linux/arch/mips/sgi-ip22/ip22-mc.c
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   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