xref: /linux/arch/parisc/kernel/head.S (revision bc75dffadc063eb46200611cc41d1e2373219e11) 
1/* This file is subject to the terms and conditions of the GNU General Public
2 * License.  See the file "COPYING" in the main directory of this archive
3 * for more details.
4 *
5 * Copyright (C) 1999-2007 by Helge Deller <deller@gmx.de>
6 * Copyright 1999 SuSE GmbH (Philipp Rumpf)
7 * Copyright 1999 Philipp Rumpf (prumpf@tux.org)
8 * Copyright 2000 Hewlett Packard (Paul Bame, bame@puffin.external.hp.com)
9 * Copyright (C) 2001 Grant Grundler (Hewlett Packard)
10 * Copyright (C) 2004 Kyle McMartin <kyle@debian.org>
11 *
12 * Initial Version 04-23-1999 by Helge Deller <deller@gmx.de>
13 */
14
15#include <asm/asm-offsets.h>
16#include <asm/psw.h>
17#include <asm/pdc.h>
18
19#include <asm/assembly.h>
20
21#include <linux/linkage.h>
22#include <linux/init.h>
23#include <linux/pgtable.h>
24
25	.level	1.1
26
27	__INITDATA
28ENTRY(boot_args)
29	.word 0 /* arg0 */
30	.word 0 /* arg1 */
31	.word 0 /* arg2 */
32	.word 0 /* arg3 */
33END(boot_args)
34
35	__HEAD
36
37	.align	4
38	.import init_task,data
39	.import init_stack,data
40	.import fault_vector_20,code    /* IVA parisc 2.0 32 bit */
41#ifndef CONFIG_64BIT
42        .import fault_vector_11,code    /* IVA parisc 1.1 32 bit */
43	.import	$global$		/* forward declaration */
44#endif /*!CONFIG_64BIT*/
45ENTRY(parisc_kernel_start)
46	.proc
47	.callinfo
48
49	/* Make sure sr4-sr7 are set to zero for the kernel address space */
50	mtsp	%r0,%sr4
51	mtsp	%r0,%sr5
52	mtsp	%r0,%sr6
53	mtsp	%r0,%sr7
54
55	/* Clear BSS (shouldn't the boot loader do this?) */
56
57	.import __bss_start,data
58	.import __bss_stop,data
59
60	load32		PA(__bss_start),%r3
61	load32		PA(__bss_stop),%r4
62$bss_loop:
63	cmpb,<<,n       %r3,%r4,$bss_loop
64	stw,ma          %r0,4(%r3)
65
66	/* Save away the arguments the boot loader passed in (32 bit args) */
67	load32		PA(boot_args),%r1
68	stw,ma          %arg0,4(%r1)
69	stw,ma          %arg1,4(%r1)
70	stw,ma          %arg2,4(%r1)
71	stw,ma          %arg3,4(%r1)
72
73#if defined(CONFIG_PA20)
74	/* check for 64-bit capable CPU as required by current kernel */
75	ldi		32,%r10
76	mtctl		%r10,%cr11
77	.level 2.0
78	mfctl,w		%cr11,%r10
79	.level 1.1
80	comib,<>,n	0,%r10,$cpu_ok
81
82	load32		PA(msg1),%arg0
83	ldi		msg1_end-msg1,%arg1
84$iodc_panic:
85	copy		%arg0, %r10
86	copy		%arg1, %r11
87	load32		PA(init_stack),%sp
88#define MEM_CONS 0x3A0
89	ldw		MEM_CONS+32(%r0),%arg0	// HPA
90	ldi		ENTRY_IO_COUT,%arg1
91	ldw		MEM_CONS+36(%r0),%arg2	// SPA
92	ldw		MEM_CONS+8(%r0),%arg3	// layers
93	load32		PA(__bss_start),%r1
94	stw		%r1,-52(%sp)		// arg4
95	stw		%r0,-56(%sp)		// arg5
96	stw		%r10,-60(%sp)		// arg6 = ptr to text
97	stw		%r11,-64(%sp)		// arg7 = len
98	stw		%r0,-68(%sp)		// arg8
99	load32		PA(.iodc_panic_ret), %rp
100	ldw		MEM_CONS+40(%r0),%r1	// ENTRY_IODC
101	bv,n		(%r1)
102.iodc_panic_ret:
