xref: /openbmc/linux/arch/mips/sgi-ip22/ip22-mc.c (revision 19c233b7)
1 /*
2  * ip22-mc.c: Routines for manipulating SGI Memory Controller.
3  *
4  * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
5  * Copyright (C) 1999 Andrew R. Baker (andrewb@uab.edu) - Indigo2 changes
6  * Copyright (C) 2003 Ladislav Michl  (ladis@linux-mips.org)
7  * Copyright (C) 2004 Peter Fuerst    (pf@net.alphadv.de) - IP28
8  */
9 
10 #include <linux/init.h>
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 
14 #include <asm/io.h>
15 #include <asm/bootinfo.h>
16 #include <asm/sgialib.h>
17 #include <asm/sgi/mc.h>
18 #include <asm/sgi/hpc3.h>
19 #include <asm/sgi/ip22.h>
20 
21 struct sgimc_regs *sgimc;
22 
23 EXPORT_SYMBOL(sgimc);
24 
25 static inline unsigned long get_bank_addr(unsigned int memconfig)
26 {
27 	return (memconfig & SGIMC_MCONFIG_BASEADDR) << ((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) << ((sgimc->systemid & SGIMC_SYSID_MASKREV) >= 5 ? 16 : 14);
33 }
34 
35 static inline unsigned int get_bank_config(int bank)
36 {
37 	unsigned int res = bank > 1 ? sgimc->mconfig1 : sgimc->mconfig0;
38 	return bank % 2 ? res & 0xffff : res >> 16;
39 }
40 
41 struct mem {
42 	unsigned long addr;
43 	unsigned long size;
44 };
45 
46 /*
47  * Detect installed memory, do some sanity checks and notify kernel about it
48  */
49 static void __init probe_memory(void)
50 {
51 	int i, j, found, cnt = 0;
52 	struct mem bank[4];
53 	struct mem space[2] = {{SGIMC_SEG0_BADDR, 0}, {SGIMC_SEG1_BADDR, 0}};
54 
55 	printk(KERN_INFO "MC: Probing memory configuration:\n");
56 	for (i = 0; i < ARRAY_SIZE(bank); i++) {
57 		unsigned int tmp = get_bank_config(i);
58 		if (!(tmp & SGIMC_MCONFIG_BVALID))
59 			continue;
60 
61 		bank[cnt].size = get_bank_size(tmp);
62 		bank[cnt].addr = get_bank_addr(tmp);
63 		printk(KERN_INFO " bank%d: %3ldM @ %08lx\n",
64 			i, bank[cnt].size / 1024 / 1024, bank[cnt].addr);
65 		cnt++;
66 	}
67 
68 	/* And you thought bubble sort is dead algorithm... */
69 	do {
70 		unsigned long addr, size;
71 
72 		found = 0;
73 		for (i = 1; i < cnt; i++)
74 			if (bank[i-1].addr > bank[i].addr) {
75 				addr = bank[i].addr;
76 				size = bank[i].size;
77 				bank[i].addr = bank[i-1].addr;
78 				bank[i].size = bank[i-1].size;
79 				bank[i-1].addr = addr;
80 				bank[i-1].size = size;
81 				found = 1;
82 			}
83 	} while (found);
84 
85 	/* Figure out how are memory banks mapped into spaces */
86 	for (i = 0; i < cnt; i++) {
87 		found = 0;
88 		for (j = 0; j < ARRAY_SIZE(space) && !found; j++)
89 			if (space[j].addr + space[j].size == bank[i].addr) {
90 				space[j].size += bank[i].size;
91 				found = 1;
92 			}
93 		/* There is either hole or overlapping memory */
94 		if (!found)
95 			printk(KERN_CRIT "MC: Memory configuration mismatch "
96 					 "(%08lx), expect Bus Error soon\n",
97 					 bank[i].addr);
98 	}
99 
100 	for (i = 0; i < ARRAY_SIZE(space); i++)
101 		if (space[i].size)
102 			add_memory_region(space[i].addr, space[i].size,
103 					  BOOT_MEM_RAM);
104 }
105 
106 void __init sgimc_init(void)
107 {
108 	u32 tmp;
109 
110 	/* ioremap can't fail */
111 	sgimc = (struct sgimc_regs *)
112 		ioremap(SGIMC_BASE, sizeof(struct sgimc_regs));
113 
114 	printk(KERN_INFO "MC: SGI memory controller Revision %d\n",
115 	       (int) sgimc->systemid & SGIMC_SYSID_MASKREV);
116 
117 	/* Place the MC into a known state.  This must be done before
118 	 * interrupts are first enabled etc.
119 	 */
120 
121 	/* Step 0: Make sure we turn off the watchdog in case it's
122 	 *	   still running (which might be the case after a
123 	 *	   soft reboot).
124 	 */
125 	tmp = sgimc->cpuctrl0;
126 	tmp &= ~SGIMC_CCTRL0_WDOG;
127 	sgimc->cpuctrl0 = tmp;
128 
129 	/* Step 1: The CPU/GIO error status registers will not latch
130 	 *	   up a new error status until the register has been
131 	 *	   cleared by the cpu.	These status registers are
132 	 *	   cleared by writing any value to them.
