xref: /openbmc/linux/arch/parisc/kernel/head.S (revision 0da85d1e) 
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#include <asm/pgtable.h>
21
22#include <linux/linkage.h>
23#include <linux/init.h>
24
25	.level	LEVEL
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_thread_union,data
39	.import fault_vector_20,code    /* IVA parisc 2.0 32 bit */
40#ifndef CONFIG_64BIT
41        .import fault_vector_11,code    /* IVA parisc 1.1 32 bit */
42	.import	$global$		/* forward declaration */
43#endif /*!CONFIG_64BIT*/
44ENTRY(parisc_kernel_start)
45	.proc
46	.callinfo
47
48	/* Make sure sr4-sr7 are set to zero for the kernel address space */
49	mtsp	%r0,%sr4
50	mtsp	%r0,%sr5
51	mtsp	%r0,%sr6
52	mtsp	%r0,%sr7
53
54	/* Clear BSS (shouldn't the boot loader do this?) */
55
56	.import __bss_start,data
57	.import __bss_stop,data
58
59	load32		PA(__bss_start),%r3
60	load32		PA(__bss_stop),%r4
61$bss_loop:
62	cmpb,<<,n       %r3,%r4,$bss_loop
63	stw,ma          %r0,4(%r3)
64
65	/* Save away the arguments the boot loader passed in (32 bit args) */
66	load32		PA(boot_args),%r1
67	stw,ma          %arg0,4(%r1)
68	stw,ma          %arg1,4(%r1)
69	stw,ma          %arg2,4(%r1)
70	stw,ma          %arg3,4(%r1)
71
72	/* Initialize startup VM. Just map first 8/16 MB of memory */
73	load32		PA(swapper_pg_dir),%r4
74	mtctl		%r4,%cr24	/* Initialize kernel root pointer */
75	mtctl		%r4,%cr25	/* Initialize user root pointer */
76
77#if CONFIG_PGTABLE_LEVELS == 3
78	/* Set pmd in pgd */
79	load32		PA(pmd0),%r5
80	shrd            %r5,PxD_VALUE_SHIFT,%r3
81	ldo		(PxD_FLAG_PRESENT+PxD_FLAG_VALID)(%r3),%r3
82	stw		%r3,ASM_PGD_ENTRY*ASM_PGD_ENTRY_SIZE(%r4)
83	ldo		ASM_PMD_ENTRY*ASM_PMD_ENTRY_SIZE(%r5),%r4
84#else
85	/* 2-level page table, so pmd == pgd */
86	ldo		ASM_PGD_ENTRY*ASM_PGD_ENTRY_SIZE(%r4),%r4
87#endif
88
89	/* Fill in pmd with enough pte directories */
90	load32		PA(pg0),%r1
91	SHRREG		%r1,PxD_VALUE_SHIFT,%r3
92	ldo		(PxD_FLAG_PRESENT+PxD_FLAG_VALID)(%r3),%r3
93
94	ldi		ASM_PT_INITIAL,%r1
95
961:
97	stw		%r3,0(%r4)
98	ldo		(PAGE_SIZE >> PxD_VALUE_SHIFT)(%r3),%r3
99	addib,>		-1,%r1,1b
100#if CONFIG_PGTABLE_LEVELS == 3
101	ldo             ASM_PMD_ENTRY_SIZE(%r4),%r4
102#else
103	ldo             ASM_PGD_ENTRY_SIZE(%r4),%r4
104#endif
105
106
107	/* Now initialize the PTEs themselves.  We use RWX for
108	 * everything ... it will get remapped correctly later */
109	ldo		0+_PAGE_KERNEL_RWX(%r0),%r3 /* Hardwired 0 phys addr start */
110	ldi		(1<<(KERNEL_INITIAL_ORDER-PAGE_SHIFT)),%r11 /* PFN count */
111	load32		PA(pg0),%r1
112
113$pgt_fill_loop:
114	STREGM          %r3,ASM_PTE_ENTRY_SIZE(%r1)
115	ldo		(1<<PFN_PTE_SHIFT)(%r3),%r3 /* add one PFN */
116	addib,>		-1,%r11,$pgt_fill_loop
117	nop
118
119	/* Load the return address...er...crash 'n burn */
120	copy		%r0,%r2
121
122	/* And the RFI Target address too */
123	load32		start_parisc,%r11
124
125	/* And the initial task pointer */
126	load32		init_thread_union,%r6
127	mtctl           %r6,%cr30
128
129	/* And the stack pointer too */
130	ldo             THREAD_SZ_ALGN(%r6),%sp
131
132#ifdef CONFIG_SMP
133	/* Set the smp rendezvous address into page zero.
