[MIPS] IP28 support
Add support for SGI IP28 machines (Indigo 2 with R10k CPUs)
This work is mainly based on Peter Fuersts work.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/sgi-ip22/ip28-berr.c b/arch/mips/sgi-ip22/ip28-berr.c
new file mode 100644
index 0000000..30e12e2
--- /dev/null
+++ b/arch/mips/sgi-ip22/ip28-berr.c
@@ -0,0 +1,502 @@
+/*
+ * ip28-berr.c: Bus error handling.
+ *
+ * Copyright (C) 2002, 2003 Ladislav Michl (ladis@linux-mips.org)
+ * Copyright (C) 2005 Peter Fuerst (pf@net.alphadv.de) - IP28
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+
+#include <asm/addrspace.h>
+#include <asm/system.h>
+#include <asm/traps.h>
+#include <asm/branch.h>
+#include <asm/irq_regs.h>
+#include <asm/sgi/mc.h>
+#include <asm/sgi/hpc3.h>
+#include <asm/sgi/ioc.h>
+#include <asm/sgi/ip22.h>
+#include <asm/r4kcache.h>
+#include <asm/uaccess.h>
+#include <asm/bootinfo.h>
+
+static unsigned int count_be_is_fixup;
+static unsigned int count_be_handler;
+static unsigned int count_be_interrupt;
+static int debug_be_interrupt;
+
+static unsigned int cpu_err_stat; /* Status reg for CPU */
+static unsigned int gio_err_stat; /* Status reg for GIO */
+static unsigned int cpu_err_addr; /* Error address reg for CPU */
+static unsigned int gio_err_addr; /* Error address reg for GIO */
+static unsigned int extio_stat;
+static unsigned int hpc3_berr_stat; /* Bus error interrupt status */
+
+struct hpc3_stat {
+ unsigned long addr;
+ unsigned int ctrl;
+ unsigned int cbp;
+ unsigned int ndptr;
+};
+
+static struct {
+ struct hpc3_stat pbdma[8];
+ struct hpc3_stat scsi[2];
+ struct hpc3_stat ethrx, ethtx;
+} hpc3;
+
+static struct {
+ unsigned long err_addr;
+ struct {
+ u32 lo;
+ u32 hi;
+ } tags[1][2], tagd[4][2], tagi[4][2]; /* Way 0/1 */
+} cache_tags;
+
+static inline void save_cache_tags(unsigned busaddr)
+{
+ unsigned long addr = CAC_BASE | busaddr;
+ int i;
+ cache_tags.err_addr = addr;
+
+ /*
+ * Starting with a bus-address, save secondary cache (indexed by
+ * PA[23..18:7..6]) tags first.
+ */
+ addr &= ~1L;
+#define tag cache_tags.tags[0]
+ cache_op(Index_Load_Tag_S, addr);
+ tag[0].lo = read_c0_taglo(); /* PA[35:18], VA[13:12] */
+ tag[0].hi = read_c0_taghi(); /* PA[39:36] */
+ cache_op(Index_Load_Tag_S, addr | 1L);
+ tag[1].lo = read_c0_taglo(); /* PA[35:18], VA[13:12] */
+ tag[1].hi = read_c0_taghi(); /* PA[39:36] */
+#undef tag
+
+ /*
+ * Save all primary data cache (indexed by VA[13:5]) tags which
+ * might fit to this bus-address, knowing that VA[11:0] == PA[11:0].
+ * Saving all tags and evaluating them later is easier and safer
+ * than relying on VA[13:12] from the secondary cache tags to pick
+ * matching primary tags here already.
+ */
+ addr &= (0xffL << 56) | ((1 << 12) - 1);
+#define tag cache_tags.tagd[i]
+ for (i = 0; i < 4; ++i, addr += (1 << 12)) {
+ cache_op(Index_Load_Tag_D, addr);
+ tag[0].lo = read_c0_taglo(); /* PA[35:12] */
+ tag[0].hi = read_c0_taghi(); /* PA[39:36] */
+ cache_op(Index_Load_Tag_D, addr | 1L);
+ tag[1].lo = read_c0_taglo(); /* PA[35:12] */
+ tag[1].hi = read_c0_taghi(); /* PA[39:36] */
+ }
+#undef tag
+
+ /*
+ * Save primary instruction cache (indexed by VA[13:6]) tags
+ * the same way.
