/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* KVM/MIPS TLB handling, this file is part of the Linux host kernel so that
* TLB handlers run from KSEG0
*
* Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved.
* Authors: Sanjay Lal <sanjayl@kymasys.com>
*/
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/kvm_host.h>
#include <linux/srcu.h>
#include <asm/cpu.h>
#include <asm/bootinfo.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
#include <asm/tlb.h>
#include <asm/tlbdebug.h>
#undef [31mCONFIG_MIPS_MT[0m
#include <asm/r4kcache.h>
#define [31mCONFIG_MIPS_MT[0m
#define KVM_GUEST_PC_TLB 0
#define KVM_GUEST_SP_TLB 1
atomic_t kvm_mips_instance;
EXPORT_SYMBOL_GPL(kvm_mips_instance);
static u32 kvm_mips_get_kernel_asid(struct kvm_vcpu *vcpu)
{
int cpu = smp_processor_id();
return vcpu->arch.guest_kernel_asid[cpu] &
cpu_asid_mask(&cpu_data[cpu]);
}
static u32 kvm_mips_get_user_asid(struct kvm_vcpu *vcpu)
{
int cpu = smp_processor_id();
return vcpu->arch.guest_user_asid[cpu] &
cpu_asid_mask(&cpu_data[cpu]);
}
inline u32 kvm_mips_get_commpage_asid(struct kvm_vcpu *vcpu)
{
return vcpu->kvm->arch.commpage_tlb;
}
/* Structure defining an tlb entry data set. */
void kvm_mips_dump_host_tlbs(void)
{
unsigned long flags;
local_irq_save(flags);
kvm_info("HOST TLBs:\n");
dump_tlb_regs();
pr_info("\n");
dump_tlb_all();
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(kvm_mips_dump_host_tlbs);
void kvm_mips_dump_guest_tlbs(struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_mips_tlb tlb;
int i;
kvm_info("Guest TLBs:\n");
kvm_info("Guest EntryHi: %#lx\n", kvm_read_c0_guest_entryhi(cop0));
for (i = 0; i < KVM_MIPS_GUEST_TLB_SIZE; i++) {
tlb = vcpu->arch.guest_tlb[i];
kvm_info("TLB%c%3d Hi 0x%08lx ",
(tlb.tlb_lo[0] | tlb.tlb_lo[1]) & ENTRYLO_V
? ' ' : '*',
i, tlb.tlb_hi);
kvm_info("Lo0=0x%09llx %c%c attr %lx ",
(u64) mips3_tlbpfn_to_paddr(tlb.tlb_lo[0]),
(tlb.tlb_lo[0] & ENTRYLO_D) ? 'D' : ' ',
(tlb.tlb_lo[0] & ENTRYLO_G) ? 'G' : ' ',
(tlb.tlb_lo[0] & ENTRYLO_C) >> ENTRYLO_C_SHIFT);
kvm_info("Lo1=0x%09llx %c%c attr %lx sz=%lx\n",
(u64) mips3_tlbpfn_to_paddr(tlb.tlb_lo[1]),
(tlb.tlb_lo[1] & ENTRYLO_D) ? 'D' : ' ',
(tlb.tlb_lo[1] & ENTRYLO_G) ? 'G' : ' ',
(tlb.tlb_lo[1] & ENTRYLO_C) >> ENTRYLO_C_SHIFT,
tlb.tlb_mask);
}
}
EXPORT_SYMBOL_GPL(kvm_mips_dump_guest_tlbs);
/* XXXKYMA: Must be called with interrupts disabled */
/* set flush_dcache_mask == 0 if no dcache flush required */
int kvm_mips_host_tlb_write(struct kvm_vcpu *vcpu, unsigned long entryhi,
unsigned long entrylo0, unsigned long entrylo1,
int flush_dcache_mask)
{
unsigned long flags;
unsigned long old_entryhi;
int idx;
local_irq_save(flags);
old_entryhi = read_c0_entryhi();
write_c0_entryhi(entryhi);
mtc0_tlbw_hazard();
tlb_probe();
tlb_probe_hazard();
idx = read_c0_index();
if (idx > current_cpu_data.tlbsize) {
