arch/powerpc/sysdev/ppc4xx_soc.c

   1 /*
   2  * IBM/AMCC PPC4xx SoC setup code
   3  *
   4  * Copyright 2008 DENX Software Engineering, Stefan Roese <sr@denx.de>
   5  *
   6  * L2 cache routines cloned from arch/ppc/syslib/ibm440gx_common.c which is:
   7  *   Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
   8  *   Copyright (c) 2003 - 2006 Zultys Technologies
   9  *
  10  * This program is free software; you can redistribute  it and/or modify it
  11  * under  the terms of  the GNU General  Public License as published by the
  12  * Free Software Foundation;  either version 2 of the  License, or (at your
  13  * option) any later version.
  14  */
  15
  16 #include <linux/stddef.h>
  17 #include <linux/kernel.h>
  18 #include <linux/init.h>
  19 #include <linux/errno.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/irq.h>
  22 #include <linux/of_platform.h>
  23
  24 #include <asm/dcr.h>
  25 #include <asm/dcr-regs.h>
  26 #include <asm/reg.h>
  27
  28 static u32 dcrbase_l2c;
  29
  30 /*
  31  * L2-cache
  32  */
  33
  34 /* Issue L2C diagnostic command */
  35 static inline u32 l2c_diag(u32 addr)
  36 {
  37         mtdcr(dcrbase_l2c + DCRN_L2C0_ADDR, addr);
  38         mtdcr(dcrbase_l2c + DCRN_L2C0_CMD, L2C_CMD_DIAG);
  39         while (!(mfdcr(dcrbase_l2c + DCRN_L2C0_SR) & L2C_SR_CC))
  40                 ;
  41
  42         return mfdcr(dcrbase_l2c + DCRN_L2C0_DATA);
  43 }
  44
  45 static irqreturn_t l2c_error_handler(int irq, void *dev)
  46 {
  47         u32 sr = mfdcr(dcrbase_l2c + DCRN_L2C0_SR);
  48
  49         if (sr & L2C_SR_CPE) {
  50                 /* Read cache trapped address */
  51                 u32 addr = l2c_diag(0x42000000);
  52                 printk(KERN_EMERG "L2C: Cache Parity Error, addr[16:26] = 0x%08x\n",
  53                        addr);
  54         }
  55         if (sr & L2C_SR_TPE) {
  56                 /* Read tag trapped address */
  57                 u32 addr = l2c_diag(0x82000000) >> 16;
  58                 printk(KERN_EMERG "L2C: Tag Parity Error, addr[16:26] = 0x%08x\n",
  59                        addr);
  60         }
  61
  62         /* Clear parity errors */
  63         if (sr & (L2C_SR_CPE | L2C_SR_TPE)){
  64                 mtdcr(dcrbase_l2c + DCRN_L2C0_ADDR, 0);
  65                 mtdcr(dcrbase_l2c + DCRN_L2C0_CMD, L2C_CMD_CCP | L2C_CMD_CTE);
  66         } else {
  67                 printk(KERN_EMERG "L2C: LRU error\n");
  68         }
  69
  70         return IRQ_HANDLED;
  71 }
  72
  73 static int __init ppc4xx_l2c_probe(void)
  74 {
  75         struct device_node *np;
  76         u32 r;
  77         unsigned long flags;
  78         int irq;
  79         const u32 *dcrreg;
  80         u32 dcrbase_isram;
  81         int len;
  82         const u32 *prop;
  83         u32 l2_size;
  84
  85         np = of_find_compatible_node(NULL, NULL, "ibm,l2-cache");
  86         if (!np)
  87                 return 0;
  88
  89         /* Get l2 cache size */
  90         prop = of_get_property(np, "cache-size", NULL);
  91         if (prop == NULL) {
  92                 printk(KERN_ERR "%s: Can't get cache-size!\n", np->full_name);
  93                 of_node_put(np);
  94                 return -ENODEV;
  95         }
  96         l2_size = prop[0];
  97
  98         /* Map DCRs */
  99         dcrreg = of_get_property(np, "dcr-reg", &len);
 100         if (!dcrreg || (len != 4 * sizeof(u32))) {
 101                 printk(KERN_ERR "%s: Can't get DCR register base !",
 102                        np->full_name);
 103                 of_node_put(np);
 104                 return -ENODEV;
 105         }
 106         dcrbase_isram = dcrreg[0];
 107         dcrbase_l2c = dcrreg[2];
 108
 109         /* Get and map irq number from device tree */
 110         irq = irq_of_parse_and_map(np, 0);
 111         if (irq == NO_IRQ) {