+ */
+ addr &= (0xffL << 56) | ((1 << 12) - 1);
+#define tag cache_tags.tagi[i]
+ for (i = 0; i < 4; ++i, addr += (1 << 12)) {
+ cache_op(Index_Load_Tag_I, addr);
+ tag[0].lo = read_c0_taglo(); /* PA[35:12] */
+ tag[0].hi = read_c0_taghi(); /* PA[39:36] */
+ cache_op(Index_Load_Tag_I, addr | 1L);
+ tag[1].lo = read_c0_taglo(); /* PA[35:12] */
+ tag[1].hi = read_c0_taghi(); /* PA[39:36] */
+ }
+#undef tag
+}
+
+#define GIO_ERRMASK 0xff00
+#define CPU_ERRMASK 0x3f00
+
+static void save_and_clear_buserr(void)
+{
+ int i;
+
+ /* save status registers */
+ cpu_err_addr = sgimc->cerr;
+ cpu_err_stat = sgimc->cstat;
+ gio_err_addr = sgimc->gerr;
+ gio_err_stat = sgimc->gstat;
+ extio_stat = sgioc->extio;
+ hpc3_berr_stat = hpc3c0->bestat;
+
+ hpc3.scsi[0].addr = (unsigned long)&hpc3c0->scsi_chan0;
+ hpc3.scsi[0].ctrl = hpc3c0->scsi_chan0.ctrl; /* HPC3_SCTRL_ACTIVE ? */
+ hpc3.scsi[0].cbp = hpc3c0->scsi_chan0.cbptr;
+ hpc3.scsi[0].ndptr = hpc3c0->scsi_chan0.ndptr;
+
+ hpc3.scsi[1].addr = (unsigned long)&hpc3c0->scsi_chan1;
+ hpc3.scsi[1].ctrl = hpc3c0->scsi_chan1.ctrl; /* HPC3_SCTRL_ACTIVE ? */
+ hpc3.scsi[1].cbp = hpc3c0->scsi_chan1.cbptr;
+ hpc3.scsi[1].ndptr = hpc3c0->scsi_chan1.ndptr;
+
+ hpc3.ethrx.addr = (unsigned long)&hpc3c0->ethregs.rx_cbptr;
+ hpc3.ethrx.ctrl = hpc3c0->ethregs.rx_ctrl; /* HPC3_ERXCTRL_ACTIVE ? */
+ hpc3.ethrx.cbp = hpc3c0->ethregs.rx_cbptr;
+ hpc3.ethrx.ndptr = hpc3c0->ethregs.rx_ndptr;
+
+ hpc3.ethtx.addr = (unsigned long)&hpc3c0->ethregs.tx_cbptr;
+ hpc3.ethtx.ctrl = hpc3c0->ethregs.tx_ctrl; /* HPC3_ETXCTRL_ACTIVE ? */
+ hpc3.ethtx.cbp = hpc3c0->ethregs.tx_cbptr;
+ hpc3.ethtx.ndptr = hpc3c0->ethregs.tx_ndptr;
+
+ for (i = 0; i < 8; ++i) {
+ /* HPC3_PDMACTRL_ISACT ? */
+ hpc3.pbdma[i].addr = (unsigned long)&hpc3c0->pbdma[i];
+ hpc3.pbdma[i].ctrl = hpc3c0->pbdma[i].pbdma_ctrl;
+ hpc3.pbdma[i].cbp = hpc3c0->pbdma[i].pbdma_bptr;
+ hpc3.pbdma[i].ndptr = hpc3c0->pbdma[i].pbdma_dptr;
+ }
+ i = 0;
+ if (gio_err_stat & CPU_ERRMASK)
+ i = gio_err_addr;
+ if (cpu_err_stat & CPU_ERRMASK)
+ i = cpu_err_addr;
+ save_cache_tags(i);
+
+ sgimc->cstat = sgimc->gstat = 0;
+}
+
+static void print_cache_tags(void)
+{
+ u32 scb, scw;
+ int i;
+
