freebsd-dev/sys/arm64/arm64/mp_machdep.c
Andrew Turner d6a0af236d In ARMv8.1 ARM has added a process state bit to disable access to userspace
from the kernel. Make use of this to restrict accessing userspace to just
the functions that explicitly handle crossing the user kernel boundary.

Reported by:	kib
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D10371
2017-04-13 13:46:01 +00:00

839 lines
18 KiB
C

/*-
* Copyright (c) 2015-2016 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Andrew Turner under
* sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include "opt_acpi.h"
#include "opt_kstack_pages.h"
#include "opt_platform.h"
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
#include <vm/vm_kern.h>
#include <machine/debug_monitor.h>
#include <machine/machdep.h>
#include <machine/intr.h>
#include <machine/smp.h>
#ifdef VFP
#include <machine/vfp.h>
#endif
#ifdef DEV_ACPI
#include <contrib/dev/acpica/include/acpi.h>
#include <dev/acpica/acpivar.h>
#endif
#ifdef FDT
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_cpu.h>
#endif
#include <dev/psci/psci.h>
#include "pic_if.h"
typedef void intr_ipi_send_t(void *, cpuset_t, u_int);
typedef void intr_ipi_handler_t(void *);
#define INTR_IPI_NAMELEN (MAXCOMLEN + 1)
struct intr_ipi {
intr_ipi_handler_t * ii_handler;
void * ii_handler_arg;
intr_ipi_send_t * ii_send;
void * ii_send_arg;
char ii_name[INTR_IPI_NAMELEN];
u_long * ii_count;
};
static struct intr_ipi ipi_sources[INTR_IPI_COUNT];
static struct intr_ipi *intr_ipi_lookup(u_int);
static void intr_pic_ipi_setup(u_int, const char *, intr_ipi_handler_t *,
void *);
extern struct pcpu __pcpu[];
static device_identify_t arm64_cpu_identify;
static device_probe_t arm64_cpu_probe;
static device_attach_t arm64_cpu_attach;
static void ipi_ast(void *);
static void ipi_hardclock(void *);
static void ipi_preempt(void *);
static void ipi_rendezvous(void *);
static void ipi_stop(void *);
struct mtx ap_boot_mtx;
struct pcb stoppcbs[MAXCPU];
static device_t cpu_list[MAXCPU];
/*
* Not all systems boot from the first CPU in the device tree. To work around
* this we need to find which CPU we have booted from so when we later
* enable the secondary CPUs we skip this one.
*/
static int cpu0 = -1;
void mpentry(unsigned long cpuid);
void init_secondary(uint64_t);
uint8_t secondary_stacks[MAXCPU - 1][PAGE_SIZE * KSTACK_PAGES] __aligned(16);
/* Set to 1 once we're ready to let the APs out of the pen. */
volatile int aps_ready = 0;
/* Temporary variables for init_secondary() */
void *dpcpu[MAXCPU - 1];
static device_method_t arm64_cpu_methods[] = {
/* Device interface */
DEVMETHOD(device_identify, arm64_cpu_identify),
DEVMETHOD(device_probe, arm64_cpu_probe),
DEVMETHOD(device_attach, arm64_cpu_attach),
DEVMETHOD_END
};
static devclass_t arm64_cpu_devclass;
static driver_t arm64_cpu_driver = {
"arm64_cpu",
arm64_cpu_methods,
0
};
DRIVER_MODULE(arm64_cpu, cpu, arm64_cpu_driver, arm64_cpu_devclass, 0, 0);
static void
arm64_cpu_identify(driver_t *driver, device_t parent)
{
if (device_find_child(parent, "arm64_cpu", -1) != NULL)
return;
