linux_dsm_epyc7002/arch/powerpc/platforms/pseries/setup.c
Anton Blanchard b878dc0059 powerpc: Use smt_snooze_delay=-1 to always busy loop
Right now if we want to busy loop and not give up any time to the hypervisor
we put a very large value into smt_snooze_delay. This is sometimes useful
when running a single partition and you want to avoid any latencies due
to the hypervisor or CPU power state transitions. While this works, it's a bit
ugly - how big a number is enough now we have NO_HZ and can be idle for a very
long time.

The patch below makes smt_snooze_delay signed, and a negative value means loop
forever:

echo -1 > /sys/devices/system/cpu/cpu0/smt_snooze_delay

This change shouldn't affect the existing userspace tools (eg ppc64_cpu), but
I'm cc-ing Nathan just to be sure.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-05-21 17:31:12 +10:00

632 lines
16 KiB
C

/*
* 64-bit pSeries and RS/6000 setup code.
*
* Copyright (C) 1995 Linus Torvalds
* Adapted from 'alpha' version by Gary Thomas
* Modified by Cort Dougan (cort@cs.nmt.edu)
* Modified by PPC64 Team, IBM Corp
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
/*
* bootup setup stuff..
*/
#include <linux/cpu.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/user.h>
#include <linux/tty.h>
#include <linux/major.h>
#include <linux/interrupt.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/console.h>
#include <linux/pci.h>
#include <linux/utsname.h>
#include <linux/adb.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/seq_file.h>
#include <linux/root_dev.h>
#include <asm/mmu.h>
#include <asm/processor.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/prom.h>
#include <asm/rtas.h>
#include <asm/pci-bridge.h>
#include <asm/iommu.h>
#include <asm/dma.h>
#include <asm/machdep.h>
#include <asm/irq.h>
#include <asm/time.h>
#include <asm/nvram.h>
#include "xics.h"
#include <asm/pmc.h>
#include <asm/mpic.h>
#include <asm/ppc-pci.h>
#include <asm/i8259.h>
#include <asm/udbg.h>
#include <asm/smp.h>
#include <asm/firmware.h>
#include <asm/eeh.h>
#include <asm/pSeries_reconfig.h>
#include "plpar_wrappers.h"
#include "pseries.h"
int CMO_PrPSP = -1;
int CMO_SecPSP = -1;
unsigned long CMO_PageSize = (ASM_CONST(1) << IOMMU_PAGE_SHIFT);
EXPORT_SYMBOL(CMO_PageSize);
int fwnmi_active; /* TRUE if an FWNMI handler is present */
static void pseries_shared_idle_sleep(void);
static void pseries_dedicated_idle_sleep(void);
static struct device_node *pSeries_mpic_node;
static void pSeries_show_cpuinfo(struct seq_file *m)
{
struct device_node *root;
const char *model = "";
root = of_find_node_by_path("/");
if (root)
model = of_get_property(root, "model", NULL);
seq_printf(m, "machine\t\t: CHRP %s\n", model);
of_node_put(root);
}
/* Initialize firmware assisted non-maskable interrupts if
* the firmware supports this feature.
