xref: /openbmc/linux/arch/mips/sgi-ip22/ip22-mc.c (revision e2c75e76)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ip22-mc.c: Routines for manipulating SGI Memory Controller.
4  *
5  * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
6  * Copyright (C) 1999 Andrew R. Baker (andrewb@uab.edu) - Indigo2 changes
7  * Copyright (C) 2003 Ladislav Michl  (ladis@linux-mips.org)
8  * Copyright (C) 2004 Peter Fuerst    (pf@net.alphadv.de) - IP28
9  */
10 
11 #include <linux/init.h>
12 #include <linux/export.h>
13 #include <linux/kernel.h>
14 #include <linux/spinlock.h>
15 
16 #include <asm/io.h>
17 #include <asm/bootinfo.h>
18 #include <asm/sgialib.h>
19 #include <asm/sgi/mc.h>
20 #include <asm/sgi/hpc3.h>
21 #include <asm/sgi/ip22.h>
22 
23 struct sgimc_regs *sgimc;
24 
25 EXPORT_SYMBOL(sgimc);
26 
27 static inline unsigned long get_bank_addr(unsigned int memconfig)
28 {
29 	return (memconfig & SGIMC_MCONFIG_BASEADDR) << ((sgimc->systemid & SGIMC_SYSID_MASKREV) >= 5 ? 24 : 22);
30 }
31 
32 static inline unsigned long get_bank_size(unsigned int memconfig)
33 {
34 	return ((memconfig & SGIMC_MCONFIG_RMASK) + 0x0100) << ((sgimc->systemid & SGIMC_SYSID_MASKREV) >= 5 ? 16 : 14);
35 }
36 
37 static inline unsigned int get_bank_config(int bank)
38 {
39 	unsigned int res = bank > 1 ? sgimc->mconfig1 : sgimc->mconfig0;
40 	return bank % 2 ? res & 0xffff : res >> 16;
41 }
42 
43 struct mem {
44 	unsigned long addr;
45 	unsigned long size;
46 };
47 
48 /*
49  * Detect installed memory, do some sanity checks and notify kernel about it
50  */
51 static void __init probe_memory(void)
52 {
53 	int i, j, found, cnt = 0;
54 	struct mem bank[4];
55 	struct mem space[2] = {{SGIMC_SEG0_BADDR, 0}, {SGIMC_SEG1_BADDR, 0}};
56 
57 	printk(KERN_INFO "MC: Probing memory configuration:\n");
58 	for (i = 0; i < ARRAY_SIZE(bank); i++) {
59 		unsigned int tmp = get_bank_config(i);
60 		if (!(tmp & SGIMC_MCONFIG_BVALID))
61 			continue;
62 
63 		bank[cnt].size = get_bank_size(tmp);
64 		bank[cnt].addr = get_bank_addr(tmp);
65 		printk(KERN_INFO " bank%d: %3ldM @ %08lx\n",
66 			i, bank[cnt].size / 1024 / 1024, bank[cnt].addr);
67 		cnt++;
68 	}
69 
70 	/* And you thought bubble sort is dead algorithm... */
71 	do {
72 		unsigned long addr, size;
73 
74 		found = 0;
75 		for (i = 1; i < cnt; i++)
76 			if (bank[i-1].addr > bank[i].addr) {
77 				addr = bank[i].addr;
78 				size = bank[i].size;
79 				bank[i].addr = bank[i-1].addr;
80 				bank[i].size = bank[i-1].size;
81 				bank[i-1].addr = addr;
82 				bank[i-1].size = size;
83 				found = 1;
84 			}
85 	} while (found);
86 
87 	/* Figure out how are memory banks mapped into spaces */
88 	for (i = 0; i < cnt; i++) {
89 		found = 0;
90 		for (j = 0; j < ARRAY_SIZE(space) && !found; j++)
91 			if (space[j].addr + space[j].size == bank[i].addr) {
92 				space[j].size += bank[i].size;
93 				found = 1;
94 			}
95 		/* There is either hole or overlapping memory */
96 		if (!found)
97 			printk(KERN_CRIT "MC: Memory configuration mismatch "
98 					 "(%08lx), expect Bus Error soon\n",
99 					 bank[i].addr);
100 	}
101 
102 	for (i = 0; i < ARRAY_SIZE(space); i++)
103 		if (space[i].size)
104 			add_memory_region(space[i].addr, space[i].size,
105 					  BOOT_MEM_RAM);
106 }
107 
108 void __init sgimc_init(void)
109 {
110 	u32 tmp;
111 
112 	/* ioremap can't fail */
113 	sgimc = (struct sgimc_regs *)
114 		ioremap(SGIMC_BASE, sizeof(struct sgimc_regs));
115 
116 	printk(KERN_INFO "MC: SGI memory controller Revision %d\n",
117 	       (int) sgimc->systemid & SGIMC_SYSID_MASKREV);
118 
119 	/* Place the MC into a known state.  This must be done before
120 	 * interrupts are first enabled etc.
121 	 */
122 
123 	/* Step 0: Make sure we turn off the watchdog in case it's
124 	 *	   still running (which might be the case after a
125 	 *	   soft reboot).