103	b .				/* wait endless with ... */
104	or		%r10,%r10,%r10	/* qemu idle sleep */
105msg1:	.ascii "Can't boot kernel which was built for PA8x00 CPUs on this machine.\r\n"
106msg1_end:
107
108$cpu_ok:
109#endif
110
111	.level	PA_ASM_LEVEL
112
113	/* Initialize startup VM. Just map first 16/32 MB of memory */
114	load32		PA(swapper_pg_dir),%r4
115	mtctl		%r4,%cr24	/* Initialize kernel root pointer */
116	mtctl		%r4,%cr25	/* Initialize user root pointer */
117
118#if CONFIG_PGTABLE_LEVELS == 3
119	/* Set pmd in pgd */
120	load32		PA(pmd0),%r5
121	shrd            %r5,PxD_VALUE_SHIFT,%r3
122	ldo		(PxD_FLAG_PRESENT+PxD_FLAG_VALID)(%r3),%r3
123	stw		%r3,ASM_PGD_ENTRY*ASM_PGD_ENTRY_SIZE(%r4)
124	ldo		ASM_PMD_ENTRY*ASM_PMD_ENTRY_SIZE(%r5),%r4
125#else
126	/* 2-level page table, so pmd == pgd */
127	ldo		ASM_PGD_ENTRY*ASM_PGD_ENTRY_SIZE(%r4),%r4
128#endif
129
130	/* Fill in pmd with enough pte directories */
131	load32		PA(pg0),%r1
132	SHRREG		%r1,PxD_VALUE_SHIFT,%r3
133	ldo		(PxD_FLAG_PRESENT+PxD_FLAG_VALID)(%r3),%r3
134
135	ldi		ASM_PT_INITIAL,%r1
136
1371:
138	stw		%r3,0(%r4)
139	ldo		(PAGE_SIZE >> PxD_VALUE_SHIFT)(%r3),%r3
140	addib,>		-1,%r1,1b
141#if CONFIG_PGTABLE_LEVELS == 3
142	ldo             ASM_PMD_ENTRY_SIZE(%r4),%r4
143#else
144	ldo             ASM_PGD_ENTRY_SIZE(%r4),%r4
145#endif
146
147
148	/* Now initialize the PTEs themselves.  We use RWX for
149	 * everything ... it will get remapped correctly later */
150	ldo		0+_PAGE_KERNEL_RWX(%r0),%r3 /* Hardwired 0 phys addr start */
151	load32		(1<<(KERNEL_INITIAL_ORDER-PAGE_SHIFT)),%r11 /* PFN count */
152	load32		PA(pg0),%r1
153
154$pgt_fill_loop:
155	STREGM          %r3,ASM_PTE_ENTRY_SIZE(%r1)
156	ldo		(1<<PFN_PTE_SHIFT)(%r3),%r3 /* add one PFN */
157	addib,>		-1,%r11,$pgt_fill_loop
158	nop
159
160	/* Load the return address...er...crash 'n burn */
161	copy		%r0,%r2
162
163	/* And the RFI Target address too */
164	load32		start_parisc,%r11
165
166	/* And the initial task pointer */
167	load32		init_task,%r6
168	mtctl           %r6,%cr30
169
170	/* And the stack pointer too */
171	load32		init_stack,%sp
172	tophys_r1	%sp
173#if defined(CONFIG_64BIT) && defined(CONFIG_FUNCTION_TRACER)
174	.import _mcount,data
175	/* initialize mcount FPTR */
176	/* Get the global data pointer */
177	loadgp
178	load32		PA(_mcount), %r10
179	std		%dp,0x18(%r10)
180#endif
181
182#define MEM_PDC_LO 0x388
183#define MEM_PDC_HI 0x35C
184#ifdef CONFIG_64BIT
185	/* Get PDCE_PROC for monarch CPU. */
186	ldw             MEM_PDC_LO(%r0),%r3
187	ldw             MEM_PDC_HI(%r0),%r10
188	depd            %r10, 31, 32, %r3        /* move to upper word */
189#endif
190
191
192#ifdef CONFIG_SMP
193	/* Set the smp rendezvous address into page zero.
194	** It would be safer to do this in init_smp_config() but
195	** it's just way easier to deal with here because
196	** of 64-bit function ptrs and the address is local to this file.