*/
static void __init fwnmi_init(void)
{
unsigned long system_reset_addr, machine_check_addr;
int ibm_nmi_register = rtas_token("ibm,nmi-register");
if (ibm_nmi_register == RTAS_UNKNOWN_SERVICE)
return;
/* If the kernel's not linked at zero we point the firmware at low
* addresses anyway, and use a trampoline to get to the real code. */
system_reset_addr = __pa(system_reset_fwnmi) - PHYSICAL_START;
machine_check_addr = __pa(machine_check_fwnmi) - PHYSICAL_START;
if (0 == rtas_call(ibm_nmi_register, 2, 1, NULL, system_reset_addr,
machine_check_addr))
fwnmi_active = 1;
}
static void pseries_8259_cascade(unsigned int irq, struct irq_desc *desc)
{
unsigned int cascade_irq = i8259_irq();
if (cascade_irq != NO_IRQ)
generic_handle_irq(cascade_irq);
desc->chip->eoi(irq);
}
static void __init pseries_setup_i8259_cascade(void)
{
struct device_node *np, *old, *found = NULL;
unsigned int cascade;
const u32 *addrp;
unsigned long intack = 0;
int naddr;
for_each_node_by_type(np, "interrupt-controller") {
if (of_device_is_compatible(np, "chrp,iic")) {
found = np;
break;
}
}
if (found == NULL) {
printk(KERN_DEBUG "pic: no ISA interrupt controller\n");
return;
}
cascade = irq_of_parse_and_map(found, 0);
if (cascade == NO_IRQ) {
printk(KERN_ERR "pic: failed to map cascade interrupt");
return;
}
pr_debug("pic: cascade mapped to irq %d\n", cascade);
for (old = of_node_get(found); old != NULL ; old = np) {
np = of_get_parent(old);
of_node_put(old);
if (np == NULL)
break;
if (strcmp(np->name, "pci") != 0)
continue;
addrp = of_get_property(np, "8259-interrupt-acknowledge", NULL);
if (addrp == NULL)
continue;
naddr = of_n_addr_cells(np);
intack = addrp[naddr-1];
if (naddr > 1)
intack |= ((unsigned long)addrp[naddr-2]) << 32;
}
if (intack)
printk(KERN_DEBUG "pic: PCI 8259 intack at 0x%016lx\n", intack);
i8259_init(found, intack);
of_node_put(found);
set_irq_chained_handler(cascade, pseries_8259_cascade);
}
static void __init pseries_mpic_init_IRQ(void)
{
struct device_node *np;
const unsigned int *opprop;
unsigned long openpic_addr = 0;
int naddr, n, i, opplen;
struct mpic *mpic;
np = of_find_node_by_path("/");
naddr = of_n_addr_cells(np);
opprop = of_get_property(np, "platform-open-pic", &opplen);
if (opprop != 0) {
openpic_addr = of_read_number(opprop, naddr);
printk(KERN_DEBUG "OpenPIC addr: %lx\n", openpic_addr);
}
of_node_put(np);
BUG_ON(openpic_addr == 0);
/* Setup the openpic driver */
mpic = mpic_alloc(pSeries_mpic_node, openpic_addr,
MPIC_PRIMARY,
16, 250, /* isu size, irq count */
" MPIC ");
BUG_ON(mpic == NULL);
/* Add ISUs */
opplen /= sizeof(u32);
for (n = 0, i = naddr; i < opplen; i += naddr, n++) {
unsigned long isuaddr = of_read_number(opprop + i, naddr);
mpic_assign_isu(mpic, n, isuaddr);
}
/* All ISUs are setup, complete initialization */
mpic_init(mpic);
/* Look for cascade */
pseries_setup_i8259_cascade();
}
static void __init pseries_xics_init_IRQ(void)
{
xics_init_IRQ();
pseries_setup_i8259_cascade();
}
static void pseries_lpar_enable_pmcs(void)
{
unsigned long set, reset;
set = 1UL << 63;
reset = 0;
plpar_hcall_norets(H_PERFMON, set, reset);
}
static void __init pseries_discover_pic(void)
{
struct device_node *np;
const char *typep;
for (np = NULL; (np = of_find_node_by_name(np,
"interrupt-controller"));) {
typep = of_get_property(np, "compatible", NULL);
if (strstr(typep, "open-pic")) {