kvm_err("%s: Invalid Index: %d\n", __func__, idx);
kvm_mips_dump_host_tlbs();
local_irq_restore(flags);
return -1;
}
write_c0_entrylo0(entrylo0);
write_c0_entrylo1(entrylo1);
mtc0_tlbw_hazard();
if (idx < 0)
tlb_write_random();
else
tlb_write_indexed();
tlbw_use_hazard();
kvm_debug("@ %#lx idx: %2d [entryhi(R): %#lx] entrylo0(R): 0x%08lx, entrylo1(R): 0x%08lx\n",
vcpu->arch.pc, idx, read_c0_entryhi(),
read_c0_entrylo0(), read_c0_entrylo1());
/* Flush D-cache */
if (flush_dcache_mask) {
if (entrylo0 & ENTRYLO_V) {
++vcpu->stat.flush_dcache_exits;
flush_data_cache_page((entryhi & VPN2_MASK) &
~flush_dcache_mask);
}
if (entrylo1 & ENTRYLO_V) {
++vcpu->stat.flush_dcache_exits;
flush_data_cache_page(((entryhi & VPN2_MASK) &
~flush_dcache_mask) |
(0x1 << PAGE_SHIFT));
}
}
/* Restore old ASID */
write_c0_entryhi(old_entryhi);
mtc0_tlbw_hazard();
local_irq_restore(flags);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_mips_host_tlb_write);
int kvm_mips_handle_commpage_tlb_fault(unsigned long badvaddr,
struct kvm_vcpu *vcpu)
{
kvm_pfn_t pfn;
unsigned long flags, old_entryhi = 0, vaddr = 0;
unsigned long entrylo[2] = { 0, 0 };
unsigned int pair_idx;
pfn = PFN_DOWN(virt_to_phys(vcpu->arch.kseg0_commpage));
pair_idx = (badvaddr >> PAGE_SHIFT) & 1;
entrylo[pair_idx] = mips3_paddr_to_tlbpfn(pfn << PAGE_SHIFT) |
((_page_cachable_default >> _CACHE_SHIFT) << ENTRYLO_C_SHIFT) |
ENTRYLO_D | ENTRYLO_V;
local_irq_save(flags);
old_entryhi = read_c0_entryhi();
vaddr = badvaddr & (PAGE_MASK << 1);
write_c0_entryhi(vaddr | kvm_mips_get_kernel_asid(vcpu));
write_c0_entrylo0(entrylo[0]);
write_c0_entrylo1(entrylo[1]);
write_c0_index(kvm_mips_get_commpage_asid(vcpu));
mtc0_tlbw_hazard();
tlb_write_indexed();
tlbw_use_hazard();
kvm_debug("@ %#lx idx: %2d [entryhi(R): %#lx] entrylo0 (R): 0x%08lx, entrylo1(R): 0x%08lx\n",
vcpu->arch.pc, read_c0_index(), read_c0_entryhi(),
read_c0_entrylo0(), read_c0_entrylo1());
/* Restore old ASID */
write_c0_entryhi(old_entryhi);
mtc0_tlbw_hazard();
local_irq_restore(flags);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_mips_handle_commpage_tlb_fault);
int kvm_mips_guest_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long entryhi)
{
int i;
int index = -1;
struct kvm_mips_tlb *tlb = vcpu->arch.guest_tlb;
for (i = 0; i < KVM_MIPS_GUEST_TLB_SIZE; i++) {
if (TLB_HI_VPN2_HIT(tlb[i], entryhi) &&
TLB_HI_ASID_HIT(tlb[i], entryhi)) {
index = i;
break;
}
}
kvm_debug("%s: entryhi: %#lx, index: %d lo0: %#lx, lo1: %#lx\n",
__func__, entryhi, index, tlb[i].tlb_lo[0], tlb[i].tlb_lo[1]);
return index;
}
EXPORT_SYMBOL_GPL(kvm_mips_guest_tlb_lookup);
int kvm_mips_host_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long vaddr)
{
unsigned long old_entryhi, flags;
int idx;
local_irq_save(flags);
old_entryhi = read_c0_entryhi();
if (KVM_GUEST_KERNEL_MODE(vcpu))