+ printk(KERN_ERR "Cache tags @ %08x:\n", (unsigned)cache_tags.err_addr);
+
+ /* PA[31:12] shifted to PTag0 (PA[35:12]) format */
+ scw = (cache_tags.err_addr >> 4) & 0x0fffff00;
+
+ scb = cache_tags.err_addr & ((1 << 12) - 1) & ~((1 << 5) - 1);
+ for (i = 0; i < 4; ++i) { /* for each possible VA[13:12] value */
+ if ((cache_tags.tagd[i][0].lo & 0x0fffff00) != scw &&
+ (cache_tags.tagd[i][1].lo & 0x0fffff00) != scw)
+ continue;
+ printk(KERN_ERR
+ "D: 0: %08x %08x, 1: %08x %08x (VA[13:5] %04x)\n",
+ cache_tags.tagd[i][0].hi, cache_tags.tagd[i][0].lo,
+ cache_tags.tagd[i][1].hi, cache_tags.tagd[i][1].lo,
+ scb | (1 << 12)*i);
+ }
+ scb = cache_tags.err_addr & ((1 << 12) - 1) & ~((1 << 6) - 1);
+ for (i = 0; i < 4; ++i) { /* for each possible VA[13:12] value */
+ if ((cache_tags.tagi[i][0].lo & 0x0fffff00) != scw &&
+ (cache_tags.tagi[i][1].lo & 0x0fffff00) != scw)
+ continue;
+ printk(KERN_ERR
+ "I: 0: %08x %08x, 1: %08x %08x (VA[13:6] %04x)\n",
+ cache_tags.tagi[i][0].hi, cache_tags.tagi[i][0].lo,
+ cache_tags.tagi[i][1].hi, cache_tags.tagi[i][1].lo,
+ scb | (1 << 12)*i);
+ }
+ i = read_c0_config();
+ scb = i & (1 << 13) ? 7:6; /* scblksize = 2^[7..6] */
+ scw = ((i >> 16) & 7) + 19 - 1; /* scwaysize = 2^[24..19] / 2 */
+
+ i = ((1 << scw) - 1) & ~((1 << scb) - 1);
+ printk(KERN_ERR "S: 0: %08x %08x, 1: %08x %08x (PA[%u:%u] %05x)\n",
+ cache_tags.tags[0][0].hi, cache_tags.tags[0][0].lo,
+ cache_tags.tags[0][1].hi, cache_tags.tags[0][1].lo,
+ scw-1, scb, i & (unsigned)cache_tags.err_addr);
+}
+
+static inline const char *cause_excode_text(int cause)
+{
+ static const char *txt[32] =
+ { "Interrupt",
+ "TLB modification",
+ "TLB (load or instruction fetch)",
+ "TLB (store)",
+ "Address error (load or instruction fetch)",
+ "Address error (store)",
+ "Bus error (instruction fetch)",
+ "Bus error (data: load or store)",
+ "Syscall",
+ "Breakpoint",
+ "Reserved instruction",
+ "Coprocessor unusable",
+ "Arithmetic Overflow",
+ "Trap",
+ "14",
+ "Floating-Point",
+ "16", "17", "18", "19", "20", "21", "22",
+ "Watch Hi/Lo",
+ "24", "25", "26", "27", "28", "29", "30", "31",
+ };
+ return txt[(cause & 0x7c) >> 2];
+}
+
+static void print_buserr(const struct pt_regs *regs)
