xref: /openbmc/linux/arch/mips/sgi-ip22/ip22-mc.c (revision 64c70b1c)
1 /*
2  * ip22-mc.c: Routines for manipulating SGI Memory Controller.
3  *
4  * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
5  * Copyright (C) 1999 Andrew R. Baker (andrewb@uab.edu) - Indigo2 changes
6  * Copyright (C) 2003 Ladislav Michl  (ladis@linux-mips.org)
7  */
8 
9 #include <linux/init.h>
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 
13 #include <asm/io.h>
14 #include <asm/bootinfo.h>
15 #include <asm/sgialib.h>
16 #include <asm/sgi/mc.h>
17 #include <asm/sgi/hpc3.h>
18 #include <asm/sgi/ip22.h>
19 
20 struct sgimc_regs *sgimc;
21 
22 EXPORT_SYMBOL(sgimc);
23 
24 static inline unsigned long get_bank_addr(unsigned int memconfig)
25 {
26 	return ((memconfig & SGIMC_MCONFIG_BASEADDR) <<
27 		((sgimc->systemid & SGIMC_SYSID_MASKREV) >= 5 ? 24 : 22));
28 }
29 
30 static inline unsigned long get_bank_size(unsigned int memconfig)
31 {
32 	return ((memconfig & SGIMC_MCONFIG_RMASK) + 0x0100) <<
33 		((sgimc->systemid & SGIMC_SYSID_MASKREV) >= 5 ? 16 : 14);
34 }
35 
36 static inline unsigned int get_bank_config(int bank)
37 {
38 	unsigned int res = bank > 1 ? sgimc->mconfig1 : sgimc->mconfig0;
39 	return bank % 2 ? res & 0xffff : res >> 16;
40 }
41 
42 struct mem {
43 	unsigned long addr;
44 	unsigned long size;
45 };
46 
47 /*
48  * Detect installed memory, do some sanity checks and notify kernel about it
49  */
50 static void probe_memory(void)
51 {
52 	int i, j, found, cnt = 0;
53 	struct mem bank[4];
54 	struct mem space[2] = {{SGIMC_SEG0_BADDR, 0}, {SGIMC_SEG1_BADDR, 0}};
55 
56 	printk(KERN_INFO "MC: Probing memory configuration:\n");
57 	for (i = 0; i < ARRAY_SIZE(bank); i++) {
58 		unsigned int tmp = get_bank_config(i);
59 		if (!(tmp & SGIMC_MCONFIG_BVALID))
60 			continue;
61 
62 		bank[cnt].size = get_bank_size(tmp);
63 		bank[cnt].addr = get_bank_addr(tmp);
64 		printk(KERN_INFO " bank%d: %3ldM @ %08lx\n",
65 			i, bank[cnt].size / 1024 / 1024, bank[cnt].addr);
66 		cnt++;
67 	}
68 
69 	/* And you thought bubble sort is dead algorithm... */
70 	do {
71 		unsigned long addr, size;
72 
73 		found = 0;
74 		for (i = 1; i < cnt; i++)
75 			if (bank[i-1].addr > bank[i].addr) {
76 				addr = bank[i].addr;
77 				size = bank[i].size;
78 				bank[i].addr = bank[i-1].addr;
79 				bank[i].size = bank[i-1].size;
80 				bank[i-1].addr = addr;
81 				bank[i-1].size = size;
82 				found = 1;
83 			}
84 	} while (found);
85 
86 	/* Figure out how are memory banks mapped into spaces */
87 	for (i = 0; i < cnt; i++) {
88 		found = 0;
89 		for (j = 0; j < ARRAY_SIZE(space) && !found; j++)
90 			if (space[j].addr + space[j].size == bank[i].addr) {
91 				space[j].size += bank[i].size;
92 				found = 1;
93 			}
94 		/* There is either hole or overlapping memory */
95 		if (!found)
96 			printk(KERN_CRIT "MC: Memory configuration mismatch "
97 					 "(%08lx), expect Bus Error soon\n",
98 					 bank[i].addr);
99 	}
100 
101 	for (i = 0; i < ARRAY_SIZE(space); i++)
102 		if (space[i].size)
103 			add_memory_region(space[i].addr, space[i].size,
104 					  BOOT_MEM_RAM);
105 }
106 
107 void __init sgimc_init(void)
108 {
109 	u32 tmp;
110 
111 	/* ioremap can't fail */
112 	sgimc = (struct sgimc_regs *)
113 		ioremap(SGIMC_BASE, sizeof(struct sgimc_regs));
114 
115 	printk(KERN_INFO "MC: SGI memory controller Revision %d\n",
116 	       (int) sgimc->systemid & SGIMC_SYSID_MASKREV);
117 
118 	/* Place the MC into a known state.  This must be done before
119 	 * interrupts are first enabled etc.
