[mirror_ubuntu-jammy-kernel.git] / arch / mips / kernel / head.S

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1994, 1995 Waldorf Electronics
 * Written by Ralf Baechle and Andreas Busse
 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2003 Ralf Baechle
 * Copyright (C) 1996 Paul M. Antoine
 * Modified for DECStation and hence R3000 support by Paul M. Antoine
 * Further modifications by David S. Miller and Harald Koerfgen
 * Copyright (C) 1999 Silicon Graphics, Inc.
 * Kevin Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
 * Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
 */
#include <linux/config.h>
#include <linux/init.h>
#include <linux/threads.h>

#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/regdef.h>
#include <asm/page.h>
#include <asm/mipsregs.h>
#include <asm/stackframe.h>

#include <kernel-entry-init.h>

	.macro	ARC64_TWIDDLE_PC
#if defined(CONFIG_ARC64) || defined(CONFIG_MAPPED_KERNEL)
	/* We get launched at a XKPHYS address but the kernel is linked to
	   run at a KSEG0 address, so jump there.  */
	PTR_LA	t0, \@f
	jr	t0
\@:
#endif
	.endm

	/*
	 * inputs are the text nasid in t1, data nasid in t2.
	 */
	.macro MAPPED_KERNEL_SETUP_TLB
#ifdef CONFIG_MAPPED_KERNEL
	/*
	 * This needs to read the nasid - assume 0 for now.
	 * Drop in 0xffffffffc0000000 in tlbhi, 0+VG in tlblo_0,
	 * 0+DVG in tlblo_1.
	 */
	dli	t0, 0xffffffffc0000000
	dmtc0	t0, CP0_ENTRYHI
	li	t0, 0x1c000		# Offset of text into node memory
	dsll	t1, NASID_SHFT		# Shift text nasid into place
	dsll	t2, NASID_SHFT		# Same for data nasid
	or	t1, t1, t0		# Physical load address of kernel text
	or	t2, t2, t0		# Physical load address of kernel data
	dsrl	t1, 12			# 4K pfn
	dsrl	t2, 12			# 4K pfn
	dsll	t1, 6			# Get pfn into place
	dsll	t2, 6			# Get pfn into place
	li	t0, ((_PAGE_GLOBAL|_PAGE_VALID| _CACHE_CACHABLE_COW) >> 6)
	or	t0, t0, t1
	mtc0	t0, CP0_ENTRYLO0	# physaddr, VG, cach exlwr
	li	t0, ((_PAGE_GLOBAL|_PAGE_VALID| _PAGE_DIRTY|_CACHE_CACHABLE_COW) >> 6)
	or	t0, t0, t2
	mtc0	t0, CP0_ENTRYLO1	# physaddr, DVG, cach exlwr
	li	t0, 0x1ffe000		# MAPPED_KERN_TLBMASK, TLBPGMASK_16M
	mtc0	t0, CP0_PAGEMASK
	li	t0, 0			# KMAP_INX
	mtc0	t0, CP0_INDEX
	li	t0, 1
	mtc0	t0, CP0_WIRED
	tlbwi
#else
	mtc0	zero, CP0_WIRED
#endif
	.endm

	/*
	 * For the moment disable interrupts, mark the kernel mode and
	 * set ST0_KX so that the CPU does not spit fire when using
	 * 64-bit addresses.  A full initialization of the CPU's status
	 * register is done later in per_cpu_trap_init().
	 */
	.macro	setup_c0_status set clr
	.set	push
#ifdef CONFIG_MIPS_MT_SMTC
	/*
	 * For SMTC, we need to set privilege and disable interrupts only for
	 * the current TC, using the TCStatus register.
	 */
	mfc0	t0, CP0_TCSTATUS
	/* Fortunately CU 0 is in the same place in both registers */
	/* Set TCU0, TMX, TKSU (for later inversion) and IXMT */
	li	t1, ST0_CU0 | 0x08001c00
	or	t0, t1
	/* Clear TKSU, leave IXMT */
	xori	t0, 0x00001800
	mtc0	t0, CP0_TCSTATUS
	ehb
	/* We need to leave the global IE bit set, but clear EXL...*/
	mfc0	t0, CP0_STATUS
	or	t0, ST0_CU0 | ST0_EXL | ST0_ERL | \set | \clr
	xor	t0, ST0_EXL | ST0_ERL | \clr
	mtc0	t0, CP0_STATUS
#else
	mfc0	t0, CP0_STATUS
	or	t0, ST0_CU0|\set|0x1f|\clr
	xor	t0, 0x1f|\clr
	mtc0	t0, CP0_STATUS
	.set	noreorder
	sll	zero,3				# ehb
#endif
	.set	pop
	.endm

