xref: /openbmc/linux/arch/parisc/kernel/head.S (revision bfb41e46) 
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_64BIT) && defined(CONFIG_PA20)
74	/* This 32-bit kernel was compiled for PA2.0 CPUs. Check current CPU
75	 * and halt kernel if we detect a PA1.x CPU. */
76	ldi		32,%r10
77	mtctl		%r10,%cr11
78	.level 2.0
79	mfctl,w		%cr11,%r10
80	.level 1.1
81	comib,<>,n	0,%r10,$cpu_ok
82
83	load32		PA(msg1),%arg0
84	ldi		msg1_end-msg1,%arg1
85$iodc_panic:
86	copy		%arg0, %r10
87	copy		%arg1, %r11
88	load32		PA(init_stack),%sp
89#define MEM_CONS 0x3A0
90	ldw		MEM_CONS+32(%r0),%arg0	// HPA
91	ldi		ENTRY_IO_COUT,%arg1
92	ldw		MEM_CONS+36(%r0),%arg2	// SPA
93	ldw		MEM_CONS+8(%r0),%arg3	// layers
94	load32		PA(__bss_start),%r1
95	stw		%r1,-52(%sp)		// arg4
96	stw		%r0,-56(%sp)		// arg5
97	stw		%r10,-60(%sp)		// arg6 = ptr to text
98	stw		%r11,-64(%sp)		// arg7 = len
99	stw		%r0,-68(%sp)		// arg8
100	load32		PA(.iodc_panic_ret), %rp
101	ldw		MEM_CONS+40(%r0),%r1	// ENTRY_IODC
102	bv,n		(%r1)
103.iodc_panic_ret:
104	b .				/* wait endless with ... */
105	or		%r10,%r10,%r10	/* qemu idle sleep */
106msg1:	.ascii "Can't boot kernel which was built for PA8x00 CPUs on this machine.\r\n"
107msg1_end:
108
109$cpu_ok:
110#endif
111
112	.level	PA_ASM_LEVEL
113
114	/* Initialize startup VM. Just map first 16/32 MB of memory */
115	load32		PA(swapper_pg_dir),%r4
116	mtctl		%r4,%cr24	/* Initialize kernel root pointer */
117	mtctl		%r4,%cr25	/* Initialize user root pointer */
118
119#if CONFIG_PGTABLE_LEVELS == 3
120	/* Set pmd in pgd */
121	load32		PA(pmd0),%r5
122	shrd            %r5,PxD_VALUE_SHIFT,%r3
123	ldo		(PxD_FLAG_PRESENT+PxD_FLAG_VALID)(%r3),%r3
124	stw		%r3,ASM_PGD_ENTRY*ASM_PGD_ENTRY_SIZE(%r4)
125	ldo		ASM_PMD_ENTRY*ASM_PMD_ENTRY_SIZE(%r5),%r4
126#else
127	/* 2-level page table, so pmd == pgd */
128	ldo		ASM_PGD_ENTRY*ASM_PGD_ENTRY_SIZE(%r4),%r4
129#endif
130
131	/* Fill in pmd with enough pte directories */
132	load32		PA(pg0),%r1
133	SHRREG		%r1,PxD_VALUE_SHIFT,%r3
134	ldo		(PxD_FLAG_PRESENT+PxD_FLAG_VALID)(%r3),%r3
135
136	ldi		ASM_PT_INITIAL,%r1
137
1381:
139	stw		%r3,0(%r4)
140	ldo		(PAGE_SIZE >> PxD_VALUE_SHIFT)(%r3),%r3
141	addib,>		-1,%r1,1b
142#if CONFIG_PGTABLE_LEVELS == 3
143	ldo             ASM_PMD_ENTRY_SIZE(%r4),%r4
144#else
145	ldo             ASM_PGD_ENTRY_SIZE(%r4),%r4
146#endif
147
148
149	/* Now initialize the PTEs themselves.  We use RWX for
150	 * everything ... it will get remapped correctly later */
151	ldo		0+_PAGE_KERNEL_RWX(%r0),%r3 /* Hardwired 0 phys addr start */
152	load32		(1<<(KERNEL_INITIAL_ORDER-PAGE_SHIFT)),%r11 /* PFN count */
153	load32		PA(pg0),%r1
154
155$pgt_fill_loop:
156	STREGM          %r3,ASM_PTE_ENTRY_SIZE(%r1)
157	ldo		(1<<PFN_PTE_SHIFT)(%r3),%r3 /* add one PFN */
158	addib,>		-1,%r11,$pgt_fill_loop
159	nop
160
161	/* Load the return address...er...crash 'n burn */
162	copy		%r0,%r2
163
164	/* And the RFI Target address too */
165	load32		start_parisc,%r11
166
167	/* And the initial task pointer */
168	load32		init_task,%r6
169	mtctl           %r6,%cr30
170
171	/* And the stack pointer too */
172	load32		init_stack,%sp
173	tophys_r1	%sp
174#if defined(CONFIG_64BIT) && defined(CONFIG_FUNCTION_TRACER)
175	.import _mcount,data
176	/* initialize mcount FPTR */
177	/* Get the global data pointer */
178	loadgp
179	load32		PA(_mcount), %r10
180	std		%dp,0x18(%r10)
181#endif
182
183#ifdef CONFIG_64BIT
184	/* Get PDCE_PROC for monarch CPU. */
185#define MEM_PDC_LO 0x388
186#define MEM_PDC_HI 0x35C
187	ldw             MEM_PDC_LO(%r0),%r3
188	ldw             MEM_PDC_HI(%r0),%r10
189	depd            %r10, 31, 32, %r3        /* move to upper word */
190#endif
191
192
193#ifdef CONFIG_SMP
194	/* Set the smp rendezvous address into page zero.
