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linux/arch/s390/kvm/sigp.c
Christian Borntraeger b037a4f34e KVM: s390: optimize float int lock: spin_lock_bh --> spin_lock 
The floating interrupt lock is only taken in process context. We can
replace all spin_lock_bh with standard spin_lock calls.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Ehrhardt <ehrhardt@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-06-10 11:48:56 +03:00

293 lines
7.4 KiB
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/*
* sigp.c - handlinge interprocessor communication
*
* Copyright IBM Corp. 2008
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License (version 2 only)
* as published by the Free Software Foundation.
*
* Author(s): Carsten Otte <cotte@de.ibm.com>
* Christian Borntraeger <borntraeger@de.ibm.com>
*/
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include "gaccess.h"
#include "kvm-s390.h"
/* sigp order codes */
#define SIGP_SENSE 0x01
#define SIGP_EXTERNAL_CALL 0x02
#define SIGP_EMERGENCY 0x03
#define SIGP_START 0x04
#define SIGP_STOP 0x05
#define SIGP_RESTART 0x06
#define SIGP_STOP_STORE_STATUS 0x09
#define SIGP_INITIAL_CPU_RESET 0x0b
#define SIGP_CPU_RESET 0x0c
#define SIGP_SET_PREFIX 0x0d
#define SIGP_STORE_STATUS_ADDR 0x0e
#define SIGP_SET_ARCH 0x12
/* cpu status bits */
#define SIGP_STAT_EQUIPMENT_CHECK 0x80000000UL
#define SIGP_STAT_INCORRECT_STATE 0x00000200UL
#define SIGP_STAT_INVALID_PARAMETER 0x00000100UL
#define SIGP_STAT_EXT_CALL_PENDING 0x00000080UL
#define SIGP_STAT_STOPPED 0x00000040UL
#define SIGP_STAT_OPERATOR_INTERV 0x00000020UL
#define SIGP_STAT_CHECK_STOP 0x00000010UL
#define SIGP_STAT_INOPERATIVE 0x00000004UL
#define SIGP_STAT_INVALID_ORDER 0x00000002UL
#define SIGP_STAT_RECEIVER_CHECK 0x00000001UL
static int __sigp_sense(struct kvm_vcpu *vcpu, u16 cpu_addr,
unsigned long *reg)
{
struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
int rc;
if (cpu_addr >= KVM_MAX_VCPUS)
return 3; /* not operational */
spin_lock(&fi->lock);
if (fi->local_int[cpu_addr] == NULL)
rc = 3; /* not operational */
else if (atomic_read(fi->local_int[cpu_addr]->cpuflags)
& CPUSTAT_RUNNING) {
*reg &= 0xffffffff00000000UL;
rc = 1; /* status stored */
} else {
*reg &= 0xffffffff00000000UL;
*reg |= SIGP_STAT_STOPPED;
rc = 1; /* status stored */
}
spin_unlock(&fi->lock);
VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", cpu_addr, rc);
return rc;
}
static int __sigp_emergency(struct kvm_vcpu *vcpu, u16 cpu_addr)
{
struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
struct kvm_s390_local_interrupt *li;
struct kvm_s390_interrupt_info *inti;
int rc;
if (cpu_addr >= KVM_MAX_VCPUS)
return 3; /* not operational */
inti = kzalloc(sizeof(*inti), GFP_KERNEL);
if (!inti)
return -ENOMEM;
inti->type = KVM_S390_INT_EMERGENCY;
spin_lock(&fi->lock);
li = fi->local_int[cpu_addr];
if (li == NULL) {
rc = 3; /* not operational */
kfree(inti);
goto unlock;
}
spin_lock_bh(&li->lock);
list_add_tail(&inti->list, &li->list);
atomic_set(&li->active, 1);
atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags);
if (waitqueue_active(&li->wq))
wake_up_interruptible(&li->wq);
spin_unlock_bh(&li->lock);
rc = 0; /* order accepted */
unlock:
spin_unlock(&fi->lock);
VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x", cpu_addr);
return rc;
}
static int __sigp_stop(struct kvm_vcpu *vcpu, u16 cpu_addr, int store)
{
struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
struct kvm_s390_local_interrupt *li;
struct kvm_s390_interrupt_info *inti;
int rc;
if (cpu_addr >= KVM_MAX_VCPUS)
return 3; /* not operational */
inti = kzalloc(sizeof(*inti), GFP_KERNEL);
if (!inti)
return -ENOMEM;
inti->type = KVM_S390_SIGP_STOP;
spin_lock(&fi->lock);
li = fi->local_int[cpu_addr];
if (li == NULL) {
rc = 3; /* not operational */
kfree(inti);
goto unlock;
}
spin_lock_bh(&li->lock);
