kernel-fxtec-pro1x/arch/powerpc/include/asm/kvm_book3s_64.h
Paul Mackerras 075295dd32 KVM: PPC: Make the H_ENTER hcall more reliable
At present, our implementation of H_ENTER only makes one try at locking
each slot that it looks at, and doesn't even retry the ldarx/stdcx.
atomic update sequence that it uses to attempt to lock the slot.  Thus
it can return the H_PTEG_FULL error unnecessarily, particularly when
the H_EXACT flag is set, meaning that the caller wants a specific PTEG
slot.

This improves the situation by making a second pass when no free HPTE
slot is found, where we spin until we succeed in locking each slot in
turn and then check whether it is full while we hold the lock.  If the
second pass fails, then we return H_PTEG_FULL.

This also moves lock_hpte to a header file (since later commits in this
series will need to use it from other source files) and renames it to
try_lock_hpte, which is a somewhat less misleading name.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:52:36 +02:00

104 lines
2.9 KiB
C

/*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright SUSE Linux Products GmbH 2010
*
* Authors: Alexander Graf <agraf@suse.de>
*/
#ifndef __ASM_KVM_BOOK3S_64_H__
#define __ASM_KVM_BOOK3S_64_H__
#ifdef CONFIG_KVM_BOOK3S_PR
static inline struct kvmppc_book3s_shadow_vcpu *svcpu_get(struct kvm_vcpu *vcpu)
{
preempt_disable();
return &get_paca()->shadow_vcpu;
}
static inline void svcpu_put(struct kvmppc_book3s_shadow_vcpu *svcpu)
{
preempt_enable();
}
#endif
#define SPAPR_TCE_SHIFT 12
#ifdef CONFIG_KVM_BOOK3S_64_HV
/* For now use fixed-size 16MB page table */
#define HPT_ORDER 24
#define HPT_NPTEG (1ul << (HPT_ORDER - 7)) /* 128B per pteg */
#define HPT_NPTE (HPT_NPTEG << 3) /* 8 PTEs per PTEG */
#define HPT_HASH_MASK (HPT_NPTEG - 1)
#endif
/*
* We use a lock bit in HPTE dword 0 to synchronize updates and
* accesses to each HPTE, and another bit to indicate non-present
* HPTEs.
*/
#define HPTE_V_HVLOCK 0x40UL
static inline long try_lock_hpte(unsigned long *hpte, unsigned long bits)
{
unsigned long tmp, old;
asm volatile(" ldarx %0,0,%2\n"
" and. %1,%0,%3\n"
" bne 2f\n"
" ori %0,%0,%4\n"
" stdcx. %0,0,%2\n"
" beq+ 2f\n"
" li %1,%3\n"
"2: isync"
: "=&r" (tmp), "=&r" (old)
: "r" (hpte), "r" (bits), "i" (HPTE_V_HVLOCK)
: "cc", "memory");
return old == 0;
}
static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r,
unsigned long pte_index)
{
unsigned long rb, va_low;
rb = (v & ~0x7fUL) << 16; /* AVA field */
va_low = pte_index >> 3;
if (v & HPTE_V_SECONDARY)
va_low = ~va_low;
/* xor vsid from AVA */
if (!(v & HPTE_V_1TB_SEG))
va_low ^= v >> 12;
else
va_low ^= v >> 24;
va_low &= 0x7ff;
if (v & HPTE_V_LARGE) {
rb |= 1; /* L field */
if (cpu_has_feature(CPU_FTR_ARCH_206) &&
(r & 0xff000)) {
/* non-16MB large page, must be 64k */
/* (masks depend on page size) */
rb |= 0x1000; /* page encoding in LP field */
rb |= (va_low & 0x7f) << 16; /* 7b of VA in AVA/LP field */
rb |= (va_low & 0xfe); /* AVAL field (P7 doesn't seem to care) */
}
} else {
/* 4kB page */
rb |= (va_low & 0x7ff) << 12; /* remaining 11b of VA */
}
rb |= (v >> 54) & 0x300; /* B field */
return rb;
}
#endif /* __ASM_KVM_BOOK3S_64_H__ */