write_c0_entryhi((vaddr & VPN2_MASK) |
kvm_mips_get_kernel_asid(vcpu));
else {
write_c0_entryhi((vaddr & VPN2_MASK) |
kvm_mips_get_user_asid(vcpu));
}
mtc0_tlbw_hazard();
tlb_probe();
tlb_probe_hazard();
idx = read_c0_index();
/* Restore old ASID */
write_c0_entryhi(old_entryhi);
mtc0_tlbw_hazard();
local_irq_restore(flags);
kvm_debug("Host TLB lookup, %#lx, idx: %2d\n", vaddr, idx);
return idx;
}
EXPORT_SYMBOL_GPL(kvm_mips_host_tlb_lookup);
int kvm_mips_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long va)
{
int idx;
unsigned long flags, old_entryhi;
local_irq_save(flags);
old_entryhi = read_c0_entryhi();
write_c0_entryhi((va & VPN2_MASK) | kvm_mips_get_user_asid(vcpu));
mtc0_tlbw_hazard();
tlb_probe();
tlb_probe_hazard();
idx = read_c0_index();
if (idx >= current_cpu_data.tlbsize)
BUG();
if (idx > 0) {
write_c0_entryhi(UNIQUE_ENTRYHI(idx));
write_c0_entrylo0(0);
write_c0_entrylo1(0);
mtc0_tlbw_hazard();
tlb_write_indexed();
tlbw_use_hazard();
}
write_c0_entryhi(old_entryhi);
mtc0_tlbw_hazard();
local_irq_restore(flags);
if (idx > 0)
kvm_debug("%s: Invalidated entryhi %#lx @ idx %d\n", __func__,
(va & VPN2_MASK) | kvm_mips_get_user_asid(vcpu), idx);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_mips_host_tlb_inv);
void kvm_mips_flush_host_tlb(int skip_kseg0)
{
unsigned long flags;
unsigned long old_entryhi, entryhi;
unsigned long old_pagemask;
int entry = 0;
int maxentry = current_cpu_data.tlbsize;
local_irq_save(flags);
old_entryhi = read_c0_entryhi();
old_pagemask = read_c0_pagemask();
/* Blast 'em all away. */
for (entry = 0; entry < maxentry; entry++) {
write_c0_index(entry);
if (skip_kseg0) {
mtc0_tlbr_hazard();
tlb_read();
tlb_read_hazard();
entryhi = read_c0_entryhi();
/* Don't blow away guest kernel entries */
if (KVM_GUEST_KSEGX(entryhi) == KVM_GUEST_KSEG0)
continue;
write_c0_pagemask(old_pagemask);
}
/* Make sure all entries differ. */
write_c0_entryhi(UNIQUE_ENTRYHI(entry));
write_c0_entrylo0(0);
write_c0_entrylo1(0);
mtc0_tlbw_hazard();
tlb_write_indexed();
tlbw_use_hazard();
}
write_c0_entryhi(old_entryhi);
write_c0_pagemask(old_pagemask);
mtc0_tlbw_hazard();
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(kvm_mips_flush_host_tlb);
void kvm_local_flush_tlb_all(void)
{
unsigned long flags;
unsigned long old_ctx;
int entry = 0;
local_irq_save(flags);
/* Save old context and create impossible VPN2 value */
old_ctx = read_c0_entryhi();
write_c0_entrylo0(0);
write_c0_entrylo1(0);
/* Blast 'em all away. */
while (entry < current_cpu_data.tlbsize) {
/* Make sure all entries differ. */
write_c0_entryhi(UNIQUE_ENTRYHI(entry));
write_c0_index(entry);
mtc0_tlbw_hazard();
tlb_write_indexed();
tlbw_use_hazard();
entry++;
}
write_c0_entryhi(old_ctx);
mtc0_tlbw_hazard();
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(kvm_local_flush_tlb_all);