linux/arch/x86/kernel/apic/bigsmp_32.c
Suresh Siddha 18374d89e5 x86, irq: Allow 0xff for /proc/irq/[n]/smp_affinity on an 8-cpu system
John Blackwood reported:
> on an older Dell PowerEdge 6650 system with 8 cpus (4 are hyper-threaded),
> and  32 bit (x86) kernel, once you change the irq smp_affinity of an irq
> to be less than all cpus in the system, you can never change really the
> irq smp_affinity back to be all cpus in the system (0xff) again,
> even though no error status is returned on the "/bin/echo ff >
> /proc/irq/[n]/smp_affinity" operation.
>
> This is due to that fact that BAD_APICID has the same value as
> all cpus (0xff) on 32bit kernels, and thus the value returned from
> set_desc_affinity() via the cpu_mask_to_apicid_and() function is treated
> as a failure in set_ioapic_affinity_irq_desc(), and no affinity changes
> are made.

set_desc_affinity() is already checking if the incoming cpu mask
intersects with the cpu online mask or not. So there is no need
for the apic op cpu_mask_to_apicid_and() to check again
and return BAD_APICID.

Remove the BAD_APICID return value from cpu_mask_to_apicid_and()
and also fix set_desc_affinity() to return -1 instead of using BAD_APICID
to represent error conditions (as cpu_mask_to_apicid_and() can return
logical or physical apicid values and BAD_APICID is really to represent
bad physical apic id).

Reported-by: John Blackwood <john.blackwood@ccur.com>
Root-caused-by: John Blackwood <john.blackwood@ccur.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1261103386.2535.409.camel@sbs-t61>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-12-17 22:03:06 -08:00

