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alistair23-linux/arch/powerpc/kvm/e500mc.c
Christoph Lameter 69111bac42 powerpc: Replace __get_cpu_var uses 
This still has not been merged and now powerpc is the only arch that does
not have this change. Sorry about missing linuxppc-dev before.

V2->V2
  - Fix up to work against 3.18-rc1

__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x).  This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.

Other use cases are for storing and retrieving data from the current
processors percpu area.  __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.

This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset.  Thereby address calculations are avoided and less registers
are used when code is generated.

At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.

The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e.  using a global
register that may be set to the per cpu base.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu
variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&x, this_cpu_ptr(&y), sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	__this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	__this_cpu_inc(y)

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
[mpe: Fix build errors caused by set/or_softirq_pending(), and rework
      assignment in __set_breakpoint() to use memcpy().]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-11-03 12:12:32 +11:00

444 lines
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/*
* Copyright (C) 2010,2012 Freescale Semiconductor, Inc. All rights reserved.
*
* Author: Varun Sethi, <varun.sethi@freescale.com>
*
* Description:
* This file is derived from arch/powerpc/kvm/e500.c,
* by Yu Liu <yu.liu@freescale.com>.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*/
#include <linux/kvm_host.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <asm/reg.h>
#include <asm/cputable.h>
#include <asm/tlbflush.h>
#include <asm/kvm_ppc.h>
#include <asm/dbell.h>
#include "booke.h"
#include "e500.h"
void kvmppc_set_pending_interrupt(struct kvm_vcpu *vcpu, enum int_class type)
{
enum ppc_dbell dbell_type;
unsigned long tag;
switch (type) {
case INT_CLASS_NONCRIT:
dbell_type = PPC_G_DBELL;
break;
case INT_CLASS_CRIT:
dbell_type = PPC_G_DBELL_CRIT;
break;
case INT_CLASS_MC:
dbell_type = PPC_G_DBELL_MC;
break;
default:
WARN_ONCE(1, "%s: unknown int type %d\n", __func__, type);
return;
}
preempt_disable();
tag = PPC_DBELL_LPID(get_lpid(vcpu)) | vcpu->vcpu_id;
mb();
ppc_msgsnd(dbell_type, 0, tag);
preempt_enable();
}
/* gtlbe must not be mapped by more than one host tlb entry */
void kvmppc_e500_tlbil_one(struct kvmppc_vcpu_e500 *vcpu_e500,
struct kvm_book3e_206_tlb_entry *gtlbe)
{
unsigned int tid, ts;
gva_t eaddr;
u32 val;
unsigned long flags;
ts = get_tlb_ts(gtlbe);
tid = get_tlb_tid(gtlbe);
/* We search the host TLB to invalidate its shadow TLB entry */
val = (tid << 16) | ts;
