xref: /linux/arch/mips/sgi-ip30/ip30-setup.c (revision ab58a2f3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SGI IP30 miscellaneous setup bits.
4  *
5  * Copyright (C) 2004-2007 Stanislaw Skowronek <skylark@unaligned.org>
6  *               2007 Joshua Kinard <kumba@gentoo.org>
7  *               2009 Johannes Dickgreber <tanzy@gmx.de>
8  */
9 
10 #include <linux/init.h>
11 #include <linux/io.h>
12 #include <linux/kernel.h>
13 #include <linux/types.h>
14 #include <linux/percpu.h>
15 #include <linux/memblock.h>
16 
17 #include <asm/bootinfo.h>
18 #include <asm/smp-ops.h>
19 #include <asm/sgialib.h>
20 #include <asm/time.h>
21 #include <asm/sgi/heart.h>
22 
23 #include "ip30-common.h"
24 
25 /* Structure of accessible HEART registers located in XKPHYS space. */
26 struct ip30_heart_regs __iomem *heart_regs = HEART_XKPHYS_BASE;
27 
28 /*
29  * ARCS will report up to the first 1GB of
30  * memory if queried.  Anything beyond that
31  * is marked as reserved.
32  */
33 #define IP30_MAX_PROM_MEMORY	_AC(0x40000000, UL)
34 
35 /*
36  * Memory in the Octane starts at 512MB
37  */
38 #define IP30_MEMORY_BASE	_AC(0x20000000, UL)
39 
40 /*
41  * If using ARCS to probe for memory, then
42  * remaining memory will start at this offset.
43  */
44 #define IP30_REAL_MEMORY_START  (IP30_MEMORY_BASE + IP30_MAX_PROM_MEMORY)
45 
46 #define MEM_SHIFT(x) ((x) >> 20)
47 
ip30_mem_init(void)48 static void __init ip30_mem_init(void)
49 {
50 	unsigned long total_mem;
51 	phys_addr_t addr;
52 	phys_addr_t size;
53 	u32 memcfg;
54 	int i;
55 
56 	total_mem = 0;
57 	for (i = 0; i < HEART_MEMORY_BANKS; i++) {
58 		memcfg = __raw_readl(&heart_regs->mem_cfg.l[i]);
59 		if (!(memcfg & HEART_MEMCFG_VALID))
60 			continue;
61 
62 		addr = memcfg & HEART_MEMCFG_ADDR_MASK;
63 		addr <<= HEART_MEMCFG_UNIT_SHIFT;
64 		addr += IP30_MEMORY_BASE;
65 		size = memcfg & HEART_MEMCFG_SIZE_MASK;
66 		size >>= HEART_MEMCFG_SIZE_SHIFT;
67 		size += 1;
68 		size <<= HEART_MEMCFG_UNIT_SHIFT;
69 
70 		total_mem += size;
71 
72 		if (addr >= IP30_REAL_MEMORY_START)
73 			memblock_phys_free(addr, size);
74 		else if ((addr + size) > IP30_REAL_MEMORY_START)
75 			memblock_phys_free(IP30_REAL_MEMORY_START,
76 					   size - IP30_MAX_PROM_MEMORY);
77 	}
78 	pr_info("Detected %luMB of physical memory.\n", MEM_SHIFT(total_mem));
79 }
80 
81 /**
82  * ip30_cpu_time_init - platform time initialization.
83  */
ip30_cpu_time_init(void)84 static void __init ip30_cpu_time_init(void)
85 {
86 	int cpu = smp_processor_id();
87 	u64 heart_compare;
88 	unsigned int start, end;
89 	int time_diff;
90 
91 	heart_compare = (heart_read(&heart_regs->count) +
92 			 (HEART_CYCLES_PER_SEC / 10));
93 	start = read_c0_count();
94 	while ((heart_read(&heart_regs->count) - heart_compare) & 0x800000)
95 		cpu_relax();
96 
97 	end = read_c0_count();
98 	time_diff = (int)end - (int)start;
99 	mips_hpt_frequency = time_diff * 10;
100 	pr_info("IP30: CPU%d: %d MHz CPU detected.\n", cpu,
101 		(mips_hpt_frequency * 2) / 1000000);
102 }
103 
ip30_per_cpu_init(void)104 void __init ip30_per_cpu_init(void)
105 {
106 	/* Disable all interrupts. */
107 	clear_c0_status(ST0_IM);
108 
109 	ip30_cpu_time_init();
110 #ifdef CONFIG_SMP
111 	ip30_install_ipi();
112 #endif
113 
114 	enable_percpu_irq(IP30_HEART_L0_IRQ, IRQ_TYPE_NONE);
115 	enable_percpu_irq(IP30_HEART_L1_IRQ, IRQ_TYPE_NONE);
116 	enable_percpu_irq(IP30_HEART_L2_IRQ, IRQ_TYPE_NONE);
117 	enable_percpu_irq(IP30_HEART_ERR_IRQ, IRQ_TYPE_NONE);
118 }
119 
120 /**
121  * plat_mem_setup - despite the name, misc setup happens here.
122  */
plat_mem_setup(void)123 void __init plat_mem_setup(void)
124 {
125 	ip30_mem_init();
126 
127 	/* XXX: Hard lock on /sbin/init if this flag isn't specified. */
128 	prom_flags |= PROM_FLAG_DONT_FREE_TEMP;
129 
130 #ifdef CONFIG_SMP
131 	register_smp_ops(&ip30_smp_ops);
132 #else
133 	ip30_per_cpu_init();
134 #endif
135 
136 	ioport_resource.start = 0;
137 	ioport_resource.end = ~0UL;
138 	set_io_port_base(IO_BASE);
139 }
140