+{
+ const int field = 2 * sizeof(unsigned long);
+ int error = 0;
+
+ if (extio_stat & EXTIO_MC_BUSERR) {
+ printk(KERN_ERR "MC Bus Error\n");
+ error |= 1;
+ }
+ if (extio_stat & EXTIO_HPC3_BUSERR) {
+ printk(KERN_ERR "HPC3 Bus Error 0x%x:<id=0x%x,%s,lane=0x%x>\n",
+ hpc3_berr_stat,
+ (hpc3_berr_stat & HPC3_BESTAT_PIDMASK) >>
+ HPC3_BESTAT_PIDSHIFT,
+ (hpc3_berr_stat & HPC3_BESTAT_CTYPE) ? "PIO" : "DMA",
+ hpc3_berr_stat & HPC3_BESTAT_BLMASK);
+ error |= 2;
+ }
+ if (extio_stat & EXTIO_EISA_BUSERR) {
+ printk(KERN_ERR "EISA Bus Error\n");
+ error |= 4;
+ }
+ if (cpu_err_stat & CPU_ERRMASK) {
+ printk(KERN_ERR "CPU error 0x%x<%s%s%s%s%s%s> @ 0x%08x\n",
+ cpu_err_stat,
+ cpu_err_stat & SGIMC_CSTAT_RD ? "RD " : "",
+ cpu_err_stat & SGIMC_CSTAT_PAR ? "PAR " : "",
+ cpu_err_stat & SGIMC_CSTAT_ADDR ? "ADDR " : "",
+ cpu_err_stat & SGIMC_CSTAT_SYSAD_PAR ? "SYSAD " : "",
+ cpu_err_stat & SGIMC_CSTAT_SYSCMD_PAR ? "SYSCMD " : "",
+ cpu_err_stat & SGIMC_CSTAT_BAD_DATA ? "BAD_DATA " : "",
+ cpu_err_addr);
+ error |= 8;
+ }
+ if (gio_err_stat & GIO_ERRMASK) {
+ printk(KERN_ERR "GIO error 0x%x:<%s%s%s%s%s%s%s%s> @ 0x%08x\n",
+ gio_err_stat,
+ gio_err_stat & SGIMC_GSTAT_RD ? "RD " : "",
+ gio_err_stat & SGIMC_GSTAT_WR ? "WR " : "",
+ gio_err_stat & SGIMC_GSTAT_TIME ? "TIME " : "",
+ gio_err_stat & SGIMC_GSTAT_PROM ? "PROM " : "",
+ gio_err_stat & SGIMC_GSTAT_ADDR ? "ADDR " : "",
+ gio_err_stat & SGIMC_GSTAT_BC ? "BC " : "",
+ gio_err_stat & SGIMC_GSTAT_PIO_RD ? "PIO_RD " : "",
+ gio_err_stat & SGIMC_GSTAT_PIO_WR ? "PIO_WR " : "",
+ gio_err_addr);
+ error |= 16;
+ }
+ if (!error)
+ printk(KERN_ERR "MC: Hmm, didn't find any error condition.\n");
+ else {
+ printk(KERN_ERR "CP0: config %08x, "
+ "MC: cpuctrl0/1: %08x/%05x, giopar: %04x\n"
+ "MC: cpu/gio_memacc: %08x/%05x, memcfg0/1: %08x/%08x\n",
+ read_c0_config(),
+ sgimc->cpuctrl0, sgimc->cpuctrl0, sgimc->giopar,
+ sgimc->cmacc, sgimc->gmacc,
+ sgimc->mconfig0, sgimc->mconfig1);
+ print_cache_tags();
+ }
+ printk(KERN_ALERT "%s, epc == %0*lx, ra == %0*lx\n",
+ cause_excode_text(regs->cp0_cause),
+ field, regs->cp0_epc, field, regs->regs[31]);
+}
+
+/*
+ * Check, whether MC's (virtual) DMA address caused the bus error.