pSeries_mpic_node = of_node_get(np);
ppc_md.init_IRQ = pseries_mpic_init_IRQ;
ppc_md.get_irq = mpic_get_irq;
setup_kexec_cpu_down_mpic();
smp_init_pseries_mpic();
return;
} else if (strstr(typep, "ppc-xicp")) {
ppc_md.init_IRQ = pseries_xics_init_IRQ;
setup_kexec_cpu_down_xics();
smp_init_pseries_xics();
return;
}
}
printk(KERN_ERR "pSeries_discover_pic: failed to recognize"
" interrupt-controller\n");
}
static int pci_dn_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *node)
{
struct device_node *np = node;
struct pci_dn *pci = NULL;
int err = NOTIFY_OK;
switch (action) {
case PSERIES_RECONFIG_ADD:
pci = np->parent->data;
if (pci)
update_dn_pci_info(np, pci->phb);
break;
default:
err = NOTIFY_DONE;
break;
}
return err;
}
static struct notifier_block pci_dn_reconfig_nb = {
.notifier_call = pci_dn_reconfig_notifier,
};
static void __init pSeries_setup_arch(void)
{
/* Discover PIC type and setup ppc_md accordingly */
pseries_discover_pic();
/* openpic global configuration register (64-bit format). */
/* openpic Interrupt Source Unit pointer (64-bit format). */
/* python0 facility area (mmio) (64-bit format) REAL address. */
/* init to some ~sane value until calibrate_delay() runs */
loops_per_jiffy = 50000000;
fwnmi_init();
/* Find and initialize PCI host bridges */
init_pci_config_tokens();
find_and_init_phbs();
pSeries_reconfig_notifier_register(&pci_dn_reconfig_nb);
eeh_init();
pSeries_nvram_init();
/* Choose an idle loop */
if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
vpa_init(boot_cpuid);
if (get_lppaca()->shared_proc) {
printk(KERN_DEBUG "Using shared processor idle loop\n");
ppc_md.power_save = pseries_shared_idle_sleep;
} else {
printk(KERN_DEBUG "Using dedicated idle loop\n");
ppc_md.power_save = pseries_dedicated_idle_sleep;
}
} else {
printk(KERN_DEBUG "Using default idle loop\n");
}
if (firmware_has_feature(FW_FEATURE_LPAR))
ppc_md.enable_pmcs = pseries_lpar_enable_pmcs;
else
ppc_md.enable_pmcs = power4_enable_pmcs;
}
static int __init pSeries_init_panel(void)
{
/* Manually leave the kernel version on the panel. */
ppc_md.progress("Linux ppc64\n", 0);
ppc_md.progress(init_utsname()->version, 0);
return 0;
}
arch_initcall(pSeries_init_panel);
static int pseries_set_dabr(unsigned long dabr)
{
return plpar_hcall_norets(H_SET_DABR, dabr);
}
static int pseries_set_xdabr(unsigned long dabr)
{
/* We want to catch accesses from kernel and userspace */
return plpar_hcall_norets(H_SET_XDABR, dabr,
H_DABRX_KERNEL | H_DABRX_USER);
}
#define CMO_CHARACTERISTICS_TOKEN 44
#define CMO_MAXLENGTH 1026
/**
* fw_cmo_feature_init - FW_FEATURE_CMO is not stored in ibm,hypertas-functions,
* handle that here. (Stolen from parse_system_parameter_string)
*/
void pSeries_cmo_feature_init(void)
{
char *ptr, *key, *value, *end;
int call_status;
int page_order = IOMMU_PAGE_SHIFT;
pr_debug(" -> fw_cmo_feature_init()\n");
spin_lock(&rtas_data_buf_lock);
memset(rtas_data_buf, 0, RTAS_DATA_BUF_SIZE);
call_status = rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1,
NULL,
CMO_CHARACTERISTICS_TOKEN,
__pa(rtas_data_buf),
RTAS_DATA_BUF_SIZE);
if (call_status != 0) {
spin_unlock(&rtas_data_buf_lock);
pr_debug("CMO not available\n");
pr_debug(" <- fw_cmo_feature_init()\n");
return;
}
end = rtas_data_buf + CMO_MAXLENGTH - 2;
ptr = rtas_data_buf + 2; /* step over strlen value */
key = value = ptr;