126 	 */
127 	tmp = sgimc->cpuctrl0;
128 	tmp &= ~SGIMC_CCTRL0_WDOG;
129 	sgimc->cpuctrl0 = tmp;
130 
131 	/* Step 1: The CPU/GIO error status registers will not latch
132 	 *	   up a new error status until the register has been
133 	 *	   cleared by the cpu.	These status registers are
134 	 *	   cleared by writing any value to them.
135 	 */
136 	sgimc->cstat = sgimc->gstat = 0;
137 
138 	/* Step 2: Enable all parity checking in cpu control register
139 	 *	   zero.
140 	 */
141 	/* don't touch parity settings for IP28 */
142 	tmp = sgimc->cpuctrl0;
143 #ifndef CONFIG_SGI_IP28
144 	tmp |= SGIMC_CCTRL0_EPERRGIO | SGIMC_CCTRL0_EPERRMEM;
145 #endif
146 	tmp |= SGIMC_CCTRL0_R4KNOCHKPARR;
147 	sgimc->cpuctrl0 = tmp;
148 
149 	/* Step 3: Setup the MC write buffer depth, this is controlled
150 	 *	   in cpu control register 1 in the lower 4 bits.
151 	 */
152 	tmp = sgimc->cpuctrl1;
153 	tmp &= ~0xf;
154 	tmp |= 0xd;
155 	sgimc->cpuctrl1 = tmp;
156 
157 	/* Step 4: Initialize the RPSS divider register to run as fast
158 	 *	   as it can correctly operate.	 The register is laid
159 	 *	   out as follows:
160 	 *
161 	 *	   ----------------------------------------
162 	 *	   |  RESERVED	|   INCREMENT	| DIVIDER |
163 	 *	   ----------------------------------------
164 	 *	    31	      16 15	       8 7	 0
165 	 *
166 	 *	   DIVIDER determines how often a 'tick' happens,
167 	 *	   INCREMENT determines by how the RPSS increment
168 	 *	   registers value increases at each 'tick'. Thus,
169 	 *	   for IP22 we get INCREMENT=1, DIVIDER=1 == 0x101
170 	 */
171 	sgimc->divider = 0x101;
172 
173 	/* Step 5: Initialize GIO64 arbitrator configuration register.
174 	 *
175 	 * NOTE: HPC init code in sgihpc_init() must run before us because
176 	 *	 we need to know Guiness vs. FullHouse and the board
177 	 *	 revision on this machine. You have been warned.
178 	 */
179 
180 	/* First the basic invariants across all GIO64 implementations. */
181 	tmp = sgimc->giopar & SGIMC_GIOPAR_GFX64; /* keep gfx 64bit settings */
182 	tmp |= SGIMC_GIOPAR_HPC64;	/* All 1st HPC's interface at 64bits */
183 	tmp |= SGIMC_GIOPAR_ONEBUS;	/* Only one physical GIO bus exists */
184 
185 	if (ip22_is_fullhouse()) {
186 		/* Fullhouse specific settings. */
187 		if (SGIOC_SYSID_BOARDREV(sgioc->sysid) < 2) {
188 			tmp |= SGIMC_GIOPAR_HPC264;	/* 2nd HPC at 64bits */
189 			tmp |= SGIMC_GIOPAR_PLINEEXP0;	/* exp0 pipelines */
190 			tmp |= SGIMC_GIOPAR_MASTEREXP1; /* exp1 masters */
191 			tmp |= SGIMC_GIOPAR_RTIMEEXP0;	/* exp0 is realtime */
192 		} else {
193 			tmp |= SGIMC_GIOPAR_HPC264;	/* 2nd HPC 64bits */
194 			tmp |= SGIMC_GIOPAR_PLINEEXP0;	/* exp[01] pipelined */
195 			tmp |= SGIMC_GIOPAR_PLINEEXP1;
196 			tmp |= SGIMC_GIOPAR_MASTEREISA; /* EISA masters */
197 		}
198 	} else {
199 		/* Guiness specific settings. */
200 		tmp |= SGIMC_GIOPAR_EISA64;	/* MC talks to EISA at 64bits */
201 		tmp |= SGIMC_GIOPAR_MASTEREISA; /* EISA bus can act as master */
202 	}
203 	sgimc->giopar = tmp;	/* poof */
204 
205 	probe_memory();
206 }
207 
208 void __init prom_meminit(void) {}
209 void __init prom_free_prom_memory(void)
210 {
211 #ifdef CONFIG_SGI_IP28
212 	u32 mconfig1;
213 	unsigned long flags;
214 	spinlock_t lock;
215 
216 	/*
217 	 * because ARCS accesses memory uncached we wait until ARCS
218 	 * isn't needed any longer, before we switch from slow to
219 	 * normal mode
220 	 */
221 	spin_lock_irqsave(&lock, flags);
222 	mconfig1 = sgimc->mconfig1;
223 	/* map ECC register */
224 	sgimc->mconfig1 = (mconfig1 & 0xffff0000) | 0x2060;
225 	iob();
226 	/* switch to normal mode */
227 	*(unsigned long *)PHYS_TO_XKSEG_UNCACHED(0x60000000) = 0;
228 	iob();
229 	/* reduce WR_COL */
230 	sgimc->cmacc = (sgimc->cmacc & ~0xf) | 4;
231 	iob();
232 	/* restore old config */
233 	sgimc->mconfig1 = mconfig1;
234 	iob();
235 	spin_unlock_irqrestore(&lock, flags);
236 #endif
237 }
238