if (BUS_ADD_CHILD(parent, 0, "arm64_cpu", -1) == NULL)
device_printf(parent, "add child failed\n");
}
static int
arm64_cpu_probe(device_t dev)
{
u_int cpuid;
cpuid = device_get_unit(dev);
if (cpuid >= MAXCPU || cpuid > mp_maxid)
return (EINVAL);
device_quiet(dev);
return (0);
}
static int
arm64_cpu_attach(device_t dev)
{
const uint32_t *reg;
size_t reg_size;
u_int cpuid;
int i;
cpuid = device_get_unit(dev);
if (cpuid >= MAXCPU || cpuid > mp_maxid)
return (EINVAL);
KASSERT(cpu_list[cpuid] == NULL, ("Already have cpu %u", cpuid));
reg = cpu_get_cpuid(dev, &reg_size);
if (reg == NULL)
return (EINVAL);
if (bootverbose) {
device_printf(dev, "register <");
for (i = 0; i < reg_size; i++)
printf("%s%x", (i == 0) ? "" : " ", reg[i]);
printf(">\n");
}
/* Set the device to start it later */
cpu_list[cpuid] = dev;
return (0);
}
static void
release_aps(void *dummy __unused)
{
int i;
/* Only release CPUs if they exist */
if (mp_ncpus == 1)
return;
intr_pic_ipi_setup(IPI_AST, "ast", ipi_ast, NULL);
intr_pic_ipi_setup(IPI_PREEMPT, "preempt", ipi_preempt, NULL);
intr_pic_ipi_setup(IPI_RENDEZVOUS, "rendezvous", ipi_rendezvous, NULL);
intr_pic_ipi_setup(IPI_STOP, "stop", ipi_stop, NULL);
intr_pic_ipi_setup(IPI_STOP_HARD, "stop hard", ipi_stop, NULL);
intr_pic_ipi_setup(IPI_HARDCLOCK, "hardclock", ipi_hardclock, NULL);
atomic_store_rel_int(&aps_ready, 1);
/* Wake up the other CPUs */
__asm __volatile("sev");
printf("Release APs\n");
for (i = 0; i < 2000; i++) {
if (smp_started)
return;
DELAY(1000);
}
printf("APs not started\n");
}
SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, release_aps, NULL);
void
init_secondary(uint64_t cpu)
{
struct pcpu *pcpup;
pcpup = &__pcpu[cpu];
/*
* Set the pcpu pointer with a backup in tpidr_el1 to be
* loaded when entering the kernel from userland.
*/
__asm __volatile(
"mov x18, %0 \n"
"msr tpidr_el1, %0" :: "r"(pcpup));
/* Spin until the BSP releases the APs */
while (!aps_ready)
__asm __volatile("wfe");
/* Initialize curthread */
KASSERT(PCPU_GET(idlethread) != NULL, ("no idle thread"));
pcpup->pc_curthread = pcpup->pc_idlethread;
pcpup->pc_curpcb = pcpup->pc_idlethread->td_pcb;
/*
* Identify current CPU. This is necessary to setup
* affinity registers and to provide support for
* runtime chip identification.
*/
identify_cpu();
intr_pic_init_secondary();
/* Start per-CPU event timers. */
cpu_initclocks_ap();
#ifdef VFP
vfp_init();
#endif
dbg_monitor_init();
pan_enable();
/* Enable interrupts */
intr_enable();
mtx_lock_spin(&ap_boot_mtx);
atomic_add_rel_32(&smp_cpus, 1);
if (smp_cpus == mp_ncpus) {
/* enable IPI's, tlb shootdown, freezes etc */
atomic_store_rel_int(&smp_started, 1);
}
mtx_unlock_spin(&ap_boot_mtx);
/* Enter the scheduler */
sched_throw(NULL);
panic("scheduler returned us to init_secondary");
/* NOTREACHED */
}
/*
* Send IPI thru interrupt controller.
*/
static void
pic_ipi_send(void *arg, cpuset_t cpus, u_int ipi)
{
KASSERT(intr_irq_root_dev != NULL, ("%s: no root attached", __func__));
PIC_IPI_SEND(intr_irq_root_dev, arg, cpus, ipi);
}
/*
* Setup IPI handler on interrupt controller.
*
* Not SMP coherent.
