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linux/arch/powerpc/kvm/e500.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

580 lines
15 KiB
C
Raw Blame History

/*
* Copyright (C) 2008-2011 Freescale Semiconductor, Inc. All rights reserved.
*
* Author: Yu Liu, <yu.liu@freescale.com>
*
* Description:
* This file is derived from arch/powerpc/kvm/44x.c,
* by Hollis Blanchard <hollisb@us.ibm.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/module.h>
#include <linux/miscdevice.h>
#include <asm/reg.h>
#include <asm/cputable.h>
#include <asm/tlbflush.h>
#include <asm/kvm_ppc.h>
#include "../mm/mmu_decl.h"
#include "booke.h"
#include "e500.h"
struct id {
unsigned long val;
struct id **pentry;
};
#define NUM_TIDS 256
/*
* This table provide mappings from:
* (guestAS,guestTID,guestPR) --> ID of physical cpu
* guestAS [0..1]
* guestTID [0..255]
* guestPR [0..1]
* ID [1..255]
* Each vcpu keeps one vcpu_id_table.
*/
struct vcpu_id_table {
struct id id[2][NUM_TIDS][2];
};
/*
* This table provide reversed mappings of vcpu_id_table:
* ID --> address of vcpu_id_table item.
* Each physical core has one pcpu_id_table.
*/
struct pcpu_id_table {
struct id *entry[NUM_TIDS];
};
static DEFINE_PER_CPU(struct pcpu_id_table, pcpu_sids);
/* This variable keeps last used shadow ID on local core.
* The valid range of shadow ID is [1..255] */
static DEFINE_PER_CPU(unsigned long, pcpu_last_used_sid);
/*
* Allocate a free shadow id and setup a valid sid mapping in given entry.
* A mapping is only valid when vcpu_id_table and pcpu_id_table are match.
*
* The caller must have preemption disabled, and keep it that way until
* it has finished with the returned shadow id (either written into the
* TLB or arch.shadow_pid, or discarded).
*/
static inline int local_sid_setup_one(struct id *entry)
{
unsigned long sid;
int ret = -1;
sid = __this_cpu_inc_return(pcpu_last_used_sid);
if (sid < NUM_TIDS) {
__this_cpu_write(pcpu_sids)entry[sid], entry);
entry->val = sid;
entry->pentry = this_cpu_ptr(&pcpu_sids.entry[sid]);
ret = sid;
}
/*
* If sid == NUM_TIDS, we've run out of sids. We return -1, and
* the caller will invalidate everything and start over.
*
* sid > NUM_TIDS indicates a race, which we disable preemption to
* avoid.
*/
WARN_ON(sid > NUM_TIDS);
return ret;
}
/*
* Check if given entry contain a valid shadow id mapping.
* An ID mapping is considered valid only if
* both vcpu and pcpu know this mapping.
*
* The caller must have preemption disabled, and keep it that way until
* it has finished with the returned shadow id (either written into the
* TLB or arch.shadow_pid, or discarded).
*/
static inline int local_sid_lookup(struct id *entry)
{
if (entry && entry->val != 0 &&
__this_cpu_read(pcpu_sids.entry[entry->val]) == entry &&
entry->pentry == this_cpu_ptr(&pcpu_sids.entry[entry->val]))
return entry->val;
return -1;
}
/* Invalidate all id mappings on local core -- call with preempt disabled */
static inline void local_sid_destroy_all(void)
{
__this_cpu_write(pcpu_last_used_sid, 0);
memset(this_cpu_ptr(&pcpu_sids), 0, sizeof(pcpu_sids));
}
static void *kvmppc_e500_id_table_alloc(struct kvmppc_vcpu_e500 *vcpu_e500)
{
vcpu_e500->idt = kzalloc(sizeof(struct vcpu_id_table), GFP_KERNEL);
return vcpu_e500->idt;
}
static void kvmppc_e500_id_table_free(struct kvmppc_vcpu_e500 *vcpu_e500)
{
kfree(vcpu_e500->idt);
vcpu_e500->idt = NULL;
}
/* Map guest pid to shadow.
* We use PID to keep shadow of current guest non-zero PID,
* and use PID1 to keep shadow of guest zero PID.
