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Ensure the boot CPU is CPU 0 on arm64

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We assume the boot CPU is always CPU 0 on arm64. To allow for this reserve
cpuid 0 for the boot CPU in the ACPI and FDT cases but otherwise start the
CPU as normal. We then check for the boot CPU in start_cpu and return as if
it was started.

While here extract the FDT CPU init code into a new function to simplify
cpu_mp_start and return FALSE from start_cpu when the CPU fails to start.

Reviewed by:	mmel
Sponsored by:	Innovate UK
Differential Revision:	https://reviews.freebsd.org/D27497
This commit is contained in:
Andrew Turner 2020-12-07 17:54:49 +00:00
parent eb2f5fa4dc
commit d2d350369e
1 changed files with 66 additions and 39 deletions
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105
sys/arm64/arm64/mp_machdep.c
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@ -148,6 +148,13 @@ static volatile int aps_ready;
/* Temporary variables for init_secondary() */
void *dpcpu[MAXCPU - 1];
static bool
is_boot_cpu(uint64_t target_cpu)
{
return (__pcpu[0].pc_mpidr == (target_cpu & CPU_AFF_MASK));
}
static void
release_aps(void *dummy __unused)
{
@ -428,6 +435,10 @@ cpu_mp_probe(void)
return (1);
}
/*
* Starts a given CPU. If the CPU is already running, i.e. it is the boot CPU,
* do nothing. Returns true if the CPU is present and running.
*/
static bool
start_cpu(u_int cpuid, uint64_t target_cpu)
{
@ -439,9 +450,11 @@ start_cpu(u_int cpuid, uint64_t target_cpu)
if (cpuid > mp_maxid)
return (false);
/* Skip boot CPU */
if (is_boot_cpu(target_cpu))
return (true);
KASSERT(cpuid < MAXCPU, ("Too many CPUs"));
KASSERT(__pcpu[0].pc_mpidr != (target_cpu & CPU_AFF_MASK),
("Start_cpu() was called on the boot CPU"));
pcpup = &__pcpu[cpuid];
pcpu_init(pcpup, cpuid, sizeof(struct pcpu));
@ -475,14 +488,14 @@ start_cpu(u_int cpuid, uint64_t target_cpu)
kmem_free((vm_offset_t)bootstacks[cpuid], PAGE_SIZE);
bootstacks[cpuid] = NULL;
mp_ncpus--;
} else {
/* Wait for the AP to switch to its boot stack. */
while (atomic_load_int(&aps_started) < naps + 1)
cpu_spinwait();
CPU_SET(cpuid, &all_cpus);
return (false);
}
/* Wait for the AP to switch to its boot stack. */
while (atomic_load_int(&aps_started) < naps + 1)
cpu_spinwait();
CPU_SET(cpuid, &all_cpus);
return (true);
}
@ -498,17 +511,22 @@ madt_handler(ACPI_SUBTABLE_HEADER *entry, void *arg)
case ACPI_MADT_TYPE_GENERIC_INTERRUPT:
intr = (ACPI_MADT_GENERIC_INTERRUPT *)entry;
cpuid = arg;
id = *cpuid;
/* Skip the boot CPU, but save its ACPI id. */
if (__pcpu[0].pc_mpidr == (intr->ArmMpidr & CPU_AFF_MASK)) {
__pcpu[0].pc_acpi_id = intr->Uid;
break;
if (is_boot_cpu(intr->ArmMpidr))
id = 0;
else
id = *cpuid;
if (start_cpu(id, intr->ArmMpidr)) {
__pcpu[id].pc_acpi_id = intr->Uid;
/*
* Don't increment for the boot CPU, its CPU ID is
* reserved.
*/
if (!is_boot_cpu(intr->ArmMpidr))
(*cpuid)++;
}
start_cpu(id, intr->ArmMpidr);
__pcpu[id].pc_acpi_id = intr->Uid;
(*cpuid)++;
break;
default:
break;
@ -546,10 +564,11 @@ cpu_init_acpi(void)
#ifdef FDT
static boolean_t
cpu_init_fdt(u_int id, phandle_t node, u_int addr_size, pcell_t *reg)
start_cpu_fdt(u_int id, phandle_t node, u_int addr_size, pcell_t *reg)
{
uint64_t target_cpu;
int domain;
int cpuid;
target_cpu = reg[0];
if (addr_size == 2) {
@ -557,35 +576,51 @@ cpu_init_fdt(u_int id, phandle_t node, u_int addr_size, pcell_t *reg)
target_cpu |= reg[1];
}
/* Skip boot CPU */
if (__pcpu[0].pc_mpidr == (target_cpu & CPU_AFF_MASK))
return (TRUE);
if (is_boot_cpu(target_cpu))
cpuid = 0;
else
cpuid = fdt_cpuid;
if (!start_cpu(fdt_cpuid, target_cpu))
if (!start_cpu(cpuid, target_cpu))
return (FALSE);
fdt_cpuid++;
/*
* Don't increment for the boot CPU, its CPU ID is reserved.
*/
if (!is_boot_cpu(target_cpu))
fdt_cpuid++;
/* Try to read the numa node of this cpu */
if (vm_ndomains == 1 ||
OF_getencprop(node, "numa-node-id", &domain, sizeof(domain)) <= 0)
domain = 0;
__pcpu[fdt_cpuid].pc_domain = domain;
__pcpu[cpuid].pc_domain = domain;
if (domain < MAXMEMDOM)
CPU_SET(fdt_cpuid, &cpuset_domain[domain]);
CPU_SET(cpuid, &cpuset_domain[domain]);
return (TRUE);
}
static void
cpu_init_fdt(void)
{
phandle_t node;
int i;
node = OF_peer(0);
for (i = 0; fdt_quirks[i].compat != NULL; i++) {
if (ofw_bus_node_is_compatible(node,
fdt_quirks[i].compat) != 0) {
mp_quirks = fdt_quirks[i].quirks;
}
}
fdt_cpuid = 1;
ofw_cpu_early_foreach(start_cpu_fdt, true);
}
#endif
/* Initialize and fire up non-boot processors */
void
cpu_mp_start(void)
{
#ifdef FDT
phandle_t node;
#endif
int i;
mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
/* CPU 0 is always boot CPU. */
@ -601,15 +636,7 @@ cpu_mp_start(void)
#endif
#ifdef FDT
case ARM64_BUS_FDT:
node = OF_peer(0);
for (i = 0; fdt_quirks[i].compat != NULL; i++) {
if (ofw_bus_node_is_compatible(node,
fdt_quirks[i].compat) != 0) {
mp_quirks = fdt_quirks[i].quirks;
}
}
fdt_cpuid = 1;
ofw_cpu_early_foreach(cpu_init_fdt, true);
cpu_init_fdt();
break;
#endif
default: