linux/arch/x86/kernel/apic/apic_noop.c
Thomas Gleixner a946d8f11f x86: Fix bogus warning in apic_noop.apic_write()
apic_noop is used to provide dummy apic functions. It's installed
when the CPU has no APIC or when the APIC is disabled on the kernel
command line.

The apic_noop implementation of apic_write() warns when the CPU has
an APIC or when the APIC is not disabled.

That's bogus. The warning should only happen when the CPU has an
APIC _AND_ the APIC is not disabled. apic_noop.apic_read() has the
correct check.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: <stable@kernel.org> # in <= .32 this typo resides in native_apic_write_dummy()
LKML-Reference: <alpine.LFD.2.00.0912071255420.3089@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-07 13:16:37 +01:00

201 lines
4.7 KiB
C

/*
* NOOP APIC driver.
*
* Does almost nothing and should be substituted by a real apic driver via
* probe routine.
*
* Though in case if apic is disabled (for some reason) we try
* to not uglify the caller's code and allow to call (some) apic routines
* like self-ipi, etc...
*/
#include <linux/threads.h>
#include <linux/cpumask.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <asm/fixmap.h>
#include <asm/mpspec.h>
#include <asm/apicdef.h>
#include <asm/apic.h>
#include <asm/setup.h>
#include <linux/smp.h>
#include <asm/ipi.h>
#include <linux/interrupt.h>
#include <asm/acpi.h>
#include <asm/e820.h>
static void noop_init_apic_ldr(void) { }
static void noop_send_IPI_mask(const struct cpumask *cpumask, int vector) { }
static void noop_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) { }
static void noop_send_IPI_allbutself(int vector) { }
static void noop_send_IPI_all(int vector) { }
static void noop_send_IPI_self(int vector) { }
static void noop_apic_wait_icr_idle(void) { }
static void noop_apic_icr_write(u32 low, u32 id) { }
static int noop_wakeup_secondary_cpu(int apicid, unsigned long start_eip)
{
return -1;
}
static u32 noop_safe_apic_wait_icr_idle(void)
{
return 0;
}
static u64 noop_apic_icr_read(void)
{
return 0;
}
static int noop_cpu_to_logical_apicid(int cpu)
{
return 0;
}
static int noop_phys_pkg_id(int cpuid_apic, int index_msb)
{
return 0;
}
static unsigned int noop_get_apic_id(unsigned long x)
{
return 0;
}
static int noop_probe(void)
{
/*
* NOOP apic should not ever be
* enabled via probe routine
*/
return 0;
}
static int noop_apic_id_registered(void)
{
/*
* if we would be really "pedantic"
* we should pass read_apic_id() here
* but since NOOP suppose APIC ID = 0
* lets save a few cycles
*/
return physid_isset(0, phys_cpu_present_map);
}
static const struct cpumask *noop_target_cpus(void)
{
/* only BSP here */
return cpumask_of(0);
}
static unsigned long noop_check_apicid_used(physid_mask_t *map, int apicid)
{
return physid_isset(apicid, *map);
}
static unsigned long noop_check_apicid_present(int bit)
{
return physid_isset(bit, phys_cpu_present_map);
}
static void noop_vector_allocation_domain(int cpu, struct cpumask *retmask)
{
if (cpu != 0)
pr_warning("APIC: Vector allocated for non-BSP cpu\n");
cpumask_clear(retmask);
cpumask_set_cpu(cpu, retmask);
}
int noop_apicid_to_node(int logical_apicid)
{
/* we're always on node 0 */
return 0;
}
static u32 noop_apic_read(u32 reg)
{
WARN_ON_ONCE((cpu_has_apic && !disable_apic));
return 0;
}
static void noop_apic_write(u32 reg, u32 v)
{
WARN_ON_ONCE(cpu_has_apic && !disable_apic);
}
struct apic apic_noop = {
.name = "noop",
.probe = noop_probe,
.acpi_madt_oem_check = NULL,
.apic_id_registered = noop_apic_id_registered,
.irq_delivery_mode = dest_LowestPrio,
/* logical delivery broadcast to all CPUs: */
.irq_dest_mode = 1,
.target_cpus = noop_target_cpus,
.disable_esr = 0,
.dest_logical = APIC_DEST_LOGICAL,
.check_apicid_used = noop_check_apicid_used,
.check_apicid_present = noop_check_apicid_present,
.vector_allocation_domain = noop_vector_allocation_domain,
.init_apic_ldr = noop_init_apic_ldr,
.ioapic_phys_id_map = default_ioapic_phys_id_map,
.setup_apic_routing = NULL,
.multi_timer_check = NULL,
.apicid_to_node = noop_apicid_to_node,
.cpu_to_logical_apicid = noop_cpu_to_logical_apicid,
.cpu_present_to_apicid = default_cpu_present_to_apicid,
.apicid_to_cpu_present = physid_set_mask_of_physid,
.setup_portio_remap = NULL,
.check_phys_apicid_present = default_check_phys_apicid_present,
.enable_apic_mode = NULL,
.phys_pkg_id = noop_phys_pkg_id,
.mps_oem_check = NULL,
.get_apic_id = noop_get_apic_id,
.set_apic_id = NULL,
.apic_id_mask = 0x0F << 24,
.cpu_mask_to_apicid = default_cpu_mask_to_apicid,
.cpu_mask_to_apicid_and = default_cpu_mask_to_apicid_and,
.send_IPI_mask = noop_send_IPI_mask,
.send_IPI_mask_allbutself = noop_send_IPI_mask_allbutself,
.send_IPI_allbutself = noop_send_IPI_allbutself,
.send_IPI_all = noop_send_IPI_all,
.send_IPI_self = noop_send_IPI_self,
.wakeup_secondary_cpu = noop_wakeup_secondary_cpu,
/* should be safe */
.trampoline_phys_low = DEFAULT_TRAMPOLINE_PHYS_LOW,
.trampoline_phys_high = DEFAULT_TRAMPOLINE_PHYS_HIGH,
.wait_for_init_deassert = NULL,
.smp_callin_clear_local_apic = NULL,
.inquire_remote_apic = NULL,
.read = noop_apic_read,
.write = noop_apic_write,
.icr_read = noop_apic_icr_read,
.icr_write = noop_apic_icr_write,
.wait_icr_idle = noop_apic_wait_icr_idle,
.safe_wait_icr_idle = noop_safe_apic_wait_icr_idle,
};