linux/arch/x86/xen/apic.c
Lin Ming ab6ec39a19 xen/apic: implement io apic read with hypercall
Implements xen_io_apic_read with hypercall, so it returns proper
IO-APIC information instead of fabricated one.

Fallback to return an emulated IO_APIC values if hypercall fails.

[v2: fallback to return an emulated IO_APIC values if hypercall fails]
Signed-off-by: Lin Ming <mlin@ss.pku.edu.cn>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-01 14:52:12 -04:00

31 lines
636 B
C

#include <linux/init.h>
#include <asm/x86_init.h>
#include <asm/apic.h>
#include <xen/interface/physdev.h>
#include <asm/xen/hypercall.h>
unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
{
struct physdev_apic apic_op;
int ret;
apic_op.apic_physbase = mpc_ioapic_addr(apic);
apic_op.reg = reg;
ret = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, &apic_op);
if (!ret)
return apic_op.value;
/* fallback to return an emulated IO_APIC values */
if (reg == 0x1)
return 0x00170020;
else if (reg == 0x0)
return apic << 24;
return 0xfd;
}
void __init xen_init_apic(void)
{
x86_io_apic_ops.read = xen_io_apic_read;
}