*/
static void
intr_pic_ipi_setup(u_int ipi, const char *name, intr_ipi_handler_t *hand,
void *arg)
{
struct intr_irqsrc *isrc;
struct intr_ipi *ii;
int error;
KASSERT(intr_irq_root_dev != NULL, ("%s: no root attached", __func__));
KASSERT(hand != NULL, ("%s: ipi %u no handler", __func__, ipi));
error = PIC_IPI_SETUP(intr_irq_root_dev, ipi, &isrc);
if (error != 0)
return;
isrc->isrc_handlers++;
ii = intr_ipi_lookup(ipi);
KASSERT(ii->ii_count == NULL, ("%s: ipi %u reused", __func__, ipi));
ii->ii_handler = hand;
ii->ii_handler_arg = arg;
ii->ii_send = pic_ipi_send;
ii->ii_send_arg = isrc;
strlcpy(ii->ii_name, name, INTR_IPI_NAMELEN);
ii->ii_count = intr_ipi_setup_counters(name);
}
static void
intr_ipi_send(cpuset_t cpus, u_int ipi)
{
struct intr_ipi *ii;
ii = intr_ipi_lookup(ipi);
if (ii->ii_count == NULL)
panic("%s: not setup IPI %u", __func__, ipi);
ii->ii_send(ii->ii_send_arg, cpus, ipi);
}
static void
ipi_ast(void *dummy __unused)
{
CTR0(KTR_SMP, "IPI_AST");
}
static void
ipi_hardclock(void *dummy __unused)
{
CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
hardclockintr();
}
static void
ipi_preempt(void *dummy __unused)
{
CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
sched_preempt(curthread);
}
static void
ipi_rendezvous(void *dummy __unused)
{
CTR0(KTR_SMP, "IPI_RENDEZVOUS");
smp_rendezvous_action();
}
static void
ipi_stop(void *dummy __unused)
{
u_int cpu;
CTR0(KTR_SMP, "IPI_STOP");
cpu = PCPU_GET(cpuid);
savectx(&stoppcbs[cpu]);
/* Indicate we are stopped */
CPU_SET_ATOMIC(cpu, &stopped_cpus);
/* Wait for restart */
while (!CPU_ISSET(cpu, &started_cpus))
cpu_spinwait();
CPU_CLR_ATOMIC(cpu, &started_cpus);
CPU_CLR_ATOMIC(cpu, &stopped_cpus);
CTR0(KTR_SMP, "IPI_STOP (restart)");
}
struct cpu_group *
cpu_topo(void)
{
return (smp_topo_none());
}
/* Determine if we running MP machine */
int
cpu_mp_probe(void)
{
/* ARM64TODO: Read the u bit of mpidr_el1 to determine this */
return (1);
}
static bool
start_cpu(u_int id, uint64_t target_cpu)
{
struct pcpu *pcpup;
vm_paddr_t pa;
u_int cpuid;
int err;
/* Check we are able to start this cpu */
if (id > mp_maxid)
return (false);
KASSERT(id < MAXCPU, ("Too many CPUs"));
/* We are already running on cpu 0 */
if (id == cpu0)
return (true);
/*
* Rotate the CPU IDs to put the boot CPU as CPU 0. We keep the other
* CPUs ordered as the are likely grouped into clusters so it can be
* useful to keep that property, e.g. for the GICv3 driver to send
* an IPI to all CPUs in the cluster.
*/
cpuid = id;
if (cpuid < cpu0)
cpuid += mp_maxid + 1;
cpuid -= cpu0;
pcpup = &__pcpu[cpuid];
pcpu_init(pcpup, cpuid, sizeof(struct pcpu));
dpcpu[cpuid - 1] = (void *)kmem_malloc(kernel_arena, DPCPU_SIZE,
M_WAITOK | M_ZERO);
dpcpu_init(dpcpu[cpuid - 1], cpuid);
printf("Starting CPU %u (%lx)\n", cpuid, target_cpu);
pa = pmap_extract(kernel_pmap, (vm_offset_t)mpentry);
err = psci_cpu_on(target_cpu, pa, cpuid);
if (err != PSCI_RETVAL_SUCCESS) {
/*
* Panic here if INVARIANTS are enabled and PSCI failed to
* start the requested CPU. If psci_cpu_on returns PSCI_MISSING
* to indicate we are unable to use it to start the given CPU.