* So that guest tlbe with TID=0 can be accessed at any time */
static void kvmppc_e500_recalc_shadow_pid(struct kvmppc_vcpu_e500 *vcpu_e500)
{
preempt_disable();
vcpu_e500->vcpu.arch.shadow_pid = kvmppc_e500_get_sid(vcpu_e500,
get_cur_as(&vcpu_e500->vcpu),
get_cur_pid(&vcpu_e500->vcpu),
get_cur_pr(&vcpu_e500->vcpu), 1);
vcpu_e500->vcpu.arch.shadow_pid1 = kvmppc_e500_get_sid(vcpu_e500,
get_cur_as(&vcpu_e500->vcpu), 0,
get_cur_pr(&vcpu_e500->vcpu), 1);
preempt_enable();
}
/* Invalidate all mappings on vcpu */
static void kvmppc_e500_id_table_reset_all(struct kvmppc_vcpu_e500 *vcpu_e500)
{
memset(vcpu_e500->idt, 0, sizeof(struct vcpu_id_table));
/* Update shadow pid when mappings are changed */
kvmppc_e500_recalc_shadow_pid(vcpu_e500);
}
/* Invalidate one ID mapping on vcpu */
static inline void kvmppc_e500_id_table_reset_one(
struct kvmppc_vcpu_e500 *vcpu_e500,
int as, int pid, int pr)
{
struct vcpu_id_table *idt = vcpu_e500->idt;
BUG_ON(as >= 2);
BUG_ON(pid >= NUM_TIDS);
BUG_ON(pr >= 2);
idt->id[as][pid][pr].val = 0;
idt->id[as][pid][pr].pentry = NULL;
/* Update shadow pid when mappings are changed */
kvmppc_e500_recalc_shadow_pid(vcpu_e500);
}
/*
* Map guest (vcpu,AS,ID,PR) to physical core shadow id.
* This function first lookup if a valid mapping exists,
* if not, then creates a new one.
*
* The caller must have preemption disabled, and keep it that way until
* it has finished with the returned shadow id (either written into the
* TLB or arch.shadow_pid, or discarded).
*/
unsigned int kvmppc_e500_get_sid(struct kvmppc_vcpu_e500 *vcpu_e500,
unsigned int as, unsigned int gid,
unsigned int pr, int avoid_recursion)
{
struct vcpu_id_table *idt = vcpu_e500->idt;
int sid;
BUG_ON(as >= 2);
BUG_ON(gid >= NUM_TIDS);
BUG_ON(pr >= 2);
sid = local_sid_lookup(&idt->id[as][gid][pr]);
while (sid <= 0) {
/* No mapping yet */
sid = local_sid_setup_one(&idt->id[as][gid][pr]);
if (sid <= 0) {
_tlbil_all();
local_sid_destroy_all();
}
/* Update shadow pid when mappings are changed */
if (!avoid_recursion)
kvmppc_e500_recalc_shadow_pid(vcpu_e500);
}
return sid;
}
unsigned int kvmppc_e500_get_tlb_stid(struct kvm_vcpu *vcpu,
struct kvm_book3e_206_tlb_entry *gtlbe)
{
return kvmppc_e500_get_sid(to_e500(vcpu), get_tlb_ts(gtlbe),
get_tlb_tid(gtlbe), get_cur_pr(vcpu), 0);
}
void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 pid)
{
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
if (vcpu->arch.pid != pid) {
vcpu_e500->pid[0] = vcpu->arch.pid = pid;
kvmppc_e500_recalc_shadow_pid(vcpu_e500);
}
}
/* gtlbe must not be mapped by more than one host tlbe */
void kvmppc_e500_tlbil_one(struct kvmppc_vcpu_e500 *vcpu_e500,
struct kvm_book3e_206_tlb_entry *gtlbe)
{
struct vcpu_id_table *idt = vcpu_e500->idt;
unsigned int pr, tid, ts, pid;
u32 val, eaddr;
unsigned long flags;
ts = get_tlb_ts(gtlbe);
tid = get_tlb_tid(gtlbe);
preempt_disable();
/* One guest ID may be mapped to two shadow IDs */
for (pr = 0; pr < 2; pr++) {
/*
* The shadow PID can have a valid mapping on at most one
* host CPU. In the common case, it will be valid on this
* CPU, in which case we do a local invalidation of the
* specific address.
*
* If the shadow PID is not valid on the current host CPU,
* we invalidate the entire shadow PID.
