void __init check_wait(void)
{
struct cpuinfo_mips *c = ¤t_cpu_data;
if (nowait) {
printk("Wait instruction disabled.\n");
return;
}
switch (current_cpu_type()) {
case CPU_R3081:
case CPU_R3081E:
cpu_wait = r3081_wait;
break;
case CPU_TX3927:
cpu_wait = r39xx_wait;
break;
case CPU_R4200:
/* case CPU_R4300: */
case CPU_R4600:
case CPU_R4640:
case CPU_R4650:
case CPU_R4700:
case CPU_R5000:
case CPU_R5500:
case CPU_NEVADA:
case CPU_4KC:
case CPU_4KEC:
case CPU_4KSC:
case CPU_5KC:
case CPU_25KF:
case CPU_PR4450:
case CPU_BMIPS3300:
case CPU_BMIPS4350:
case CPU_BMIPS4380:
case CPU_BMIPS5000:
case CPU_CAVIUM_OCTEON:
case CPU_CAVIUM_OCTEON_PLUS:
case CPU_CAVIUM_OCTEON2:
case CPU_CAVIUM_OCTEON3:
case CPU_JZRISC:
case CPU_LOONGSON1:
case CPU_XLR:
case CPU_XLP:
cpu_wait = r4k_wait;
break;
case CPU_RM7000:
cpu_wait = rm7k_wait_irqoff;
break;
case CPU_PROAPTIV:
case CPU_P5600:
/*
* Incoming Fast Debug Channel (FDC) data during a wait
* instruction causes the wait never to resume, even if an
* interrupt is received. Avoid using wait at all if FDC data is
* likely to be received.
*/
if (IS_ENABLED(CONFIG_MIPS_EJTAG_FDC_TTY))
break;
/* fall through */
case CPU_M14KC:
case CPU_M14KEC:
case CPU_24K:
case CPU_34K:
case CPU_1004K:
case CPU_1074K:
case CPU_INTERAPTIV:
case CPU_M5150:
case CPU_QEMU_GENERIC:
cpu_wait = r4k_wait;
if (read_c0_config7() & MIPS_CONF7_WII)
cpu_wait = r4k_wait_irqoff;
break;
case CPU_74K:
cpu_wait = r4k_wait;
if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
cpu_wait = r4k_wait_irqoff;
break;
case CPU_TX49XX:
cpu_wait = r4k_wait_irqoff;
break;
case CPU_ALCHEMY:
cpu_wait = au1k_wait;
break;
case CPU_20KC:
/*
* WAIT on Rev1.0 has E1, E2, E3 and E16.
* WAIT on Rev2.0 and Rev3.0 has E16.
* Rev3.1 WAIT is nop, why bother
*/
if ((c->processor_id & 0xff) <= 0x64)
break;
/*
* Another rev is incremeting c0_count at a reduced clock
* rate while in WAIT mode. So we basically have the choice
* between using the cp0 timer as clocksource or avoiding
* the WAIT instruction. Until more details are known,
* disable the use of WAIT for 20Kc entirely.
cpu_wait = r4k_wait;
*/
break;
default:
break;
}
}
static int __init cps_gen_flush_fsb(u32 **pp, struct uasm_label **pl,
struct uasm_reloc **pr,
const struct cpuinfo_mips *cpu_info,
int lbl)
{
unsigned i, fsb_size = 8;
unsigned num_loads = (fsb_size * 3) / 2;
unsigned line_stride = 2;
unsigned line_size = cpu_info->dcache.linesz;
unsigned perf_counter, perf_event;
unsigned revision = cpu_info->processor_id & PRID_REV_MASK;
/*
* Determine whether this CPU requires an FSB flush, and if so which
* performance counter/event reflect stalls due to a full FSB.
*/
switch (__get_cpu_type(cpu_info->cputype)) {
case CPU_INTERAPTIV:
perf_counter = 1;
perf_event = 51;
break;
case CPU_PROAPTIV:
/* Newer proAptiv cores don't require this workaround */
if (revision >= PRID_REV_ENCODE_332(1, 1, 0))
return 0;
/* On older ones it's unavailable */
return -1;
/* CPUs which do not require the workaround */
case CPU_P5600:
case CPU_I6400:
return 0;
default:
WARN_ONCE(1, "pm-cps: FSB flush unsupported for this CPU\n");
return -1;
}
/*
* Ensure that the fill/store buffer (FSB) is not holding the results
* of a prefetch, since if it is then the CPC sequencer may become
* stuck in the D3 (ClrBus) state whilst entering a low power state.
*/
/* Preserve perf counter setup */
uasm_i_mfc0(pp, t2, 25, (perf_counter * 2) + 0); /* PerfCtlN */
uasm_i_mfc0(pp, t3, 25, (perf_counter * 2) + 1); /* PerfCntN */
/* Setup perf counter to count FSB full pipeline stalls */
uasm_i_addiu(pp, t0, zero, (perf_event << 5) | 0xf);
uasm_i_mtc0(pp, t0, 25, (perf_counter * 2) + 0); /* PerfCtlN */
uasm_i_ehb(pp);
uasm_i_mtc0(pp, zero, 25, (perf_counter * 2) + 1); /* PerfCntN */
uasm_i_ehb(pp);
/* Base address for loads */
UASM_i_LA(pp, t0, (long)CKSEG0);
/* Start of clear loop */
uasm_build_label(pl, *pp, lbl);
/* Perform some loads to fill the FSB */
for (i = 0; i < num_loads; i++)
uasm_i_lw(pp, zero, i * line_size * line_stride, t0);
/*
* Invalidate the new D-cache entries so that the cache will need
* refilling (via the FSB) if the loop is executed again.
*/
for (i = 0; i < num_loads; i++) {
uasm_i_cache(pp, Hit_Invalidate_D,
i * line_size * line_stride, t0);
uasm_i_cache(pp, Hit_Writeback_Inv_SD,
i * line_size * line_stride, t0);
}
/* Completion barrier */
uasm_i_sync(pp, stype_memory);
uasm_i_ehb(pp);
/* Check whether the pipeline stalled due to the FSB being full */
uasm_i_mfc0(pp, t1, 25, (perf_counter * 2) + 1); /* PerfCntN */
/* Loop if it didn't */
uasm_il_beqz(pp, pr, t1, lbl);
uasm_i_nop(pp);
/* Restore perf counter 1. The count may well now be wrong... */
uasm_i_mtc0(pp, t2, 25, (perf_counter * 2) + 0); /* PerfCtlN */
uasm_i_ehb(pp);
uasm_i_mtc0(pp, t3, 25, (perf_counter * 2) + 1); /* PerfCntN */
uasm_i_ehb(pp);
return 0;
}