197	*/
198	load32		PA(smp_slave_stext),%r10
199	stw		%r10,0x10(%r0)	/* MEM_RENDEZ */
200	stw		%r0,0x28(%r0)	/* MEM_RENDEZ_HI - assume addr < 4GB */
201
202	/* FALLTHROUGH */
203	.procend
204
205#ifdef CONFIG_HOTPLUG_CPU
206	/* common_stext is far away in another section... jump there */
207	load32		PA(common_stext), %rp
208	bv,n		(%rp)
209
210	/* common_stext and smp_slave_stext needs to be in text section */
211	.text
212#endif
213
214	/*
215	** Code Common to both Monarch and Slave processors.
216	** Entry:
217	**
218	**  1.1:
219	**    %r11 must contain RFI target address.
220	**    %r25/%r26 args to pass to target function
221	**    %r2  in case rfi target decides it didn't like something
222	**
223	**  2.0w:
224	**    %r3  PDCE_PROC address
225	**    %r11 RFI target address
226	**
227	** Caller must init: SR4-7, %sp, %r10, %cr24/25,
228	*/
229common_stext:
230	.proc
231	.callinfo
232#else
233	/* Clear PDC entry point - we won't use it */
234	stw		%r0,0x10(%r0)	/* MEM_RENDEZ */
235	stw		%r0,0x28(%r0)	/* MEM_RENDEZ_HI */
236#endif /*CONFIG_SMP*/
237
238#ifdef CONFIG_64BIT
239	mfctl		%cr30,%r6		/* PCX-W2 firmware bug */
240	tophys_r1	%r6
241
242	/* Save the rfi target address */
243	STREG		%r11,  TASK_PT_GR11(%r6)
244	/* Switch to wide mode Superdome doesn't support narrow PDC
245	** calls.
246	*/
2471:	mfia            %rp             /* clear upper part of pcoq */
248	ldo             2f-1b(%rp),%rp
249	depdi           0,31,32,%rp
250	bv              (%rp)
251	ssm             PSW_SM_W,%r0
252
253        /* Set Wide mode as the "Default" (eg for traps)
254        ** First trap occurs *right* after (or part of) rfi for slave CPUs.
255        ** Someday, palo might not do this for the Monarch either.
256        */
2572:
258
259	ldo             PDC_PSW(%r0),%arg0              /* 21 */
260	ldo             PDC_PSW_SET_DEFAULTS(%r0),%arg1 /* 2 */
261	ldo             PDC_PSW_WIDE_BIT(%r0),%arg2     /* 2 */
262	load32          PA(stext_pdc_ret), %rp
263	bv              (%r3)
264	copy            %r0,%arg3
265
266stext_pdc_ret:
267	LDREG		TASK_PT_GR11(%r6), %r11
268	tovirt_r1	%r6
269	mtctl		%r6,%cr30		/* restore task thread info */
270#endif
271
272#ifndef CONFIG_64BIT
273	/* clear all BTLBs */
274	ldi		PDC_BLOCK_TLB,%arg0
275	load32          PA(stext_pdc_btlb_ret), %rp
276	ldw             MEM_PDC_LO(%r0),%r3
277	bv              (%r3)
278	ldi		PDC_BTLB_PURGE_ALL,%arg1
279stext_pdc_btlb_ret:
280#endif
281
282	/* PARANOID: clear user scratch/user space SR's */
283	mtsp	%r0,%sr0
284	mtsp	%r0,%sr1
285	mtsp	%r0,%sr2
286	mtsp	%r0,%sr3
287
288	/* Initialize Protection Registers */
289	mtctl	%r0,%cr8
290	mtctl	%r0,%cr9
291	mtctl	%r0,%cr12
292	mtctl	%r0,%cr13
293
294	/* Initialize the global data pointer */
295	loadgp
296
297	/* Set up our interrupt table.  HPMCs might not work after this!
298	 *
299	 * We need to install the correct iva for PA1.1 or PA2.0. The
300	 * following short sequence of instructions can determine this
301	 * (without being illegal on a PA1.1 machine).
