xref: /linux/arch/mips/include/asm/mach-cavium-octeon/kernel-entry-init.h (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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) 2005-2008 Cavium Networks, Inc
7  */
8 #ifndef __ASM_MACH_CAVIUM_OCTEON_KERNEL_ENTRY_H
9 #define __ASM_MACH_CAVIUM_OCTEON_KERNEL_ENTRY_H
10 
11 
12 #define CP0_CYCLE_COUNTER $9, 6
13 #define CP0_CVMCTL_REG $9, 7
14 #define CP0_CVMMEMCTL_REG $11,7
15 #define CP0_PRID_REG $15, 0
16 #define CP0_PRID_OCTEON_PASS1 0x000d0000
17 #define CP0_PRID_OCTEON_CN30XX 0x000d0200
18 
19 .macro	kernel_entry_setup
20 	# Registers set by bootloader:
21 	# (only 32 bits set by bootloader, all addresses are physical
22 	# addresses, and need to have the appropriate memory region set
23 	# by the kernel
24 	# a0 = argc
25 	# a1 = argv (kseg0 compat addr)
26 	# a2 = 1 if init core, zero otherwise
27 	# a3 = address of boot descriptor block
28 	.set push
29 	.set arch=octeon
30 	# Read the cavium mem control register
31 	dmfc0	v0, CP0_CVMMEMCTL_REG
32 	# Clear the lower 6 bits, the CVMSEG size
33 	dins	v0, $0, 0, 6
34 	ori	v0, CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE
35 	dmtc0	v0, CP0_CVMMEMCTL_REG	# Write the cavium mem control register
36 	dmfc0	v0, CP0_CVMCTL_REG	# Read the cavium control register
37 	# Disable unaligned load/store support but leave HW fixup enabled
38 	# Needed for octeon specific memcpy
39 	or  v0, v0, 0x5001
40 	xor v0, v0, 0x1001
41 	# Read the processor ID register
42 	mfc0 v1, CP0_PRID_REG
43 	# Disable instruction prefetching (Octeon Pass1 errata)
44 	or  v0, v0, 0x2000
45 	# Skip reenable of prefetching for Octeon Pass1
46 	beq v1, CP0_PRID_OCTEON_PASS1, skip
47 	nop
48 	# Reenable instruction prefetching, not on Pass1
49 	xor v0, v0, 0x2000
50 	# Strip off pass number off of processor id
51 	srl v1, 8
52 	sll v1, 8
53 	# CN30XX needs some extra stuff turned off for better performance
54 	bne v1, CP0_PRID_OCTEON_CN30XX, skip
55 	nop
56 	# CN30XX Use random Icache replacement
57 	or  v0, v0, 0x400
58 	# CN30XX Disable instruction prefetching
59 	or  v0, v0, 0x2000
60 skip:
61 	# First clear off CvmCtl[IPPCI] bit and move the performance
62 	# counters interrupt to IRQ 6
63 	li	v1, ~(7 << 7)
64 	and	v0, v0, v1
65 	ori	v0, v0, (6 << 7)
66 	# Write the cavium control register
67 	dmtc0	v0, CP0_CVMCTL_REG
68 	sync
69 	# Flush dcache after config change
70 	cache	9, 0($0)
71 	# Get my core id
72 	rdhwr	v0, $0
73 	# Jump the master to kernel_entry
74 	bne	a2, zero, octeon_main_processor
75 	nop
76 
77 #ifdef CONFIG_SMP
78 
79 	#
80 	# All cores other than the master need to wait here for SMP bootstrap
81 	# to begin
82 	#
83 
84 	# This is the variable where the next core to boot os stored
85 	PTR_LA	t0, octeon_processor_boot
86 octeon_spin_wait_boot:
87 	# Get the core id of the next to be booted
88 	LONG_L	t1, (t0)
89 	# Keep looping if it isn't me
90 	bne t1, v0, octeon_spin_wait_boot
91 	nop
92 	# Get my GP from the global variable
93 	PTR_LA	t0, octeon_processor_gp
94 	LONG_L	gp, (t0)
95 	# Get my SP from the global variable
96 	PTR_LA	t0, octeon_processor_sp
97 	LONG_L	sp, (t0)
98 	# Set the SP global variable to zero so the master knows we've started
99 	LONG_S	zero, (t0)
100 #ifdef __OCTEON__
101 	syncw
102 	syncw
103 #else
104 	sync
105 #endif
106 	# Jump to the normal Linux SMP entry point
107 	j   smp_bootstrap
108 	nop
109 #else /* CONFIG_SMP */
110 
111 	#
112 	# Someone tried to boot SMP with a non SMP kernel. All extra cores
113 	# will halt here.
114 	#
115 octeon_wait_forever:
116 	wait
117 	b   octeon_wait_forever
118 	nop
119 
120 #endif /* CONFIG_SMP */
121 octeon_main_processor:
122 	.set pop
123 .endm
124 
125 /*
126  * Do SMP slave processor setup necessary before we can savely execute C code.
127  */
128 	.macro	smp_slave_setup
129 	.endm
130 
131 #endif /* __ASM_MACH_CAVIUM_OCTEON_KERNEL_ENTRY_H */
132