eaddr = get_tlb_eaddr(gtlbe);
local_irq_save(flags);
mtspr(SPRN_MAS6, val);
mtspr(SPRN_MAS5, MAS5_SGS | get_lpid(&vcpu_e500->vcpu));
asm volatile("tlbsx 0, %[eaddr]\n" : : [eaddr] "r" (eaddr));
val = mfspr(SPRN_MAS1);
if (val & MAS1_VALID) {
mtspr(SPRN_MAS1, val & ~MAS1_VALID);
asm volatile("tlbwe");
}
mtspr(SPRN_MAS5, 0);
/* NOTE: tlbsx also updates mas8, so clear it for host tlbwe */
mtspr(SPRN_MAS8, 0);
isync();
local_irq_restore(flags);
}
void kvmppc_e500_tlbil_all(struct kvmppc_vcpu_e500 *vcpu_e500)
{
unsigned long flags;
local_irq_save(flags);
mtspr(SPRN_MAS5, MAS5_SGS | get_lpid(&vcpu_e500->vcpu));
asm volatile("tlbilxlpid");
mtspr(SPRN_MAS5, 0);
local_irq_restore(flags);
}
void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 pid)
{
vcpu->arch.pid = pid;
}
void kvmppc_mmu_msr_notify(struct kvm_vcpu *vcpu, u32 old_msr)
{
}
/* We use two lpids per VM */
static DEFINE_PER_CPU(struct kvm_vcpu *[KVMPPC_NR_LPIDS], last_vcpu_of_lpid);
static void kvmppc_core_vcpu_load_e500mc(struct kvm_vcpu *vcpu, int cpu)
{
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
kvmppc_booke_vcpu_load(vcpu, cpu);
mtspr(SPRN_LPID, get_lpid(vcpu));
mtspr(SPRN_EPCR, vcpu->arch.shadow_epcr);
mtspr(SPRN_GPIR, vcpu->vcpu_id);
mtspr(SPRN_MSRP, vcpu->arch.shadow_msrp);
vcpu->arch.eplc = EPC_EGS | (get_lpid(vcpu) << EPC_ELPID_SHIFT);
vcpu->arch.epsc = vcpu->arch.eplc;
mtspr(SPRN_EPLC, vcpu->arch.eplc);
mtspr(SPRN_EPSC, vcpu->arch.epsc);
mtspr(SPRN_GIVPR, vcpu->arch.ivpr);
mtspr(SPRN_GIVOR2, vcpu->arch.ivor[BOOKE_IRQPRIO_DATA_STORAGE]);
mtspr(SPRN_GIVOR8, vcpu->arch.ivor[BOOKE_IRQPRIO_SYSCALL]);
mtspr(SPRN_GSPRG0, (unsigned long)vcpu->arch.shared->sprg0);
mtspr(SPRN_GSPRG1, (unsigned long)vcpu->arch.shared->sprg1);
mtspr(SPRN_GSPRG2, (unsigned long)vcpu->arch.shared->sprg2);
mtspr(SPRN_GSPRG3, (unsigned long)vcpu->arch.shared->sprg3);
mtspr(SPRN_GSRR0, vcpu->arch.shared->srr0);
mtspr(SPRN_GSRR1, vcpu->arch.shared->srr1);
mtspr(SPRN_GEPR, vcpu->arch.epr);
mtspr(SPRN_GDEAR, vcpu->arch.shared->dar);
mtspr(SPRN_GESR, vcpu->arch.shared->esr);
if (vcpu->arch.oldpir != mfspr(SPRN_PIR) ||
__this_cpu_read(last_vcpu_of_lpid[get_lpid(vcpu)]) != vcpu) {
kvmppc_e500_tlbil_all(vcpu_e500);
__this_cpu_write(last_vcpu_of_lpid[get_lpid(vcpu)], vcpu);
}
}
static void kvmppc_core_vcpu_put_e500mc(struct kvm_vcpu *vcpu)
{
vcpu->arch.eplc = mfspr(SPRN_EPLC);
vcpu->arch.epsc = mfspr(SPRN_EPSC);
vcpu->arch.shared->sprg0 = mfspr(SPRN_GSPRG0);
vcpu->arch.shared->sprg1 = mfspr(SPRN_GSPRG1);
vcpu->arch.shared->sprg2 = mfspr(SPRN_GSPRG2);
vcpu->arch.shared->sprg3 = mfspr(SPRN_GSPRG3);
vcpu->arch.shared->srr0 = mfspr(SPRN_GSRR0);
vcpu->arch.shared->srr1 = mfspr(SPRN_GSRR1);
vcpu->arch.epr = mfspr(SPRN_GEPR);
vcpu->arch.shared->dar = mfspr(SPRN_GDEAR);
vcpu->arch.shared->esr = mfspr(SPRN_GESR);
vcpu->arch.oldpir = mfspr(SPRN_PIR);
kvmppc_booke_vcpu_put(vcpu);
}
int kvmppc_core_check_processor_compat(void)
{
int r;
if (strcmp(cur_cpu_spec->cpu_name, "e500mc") == 0)
r = 0;