 112                 printk(KERN_ERR "irq_of_parse_and_map failed\n");
 113                 of_node_put(np);
 114                 return -ENODEV;
 115         }
 116
 117         /* Install error handler */
 118         if (request_irq(irq, l2c_error_handler, IRQF_DISABLED, "L2C", 0) < 0) {
 119                 printk(KERN_ERR "Cannot install L2C error handler"
 120                        ", cache is not enabled\n");
 121                 of_node_put(np);
 122                 return -ENODEV;
 123         }
 124
 125         local_irq_save(flags);
 126         asm volatile ("sync" ::: "memory");
 127
 128         /* Disable SRAM */
 129         mtdcr(dcrbase_isram + DCRN_SRAM0_DPC,
 130               mfdcr(dcrbase_isram + DCRN_SRAM0_DPC) & ~SRAM_DPC_ENABLE);
 131         mtdcr(dcrbase_isram + DCRN_SRAM0_SB0CR,
 132               mfdcr(dcrbase_isram + DCRN_SRAM0_SB0CR) & ~SRAM_SBCR_BU_MASK);
 133         mtdcr(dcrbase_isram + DCRN_SRAM0_SB1CR,
 134               mfdcr(dcrbase_isram + DCRN_SRAM0_SB1CR) & ~SRAM_SBCR_BU_MASK);
 135         mtdcr(dcrbase_isram + DCRN_SRAM0_SB2CR,
 136               mfdcr(dcrbase_isram + DCRN_SRAM0_SB2CR) & ~SRAM_SBCR_BU_MASK);
 137         mtdcr(dcrbase_isram + DCRN_SRAM0_SB3CR,
 138               mfdcr(dcrbase_isram + DCRN_SRAM0_SB3CR) & ~SRAM_SBCR_BU_MASK);
 139
 140         /* Enable L2_MODE without ICU/DCU */
 141         r = mfdcr(dcrbase_l2c + DCRN_L2C0_CFG) &
 142                 ~(L2C_CFG_ICU | L2C_CFG_DCU | L2C_CFG_SS_MASK);
 143         r |= L2C_CFG_L2M | L2C_CFG_SS_256;
 144         mtdcr(dcrbase_l2c + DCRN_L2C0_CFG, r);
 145
 146         mtdcr(dcrbase_l2c + DCRN_L2C0_ADDR, 0);
 147
 148         /* Hardware Clear Command */
 149         mtdcr(dcrbase_l2c + DCRN_L2C0_CMD, L2C_CMD_HCC);
 150         while (!(mfdcr(dcrbase_l2c + DCRN_L2C0_SR) & L2C_SR_CC))
 151                 ;
 152
 153         /* Clear Cache Parity and Tag Errors */
 154         mtdcr(dcrbase_l2c + DCRN_L2C0_CMD, L2C_CMD_CCP | L2C_CMD_CTE);
 155
 156         /* Enable 64G snoop region starting at 0 */
 157         r = mfdcr(dcrbase_l2c + DCRN_L2C0_SNP0) &
 158                 ~(L2C_SNP_BA_MASK | L2C_SNP_SSR_MASK);
 159         r |= L2C_SNP_SSR_32G | L2C_SNP_ESR;
 160         mtdcr(dcrbase_l2c + DCRN_L2C0_SNP0, r);
 161
 162         r = mfdcr(dcrbase_l2c + DCRN_L2C0_SNP1) &
 163                 ~(L2C_SNP_BA_MASK | L2C_SNP_SSR_MASK);
 164         r |= 0x80000000 | L2C_SNP_SSR_32G | L2C_SNP_ESR;
 165         mtdcr(dcrbase_l2c + DCRN_L2C0_SNP1, r);
 166
 167         asm volatile ("sync" ::: "memory");
 168
 169         /* Enable ICU/DCU ports */
 170         r = mfdcr(dcrbase_l2c + DCRN_L2C0_CFG);
 171         r &= ~(L2C_CFG_DCW_MASK | L2C_CFG_PMUX_MASK | L2C_CFG_PMIM
 172                | L2C_CFG_TPEI | L2C_CFG_CPEI | L2C_CFG_NAM | L2C_CFG_NBRM);
 173         r |= L2C_CFG_ICU | L2C_CFG_DCU | L2C_CFG_TPC | L2C_CFG_CPC | L2C_CFG_FRAN
 174                 | L2C_CFG_CPIM | L2C_CFG_TPIM | L2C_CFG_LIM | L2C_CFG_SMCM;
 175
 176         /* Check for 460EX/GT special handling */
 177         if (of_device_is_compatible(np, "ibm,l2-cache-460ex") ||
 178             of_device_is_compatible(np, "ibm,l2-cache-460gt"))
 179                 r |= L2C_CFG_RDBW;
 180
 181         mtdcr(dcrbase_l2c + DCRN_L2C0_CFG, r);
 182
 183         asm volatile ("sync; isync" ::: "memory");
 184         local_irq_restore(flags);
 185
 186         printk(KERN_INFO "%dk L2-cache enabled\n", l2_size >> 10);
 187
 188         of_node_put(np);
 189         return 0;
 190 }
 191 arch_initcall(ppc4xx_l2c_probe);
 192
 193 /*
 194  * At present, this routine just applies a system reset.
 195  */
 196 void ppc4xx_reset_system(char *cmd)
 197 {
 198         mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_RST_SYSTEM);
 199         while (1)
 200                 ;       /* Just in case the reset doesn't work */
 201 }