195	** It would be safer to do this in init_smp_config() but
196	** it's just way easier to deal with here because
197	** of 64-bit function ptrs and the address is local to this file.
198	*/
199	load32		PA(smp_slave_stext),%r10
200	stw		%r10,0x10(%r0)	/* MEM_RENDEZ */
201	stw		%r0,0x28(%r0)	/* MEM_RENDEZ_HI - assume addr < 4GB */
202
203	/* FALLTHROUGH */
204	.procend
205
206#ifdef CONFIG_HOTPLUG_CPU
207	/* common_stext is far away in another section... jump there */
208	load32		PA(common_stext), %rp
209	bv,n		(%rp)
210
211	/* common_stext and smp_slave_stext needs to be in text section */
212	.text
213#endif
214
215	/*
216	** Code Common to both Monarch and Slave processors.
217	** Entry:
218	**
219	**  1.1:
220	**    %r11 must contain RFI target address.
221	**    %r25/%r26 args to pass to target function
222	**    %r2  in case rfi target decides it didn't like something
223	**
224	**  2.0w:
225	**    %r3  PDCE_PROC address
226	**    %r11 RFI target address
227	**
228	** Caller must init: SR4-7, %sp, %r10, %cr24/25,
229	*/
230common_stext:
231	.proc
232	.callinfo
233#else
234	/* Clear PDC entry point - we won't use it */
235	stw		%r0,0x10(%r0)	/* MEM_RENDEZ */
236	stw		%r0,0x28(%r0)	/* MEM_RENDEZ_HI */
237#endif /*CONFIG_SMP*/
238
239#ifdef CONFIG_64BIT
240	mfctl		%cr30,%r6		/* PCX-W2 firmware bug */
241	tophys_r1	%r6
242
243	/* Save the rfi target address */
244	STREG		%r11,  TASK_PT_GR11(%r6)
245	/* Switch to wide mode Superdome doesn't support narrow PDC
246	** calls.
247	*/
2481:	mfia            %rp             /* clear upper part of pcoq */
249	ldo             2f-1b(%rp),%rp
250	depdi           0,31,32,%rp
251	bv              (%rp)
252	ssm             PSW_SM_W,%r0
253
254        /* Set Wide mode as the "Default" (eg for traps)
255        ** First trap occurs *right* after (or part of) rfi for slave CPUs.
256        ** Someday, palo might not do this for the Monarch either.
257        */
2582:
259
260	ldo             PDC_PSW(%r0),%arg0              /* 21 */
261	ldo             PDC_PSW_SET_DEFAULTS(%r0),%arg1 /* 2 */
262	ldo             PDC_PSW_WIDE_BIT(%r0),%arg2     /* 2 */
263	load32          PA(stext_pdc_ret), %rp
264	bv              (%r3)
265	copy            %r0,%arg3
266
267stext_pdc_ret:
268	LDREG		TASK_PT_GR11(%r6), %r11
269	tovirt_r1	%r6
270	mtctl		%r6,%cr30		/* restore task thread info */
271#endif
272
273	/* PARANOID: clear user scratch/user space SR's */
274	mtsp	%r0,%sr0
275	mtsp	%r0,%sr1
276	mtsp	%r0,%sr2
277	mtsp	%r0,%sr3
278
279	/* Initialize Protection Registers */
280	mtctl	%r0,%cr8
281	mtctl	%r0,%cr9
282	mtctl	%r0,%cr12
283	mtctl	%r0,%cr13
284
285	/* Initialize the global data pointer */
286	loadgp
287
288	/* Set up our interrupt table.  HPMCs might not work after this!
289	 *
290	 * We need to install the correct iva for PA1.1 or PA2.0. The
291	 * following short sequence of instructions can determine this
292	 * (without being illegal on a PA1.1 machine).