while (*ptr && (ptr <= end)) {
/* Separate the key and value by replacing '=' with '\0' and
* point the value at the string after the '='
*/
if (ptr[0] == '=') {
ptr[0] = '\0';
value = ptr + 1;
} else if (ptr[0] == '\0' || ptr[0] == ',') {
/* Terminate the string containing the key/value pair */
ptr[0] = '\0';
if (key == value) {
pr_debug("Malformed key/value pair\n");
/* Never found a '=', end processing */
break;
}
if (0 == strcmp(key, "CMOPageSize"))
page_order = simple_strtol(value, NULL, 10);
else if (0 == strcmp(key, "PrPSP"))
CMO_PrPSP = simple_strtol(value, NULL, 10);
else if (0 == strcmp(key, "SecPSP"))
CMO_SecPSP = simple_strtol(value, NULL, 10);
value = key = ptr + 1;
}
ptr++;
}
/* Page size is returned as the power of 2 of the page size,
* convert to the page size in bytes before returning
*/
CMO_PageSize = 1 << page_order;
pr_debug("CMO_PageSize = %lu\n", CMO_PageSize);
if (CMO_PrPSP != -1 || CMO_SecPSP != -1) {
pr_info("CMO enabled\n");
pr_debug("CMO enabled, PrPSP=%d, SecPSP=%d\n", CMO_PrPSP,
CMO_SecPSP);
powerpc_firmware_features |= FW_FEATURE_CMO;
} else
pr_debug("CMO not enabled, PrPSP=%d, SecPSP=%d\n", CMO_PrPSP,
CMO_SecPSP);
spin_unlock(&rtas_data_buf_lock);
pr_debug(" <- fw_cmo_feature_init()\n");
}
/*
* Early initialization. Relocation is on but do not reference unbolted pages
*/
static void __init pSeries_init_early(void)
{
pr_debug(" -> pSeries_init_early()\n");
if (firmware_has_feature(FW_FEATURE_LPAR))
find_udbg_vterm();
if (firmware_has_feature(FW_FEATURE_DABR))
ppc_md.set_dabr = pseries_set_dabr;
else if (firmware_has_feature(FW_FEATURE_XDABR))
ppc_md.set_dabr = pseries_set_xdabr;
pSeries_cmo_feature_init();
iommu_init_early_pSeries();
pr_debug(" <- pSeries_init_early()\n");
}
/*
* Called very early, MMU is off, device-tree isn't unflattened
*/
static int __init pSeries_probe_hypertas(unsigned long node,
const char *uname, int depth,
void *data)
{
const char *hypertas;
unsigned long len;
if (depth != 1 ||
(strcmp(uname, "rtas") != 0 && strcmp(uname, "rtas@0") != 0))
return 0;
hypertas = of_get_flat_dt_prop(node, "ibm,hypertas-functions", &len);
if (!hypertas)
return 1;
powerpc_firmware_features |= FW_FEATURE_LPAR;
fw_feature_init(hypertas, len);
return 1;
}
static int __init pSeries_probe(void)
{
unsigned long root = of_get_flat_dt_root();
char *dtype = of_get_flat_dt_prop(root, "device_type", NULL);
if (dtype == NULL)
return 0;
if (strcmp(dtype, "chrp"))
return 0;
/* Cell blades firmware claims to be chrp while it's not. Until this
* is fixed, we need to avoid those here.
*/
if (of_flat_dt_is_compatible(root, "IBM,CPBW-1.0") ||
of_flat_dt_is_compatible(root, "IBM,CBEA"))
return 0;
pr_debug("pSeries detected, looking for LPAR capability...\n");
/* Now try to figure out if we are running on LPAR */
of_scan_flat_dt(pSeries_probe_hypertas, NULL);
if (firmware_has_feature(FW_FEATURE_LPAR))
hpte_init_lpar();
else
hpte_init_native();
pr_debug("Machine is%s LPAR !\n",
(powerpc_firmware_features & FW_FEATURE_LPAR) ? "" : " not");
return 1;
}
DECLARE_PER_CPU(long, smt_snooze_delay);
static void pseries_dedicated_idle_sleep(void)
{
unsigned int cpu = smp_processor_id();
unsigned long start_snooze;
unsigned long in_purr, out_purr;
long snooze = __get_cpu_var(smt_snooze_delay);
/*
* Indicate to the HV that we are idle. Now would be
* a good time to find other work to dispatch.
