE | SCTLR_nTLSMD | SCTLR_UCI | SCTLR_SPAN | \
856	    SCTLR_nTWE | SCTLR_nTWI | SCTLR_UCT | SCTLR_DZE | \
857	    SCTLR_I | SCTLR_SED | SCTLR_SA0 | SCTLR_SA | SCTLR_C | \
858	    SCTLR_M | SCTLR_CP15BEN)
859sctlr_clear:
860	/* Bits to clear */
861	.quad (SCTLR_EE | SCTLR_E0E | SCTLR_IESB | SCTLR_WXN | SCTLR_UMA | \
862	    SCTLR_ITD | SCTLR_A)
863LEND(start_mmu)
864
865ENTRY(abort)
866	b abort
867END(abort)
868
869	.section .init_pagetable, "aw", %nobits
870	.align PAGE_SHIFT
871	/*
872	 * 6 initial tables (in the following order):
873	 *           L2 for kernel (High addresses)
874	 *           L1 for kernel
875	 *           L0 for kernel
876	 *           L1 bootstrap for user   (Low addresses)
877	 *           L0 bootstrap for user
878	 *           L0 for user
879	 */
880	.globl pagetable_l0_ttbr1
881pagetable:
882#if PAGE_SIZE != PAGE_SIZE_4K
883	.space	(PAGE_SIZE * L3_PAGE_COUNT)
884pagetable_l2_ttbr1:
885#endif
886	.space	PAGE_SIZE
887pagetable_l1_ttbr1:
888	.space	PAGE_SIZE
889pagetable_l0_ttbr1:
890	.space	PAGE_SIZE
891pagetable_l2_ttbr0_bootstrap:
892	.space	PAGE_SIZE
893pagetable_l1_ttbr0_bootstrap:
894	.space	PAGE_SIZE
895pagetable_l0_ttbr0_boostrap:
896	.space	PAGE_SIZE
897pagetable_l0_ttbr0:
898	.space	PAGE_SIZE
899
900pagetable_end:
901
902el2_pagetable:
903	.space	PAGE_SIZE
904
905	.align	4
906initstack:
907	.space	(PAGE_SIZE * KSTACK_PAGES)
908initstack_end:
909
910
911.text
912EENTRY(aarch32_sigcode)
913	.word 0xe1a0000d	// mov r0, sp
914	.word 0xe2800040	// add r0, r0, #SIGF_UC
915	.word 0xe59f700c	// ldr r7, [pc, #12]
916	.word 0xef000000	// swi #0
917	.word 0xe59f7008	// ldr r7, [pc, #8]
918	.word 0xef000000	// swi #0
919	.word 0xeafffffa	// b . - 16
920EEND(aarch32_sigcode)
921	.word SYS_sigreturn
922	.word SYS_exit
923	.align	3
924aarch32_esigcode:
925	.data
926	.global sz_aarch32_sigcode
927sz_aarch32_sigcode:
928	.quad aarch32_esigcode - aarch32_sigcode
929