*/
KASSERT(err == PSCI_MISSING,
("Failed to start CPU %u (%lx)\n", id, target_cpu));
pcpu_destroy(pcpup);
kmem_free(kernel_arena, (vm_offset_t)dpcpu[cpuid - 1],
DPCPU_SIZE);
dpcpu[cpuid - 1] = NULL;
/* Notify the user that the CPU failed to start */
printf("Failed to start CPU %u (%lx)\n", id, target_cpu);
} else
CPU_SET(cpuid, &all_cpus);
return (true);
}
#ifdef DEV_ACPI
static void
madt_handler(ACPI_SUBTABLE_HEADER *entry, void *arg)
{
ACPI_MADT_GENERIC_INTERRUPT *intr;
u_int *cpuid;
switch(entry->Type) {
case ACPI_MADT_TYPE_GENERIC_INTERRUPT:
intr = (ACPI_MADT_GENERIC_INTERRUPT *)entry;
cpuid = arg;
start_cpu((*cpuid), intr->ArmMpidr);
(*cpuid)++;
break;
default:
break;
}
}
static void
cpu_init_acpi(void)
{
ACPI_TABLE_MADT *madt;
vm_paddr_t physaddr;
u_int cpuid;
physaddr = acpi_find_table(ACPI_SIG_MADT);
if (physaddr == 0)
return;
madt = acpi_map_table(physaddr, ACPI_SIG_MADT);
if (madt == NULL) {
printf("Unable to map the MADT, not starting APs\n");
return;
}
cpuid = 0;
acpi_walk_subtables(madt + 1, (char *)madt + madt->Header.Length,
madt_handler, &cpuid);
acpi_unmap_table(madt);
}
#endif
#ifdef FDT
static boolean_t
cpu_init_fdt(u_int id, phandle_t node, u_int addr_size, pcell_t *reg)
{
uint64_t target_cpu;
target_cpu = reg[0];
if (addr_size == 2) {
target_cpu <<= 32;
target_cpu |= reg[1];
}
return (start_cpu(id, target_cpu) ? TRUE : FALSE);
}
#endif
/* Initialize and fire up non-boot processors */
void
cpu_mp_start(void)
{
mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
CPU_SET(0, &all_cpus);
switch(arm64_bus_method) {
#ifdef DEV_ACPI
case ARM64_BUS_ACPI:
KASSERT(cpu0 >= 0, ("Current CPU was not found"));
cpu_init_acpi();
break;
#endif
#ifdef FDT
case ARM64_BUS_FDT:
KASSERT(cpu0 >= 0, ("Current CPU was not found"));
ofw_cpu_early_foreach(cpu_init_fdt, true);
break;
#endif
default:
break;
}
}
/* Introduce rest of cores to the world */
void
cpu_mp_announce(void)
{
}
#ifdef DEV_ACPI
static void
cpu_count_acpi_handler(ACPI_SUBTABLE_HEADER *entry, void *arg)
{
ACPI_MADT_GENERIC_INTERRUPT *intr;
u_int *cores = arg;
uint64_t mpidr_reg;
switch(entry->Type) {
case ACPI_MADT_TYPE_GENERIC_INTERRUPT:
intr = (ACPI_MADT_GENERIC_INTERRUPT *)entry;
if (cpu0 < 0) {
mpidr_reg = READ_SPECIALREG(mpidr_el1);
if ((mpidr_reg & 0xff00fffffful) == intr->ArmMpidr)
cpu0 = *cores;
}
(*cores)++;
break;
default:
break;
}
}
static u_int
cpu_count_acpi(void)
{
ACPI_TABLE_MADT *madt;
vm_paddr_t physaddr;
u_int cores;
physaddr = acpi_find_table(ACPI_SIG_MADT);
if (physaddr == 0)
return (0);
madt = acpi_map_table(physaddr, ACPI_SIG_MADT);
if (madt == NULL) {
printf("Unable to map the MADT, not starting APs\n");
return (0);
}
cores = 0;
acpi_walk_subtables(madt + 1, (char *)madt + madt->Header.Length,
cpu_count_acpi_handler, &cores);
acpi_unmap_table(madt);
return (cores);
}
#endif
#ifdef FDT
static boolean_t
cpu_find_cpu0_fdt(u_int id, phandle_t node, u_int addr_size, pcell_t *reg)
{
uint64_t mpidr_fdt, mpidr_reg;
if (cpu0 < 0) {
mpidr_fdt = reg[0];
if (addr_size == 2) {
mpidr_fdt <<= 32;
mpidr_fdt |= reg[1];
}
mpidr_reg = READ_SPECIALREG(mpidr_el1);
if ((mpidr_reg & 0xff00fffffful) == mpidr_fdt)
cpu0 = id;
}
return (TRUE);
}
#endif
void
cpu_mp_setmaxid(void)
{
#if defined(DEV_ACPI) || defined(FDT)
int cores;
#endif
switch(arm64_bus_method) {
#ifdef DEV_ACPI
case ARM64_BUS_ACPI:
cores = cpu_count_acpi();
if (cores > 0) {
cores = MIN(cores, MAXCPU);
if (bootverbose)
printf("Found %d CPUs in the ACPI tables\n",
cores);
mp_ncpus = cores;
mp_maxid = cores - 1;
return;
}
break;
#endif
#ifdef FDT
case ARM64_BUS_FDT:
cores = ofw_cpu_early_foreach(cpu_find_cpu0_fdt, false);
if (cores > 0) {
cores = MIN(cores, MAXCPU);
if (bootverbose)
printf("Found %d CPUs in the device tree\n",
cores);
mp_ncpus = cores;
mp_maxid = cores - 1;
return;
}
break;
#endif
default:
break;
}
if (bootverbose)
printf("No CPU data, limiting to 1 core\n");
mp_ncpus = 1;
mp_maxid = 0;
}
/*
* Lookup IPI source.