	.macro	setup_c0_status_pri
#ifdef CONFIG_64BIT
	setup_c0_status ST0_KX 0
#else
	setup_c0_status 0 0
#endif
	.endm

	.macro	setup_c0_status_sec
#ifdef CONFIG_64BIT
	setup_c0_status ST0_KX ST0_BEV
#else
	setup_c0_status 0 ST0_BEV
#endif
	.endm

	/*
	 * Reserved space for exception handlers.
	 * Necessary for machines which link their kernels at KSEG0.
	 */
	.fill	0x400

EXPORT(stext)					# used for profiling
EXPORT(_stext)

#if defined(CONFIG_QEMU) || defined(CONFIG_MIPS_SIM)
	/*
	 * Give us a fighting chance of running if execution beings at the
	 * kernel load address.  This is needed because this platform does
	 * not have a ELF loader yet.
	 */
	j	kernel_entry
#endif
	__INIT

NESTED(kernel_entry, 16, sp)			# kernel entry point

	kernel_entry_setup			# cpu specific setup

	setup_c0_status_pri

	ARC64_TWIDDLE_PC

#ifdef CONFIG_MIPS_MT_SMTC
	/*
	 * In SMTC kernel, "CLI" is thread-specific, in TCStatus.
	 * We still need to enable interrupts globally in Status,
	 * and clear EXL/ERL.
	 *
	 * TCContext is used to track interrupt levels under
	 * service in SMTC kernel. Clear for boot TC before
	 * allowing any interrupts.
	 */
	mtc0	zero, CP0_TCCONTEXT

	mfc0	t0, CP0_STATUS
	ori	t0, t0, 0xff1f
	xori	t0, t0, 0x001e
	mtc0	t0, CP0_STATUS
#endif /* CONFIG_MIPS_MT_SMTC */

	PTR_LA		t0, __bss_start		# clear .bss
	LONG_S		zero, (t0)
	PTR_LA		t1, __bss_stop - LONGSIZE
1:
	PTR_ADDIU	t0, LONGSIZE
	LONG_S		zero, (t0)
	bne		t0, t1, 1b

	LONG_S		a0, fw_arg0		# firmware arguments
	LONG_S		a1, fw_arg1
	LONG_S		a2, fw_arg2
	LONG_S		a3, fw_arg3

	MTC0		zero, CP0_CONTEXT	# clear context register
	PTR_LA		$28, init_thread_union
	PTR_ADDIU	sp, $28, _THREAD_SIZE - 32
	set_saved_sp	sp, t0, t1
	PTR_SUBU	sp, 4 * SZREG		# init stack pointer

	j		start_kernel
	END(kernel_entry)

#ifdef CONFIG_QEMU
	__INIT
#endif

#ifdef CONFIG_SMP
/*
 * SMP slave cpus entry point.  Board specific code for bootstrap calls this
 * function after setting up the stack and gp registers.
 */
NESTED(smp_bootstrap, 16, sp)
#ifdef CONFIG_MIPS_MT_SMTC
	/*
	 * Read-modify-writes of Status must be atomic, and this
	 * is one case where CLI is invoked without EXL being
	 * necessarily set. The CLI and setup_c0_status will
	 * in fact be redundant for all but the first TC of
	 * each VPE being booted.
	 */
	DMT	10	# dmt t2 /* t0, t1 are used by CLI and setup_c0_status() */
	jal	mips_ihb
#endif /* CONFIG_MIPS_MT_SMTC */
	setup_c0_status_sec
	smp_slave_setup
#ifdef CONFIG_MIPS_MT_SMTC
	andi	t2, t2, VPECONTROL_TE
	beqz	t2, 2f
	EMT		# emt
2:
#endif /* CONFIG_MIPS_MT_SMTC */
	j	start_secondary
	END(smp_bootstrap)
#endif /* CONFIG_SMP */