else if (strcmp(cur_cpu_spec->cpu_name, "e5500") == 0)
r = 0;
#ifdef CONFIG_ALTIVEC
/*
* Since guests have the priviledge to enable AltiVec, we need AltiVec
* support in the host to save/restore their context.
* Don't use CPU_FTR_ALTIVEC to identify cores with AltiVec unit
* because it's cleared in the absence of CONFIG_ALTIVEC!
*/
else if (strcmp(cur_cpu_spec->cpu_name, "e6500") == 0)
r = 0;
#endif
else
r = -ENOTSUPP;
return r;
}
int kvmppc_core_vcpu_setup(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
vcpu->arch.shadow_epcr = SPRN_EPCR_DSIGS | SPRN_EPCR_DGTMI | \
SPRN_EPCR_DUVD;
#ifdef CONFIG_64BIT
vcpu->arch.shadow_epcr |= SPRN_EPCR_ICM;
#endif
vcpu->arch.shadow_msrp = MSRP_UCLEP | MSRP_PMMP;
vcpu->arch.pvr = mfspr(SPRN_PVR);
vcpu_e500->svr = mfspr(SPRN_SVR);
vcpu->arch.cpu_type = KVM_CPU_E500MC;
return 0;
}
static int kvmppc_core_get_sregs_e500mc(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
sregs->u.e.features |= KVM_SREGS_E_ARCH206_MMU | KVM_SREGS_E_PM |
KVM_SREGS_E_PC;
sregs->u.e.impl_id = KVM_SREGS_E_IMPL_FSL;
sregs->u.e.impl.fsl.features = 0;
sregs->u.e.impl.fsl.svr = vcpu_e500->svr;
sregs->u.e.impl.fsl.hid0 = vcpu_e500->hid0;
sregs->u.e.impl.fsl.mcar = vcpu_e500->mcar;
kvmppc_get_sregs_e500_tlb(vcpu, sregs);
sregs->u.e.ivor_high[3] =
vcpu->arch.ivor[BOOKE_IRQPRIO_PERFORMANCE_MONITOR];
sregs->u.e.ivor_high[4] = vcpu->arch.ivor[BOOKE_IRQPRIO_DBELL];
sregs->u.e.ivor_high[5] = vcpu->arch.ivor[BOOKE_IRQPRIO_DBELL_CRIT];
return kvmppc_get_sregs_ivor(vcpu, sregs);
}
static int kvmppc_core_set_sregs_e500mc(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
int ret;
if (sregs->u.e.impl_id == KVM_SREGS_E_IMPL_FSL) {
vcpu_e500->svr = sregs->u.e.impl.fsl.svr;
vcpu_e500->hid0 = sregs->u.e.impl.fsl.hid0;
vcpu_e500->mcar = sregs->u.e.impl.fsl.mcar;
}
ret = kvmppc_set_sregs_e500_tlb(vcpu, sregs);
if (ret < 0)
return ret;
if (!(sregs->u.e.features & KVM_SREGS_E_IVOR))
return 0;
if (sregs->u.e.features & KVM_SREGS_E_PM) {
vcpu->arch.ivor[BOOKE_IRQPRIO_PERFORMANCE_MONITOR] =
sregs->u.e.ivor_high[3];
}
if (sregs->u.e.features & KVM_SREGS_E_PC) {
vcpu->arch.ivor[BOOKE_IRQPRIO_DBELL] =
sregs->u.e.ivor_high[4];
vcpu->arch.ivor[BOOKE_IRQPRIO_DBELL_CRIT] =
sregs->u.e.ivor_high[5];
}
return kvmppc_set_sregs_ivor(vcpu, sregs);
}
static int kvmppc_get_one_reg_e500mc(struct kvm_vcpu *vcpu, u64 id,
union kvmppc_one_reg *val)
{
int r = 0;
switch (id) {
case KVM_REG_PPC_SPRG9:
*val = get_reg_val(id, vcpu->arch.sprg9);
break;
default:
r = kvmppc_get_one_reg_e500_tlb(vcpu, id, val);
}
return r;
}
static int kvmppc_set_one_reg_e500mc(struct kvm_vcpu *vcpu, u64 id,
union kvmppc_one_reg *val)
{
int r = 0;
switch (id) {
case KVM_REG_PPC_SPRG9:
vcpu->arch.sprg9 = set_reg_val(id, *val);
break;
default:
r = kvmppc_set_one_reg_e500_tlb(vcpu, id, val);
}
return r;
}
static struct kvm_vcpu *kvmppc_core_vcpu_create_e500mc(struct kvm *kvm,
unsigned int id)
{
struct kvmppc_vcpu_e500 *vcpu_e500;
struct kvm_vcpu *vcpu;
int err;