260 lines
6.1 KiB
C

/*
* APIC driver for "bigsmp" xAPIC machines with more than 8 virtual CPUs.
*
* Drives the local APIC in "clustered mode".
*/
#include <linux/threads.h>
#include <linux/cpumask.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/dmi.h>
#include <linux/smp.h>
#include <asm/apicdef.h>
#include <asm/fixmap.h>
#include <asm/mpspec.h>
#include <asm/apic.h>
#include <asm/ipi.h>
static unsigned bigsmp_get_apic_id(unsigned long x)
{
return (x >> 24) & 0xFF;
}
static int bigsmp_apic_id_registered(void)
{
return 1;
}
static const struct cpumask *bigsmp_target_cpus(void)
{
#ifdef CONFIG_SMP
return cpu_online_mask;
#else
return cpumask_of(0);
#endif
}
static unsigned long bigsmp_check_apicid_used(physid_mask_t *map, int apicid)
{
return 0;
}
static unsigned long bigsmp_check_apicid_present(int bit)
{
return 1;
}
static inline unsigned long calculate_ldr(int cpu)
{
unsigned long val, id;
val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
id = per_cpu(x86_bios_cpu_apicid, cpu);
val |= SET_APIC_LOGICAL_ID(id);
return val;
}
/*
* Set up the logical destination ID.
*
* Intel recommends to set DFR, LDR and TPR before enabling
* an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel
* document number 292116). So here it goes...
*/
static void bigsmp_init_apic_ldr(void)
{
unsigned long val;
int cpu = smp_processor_id();
apic_write(APIC_DFR, APIC_DFR_FLAT);
val = calculate_ldr(cpu);
apic_write(APIC_LDR, val);
}
static void bigsmp_setup_apic_routing(void)
{
printk(KERN_INFO
"Enabling APIC mode: Physflat. Using %d I/O APICs\n",
nr_ioapics);
}
static int bigsmp_apicid_to_node(int logical_apicid)
{
return apicid_2_node[hard_smp_processor_id()];
}
static int bigsmp_cpu_present_to_apicid(int mps_cpu)
{
if (mps_cpu < nr_cpu_ids)
return (int) per_cpu(x86_bios_cpu_apicid, mps_cpu);
return BAD_APICID;
}
/* Mapping from cpu number to logical apicid */
static inline int bigsmp_cpu_to_logical_apicid(int cpu)
{
if (cpu >= nr_cpu_ids)
return BAD_APICID;
return cpu_physical_id(cpu);
}
static void bigsmp_ioapic_phys_id_map(physid_mask_t *phys_map, physid_mask_t *retmap)
{
/* For clustered we don't have a good way to do this yet - hack */
physids_promote(0xFFL, retmap);
}
static int bigsmp_check_phys_apicid_present(int phys_apicid)
{
return 1;
}
/* As we are using single CPU as destination, pick only one CPU here */
static unsigned int bigsmp_cpu_mask_to_apicid(const struct cpumask *cpumask)
{
return bigsmp_cpu_to_logical_apicid(cpumask_first(cpumask));
}
static unsigned int bigsmp_cpu_mask_to_apicid_and(const struct cpumask *cpumask,
const struct cpumask *andmask)
{
int cpu;
/*
* We're using fixed IRQ delivery, can only return one phys APIC ID.
* May as well be the first.
*/
for_each_cpu_and(cpu, cpumask, andmask) {
if (cpumask_test_cpu(cpu, cpu_online_mask))
break;
}
return bigsmp_cpu_to_logical_apicid(cpu);
}
static int bigsmp_phys_pkg_id(int cpuid_apic, int index_msb)
{
return cpuid_apic >> index_msb;
}
static inline void bigsmp_send_IPI_mask(const struct cpumask *mask, int vector)
{
default_send_IPI_mask_sequence_phys(mask, vector);
}
static void bigsmp_send_IPI_allbutself(int vector)
{
default_send_IPI_mask_allbutself_phys(cpu_online_mask, vector);
}
static void bigsmp_send_IPI_all(int vector)
{
bigsmp_send_IPI_mask(cpu_online_mask, vector);
}
static int dmi_bigsmp; /* can be set by dmi scanners */
static int hp_ht_bigsmp(const struct dmi_system_id *d)
{
printk(KERN_NOTICE "%s detected: force use of apic=bigsmp\n", d->ident);
dmi_bigsmp = 1;
return 0;
}
static const struct dmi_system_id bigsmp_dmi_table[] = {
{ hp_ht_bigsmp, "HP ProLiant DL760 G2",
{ DMI_MATCH(DMI_BIOS_VENDOR, "HP"),
DMI_MATCH(DMI_BIOS_VERSION, "P44-"),
}
},
{ hp_ht_bigsmp, "HP ProLiant DL740",
{ DMI_MATCH(DMI_BIOS_VENDOR, "HP"),
DMI_MATCH(DMI_BIOS_VERSION, "P47-"),
}
},
{ } /* NULL entry stops DMI scanning */
};
static void bigsmp_vector_allocation_domain(int cpu, struct cpumask *retmask)
{
cpumask_clear(retmask);
cpumask_set_cpu(cpu, retmask);
}
static int probe_bigsmp(void)
{
if (def_to_bigsmp)
dmi_bigsmp = 1;
else
dmi_check_system(bigsmp_dmi_table);
return dmi_bigsmp;
}
struct apic apic_bigsmp = {
.name = "bigsmp",
.probe = probe_bigsmp,
.acpi_madt_oem_check = NULL,
.apic_id_registered = bigsmp_apic_id_registered,
.irq_delivery_mode = dest_Fixed,
/* phys delivery to target CPU: */
.irq_dest_mode = 0,
.target_cpus = bigsmp_target_cpus,
.disable_esr = 1,
.dest_logical = 0,
.check_apicid_used = bigsmp_check_apicid_used,
.check_apicid_present = bigsmp_check_apicid_present,
.vector_allocation_domain = bigsmp_vector_allocation_domain,
.init_apic_ldr = bigsmp_init_apic_ldr,
.ioapic_phys_id_map = bigsmp_ioapic_phys_id_map,
.setup_apic_routing = bigsmp_setup_apic_routing,
.multi_timer_check = NULL,
.apicid_to_node = bigsmp_apicid_to_node,
.cpu_to_logical_apicid = bigsmp_cpu_to_logical_apicid,
.cpu_present_to_apicid = bigsmp_cpu_present_to_apicid,
.apicid_to_cpu_present = physid_set_mask_of_physid,
.setup_portio_remap = NULL,
.check_phys_apicid_present = bigsmp_check_phys_apicid_present,
.enable_apic_mode = NULL,
.phys_pkg_id = bigsmp_phys_pkg_id,
.mps_oem_check = NULL,
.get_apic_id = bigsmp_get_apic_id,
.set_apic_id = NULL,
.apic_id_mask = 0xFF << 24,
.cpu_mask_to_apicid = bigsmp_cpu_mask_to_apicid,
.cpu_mask_to_apicid_and = bigsmp_cpu_mask_to_apicid_and,
.send_IPI_mask = bigsmp_send_IPI_mask,
.send_IPI_mask_allbutself = NULL,
.send_IPI_allbutself = bigsmp_send_IPI_allbutself,
.send_IPI_all = bigsmp_send_IPI_all,
.send_IPI_self = default_send_IPI_self,
.trampoline_phys_low = DEFAULT_TRAMPOLINE_PHYS_LOW,
.trampoline_phys_high = DEFAULT_TRAMPOLINE_PHYS_HIGH,
.wait_for_init_deassert = default_wait_for_init_deassert,
.smp_callin_clear_local_apic = NULL,
.inquire_remote_apic = default_inquire_remote_apic,
.read = native_apic_mem_read,
.write = native_apic_mem_write,
.icr_read = native_apic_icr_read,
.icr_write = native_apic_icr_write,
.wait_icr_idle = native_apic_wait_icr_idle,
.safe_wait_icr_idle = native_safe_apic_wait_icr_idle,
};