134	** It would be safer to do this in init_smp_config() but
135	** it's just way easier to deal with here because
136	** of 64-bit function ptrs and the address is local to this file.
137	*/
138	load32		PA(smp_slave_stext),%r10
139	stw		%r10,0x10(%r0)	/* MEM_RENDEZ */
140	stw		%r0,0x28(%r0)	/* MEM_RENDEZ_HI - assume addr < 4GB */
141
142	/* FALLTHROUGH */
143	.procend
144
145	/*
146	** Code Common to both Monarch and Slave processors.
147	** Entry:
148	**
149	**  1.1:
150	**    %r11 must contain RFI target address.
151	**    %r25/%r26 args to pass to target function
152	**    %r2  in case rfi target decides it didn't like something
153	**
154	**  2.0w:
155	**    %r3  PDCE_PROC address
156	**    %r11 RFI target address
157	**
158	** Caller must init: SR4-7, %sp, %r10, %cr24/25,
159	*/
160common_stext:
161	.proc
162	.callinfo
163#else
164	/* Clear PDC entry point - we won't use it */
165	stw		%r0,0x10(%r0)	/* MEM_RENDEZ */
166	stw		%r0,0x28(%r0)	/* MEM_RENDEZ_HI */
167#endif /*CONFIG_SMP*/
168
169#ifdef CONFIG_64BIT
170	tophys_r1	%sp
171
172	/* Save the rfi target address */
173	ldd             TI_TASK-THREAD_SZ_ALGN(%sp), %r10
174	tophys_r1       %r10
175	std             %r11,  TASK_PT_GR11(%r10)
176	/* Switch to wide mode Superdome doesn't support narrow PDC
177	** calls.
178	*/
1791:	mfia            %rp             /* clear upper part of pcoq */
180	ldo             2f-1b(%rp),%rp
181	depdi           0,31,32,%rp
182	bv              (%rp)
183	ssm             PSW_SM_W,%r0
184
185        /* Set Wide mode as the "Default" (eg for traps)
186        ** First trap occurs *right* after (or part of) rfi for slave CPUs.
187        ** Someday, palo might not do this for the Monarch either.
188        */
1892:
190#define MEM_PDC_LO 0x388
191#define MEM_PDC_HI 0x35C
192	ldw             MEM_PDC_LO(%r0),%r3
193	ldw             MEM_PDC_HI(%r0),%r6
194	depd            %r6, 31, 32, %r3        /* move to upper word */
195
196	mfctl		%cr30,%r6		/* PCX-W2 firmware bug */
197
198	ldo             PDC_PSW(%r0),%arg0              /* 21 */
199	ldo             PDC_PSW_SET_DEFAULTS(%r0),%arg1 /* 2 */
200	ldo             PDC_PSW_WIDE_BIT(%r0),%arg2     /* 2 */
201	load32          PA(stext_pdc_ret), %rp
202	bv              (%r3)
203	copy            %r0,%arg3
204
205stext_pdc_ret:
206	mtctl		%r6,%cr30		/* restore task thread info */
207
208	/* restore rfi target address*/
209	ldd             TI_TASK-THREAD_SZ_ALGN(%sp), %r10
210	tophys_r1       %r10
211	ldd             TASK_PT_GR11(%r10), %r11
212	tovirt_r1       %sp
213#endif
214
215	/* PARANOID: clear user scratch/user space SR's */
216	mtsp	%r0,%sr0
217	mtsp	%r0,%sr1
218	mtsp	%r0,%sr2
219	mtsp	%r0,%sr3
220
221	/* Initialize Protection Registers */
222	mtctl	%r0,%cr8
223	mtctl	%r0,%cr9
224	mtctl	%r0,%cr12
225	mtctl	%r0,%cr13
226
227	/* Initialize the global data pointer */
228	loadgp
229
230	/* Set up our interrupt table.  HPMCs might not work after this!