vcpu_e500 = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
if (!vcpu_e500) {
err = -ENOMEM;
goto out;
}
vcpu = &vcpu_e500->vcpu;
/* Invalid PIR value -- this LPID dosn't have valid state on any cpu */
vcpu->arch.oldpir = 0xffffffff;
err = kvm_vcpu_init(vcpu, kvm, id);
if (err)
goto free_vcpu;
err = kvmppc_e500_tlb_init(vcpu_e500);
if (err)
goto uninit_vcpu;
vcpu->arch.shared = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
if (!vcpu->arch.shared)
goto uninit_tlb;
return vcpu;
uninit_tlb:
kvmppc_e500_tlb_uninit(vcpu_e500);
uninit_vcpu:
kvm_vcpu_uninit(vcpu);
free_vcpu:
kmem_cache_free(kvm_vcpu_cache, vcpu_e500);
out:
return ERR_PTR(err);
}
static void kvmppc_core_vcpu_free_e500mc(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
free_page((unsigned long)vcpu->arch.shared);
kvmppc_e500_tlb_uninit(vcpu_e500);
kvm_vcpu_uninit(vcpu);
kmem_cache_free(kvm_vcpu_cache, vcpu_e500);
}
static int kvmppc_core_init_vm_e500mc(struct kvm *kvm)
{
int lpid;
lpid = kvmppc_alloc_lpid();
if (lpid < 0)
return lpid;
/*
* Use two lpids per VM on cores with two threads like e6500. Use
* even numbers to speedup vcpu lpid computation with consecutive lpids
* per VM. vm1 will use lpids 2 and 3, vm2 lpids 4 and 5, and so on.
*/
if (threads_per_core == 2)
lpid <<= 1;
kvm->arch.lpid = lpid;
return 0;
}
static void kvmppc_core_destroy_vm_e500mc(struct kvm *kvm)
{
int lpid = kvm->arch.lpid;
if (threads_per_core == 2)
lpid >>= 1;
kvmppc_free_lpid(lpid);
}
static struct kvmppc_ops kvm_ops_e500mc = {
.get_sregs = kvmppc_core_get_sregs_e500mc,
.set_sregs = kvmppc_core_set_sregs_e500mc,
.get_one_reg = kvmppc_get_one_reg_e500mc,
.set_one_reg = kvmppc_set_one_reg_e500mc,
.vcpu_load = kvmppc_core_vcpu_load_e500mc,
.vcpu_put = kvmppc_core_vcpu_put_e500mc,
.vcpu_create = kvmppc_core_vcpu_create_e500mc,
.vcpu_free = kvmppc_core_vcpu_free_e500mc,
.mmu_destroy = kvmppc_mmu_destroy_e500,
.init_vm = kvmppc_core_init_vm_e500mc,
.destroy_vm = kvmppc_core_destroy_vm_e500mc,
.emulate_op = kvmppc_core_emulate_op_e500,
.emulate_mtspr = kvmppc_core_emulate_mtspr_e500,
.emulate_mfspr = kvmppc_core_emulate_mfspr_e500,
};
static int __init kvmppc_e500mc_init(void)
{
int r;
r = kvmppc_booke_init();
if (r)
goto err_out;
/*
* Use two lpids per VM on dual threaded processors like e6500
* to workarround the lack of tlb write conditional instruction.
* Expose half the number of available hardware lpids to the lpid
* allocator.
*/
kvmppc_init_lpid(KVMPPC_NR_LPIDS/threads_per_core);
kvmppc_claim_lpid(0); /* host */
r = kvm_init(NULL, sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
if (r)
goto err_out;
kvm_ops_e500mc.owner = THIS_MODULE;
kvmppc_pr_ops = &kvm_ops_e500mc;
err_out:
return r;
}
static void __exit kvmppc_e500mc_exit(void)
{
kvmppc_pr_ops = NULL;
kvmppc_booke_exit();
}
module_init(kvmppc_e500mc_init);
module_exit(kvmppc_e500mc_exit);
MODULE_ALIAS_MISCDEV(KVM_MINOR);
MODULE_ALIAS("devname:kvm");
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