	__FINIT

	.comm	kernelsp,    NR_CPUS * 8, 8
	.comm	pgd_current, NR_CPUS * 8, 8

	.comm	fw_arg0, SZREG, SZREG		# firmware arguments
	.comm	fw_arg1, SZREG, SZREG
	.comm	fw_arg2, SZREG, SZREG
	.comm	fw_arg3, SZREG, SZREG

	.macro page name, order
	.comm	\name, (_PAGE_SIZE << \order), (_PAGE_SIZE << \order)
	.endm

	/*
	 * On 64-bit we've got three-level pagetables with a slightly
	 * different layout ...
	 */
	page	swapper_pg_dir, _PGD_ORDER
#ifdef CONFIG_64BIT
	page	invalid_pmd_table, _PMD_ORDER
#endif
	page	invalid_pte_table, _PTE_ORDER
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This file is subject to the terms and conditions of the GNU General Public
	3	* License. See the file "COPYING" in the main directory of this archive
	4	* for more details.
	5	*
	6	* Copyright (C) 1994, 1995 Waldorf Electronics
	7	* Written by Ralf Baechle and Andreas Busse
	8	* Copyright (C) 1994, 95, 96, 97, 98, 99, 2003 Ralf Baechle
	9	* Copyright (C) 1996 Paul M. Antoine
	10	* Modified for DECStation and hence R3000 support by Paul M. Antoine
	11	* Further modifications by David S. Miller and Harald Koerfgen
	12	* Copyright (C) 1999 Silicon Graphics, Inc.
	13	* Kevin Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
	14	* Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved.
	15	*/
	16	#include <linux/config.h>
	17	#include <linux/init.h>
	18	#include <linux/threads.h>
	19
	20	#include <asm/asm.h>
41c594ab	21	#include <asm/asmmacro.h>
1da177e4 LT	22	#include <asm/regdef.h>
	23	#include <asm/page.h>
	24	#include <asm/mipsregs.h>
	25	#include <asm/stackframe.h>
7e35952b RB	26
7e35952b RB	27	#include <kernel-entry-init.h>
1da177e4 LT	28
	29	.macro ARC64_TWIDDLE_PC
	30	#if defined(CONFIG_ARC64) \|\| defined(CONFIG_MAPPED_KERNEL)
	31	/* We get launched at a XKPHYS address but the kernel is linked to
	32	run at a KSEG0 address, so jump there. */
	33	PTR_LA t0, \@f
	34	jr t0
	35	\@:
	36	#endif
	37	.endm
	38
1da177e4 LT	39	/*
	40	* inputs are the text nasid in t1, data nasid in t2.
	41	*/
	42	.macro MAPPED_KERNEL_SETUP_TLB
	43	#ifdef CONFIG_MAPPED_KERNEL
	44	/*
	45	* This needs to read the nasid - assume 0 for now.
	46	* Drop in 0xffffffffc0000000 in tlbhi, 0+VG in tlblo_0,
	47	* 0+DVG in tlblo_1.
	48	*/
	49	dli t0, 0xffffffffc0000000
	50	dmtc0 t0, CP0_ENTRYHI
	51	li t0, 0x1c000 # Offset of text into node memory
	52	dsll t1, NASID_SHFT # Shift text nasid into place
	53	dsll t2, NASID_SHFT # Same for data nasid
	54	or t1, t1, t0 # Physical load address of kernel text
	55	or t2, t2, t0 # Physical load address of kernel data
	56	dsrl t1, 12 # 4K pfn
	57	dsrl t2, 12 # 4K pfn
	58	dsll t1, 6 # Get pfn into place
	59	dsll t2, 6 # Get pfn into place
	60	li t0, ((_PAGE_GLOBAL\|_PAGE_VALID\| _CACHE_CACHABLE_COW) >> 6)
	61	or t0, t0, t1
	62	mtc0 t0, CP0_ENTRYLO0 # physaddr, VG, cach exlwr