+ * See "Virtual DMA Specification", Draft 1.5, Feb 13 1992, SGI
+ */
+
+static int addr_is_ram(unsigned long addr, unsigned sz)
+{
+ int i;
+
+ for (i = 0; i < boot_mem_map.nr_map; i++) {
+ unsigned long a = boot_mem_map.map[i].addr;
+ if (a <= addr && addr+sz <= a+boot_mem_map.map[i].size)
+ return 1;
+ }
+ return 0;
+}
+
+static int check_microtlb(u32 hi, u32 lo, unsigned long vaddr)
+{
+ /* This is likely rather similar to correct code ;-) */
+
+ vaddr &= 0x7fffffff; /* Doc. states that top bit is ignored */
+
+ /* If tlb-entry is valid and VPN-high (bits [30:21] ?) matches... */
+ if ((lo & 2) && (vaddr >> 21) == ((hi<<1) >> 22)) {
+ u32 ctl = sgimc->dma_ctrl;
+ if (ctl & 1) {
+ unsigned int pgsz = (ctl & 2) ? 14:12; /* 16k:4k */
+ /* PTEIndex is VPN-low (bits [22:14]/[20:12] ?) */
+ unsigned long pte = (lo >> 6) << 12; /* PTEBase */
+ pte += 8*((vaddr >> pgsz) & 0x1ff);
+ if (addr_is_ram(pte, 8)) {
+ /*
+ * Note: Since DMA hardware does look up
+ * translation on its own, this PTE *must*
+ * match the TLB/EntryLo-register format !
+ */
+ unsigned long a = *(unsigned long *)
+ PHYS_TO_XKSEG_UNCACHED(pte);
+ a = (a & 0x3f) << 6; /* PFN */
+ a += vaddr & ((1 << pgsz) - 1);
+ return (cpu_err_addr == a);
+ }
+ }
+ }
+ return 0;
+}
+
+static int check_vdma_memaddr(void)
+{
+ if (cpu_err_stat & CPU_ERRMASK) {
+ u32 a = sgimc->maddronly;
+
+ if (!(sgimc->dma_ctrl & 0x100)) /* Xlate-bit clear ? */
+ return (cpu_err_addr == a);
+
+ if (check_microtlb(sgimc->dtlb_hi0, sgimc->dtlb_lo0, a) ||
+ check_microtlb(sgimc->dtlb_hi1, sgimc->dtlb_lo1, a) ||
+ check_microtlb(sgimc->dtlb_hi2, sgimc->dtlb_lo2, a) ||
+ check_microtlb(sgimc->dtlb_hi3, sgimc->dtlb_lo3, a))
+ return 1;
+ }
+ return 0;
+}
+
+static int check_vdma_gioaddr(void)
+{
+ if (gio_err_stat & GIO_ERRMASK) {
+ u32 a = sgimc->gio_dma_trans;
+ a = (sgimc->gmaddronly & ~a) | (sgimc->gio_dma_sbits & a);
+ return (gio_err_addr == a);
+ }
+ return 0;
+}
+
+/*
+ * MC sends an interrupt whenever bus or parity errors occur. In addition,
+ * if the error happened during a CPU read, it also asserts the bus error
+ * pin on the R4K. Code in bus error handler save the MC bus error registers
+ * and then clear the interrupt when this happens.
+ */
+
+static int ip28_be_interrupt(const struct pt_regs *regs)
+{
+ int i;
+
+ save_and_clear_buserr();
+ /*
+ * Try to find out, whether we got here by a mispredicted speculative
+ * load/store operation. If so, it's not fatal, we can go on.
+ */
+ /* Any cause other than "Interrupt" (ExcCode 0) is fatal. */
+ if (regs->cp0_cause & CAUSEF_EXCCODE)
+ goto mips_be_fatal;
+
+ /* Any cause other than "Bus error interrupt" (IP6) is weird. */
+ if ((regs->cp0_cause & CAUSEF_IP6) != CAUSEF_IP6)
+ goto mips_be_fatal;
+
+ if (extio_stat & (EXTIO_HPC3_BUSERR | EXTIO_EISA_BUSERR))
+ goto mips_be_fatal;
+
+ /* Any state other than "Memory bus error" is fatal. */
+ if (cpu_err_stat & CPU_ERRMASK & ~SGIMC_CSTAT_ADDR)
+ goto mips_be_fatal;
+
+ /* GIO errors other than timeouts are fatal */
+ if (gio_err_stat & GIO_ERRMASK & ~SGIMC_GSTAT_TIME)
+ goto mips_be_fatal;
+
+ /*
+ * Now we have an asynchronous bus error, speculatively or DMA caused.