*/
pid = local_sid_lookup(&idt->id[ts][tid][pr]);
if (pid <= 0) {
kvmppc_e500_id_table_reset_one(vcpu_e500, ts, tid, pr);
continue;
}
/*
* The guest is invalidating a 4K entry which is in a PID
* that has a valid shadow mapping on this host CPU. We
* search host TLB to invalidate it's shadow TLB entry,
* similar to __tlbil_va except that we need to look in AS1.
*/
val = (pid << MAS6_SPID_SHIFT) | MAS6_SAS;
eaddr = get_tlb_eaddr(gtlbe);
local_irq_save(flags);
mtspr(SPRN_MAS6, val);
asm volatile("tlbsx 0, %[eaddr]" : : [eaddr] "r" (eaddr));
val = mfspr(SPRN_MAS1);
if (val & MAS1_VALID) {
mtspr(SPRN_MAS1, val & ~MAS1_VALID);
asm volatile("tlbwe");
}
local_irq_restore(flags);
}
preempt_enable();
}
void kvmppc_e500_tlbil_all(struct kvmppc_vcpu_e500 *vcpu_e500)
{
kvmppc_e500_id_table_reset_all(vcpu_e500);
}
void kvmppc_mmu_msr_notify(struct kvm_vcpu *vcpu, u32 old_msr)
{
/* Recalc shadow pid since MSR changes */
kvmppc_e500_recalc_shadow_pid(to_e500(vcpu));
}
void kvmppc_core_load_host_debugstate(struct kvm_vcpu *vcpu)
{
}
void kvmppc_core_load_guest_debugstate(struct kvm_vcpu *vcpu)
{
}
static void kvmppc_core_vcpu_load_e500(struct kvm_vcpu *vcpu, int cpu)
{
kvmppc_booke_vcpu_load(vcpu, cpu);
/* Shadow PID may be expired on local core */
kvmppc_e500_recalc_shadow_pid(to_e500(vcpu));
}
static void kvmppc_core_vcpu_put_e500(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_SPE
if (vcpu->arch.shadow_msr & MSR_SPE)
kvmppc_vcpu_disable_spe(vcpu);
#endif
kvmppc_booke_vcpu_put(vcpu);
}
int kvmppc_core_check_processor_compat(void)
{
int r;
if (strcmp(cur_cpu_spec->cpu_name, "e500v2") == 0)
r = 0;
else
r = -ENOTSUPP;
return r;
}
static void kvmppc_e500_tlb_setup(struct kvmppc_vcpu_e500 *vcpu_e500)
{
struct kvm_book3e_206_tlb_entry *tlbe;
/* Insert large initial mapping for guest. */
tlbe = get_entry(vcpu_e500, 1, 0);
tlbe->mas1 = MAS1_VALID | MAS1_TSIZE(BOOK3E_PAGESZ_256M);
tlbe->mas2 = 0;
tlbe->mas7_3 = E500_TLB_SUPER_PERM_MASK;
/* 4K map for serial output. Used by kernel wrapper. */
tlbe = get_entry(vcpu_e500, 1, 1);
tlbe->mas1 = MAS1_VALID | MAS1_TSIZE(BOOK3E_PAGESZ_4K);
tlbe->mas2 = (0xe0004500 & 0xFFFFF000) | MAS2_I | MAS2_G;
tlbe->mas7_3 = (0xe0004500 & 0xFFFFF000) | E500_TLB_SUPER_PERM_MASK;
}
int kvmppc_core_vcpu_setup(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
kvmppc_e500_tlb_setup(vcpu_e500);
/* Registers init */
vcpu->arch.pvr = mfspr(SPRN_PVR);
vcpu_e500->svr = mfspr(SPRN_SVR);
vcpu->arch.cpu_type = KVM_CPU_E500V2;
return 0;
}
static int kvmppc_core_get_sregs_e500(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_SPE |
KVM_SREGS_E_PM;
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;
sregs->u.e.ivor_high[0] = vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_UNAVAIL];
sregs->u.e.ivor_high[1] = vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_FP_DATA];
sregs->u.e.ivor_high[2] = vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_FP_ROUND];
sregs->u.e.ivor_high[3] =
vcpu->arch.ivor[BOOKE_IRQPRIO_PERFORMANCE_MONITOR];
kvmppc_get_sregs_ivor(vcpu, sregs);
kvmppc_get_sregs_e500_tlb(vcpu, sregs);
return 0;
}
static int kvmppc_core_set_sregs_e500(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_SPE) {
vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_UNAVAIL] =