*/
get_lppaca()->idle = 1;
get_lppaca()->donate_dedicated_cpu = 1;
in_purr = mfspr(SPRN_PURR);
/*
* We come in with interrupts disabled, and need_resched()
* has been checked recently. If we should poll for a little
* while, do so.
*/
if (snooze) {
start_snooze = get_tb() + snooze * tb_ticks_per_usec;
local_irq_enable();
set_thread_flag(TIF_POLLING_NRFLAG);
while ((snooze < 0) || (get_tb() < start_snooze)) {
if (need_resched() || cpu_is_offline(cpu))
goto out;
ppc64_runlatch_off();
HMT_low();
HMT_very_low();
}
HMT_medium();
clear_thread_flag(TIF_POLLING_NRFLAG);
smp_mb();
local_irq_disable();
if (need_resched() || cpu_is_offline(cpu))
goto out;
}
cede_processor();
out:
HMT_medium();
out_purr = mfspr(SPRN_PURR);
get_lppaca()->wait_state_cycles += out_purr - in_purr;
get_lppaca()->donate_dedicated_cpu = 0;
get_lppaca()->idle = 0;
}
static void pseries_shared_idle_sleep(void)
{
/*
* Indicate to the HV that we are idle. Now would be
* a good time to find other work to dispatch.
*/
get_lppaca()->idle = 1;
/*
* Yield the processor to the hypervisor. We return if
* an external interrupt occurs (which are driven prior
* to returning here) or if a prod occurs from another
* processor. When returning here, external interrupts
* are enabled.
*/
cede_processor();
get_lppaca()->idle = 0;
}
static int pSeries_pci_probe_mode(struct pci_bus *bus)
{
if (firmware_has_feature(FW_FEATURE_LPAR))
return PCI_PROBE_DEVTREE;
return PCI_PROBE_NORMAL;
}
/**
* pSeries_power_off - tell firmware about how to power off the system.
*
* This function calls either the power-off rtas token in normal cases
* or the ibm,power-off-ups token (if present & requested) in case of
* a power failure. If power-off token is used, power on will only be
* possible with power button press. If ibm,power-off-ups token is used
* it will allow auto poweron after power is restored.
*/
static void pSeries_power_off(void)
{
int rc;
int rtas_poweroff_ups_token = rtas_token("ibm,power-off-ups");
if (rtas_flash_term_hook)
rtas_flash_term_hook(SYS_POWER_OFF);
if (rtas_poweron_auto == 0 ||
rtas_poweroff_ups_token == RTAS_UNKNOWN_SERVICE) {
rc = rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1);
printk(KERN_INFO "RTAS power-off returned %d\n", rc);
} else {
rc = rtas_call(rtas_poweroff_ups_token, 0, 1, NULL);
printk(KERN_INFO "RTAS ibm,power-off-ups returned %d\n", rc);
}
for (;;);
}
#ifndef CONFIG_PCI
void pSeries_final_fixup(void) { }
#endif
define_machine(pseries) {
.name = "pSeries",
.probe = pSeries_probe,
.setup_arch = pSeries_setup_arch,
.init_early = pSeries_init_early,
.show_cpuinfo = pSeries_show_cpuinfo,
.log_error = pSeries_log_error,
.pcibios_fixup = pSeries_final_fixup,
.pci_probe_mode = pSeries_pci_probe_mode,
.restart = rtas_restart,
.power_off = pSeries_power_off,
.halt = rtas_halt,
.panic = rtas_os_term,
.get_boot_time = rtas_get_boot_time,
.get_rtc_time = rtas_get_rtc_time,
.set_rtc_time = rtas_set_rtc_time,
.calibrate_decr = generic_calibrate_decr,
.progress = rtas_progress,
.system_reset_exception = pSeries_system_reset_exception,
.machine_check_exception = pSeries_machine_check_exception,
};