*/
static struct intr_ipi *
intr_ipi_lookup(u_int ipi)
{
if (ipi >= INTR_IPI_COUNT)
panic("%s: no such IPI %u", __func__, ipi);
return (&ipi_sources[ipi]);
}
/*
* interrupt controller dispatch function for IPIs. It should
* be called straight from the interrupt controller, when associated
* interrupt source is learned. Or from anybody who has an interrupt
* source mapped.
*/
void
intr_ipi_dispatch(u_int ipi, struct trapframe *tf)
{
void *arg;
struct intr_ipi *ii;
ii = intr_ipi_lookup(ipi);
if (ii->ii_count == NULL)
panic("%s: not setup IPI %u", __func__, ipi);
intr_ipi_increment_count(ii->ii_count, PCPU_GET(cpuid));
/*
* Supply ipi filter with trapframe argument
* if none is registered.
*/
arg = ii->ii_handler_arg != NULL ? ii->ii_handler_arg : tf;
ii->ii_handler(arg);
}
#ifdef notyet
/*
* Map IPI into interrupt controller.
*
* Not SMP coherent.
*/
static int
ipi_map(struct intr_irqsrc *isrc, u_int ipi)
{
boolean_t is_percpu;
int error;
if (ipi >= INTR_IPI_COUNT)
panic("%s: no such IPI %u", __func__, ipi);
KASSERT(intr_irq_root_dev != NULL, ("%s: no root attached", __func__));
isrc->isrc_type = INTR_ISRCT_NAMESPACE;
isrc->isrc_nspc_type = INTR_IRQ_NSPC_IPI;
isrc->isrc_nspc_num = ipi_next_num;
error = PIC_REGISTER(intr_irq_root_dev, isrc, &is_percpu);
if (error == 0) {
isrc->isrc_dev = intr_irq_root_dev;
ipi_next_num++;
}
return (error);
}
/*
* Setup IPI handler to interrupt source.
*
* Note that there could be more ways how to send and receive IPIs
* on a platform like fast interrupts for example. In that case,
* one can call this function with ASIF_NOALLOC flag set and then
* call intr_ipi_dispatch() when appropriate.
*
* Not SMP coherent.
*/
int
intr_ipi_set_handler(u_int ipi, const char *name, intr_ipi_filter_t *filter,
void *arg, u_int flags)
{
struct intr_irqsrc *isrc;
int error;
if (filter == NULL)
return(EINVAL);
isrc = intr_ipi_lookup(ipi);
if (isrc->isrc_ipifilter != NULL)
return (EEXIST);
if ((flags & AISHF_NOALLOC) == 0) {
error = ipi_map(isrc, ipi);
if (error != 0)
return (error);
}
isrc->isrc_ipifilter = filter;
isrc->isrc_arg = arg;
isrc->isrc_handlers = 1;
isrc->isrc_count = intr_ipi_setup_counters(name);
isrc->isrc_index = 0; /* it should not be used in IPI case */
if (isrc->isrc_dev != NULL) {
PIC_ENABLE_INTR(isrc->isrc_dev, isrc);
PIC_ENABLE_SOURCE(isrc->isrc_dev, isrc);
}
return (0);
}
#endif
/* Sending IPI */
void
ipi_all_but_self(u_int ipi)
{
cpuset_t cpus;
cpus = all_cpus;
CPU_CLR(PCPU_GET(cpuid), &cpus);
CTR2(KTR_SMP, "%s: ipi: %x", __func__, ipi);
intr_ipi_send(cpus, ipi);
}
void
ipi_cpu(int cpu, u_int ipi)
{
cpuset_t cpus;
CPU_ZERO(&cpus);
CPU_SET(cpu, &cpus);
CTR3(KTR_SMP, "%s: cpu: %d, ipi: %x", __func__, cpu, ipi);
intr_ipi_send(cpus, ipi);
}
void
ipi_selected(cpuset_t cpus, u_int ipi)
{
CTR2(KTR_SMP, "%s: ipi: %x", __func__, ipi);
intr_ipi_send(cpus, ipi);
}