// SPDX-License-Identifier: GPL-2.0
/*
* ip28-berr.c: Bus error handling.
*
* Copyright (C) 2002, 2003 Ladislav Michl ([email protected])
* Copyright (C) 2005 Peter Fuerst ([email protected]) - IP28
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/signal.h>
#include <linux/seq_file.h>
#include <asm/addrspace.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 <linux/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]);
}
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 (page_is_ram(PFN_DOWN(pte))) {
/*
* 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)
{
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);
} else if (debug_be_interrupt)
show_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)
{
mips_set_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);
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