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/memblock.h>
15#include <linux/spinlock.h>
16
17#include <asm/io.h>
18#include <asm/bootinfo.h>
19#include <asm/sgialib.h>
20#include <asm/sgi/mc.h>
21#include <asm/sgi/hpc3.h>
22#include <asm/sgi/ip22.h>
23
24struct sgimc_regs *sgimc;
25
26EXPORT_SYMBOL(sgimc);
27
28static inline unsigned long get_bank_addr(unsigned int memconfig)
29{
30	return (memconfig & SGIMC_MCONFIG_BASEADDR) << ((sgimc->systemid & SGIMC_SYSID_MASKREV) >= 5 ? 24 : 22);
31}
32
33static inline unsigned long get_bank_size(unsigned int memconfig)
34{
35	return ((memconfig & SGIMC_MCONFIG_RMASK) + 0x0100) << ((sgimc->systemid & SGIMC_SYSID_MASKREV) >= 5 ? 16 : 14);
36}
37
38static inline unsigned int get_bank_config(int bank)
39{
40	unsigned int res = bank > 1 ? sgimc->mconfig1 : sgimc->mconfig0;
41	return bank % 2 ? res & 0xffff : res >> 16;
42}
43
44#if defined(CONFIG_SGI_IP28) || defined(CONFIG_32BIT)
45static void __init probe_memory(void)
46{
47	/* prom detects all usable memory */
48}
49#else
50/*
51 * Detect installed memory, which PROM misses
52 */
53static void __init probe_memory(void)
54{
55	unsigned long addr, size;
56	int i;
57
58	printk(KERN_INFO "MC: Probing memory configuration:\n");
59	for (i = 0; i < 4; i++) {
60		unsigned int tmp = get_bank_config(i);
61		if (!(tmp & SGIMC_MCONFIG_BVALID))
62			continue;
63
64		size = get_bank_size(tmp);
65		addr = get_bank_addr(tmp);
66		printk(KERN_INFO " bank%d: %3ldM @ %08lx\n",
67			i, size / 1024 / 1024, addr);
68
69		if (addr >= SGIMC_SEG1_BADDR)
70			memblock_add(addr, size);
71	}
72}
73#endif
74
75void __init sgimc_init(void)
76{
77	u32 tmp;
78
79	/* ioremap can't fail */
80	sgimc = (struct sgimc_regs *)
81		ioremap(SGIMC_BASE, sizeof(struct sgimc_regs));
82
83	printk(KERN_INFO "MC: SGI memory controller Revision %d\n",
84	       (int) sgimc->systemid & SGIMC_SYSID_MASKREV);
85
86	/* Place the MC into a known state.  This must be done before
87	 * interrupts are first enabled etc.
88	 */
89
90	/* Step 0: Make sure we turn off the watchdog in case it's
91	 *	   still running (which might be the case after a
92	 *	   soft reboot).
93	 */
94	tmp = sgimc->cpuctrl0;
95	tmp &= ~SGIMC_CCTRL0_WDOG;
96	sgimc->cpuctrl0 = tmp;
97
98	/* Step 1: The CPU/GIO error status registers will not latch
99	 *	   up a new error status until the register has been
100	 *	   cleared by the cpu.	These status registers are
101	 *	   cleared by writing any value to them.
102	 */
103	sgimc->cstat = sgimc->gstat = 0;
104
105	/* Step 2: Enable all parity checking in cpu control register
106	 *	   zero.
107	 */
108	/* don't touch parity settings for IP28 */
109	tmp = sgimc->cpuctrl0;
110#ifndef CONFIG_SGI_IP28
111	tmp |= SGIMC_CCTRL0_EPERRGIO | SGIMC_CCTRL0_EPERRMEM;
112#endif
113	tmp |= SGIMC_CCTRL0_R4KNOCHKPARR;
114	sgimc->cpuctrl0 = tmp;
115
116	/* Step 3: Setup the MC write buffer depth, this is controlled
117	 *	   in cpu control register 1 in the lower 4 bits.