133 	 */
134 	sgimc->cstat = sgimc->gstat = 0;
135 
136 	/* Step 2: Enable all parity checking in cpu control register
137 	 *	   zero.
138 	 */
139 	/* don't touch parity settings for IP28 */
140 	tmp = sgimc->cpuctrl0;
141 #ifndef CONFIG_SGI_IP28
142 	tmp |= SGIMC_CCTRL0_EPERRGIO | SGIMC_CCTRL0_EPERRMEM;
143 #endif
144 	tmp |= SGIMC_CCTRL0_R4KNOCHKPARR;
145 	sgimc->cpuctrl0 = tmp;
146 
147 	/* Step 3: Setup the MC write buffer depth, this is controlled
148 	 *	   in cpu control register 1 in the lower 4 bits.
149 	 */
150 	tmp = sgimc->cpuctrl1;
151 	tmp &= ~0xf;
152 	tmp |= 0xd;
153 	sgimc->cpuctrl1 = tmp;
154 
155 	/* Step 4: Initialize the RPSS divider register to run as fast
156 	 *	   as it can correctly operate.	 The register is laid
157 	 *	   out as follows:
158 	 *
159 	 *	   ----------------------------------------
160 	 *	   |  RESERVED	|   INCREMENT	| DIVIDER |
161 	 *	   ----------------------------------------
162 	 *	    31	      16 15	       8 7	 0
163 	 *
164 	 *	   DIVIDER determines how often a 'tick' happens,
165 	 *	   INCREMENT determines by how the RPSS increment
166 	 *	   registers value increases at each 'tick'. Thus,
167 	 *	   for IP22 we get INCREMENT=1, DIVIDER=1 == 0x101
168 	 */
169 	sgimc->divider = 0x101;
170 
171 	/* Step 5: Initialize GIO64 arbitrator configuration register.
172 	 *
173 	 * NOTE: HPC init code in sgihpc_init() must run before us because
174 	 *	 we need to know Guiness vs. FullHouse and the board
175 	 *	 revision on this machine. You have been warned.
176 	 */
177 
178 	/* First the basic invariants across all GIO64 implementations. */
179 	tmp = sgimc->giopar & SGIMC_GIOPAR_GFX64; /* keep gfx 64bit settings */
180 	tmp |= SGIMC_GIOPAR_HPC64;	/* All 1st HPC's interface at 64bits */
181 	tmp |= SGIMC_GIOPAR_ONEBUS;	/* Only one physical GIO bus exists */
182 
183 	if (ip22_is_fullhouse()) {
184 		/* Fullhouse specific settings. */
185 		if (SGIOC_SYSID_BOARDREV(sgioc->sysid) < 2) {
186 			tmp |= SGIMC_GIOPAR_HPC264;	/* 2nd HPC at 64bits */
187 			tmp |= SGIMC_GIOPAR_PLINEEXP0;	/* exp0 pipelines */
188 			tmp |= SGIMC_GIOPAR_MASTEREXP1; /* exp1 masters */
189 			tmp |= SGIMC_GIOPAR_RTIMEEXP0;	/* exp0 is realtime */
190 		} else {
191 			tmp |= SGIMC_GIOPAR_HPC264;	/* 2nd HPC 64bits */
192 			tmp |= SGIMC_GIOPAR_PLINEEXP0;	/* exp[01] pipelined */
193 			tmp |= SGIMC_GIOPAR_PLINEEXP1;
194 			tmp |= SGIMC_GIOPAR_MASTEREISA; /* EISA masters */
195 		}
196 	} else {
197 		/* Guiness specific settings. */
198 		tmp |= SGIMC_GIOPAR_EISA64;	/* MC talks to EISA at 64bits */
199 		tmp |= SGIMC_GIOPAR_MASTEREISA; /* EISA bus can act as master */
200 	}
201 	sgimc->giopar = tmp;	/* poof */
202 
203 	probe_memory();
204 }
205 
206 void __init prom_meminit(void) {}
207 void __init prom_free_prom_memory(void)
208 {
209 #ifdef CONFIG_SGI_IP28
210 	u32 mconfig1;
211 	unsigned long flags;
212 	spinlock_t lock;
213 
214 	/*
215 	 * because ARCS accesses memory uncached we wait until ARCS
216 	 * isn't needed any longer, before we switch from slow to
217 	 * normal mode
218 	 */
219 	spin_lock_irqsave(&lock, flags);
220 	mconfig1 = sgimc->mconfig1;
221 	/* map ECC register */
222 	sgimc->mconfig1 = (mconfig1 & 0xffff0000) | 0x2060;
223 	iob();
224 	/* switch to normal mode */
225 	*(unsigned long *)PHYS_TO_XKSEG_UNCACHED(0x60000000) = 0;
226 	iob();
227 	/* reduce WR_COL */
228 	sgimc->cmacc = (sgimc->cmacc & ~0xf) | 4;
229 	iob();
230 	/* restore old config */
231 	sgimc->mconfig1 = mconfig1;
232 	iob();
233 	spin_unlock_irqrestore(&lock, flags);
234 #endif
235 }
236