sregs->u.e.ivor_high[0];
vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_FP_DATA] =
sregs->u.e.ivor_high[1];
vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_FP_ROUND] =
sregs->u.e.ivor_high[2];
}
if (sregs->u.e.features & KVM_SREGS_E_PM) {
vcpu->arch.ivor[BOOKE_IRQPRIO_PERFORMANCE_MONITOR] =
sregs->u.e.ivor_high[3];
}
return kvmppc_set_sregs_ivor(vcpu, sregs);
}
static int kvmppc_get_one_reg_e500(struct kvm_vcpu *vcpu, u64 id,
union kvmppc_one_reg *val)
{
int r = kvmppc_get_one_reg_e500_tlb(vcpu, id, val);
return r;
}
static int kvmppc_set_one_reg_e500(struct kvm_vcpu *vcpu, u64 id,
union kvmppc_one_reg *val)
{
int r = kvmppc_get_one_reg_e500_tlb(vcpu, id, val);
return r;
}
static struct kvm_vcpu *kvmppc_core_vcpu_create_e500(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;
err = kvm_vcpu_init(vcpu, kvm, id);
if (err)
goto free_vcpu;
if (kvmppc_e500_id_table_alloc(vcpu_e500) == NULL)
goto uninit_vcpu;
err = kvmppc_e500_tlb_init(vcpu_e500);
if (err)
goto uninit_id;
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_id:
kvmppc_e500_id_table_free(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_e500(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);
kvmppc_e500_id_table_free(vcpu_e500);
kvm_vcpu_uninit(vcpu);
kmem_cache_free(kvm_vcpu_cache, vcpu_e500);
}
static int kvmppc_core_init_vm_e500(struct kvm *kvm)
{
return 0;
}
static void kvmppc_core_destroy_vm_e500(struct kvm *kvm)
{
}
static struct kvmppc_ops kvm_ops_e500 = {
.get_sregs = kvmppc_core_get_sregs_e500,
.set_sregs = kvmppc_core_set_sregs_e500,
.get_one_reg = kvmppc_get_one_reg_e500,
.set_one_reg = kvmppc_set_one_reg_e500,
.vcpu_load = kvmppc_core_vcpu_load_e500,
.vcpu_put = kvmppc_core_vcpu_put_e500,
.vcpu_create = kvmppc_core_vcpu_create_e500,
.vcpu_free = kvmppc_core_vcpu_free_e500,
.mmu_destroy = kvmppc_mmu_destroy_e500,
.init_vm = kvmppc_core_init_vm_e500,
.destroy_vm = kvmppc_core_destroy_vm_e500,
.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_e500_init(void)
{
int r, i;
unsigned long ivor[3];
/* Process remaining handlers above the generic first 16 */
unsigned long *handler = &kvmppc_booke_handler_addr[16];
unsigned long handler_len;
unsigned long max_ivor = 0;
r = kvmppc_core_check_processor_compat();
if (r)
goto err_out;
r = kvmppc_booke_init();
if (r)
goto err_out;
/* copy extra E500 exception handlers */
ivor[0] = mfspr(SPRN_IVOR32);
ivor[1] = mfspr(SPRN_IVOR33);
ivor[2] = mfspr(SPRN_IVOR34);
for (i = 0; i < 3; i++) {
if (ivor[i] > ivor[max_ivor])
max_ivor = i;
handler_len = handler[i + 1] - handler[i];
memcpy((void *)kvmppc_booke_handlers + ivor[i],
(void *)handler[i], handler_len);
}
handler_len = handler[max_ivor + 1] - handler[max_ivor];
flush_icache_range(kvmppc_booke_handlers, kvmppc_booke_handlers +
ivor[max_ivor] + handler_len);
r = kvm_init(NULL, sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
if (r)
goto err_out;
kvm_ops_e500.owner = THIS_MODULE;
kvmppc_pr_ops = &kvm_ops_e500;
err_out:
return r;
}
static void __exit kvmppc_e500_exit(void)
{
kvmppc_pr_ops = NULL;
kvmppc_booke_exit();
}
module_init(kvmppc_e500_init);
module_exit(kvmppc_e500_exit);
MODULE_ALIAS_MISCDEV(KVM_MINOR);
MODULE_ALIAS("devname:kvm");
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