xref: /openbmc/linux/arch/mips/sgi-ip30/ip30-setup.c (revision e1cd7b80)
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/smp-ops.h>
18 #include <asm/sgialib.h>
19 #include <asm/time.h>
20 #include <asm/sgi/heart.h>
21 
22 #include "ip30-common.h"
23 
24 /* Structure of accessible HEART registers located in XKPHYS space. */
25 struct ip30_heart_regs __iomem *heart_regs = HEART_XKPHYS_BASE;
26 
27 /*
28  * ARCS will report up to the first 1GB of
29  * memory if queried.  Anything beyond that
30  * is marked as reserved.
31  */
32 #define IP30_MAX_PROM_MEMORY	_AC(0x40000000, UL)
33 
34 /*
35  * Memory in the Octane starts at 512MB
36  */
37 #define IP30_MEMORY_BASE	_AC(0x20000000, UL)
38 
39 /*
40  * If using ARCS to probe for memory, then
41  * remaining memory will start at this offset.
42  */
43 #define IP30_REAL_MEMORY_START  (IP30_MEMORY_BASE + IP30_MAX_PROM_MEMORY)
44 
45 #define MEM_SHIFT(x) ((x) >> 20)
46 
47 static void __init ip30_mem_init(void)
48 {
49 	unsigned long total_mem;
50 	phys_addr_t addr;
51 	phys_addr_t size;
52 	u32 memcfg;
53 	int i;
54 
55 	total_mem = 0;
56 	for (i = 0; i < HEART_MEMORY_BANKS; i++) {
57 		memcfg = __raw_readl(&heart_regs->mem_cfg.l[i]);
58 		if (!(memcfg & HEART_MEMCFG_VALID))
59 			continue;
60 
61 		addr = memcfg & HEART_MEMCFG_ADDR_MASK;
62 		addr <<= HEART_MEMCFG_UNIT_SHIFT;
63 		addr += IP30_MEMORY_BASE;
64 		size = memcfg & HEART_MEMCFG_SIZE_MASK;
65 		size >>= HEART_MEMCFG_SIZE_SHIFT;
66 		size += 1;
67 		size <<= HEART_MEMCFG_UNIT_SHIFT;
68 
69 		total_mem += size;
70 
71 		if (addr >= IP30_REAL_MEMORY_START)
72 			memblock_free(addr, size);
73 		else if ((addr + size) > IP30_REAL_MEMORY_START)
74 			memblock_free(IP30_REAL_MEMORY_START,
75 				     size - IP30_MAX_PROM_MEMORY);
76 	}
77 	pr_info("Detected %luMB of physical memory.\n", MEM_SHIFT(total_mem));
78 }
79 
80 /**
81  * ip30_cpu_time_init - platform time initialization.
82  */
83 static void __init ip30_cpu_time_init(void)
84 {
85 	int cpu = smp_processor_id();
86 	u64 heart_compare;
87 	unsigned int start, end;
88 	int time_diff;
89 
90 	heart_compare = (heart_read(&heart_regs->count) +
91 			 (HEART_CYCLES_PER_SEC / 10));
92 	start = read_c0_count();
93 	while ((heart_read(&heart_regs->count) - heart_compare) & 0x800000)
94 		cpu_relax();
95 
96 	end = read_c0_count();
97 	time_diff = (int)end - (int)start;
98 	mips_hpt_frequency = time_diff * 10;
99 	pr_info("IP30: CPU%d: %d MHz CPU detected.\n", cpu,
100 		(mips_hpt_frequency * 2) / 1000000);
101 }
102 
103 void __init ip30_per_cpu_init(void)
104 {
105 	/* Disable all interrupts. */
106 	clear_c0_status(ST0_IM);
107 
108 	ip30_cpu_time_init();
109 #ifdef CONFIG_SMP
110 	ip30_install_ipi();
111 #endif
112 
113 	enable_percpu_irq(IP30_HEART_L0_IRQ, IRQ_TYPE_NONE);
114 	enable_percpu_irq(IP30_HEART_L1_IRQ, IRQ_TYPE_NONE);
115 	enable_percpu_irq(IP30_HEART_L2_IRQ, IRQ_TYPE_NONE);
116 	enable_percpu_irq(IP30_HEART_ERR_IRQ, IRQ_TYPE_NONE);
117 }
118 
119 /**
120  * plat_mem_setup - despite the name, misc setup happens here.
121  */
122 void __init plat_mem_setup(void)
123 {
124 	ip30_mem_init();
125 
126 	/* XXX: Hard lock on /sbin/init if this flag isn't specified. */
127 	prom_flags |= PROM_FLAG_DONT_FREE_TEMP;
128 
129 #ifdef CONFIG_SMP
130 	register_smp_ops(&ip30_smp_ops);
131 #else
132 	ip30_per_cpu_init();
133 #endif
134 
135 	ioport_resource.start = 0;
136 	ioport_resource.end = ~0UL;
137 	set_io_port_base(IO_BASE);
138 }
139