120 	 */
121 
122 	/* Step 0: Make sure we turn off the watchdog in case it's
123 	 *         still running (which might be the case after a
124 	 *         soft reboot).
125 	 */
126 	tmp = sgimc->cpuctrl0;
127 	tmp &= ~SGIMC_CCTRL0_WDOG;
128 	sgimc->cpuctrl0 = tmp;
129 
130 	/* Step 1: The CPU/GIO error status registers will not latch
131 	 *         up a new error status until the register has been
132 	 *         cleared by the cpu.  These status registers are
133 	 *         cleared by writing any value to them.
134 	 */
135 	sgimc->cstat = sgimc->gstat = 0;
136 
137 	/* Step 2: Enable all parity checking in cpu control register
138 	 *         zero.
139 	 */
140 	tmp = sgimc->cpuctrl0;
141 	tmp |= (SGIMC_CCTRL0_EPERRGIO | SGIMC_CCTRL0_EPERRMEM |
142 		SGIMC_CCTRL0_R4KNOCHKPARR);
143 	sgimc->cpuctrl0 = tmp;
144 
145 	/* Step 3: Setup the MC write buffer depth, this is controlled
146 	 *         in cpu control register 1 in the lower 4 bits.
147 	 */
148 	tmp = sgimc->cpuctrl1;
149 	tmp &= ~0xf;
150 	tmp |= 0xd;
151 	sgimc->cpuctrl1 = tmp;
152 
153 	/* Step 4: Initialize the RPSS divider register to run as fast
154 	 *         as it can correctly operate.  The register is laid
155 	 *         out as follows:
156 	 *
157 	 *         ----------------------------------------
158 	 *         |  RESERVED  |   INCREMENT   | DIVIDER |
159 	 *         ----------------------------------------
160 	 *          31        16 15            8 7       0
161 	 *
162 	 *         DIVIDER determines how often a 'tick' happens,
163 	 *         INCREMENT determines by how the RPSS increment
164 	 *         registers value increases at each 'tick'. Thus,
165 	 *         for IP22 we get INCREMENT=1, DIVIDER=1 == 0x101
166 	 */
167 	sgimc->divider = 0x101;
168 
169 	/* Step 5: Initialize GIO64 arbitrator configuration register.
170 	 *
171 	 * NOTE: HPC init code in sgihpc_init() must run before us because
172 	 *       we need to know Guiness vs. FullHouse and the board
173 	 *       revision on this machine. You have been warned.
174 	 */
175 
176 	/* First the basic invariants across all GIO64 implementations. */
177 	tmp = SGIMC_GIOPAR_HPC64;	/* All 1st HPC's interface at 64bits */
178 	tmp |= SGIMC_GIOPAR_ONEBUS;	/* Only one physical GIO bus exists */
179 
180 	if (ip22_is_fullhouse()) {
181 		/* Fullhouse specific settings. */
182 		if (SGIOC_SYSID_BOARDREV(sgioc->sysid) < 2) {
183 			tmp |= SGIMC_GIOPAR_HPC264;	/* 2nd HPC at 64bits */
184 			tmp |= SGIMC_GIOPAR_PLINEEXP0;	/* exp0 pipelines */
185 			tmp |= SGIMC_GIOPAR_MASTEREXP1;	/* exp1 masters */
186 			tmp |= SGIMC_GIOPAR_RTIMEEXP0;	/* exp0 is realtime */
187 		} else {
188 			tmp |= SGIMC_GIOPAR_HPC264;	/* 2nd HPC 64bits */
189 			tmp |= SGIMC_GIOPAR_PLINEEXP0;	/* exp[01] pipelined */
190 			tmp |= SGIMC_GIOPAR_PLINEEXP1;
191 			tmp |= SGIMC_GIOPAR_MASTEREISA;	/* EISA masters */
192 			tmp |= SGIMC_GIOPAR_GFX64;	/* GFX at 64 bits */
193 		}
194 	} else {
195 		/* Guiness specific settings. */
196 		tmp |= SGIMC_GIOPAR_EISA64;	/* MC talks to EISA at 64bits */
197 		tmp |= SGIMC_GIOPAR_MASTEREISA;	/* EISA bus can act as master */
198 	}
199 	sgimc->giopar = tmp;	/* poof */
200 
201 	probe_memory();
202 }
203 
204 void __init prom_meminit(void) {}
205 void __init prom_free_prom_memory(void)
206 {
207 }
208