+ * Need to search all DMA descriptors for the error address.
+ */
+ for (i = 0; i < sizeof(hpc3)/sizeof(struct hpc3_stat); ++i) {
+ struct hpc3_stat *hp = (struct hpc3_stat *)&hpc3 + i;
+ if ((cpu_err_stat & CPU_ERRMASK) &&
+ (cpu_err_addr == hp->ndptr || cpu_err_addr == hp->cbp))
+ break;
+ if ((gio_err_stat & GIO_ERRMASK) &&
+ (gio_err_addr == hp->ndptr || gio_err_addr == hp->cbp))
+ break;
+ }
+ if (i < sizeof(hpc3)/sizeof(struct hpc3_stat)) {
+ struct hpc3_stat *hp = (struct hpc3_stat *)&hpc3 + i;
+ printk(KERN_ERR "at DMA addresses: HPC3 @ %08lx:"
+ " ctl %08x, ndp %08x, cbp %08x\n",
+ CPHYSADDR(hp->addr), hp->ctrl, hp->ndptr, hp->cbp);
+ goto mips_be_fatal;
+ }
+ /* Check MC's virtual DMA stuff. */
+ if (check_vdma_memaddr()) {
+ printk(KERN_ERR "at GIO DMA: mem address 0x%08x.\n",
+ sgimc->maddronly);
+ goto mips_be_fatal;
+ }
+ if (check_vdma_gioaddr()) {
+ printk(KERN_ERR "at GIO DMA: gio address 0x%08x.\n",
+ sgimc->gmaddronly);
+ goto mips_be_fatal;
+ }
+ /* A speculative bus error... */
+ if (debug_be_interrupt) {
+ print_buserr(regs);
+ printk(KERN_ERR "discarded!\n");
+ }
+ return MIPS_BE_DISCARD;
+
+mips_be_fatal:
+ print_buserr(regs);
+ return MIPS_BE_FATAL;
+}
+
+void ip22_be_interrupt(int irq)
+{
+ const struct pt_regs *regs = get_irq_regs();
+
+ count_be_interrupt++;
+
+ if (ip28_be_interrupt(regs) != MIPS_BE_DISCARD) {
+ /* Assume it would be too dangerous to continue ... */
+ die_if_kernel("Oops", regs);
+ force_sig(SIGBUS, current);
+ } else if (debug_be_interrupt)
+ show_regs((struct pt_regs *)regs);
+}
+
+static int ip28_be_handler(struct pt_regs *regs, int is_fixup)
+{
+ /*
+ * We arrive here only in the unusual case of do_be() invocation,
+ * i.e. by a bus error exception without a bus error interrupt.
+ */
+ if (is_fixup) {
+ count_be_is_fixup++;
+ save_and_clear_buserr();
+ return MIPS_BE_FIXUP;
+ }
+ count_be_handler++;
+ return ip28_be_interrupt(regs);
+}
+
+void __init ip22_be_init(void)
+{
+ board_be_handler = ip28_be_handler;
+}
+
+int ip28_show_be_info(struct seq_file *m)
+{
+ seq_printf(m, "IP28 be fixups\t\t: %u\n", count_be_is_fixup);
+ seq_printf(m, "IP28 be interrupts\t: %u\n", count_be_interrupt);
+ seq_printf(m, "IP28 be handler\t\t: %u\n", count_be_handler);
+
+ return 0;
+}
+
+static int __init debug_be_setup(char *str)
+{
+ debug_be_interrupt++;
+ return 1;
+}
+__setup("ip28_debug_be", debug_be_setup);