118	 */
119	tmp = sgimc->cpuctrl1;
120	tmp &= ~0xf;
121	tmp |= 0xd;
122	sgimc->cpuctrl1 = tmp;
123
124	/* Step 4: Initialize the RPSS divider register to run as fast
125	 *	   as it can correctly operate.	 The register is laid
126	 *	   out as follows:
127	 *
128	 *	   ----------------------------------------
129	 *	   |  RESERVED	|   INCREMENT	| DIVIDER |
130	 *	   ----------------------------------------
131	 *	    31	      16 15	       8 7	 0
132	 *
133	 *	   DIVIDER determines how often a 'tick' happens,
134	 *	   INCREMENT determines by how the RPSS increment
135	 *	   registers value increases at each 'tick'. Thus,
136	 *	   for IP22 we get INCREMENT=1, DIVIDER=1 == 0x101
137	 */
138	sgimc->divider = 0x101;
139
140	/* Step 5: Initialize GIO64 arbitrator configuration register.
141	 *
142	 * NOTE: HPC init code in sgihpc_init() must run before us because
143	 *	 we need to know Guiness vs. FullHouse and the board
144	 *	 revision on this machine. You have been warned.
145	 */
146
147	/* First the basic invariants across all GIO64 implementations. */
148	tmp = sgimc->giopar & SGIMC_GIOPAR_GFX64; /* keep gfx 64bit settings */
149	tmp |= SGIMC_GIOPAR_HPC64;	/* All 1st HPC's interface at 64bits */
150	tmp |= SGIMC_GIOPAR_ONEBUS;	/* Only one physical GIO bus exists */
151
152	if (ip22_is_fullhouse()) {
153		/* Fullhouse specific settings. */
154		if (SGIOC_SYSID_BOARDREV(sgioc->sysid) < 2) {
155			tmp |= SGIMC_GIOPAR_HPC264;	/* 2nd HPC at 64bits */
156			tmp |= SGIMC_GIOPAR_PLINEEXP0;	/* exp0 pipelines */
157			tmp |= SGIMC_GIOPAR_MASTEREXP1; /* exp1 masters */
158			tmp |= SGIMC_GIOPAR_RTIMEEXP0;	/* exp0 is realtime */
159		} else {
160			tmp |= SGIMC_GIOPAR_HPC264;	/* 2nd HPC 64bits */
161			tmp |= SGIMC_GIOPAR_PLINEEXP0;	/* exp[01] pipelined */
162			tmp |= SGIMC_GIOPAR_PLINEEXP1;
163			tmp |= SGIMC_GIOPAR_MASTEREISA; /* EISA masters */
164		}
165	} else {
166		/* Guiness specific settings. */
167		tmp |= SGIMC_GIOPAR_EISA64;	/* MC talks to EISA at 64bits */
168		tmp |= SGIMC_GIOPAR_MASTEREISA; /* EISA bus can act as master */
169	}
170	sgimc->giopar = tmp;	/* poof */
171
172	probe_memory();
173}
174
175#ifdef CONFIG_SGI_IP28
176void __init prom_cleanup(void)
177{
178	u32 mconfig1;
179	unsigned long flags;
180	spinlock_t lock;
181
182	/*
183	 * because ARCS accesses memory uncached we wait until ARCS
184	 * isn't needed any longer, before we switch from slow to
185	 * normal mode
186	 */
187	spin_lock_irqsave(&lock, flags);
188	mconfig1 = sgimc->mconfig1;
189	/* map ECC register */
190	sgimc->mconfig1 = (mconfig1 & 0xffff0000) | 0x2060;
191	iob();
192	/* switch to normal mode */
193	*(unsigned long *)PHYS_TO_XKSEG_UNCACHED(0x60000000) = 0;
194	iob();
195	/* reduce WR_COL */
196	sgimc->cmacc = (sgimc->cmacc & ~0xf) | 4;
197	iob();
198	/* restore old config */
199	sgimc->mconfig1 = mconfig1;
200	iob();
201	spin_unlock_irqrestore(&lock, flags);
202}
203#endif
204