293	 */
294#ifndef CONFIG_64BIT
295	ldi		32,%r10
296	mtctl		%r10,%cr11
297	.level 2.0
298	mfctl,w		%cr11,%r10
299	.level 1.1
300	comib,<>,n	0,%r10,$is_pa20
301	ldil		L%PA(fault_vector_11),%r10
302	b		$install_iva
303	ldo		R%PA(fault_vector_11)(%r10),%r10
304
305$is_pa20:
306	.level		PA_ASM_LEVEL /* restore 1.1 || 2.0w */
307#endif /*!CONFIG_64BIT*/
308	load32		PA(fault_vector_20),%r10
309
310$install_iva:
311	mtctl		%r10,%cr14
312
313	b		aligned_rfi  /* Prepare to RFI! Man all the cannons! */
314	nop
315
316	.align 128
317aligned_rfi:
318	pcxt_ssm_bug
319
320	copy		%r3, %arg0	/* PDCE_PROC for smp_callin() */
321
322	rsm		PSW_SM_QUIET,%r0	/* off troublesome PSW bits */
323	/* Don't need NOPs, have 8 compliant insn before rfi */
324
325	mtctl		%r0,%cr17	/* Clear IIASQ tail */
326	mtctl		%r0,%cr17	/* Clear IIASQ head */
327
328	/* Load RFI target into PC queue */
329	mtctl		%r11,%cr18	/* IIAOQ head */
330	ldo		4(%r11),%r11
331	mtctl		%r11,%cr18	/* IIAOQ tail */
332
333	load32		KERNEL_PSW,%r10
334	mtctl		%r10,%ipsw
335
336	tovirt_r1	%sp
337
338	/* Jump through hyperspace to Virt Mode */
339	rfi
340	nop
341
342	.procend
343
344#ifdef CONFIG_SMP
345
346	.import smp_init_current_idle_task,data
347	.import	smp_callin,code
348
349#ifndef CONFIG_64BIT
350smp_callin_rtn:
351        .proc
352	.callinfo
353	break	1,1		/*  Break if returned from start_secondary */
354	nop
355	nop
356        .procend
357#endif /*!CONFIG_64BIT*/
358
359/***************************************************************************
360* smp_slave_stext is executed by all non-monarch Processors when the Monarch
361* pokes the slave CPUs in smp.c:smp_boot_cpus().
362*
363* Once here, registers values are initialized in order to branch to virtual
364* mode. Once all available/eligible CPUs are in virtual mode, all are
365* released and start out by executing their own idle task.
366*****************************************************************************/
367smp_slave_stext:
368        .proc
369	.callinfo
370
371	/*
372	** Initialize Space registers
373	*/
374	mtsp	   %r0,%sr4
375	mtsp	   %r0,%sr5
376	mtsp	   %r0,%sr6
377	mtsp	   %r0,%sr7
378
379#ifdef CONFIG_64BIT
380	/*
381	 *  Enable Wide mode early, in case the task_struct for the idle
382	 *  task in smp_init_current_idle_task was allocated above 4GB.
383	 */
3841:	mfia            %rp             /* clear upper part of pcoq */
385	ldo             2f-1b(%rp),%rp
386	depdi           0,31,32,%rp
387	bv              (%rp)
388	ssm             PSW_SM_W,%r0
3892:
390#endif
391
392	/*  Initialize the SP - monarch sets up smp_init_current_idle_task */
393	load32		PA(smp_init_current_idle_task),%r6
394	LDREG		0(%r6),%r6
395	mtctl		%r6,%cr30
396	tophys_r1	%r6
397	LDREG           TASK_STACK(%r6),%sp
398	tophys_r1	%sp
399	ldo		FRAME_SIZE(%sp),%sp
400
401	/* point CPU to kernel page tables */
402	load32		PA(swapper_pg_dir),%r4
403	mtctl		%r4,%cr24	/* Initialize kernel root pointer */
404	mtctl		%r4,%cr25	/* Initialize user root pointer */
405
406#ifdef CONFIG_64BIT
407	/* Setup PDCE_PROC entry */
408	copy            %arg0,%r3
409#else
410	/* Load RFI *return* address in case smp_callin bails */
411	load32		smp_callin_rtn,%r2
412#endif
413
414	/* Load RFI target address.  */
415	load32		smp_callin,%r11
416
417	/* ok...common code can handle the rest */
418	b		common_stext
419	nop
420
421	.procend
422#endif /* CONFIG_SMP */
423
424#ifndef CONFIG_64BIT
425	.section .data..ro_after_init
426
427	.align	4
428	.export	$global$,data
429
430	.type	$global$,@object
431	.size	$global$,4
432$global$:
433	.word 0
434#endif /*!CONFIG_64BIT*/
435