	63	li t0, ((_PAGE_GLOBAL\|_PAGE_VALID\| _PAGE_DIRTY\|_CACHE_CACHABLE_COW) >> 6)
	64	or t0, t0, t2
	65	mtc0 t0, CP0_ENTRYLO1 # physaddr, DVG, cach exlwr
	66	li t0, 0x1ffe000 # MAPPED_KERN_TLBMASK, TLBPGMASK_16M
	67	mtc0 t0, CP0_PAGEMASK
	68	li t0, 0 # KMAP_INX
	69	mtc0 t0, CP0_INDEX
	70	li t0, 1
	71	mtc0 t0, CP0_WIRED
	72	tlbwi
	73	#else
	74	mtc0 zero, CP0_WIRED
	75	#endif
	76	.endm
	77
	78	/*
	79	* For the moment disable interrupts, mark the kernel mode and
	80	* set ST0_KX so that the CPU does not spit fire when using
	81	* 64-bit addresses. A full initialization of the CPU's status
	82	* register is done later in per_cpu_trap_init().
	83	*/
	84	.macro setup_c0_status set clr
	85	.set push
41c594ab RB	86	#ifdef CONFIG_MIPS_MT_SMTC
	87	/*
	88	* For SMTC, we need to set privilege and disable interrupts only for
	89	* the current TC, using the TCStatus register.
	90	*/
	91	mfc0 t0, CP0_TCSTATUS
	92	/* Fortunately CU 0 is in the same place in both registers */
	93	/* Set TCU0, TMX, TKSU (for later inversion) and IXMT */
	94	li t1, ST0_CU0 \| 0x08001c00
	95	or t0, t1
	96	/* Clear TKSU, leave IXMT */
	97	xori t0, 0x00001800
	98	mtc0 t0, CP0_TCSTATUS
	99	ehb
	100	/* We need to leave the global IE bit set, but clear EXL...*/
	101	mfc0 t0, CP0_STATUS
	102	or t0, ST0_CU0 \| ST0_EXL \| ST0_ERL \| \set \| \clr
	103	xor t0, ST0_EXL \| ST0_ERL \| \clr
	104	mtc0 t0, CP0_STATUS
	105	#else
1da177e4 LT	106	mfc0 t0, CP0_STATUS
	107	or t0, ST0_CU0\|\set\|0x1f\|\clr
	108	xor t0, 0x1f\|\clr
	109	mtc0 t0, CP0_STATUS
	110	.set noreorder
	111	sll zero,3 # ehb
41c594ab	112	#endif
1da177e4 LT	113	.set pop
	114	.endm
	115
	116	.macro setup_c0_status_pri
875d43e7	117	#ifdef CONFIG_64BIT
1da177e4 LT	118	setup_c0_status ST0_KX 0
	119	#else
	120	setup_c0_status 0 0
	121	#endif
	122	.endm
	123
	124	.macro setup_c0_status_sec
875d43e7	125	#ifdef CONFIG_64BIT
1da177e4 LT	126	setup_c0_status ST0_KX ST0_BEV
	127	#else
	128	setup_c0_status 0 ST0_BEV
	129	#endif
	130	.endm
	131
	132	/*
	133	* Reserved space for exception handlers.
	134	* Necessary for machines which link their kernels at KSEG0.
	135	*/
	136	.fill 0x400
	137
	138	EXPORT(stext) # used for profiling
	139	EXPORT(_stext)
	140
c78cbf49	141	#if defined(CONFIG_QEMU) \|\| defined(CONFIG_MIPS_SIM)
b490ff42 RB	142	/*
	143	* Give us a fighting chance of running if execution beings at the
	144	* kernel load address. This is needed because this platform does
	145	* not have a ELF loader yet.
	146	*/
	147	j kernel_entry
	148	#endif
1da177e4 LT	149	__INIT
	150
	151	NESTED(kernel_entry, 16, sp) # kernel entry point
1da177e4	152
7e35952b RB	153	kernel_entry_setup # cpu specific setup
	154
	155	setup_c0_status_pri
1da177e4 LT	156
	157	ARC64_TWIDDLE_PC
	158
41c594ab RB	159	#ifdef CONFIG_MIPS_MT_SMTC
	160	/*
	161	* In SMTC kernel, "CLI" is thread-specific, in TCStatus.