302	 */
303#ifndef CONFIG_64BIT
304	ldi		32,%r10
305	mtctl		%r10,%cr11
306	.level 2.0
307	mfctl,w		%cr11,%r10
308	.level 1.1
309	comib,<>,n	0,%r10,$is_pa20
310	ldil		L%PA(fault_vector_11),%r10
311	b		$install_iva
312	ldo		R%PA(fault_vector_11)(%r10),%r10
313
314$is_pa20:
315	.level		PA_ASM_LEVEL /* restore 1.1 || 2.0w */
316#endif /*!CONFIG_64BIT*/
317	load32		PA(fault_vector_20),%r10
318
319$install_iva:
320	mtctl		%r10,%cr14
321
322	b		aligned_rfi  /* Prepare to RFI! Man all the cannons! */
323	nop
324
325	.align 128
326aligned_rfi:
327	pcxt_ssm_bug
328
329	copy		%r3, %arg0	/* PDCE_PROC for smp_callin() */
330
331	rsm		PSW_SM_QUIET,%r0	/* off troublesome PSW bits */
332	/* Don't need NOPs, have 8 compliant insn before rfi */
333
334	mtctl		%r0,%cr17	/* Clear IIASQ tail */
335	mtctl		%r0,%cr17	/* Clear IIASQ head */
336
337	/* Load RFI target into PC queue */
338	mtctl		%r11,%cr18	/* IIAOQ head */
339	ldo		4(%r11),%r11
340	mtctl		%r11,%cr18	/* IIAOQ tail */
341
342	load32		KERNEL_PSW,%r10
343	mtctl		%r10,%ipsw
344
345	tovirt_r1	%sp
346
347	/* Jump through hyperspace to Virt Mode */
348	rfi
349	nop
350
351	.procend
352
353#ifdef CONFIG_SMP
354
355	.import smp_init_current_idle_task,data
356	.import	smp_callin,code
357
358#ifndef CONFIG_64BIT
359smp_callin_rtn:
360        .proc
361	.callinfo
362	break	1,1		/*  Break if returned from start_secondary */
363	nop
364	nop
365        .procend
366#endif /*!CONFIG_64BIT*/
367
368/***************************************************************************
369* smp_slave_stext is executed by all non-monarch Processors when the Monarch
370* pokes the slave CPUs in smp.c:smp_boot_cpus().
371*
372* Once here, registers values are initialized in order to branch to virtual
373* mode. Once all available/eligible CPUs are in virtual mode, all are
374* released and start out by executing their own idle task.
375*****************************************************************************/
376smp_slave_stext:
377        .proc
378	.callinfo
379
380	/*
381	** Initialize Space registers
382	*/
383	mtsp	   %r0,%sr4
384	mtsp	   %r0,%sr5
385	mtsp	   %r0,%sr6
386	mtsp	   %r0,%sr7
387
388#ifdef CONFIG_64BIT
389	/*
390	 *  Enable Wide mode early, in case the task_struct for the idle
391	 *  task in smp_init_current_idle_task was allocated above 4GB.
392	 */
3931:	mfia            %rp             /* clear upper part of pcoq */
394	ldo             2f-1b(%rp),%rp
395	depdi           0,31,32,%rp
396	bv              (%rp)
397	ssm             PSW_SM_W,%r0
3982:
399#endif
400
401	/*  Initialize the SP - monarch sets up smp_init_current_idle_task */
402	load32		PA(smp_init_current_idle_task),%r6
403	LDREG		0(%r6),%r6
404	mtctl		%r6,%cr30
405	tophys_r1	%r6
406	LDREG           TASK_STACK(%r6),%sp
407	tophys_r1	%sp
408	ldo		FRAME_SIZE(%sp),%sp
409
410	/* point CPU to kernel page tables */
411	load32		PA(swapper_pg_dir),%r4
412	mtctl		%r4,%cr24	/* Initialize kernel root pointer */
413	mtctl		%r4,%cr25	/* Initialize user root pointer */
414
415#ifdef CONFIG_64BIT
416	/* Setup PDCE_PROC entry */
417	copy            %arg0,%r3
418#else
419	/* Load RFI *return* address in case smp_callin bails */
420	load32		smp_callin_rtn,%r2
421#endif
422
423	/* Load RFI target address.  */
424	load32		smp_callin,%r11
425
426	/* ok...common code can handle the rest */
427	b		common_stext
428	nop
429
430	.procend
431#endif /* CONFIG_SMP */
432
433#ifndef CONFIG_64BIT
434	.section .data..ro_after_init
435
436	.align	4
437	.export	$global$,data
438
439	.type	$global$,@object
440	.size	$global$,4
441$global$:
442	.word 0
443#endif /*!CONFIG_64BIT*/
444