list_add_tail(&inti->list, &li->list);
atomic_set(&li->active, 1);
atomic_set_mask(CPUSTAT_STOP_INT, li->cpuflags);
if (store)
li->action_bits |= ACTION_STORE_ON_STOP;
li->action_bits |= ACTION_STOP_ON_STOP;
if (waitqueue_active(&li->wq))
wake_up_interruptible(&li->wq);
spin_unlock_bh(&li->lock);
rc = 0; /* order accepted */
unlock:
spin_unlock(&fi->lock);
VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x", cpu_addr);
return rc;
}
static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter)
{
int rc;
switch (parameter & 0xff) {
case 0:
rc = 3; /* not operational */
break;
case 1:
case 2:
rc = 0; /* order accepted */
break;
default:
rc = -ENOTSUPP;
}
return rc;
}
static int __sigp_set_prefix(struct kvm_vcpu *vcpu, u16 cpu_addr, u32 address,
unsigned long *reg)
{
struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
struct kvm_s390_local_interrupt *li;
struct kvm_s390_interrupt_info *inti;
int rc;
u8 tmp;
/* make sure that the new value is valid memory */
address = address & 0x7fffe000u;
if ((copy_from_guest(vcpu, &tmp,
(u64) (address + vcpu->kvm->arch.guest_origin) , 1)) ||
(copy_from_guest(vcpu, &tmp, (u64) (address +
vcpu->kvm->arch.guest_origin + PAGE_SIZE), 1))) {
*reg |= SIGP_STAT_INVALID_PARAMETER;
return 1; /* invalid parameter */
}
inti = kzalloc(sizeof(*inti), GFP_KERNEL);
if (!inti)
return 2; /* busy */
spin_lock(&fi->lock);
li = fi->local_int[cpu_addr];
if ((cpu_addr >= KVM_MAX_VCPUS) || (li == NULL)) {
rc = 1; /* incorrect state */
*reg &= SIGP_STAT_INCORRECT_STATE;
kfree(inti);
goto out_fi;
}
spin_lock_bh(&li->lock);
/* cpu must be in stopped state */
if (atomic_read(li->cpuflags) & CPUSTAT_RUNNING) {
rc = 1; /* incorrect state */
*reg &= SIGP_STAT_INCORRECT_STATE;
kfree(inti);
goto out_li;
}
inti->type = KVM_S390_SIGP_SET_PREFIX;
inti->prefix.address = address;
list_add_tail(&inti->list, &li->list);
atomic_set(&li->active, 1);
if (waitqueue_active(&li->wq))
wake_up_interruptible(&li->wq);
rc = 0; /* order accepted */
VCPU_EVENT(vcpu, 4, "set prefix of cpu %02x to %x", cpu_addr, address);
out_li:
spin_unlock_bh(&li->lock);
out_fi:
spin_unlock(&fi->lock);
return rc;
}
int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
{
int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
int r3 = vcpu->arch.sie_block->ipa & 0x000f;
int base2 = vcpu->arch.sie_block->ipb >> 28;
int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
u32 parameter;
u16 cpu_addr = vcpu->arch.guest_gprs[r3];
u8 order_code;
int rc;
/* sigp in userspace can exit */
if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
return kvm_s390_inject_program_int(vcpu,
PGM_PRIVILEGED_OPERATION);
order_code = disp2;
if (base2)
order_code += vcpu->arch.guest_gprs[base2];
if (r1 % 2)
parameter = vcpu->arch.guest_gprs[r1];
else
parameter = vcpu->arch.guest_gprs[r1 + 1];
switch (order_code) {
case SIGP_SENSE:
vcpu->stat.instruction_sigp_sense++;
rc = __sigp_sense(vcpu, cpu_addr,
&vcpu->arch.guest_gprs[r1]);
break;
case SIGP_EMERGENCY:
vcpu->stat.instruction_sigp_emergency++;
rc = __sigp_emergency(vcpu, cpu_addr);
break;
case SIGP_STOP:
vcpu->stat.instruction_sigp_stop++;
rc = __sigp_stop(vcpu, cpu_addr, 0);
break;
case SIGP_STOP_STORE_STATUS:
vcpu->stat.instruction_sigp_stop++;
rc = __sigp_stop(vcpu, cpu_addr, 1);
break;
case SIGP_SET_ARCH:
vcpu->stat.instruction_sigp_arch++;
rc = __sigp_set_arch(vcpu, parameter);
break;
case SIGP_SET_PREFIX:
vcpu->stat.instruction_sigp_prefix++;
rc = __sigp_set_prefix(vcpu, cpu_addr, parameter,
&vcpu->arch.guest_gprs[r1]);
break;
case SIGP_RESTART:
vcpu->stat.instruction_sigp_restart++;
/* user space must know about restart */
default:
return -ENOTSUPP;
}
if (rc < 0)
return rc;
vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
vcpu->arch.sie_block->gpsw.mask |= (rc & 3ul) << 44;
return 0;
}
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