	162	* We still need to enable interrupts globally in Status,
	163	* and clear EXL/ERL.
	164	*
	165	* TCContext is used to track interrupt levels under
	166	* service in SMTC kernel. Clear for boot TC before
	167	* allowing any interrupts.
	168	*/
	169	mtc0 zero, CP0_TCCONTEXT
	170
	171	mfc0 t0, CP0_STATUS
	172	ori t0, t0, 0xff1f
	173	xori t0, t0, 0x001e
	174	mtc0 t0, CP0_STATUS
	175	#endif /* CONFIG_MIPS_MT_SMTC */
	176
1da177e4 LT	177	PTR_LA t0, __bss_start # clear .bss
	178	LONG_S zero, (t0)
	179	PTR_LA t1, __bss_stop - LONGSIZE
	180	1:
	181	PTR_ADDIU t0, LONGSIZE
	182	LONG_S zero, (t0)
	183	bne t0, t1, 1b
	184
	185	LONG_S a0, fw_arg0 # firmware arguments
	186	LONG_S a1, fw_arg1
	187	LONG_S a2, fw_arg2
	188	LONG_S a3, fw_arg3
	189
1b3a6e97	190	MTC0 zero, CP0_CONTEXT # clear context register
1da177e4 LT	191	PTR_LA $28, init_thread_union
	192	PTR_ADDIU sp, $28, _THREAD_SIZE - 32
	193	set_saved_sp sp, t0, t1
	194	PTR_SUBU sp, 4 * SZREG # init stack pointer
	195
	196	j start_kernel
	197	END(kernel_entry)
	198
b490ff42 RB	199	#ifdef CONFIG_QEMU
	200	__INIT
	201	#endif
	202
1da177e4 LT	203	#ifdef CONFIG_SMP
	204	/*
	205	* SMP slave cpus entry point. Board specific code for bootstrap calls this
	206	* function after setting up the stack and gp registers.
	207	*/
	208	NESTED(smp_bootstrap, 16, sp)
41c594ab RB	209	#ifdef CONFIG_MIPS_MT_SMTC
	210	/*
	211	* Read-modify-writes of Status must be atomic, and this
	212	* is one case where CLI is invoked without EXL being
	213	* necessarily set. The CLI and setup_c0_status will
	214	* in fact be redundant for all but the first TC of
	215	* each VPE being booted.
	216	*/
	217	DMT 10 # dmt t2 /* t0, t1 are used by CLI and setup_c0_status() */
	218	jal mips_ihb
	219	#endif /* CONFIG_MIPS_MT_SMTC */
1da177e4	220	setup_c0_status_sec
7e35952b	221	smp_slave_setup
41c594ab RB	222	#ifdef CONFIG_MIPS_MT_SMTC
	223	andi t2, t2, VPECONTROL_TE
	224	beqz t2, 2f
	225	EMT # emt
	226	2:
	227	#endif /* CONFIG_MIPS_MT_SMTC */
1da177e4 LT	228	j start_secondary
	229	END(smp_bootstrap)
	230	#endif /* CONFIG_SMP */
	231
	232	__FINIT
	233
	234	.comm kernelsp, NR_CPUS * 8, 8
	235	.comm pgd_current, NR_CPUS * 8, 8
	236
	237	.comm fw_arg0, SZREG, SZREG # firmware arguments
	238	.comm fw_arg1, SZREG, SZREG
	239	.comm fw_arg2, SZREG, SZREG
	240	.comm fw_arg3, SZREG, SZREG
	241
0964ce24 TS	242	.macro page name, order
0964ce24 TS	243	.comm \name, (_PAGE_SIZE << \order), (_PAGE_SIZE << \order)
1da177e4 LT	244	.endm
1da177e4 LT	245
1da177e4	246	/*
0964ce24 TS	247	* On 64-bit we've got three-level pagetables with a slightly
0964ce24 TS	248	* different layout ...
1da177e4 LT	249	*/
1da177e4 LT	250	page swapper_pg_dir, _PGD_ORDER
875d43e7	251	#ifdef CONFIG_64BIT
1da177e4 LT	252	page invalid_pmd_table, _PMD_ORDER
	253	#endif
	254	page invalid_pte_table, _PTE_ORDER