231	 *
232	 * We need to install the correct iva for PA1.1 or PA2.0. The
233	 * following short sequence of instructions can determine this
234	 * (without being illegal on a PA1.1 machine).
235	 */
236#ifndef CONFIG_64BIT
237	ldi		32,%r10
238	mtctl		%r10,%cr11
239	.level 2.0
240	mfctl,w		%cr11,%r10
241	.level 1.1
242	comib,<>,n	0,%r10,$is_pa20
243	ldil		L%PA(fault_vector_11),%r10
244	b		$install_iva
245	ldo		R%PA(fault_vector_11)(%r10),%r10
246
247$is_pa20:
248	.level		LEVEL /* restore 1.1 || 2.0w */
249#endif /*!CONFIG_64BIT*/
250	load32		PA(fault_vector_20),%r10
251
252$install_iva:
253	mtctl		%r10,%cr14
254
255	b		aligned_rfi  /* Prepare to RFI! Man all the cannons! */
256	nop
257
258	.align 128
259aligned_rfi:
260	pcxt_ssm_bug
261
262	rsm		PSW_SM_QUIET,%r0	/* off troublesome PSW bits */
263	/* Don't need NOPs, have 8 compliant insn before rfi */
264
265	mtctl		%r0,%cr17	/* Clear IIASQ tail */
266	mtctl		%r0,%cr17	/* Clear IIASQ head */
267
268	/* Load RFI target into PC queue */
269	mtctl		%r11,%cr18	/* IIAOQ head */
270	ldo		4(%r11),%r11
271	mtctl		%r11,%cr18	/* IIAOQ tail */
272
273	load32		KERNEL_PSW,%r10
274	mtctl		%r10,%ipsw
275
276	/* Jump through hyperspace to Virt Mode */
277	rfi
278	nop
279
280	.procend
281
282#ifdef CONFIG_SMP
283
284	.import smp_init_current_idle_task,data
285	.import	smp_callin,code
286
287#ifndef CONFIG_64BIT
288smp_callin_rtn:
289        .proc
290	.callinfo
291	break	1,1		/*  Break if returned from start_secondary */
292	nop
293	nop
294        .procend
295#endif /*!CONFIG_64BIT*/
296
297/***************************************************************************
298* smp_slave_stext is executed by all non-monarch Processors when the Monarch
299* pokes the slave CPUs in smp.c:smp_boot_cpus().
300*
301* Once here, registers values are initialized in order to branch to virtual
302* mode. Once all available/eligible CPUs are in virtual mode, all are
303* released and start out by executing their own idle task.
304*****************************************************************************/
305smp_slave_stext:
306        .proc
307	.callinfo
308
309	/*
310	** Initialize Space registers
311	*/
312	mtsp	   %r0,%sr4
313	mtsp	   %r0,%sr5
314	mtsp	   %r0,%sr6
315	mtsp	   %r0,%sr7
316
317	/*  Initialize the SP - monarch sets up smp_init_current_idle_task */
318	load32		PA(smp_init_current_idle_task),%sp
319	LDREG		0(%sp),%sp	/* load task address */
320	tophys_r1	%sp
321	LDREG		TASK_THREAD_INFO(%sp),%sp
322	mtctl           %sp,%cr30       /* store in cr30 */
323	ldo             THREAD_SZ_ALGN(%sp),%sp
324
325	/* point CPU to kernel page tables */
326	load32		PA(swapper_pg_dir),%r4
327	mtctl		%r4,%cr24	/* Initialize kernel root pointer */
328	mtctl		%r4,%cr25	/* Initialize user root pointer */
329
330#ifdef CONFIG_64BIT
331	/* Setup PDCE_PROC entry */
332	copy            %arg0,%r3
333#else
334	/* Load RFI *return* address in case smp_callin bails */
335	load32		smp_callin_rtn,%r2
336#endif
337
338	/* Load RFI target address.  */
339	load32		smp_callin,%r11
340
341	/* ok...common code can handle the rest */
342	b		common_stext
343	nop
344
345	.procend
346#endif /* CONFIG_SMP */
347
348ENDPROC(parisc_kernel_start)
349
350#ifndef CONFIG_64BIT
351	.section .data..read_mostly
352
353	.align	4
354	.export	$global$,data
355
356	.type	$global$,@object
357	.size	$global$,4
358$global$:
359	.word 0
360#endif /*!CONFIG_64BIT*/
361