diff options
Diffstat (limited to 'arch/mips/kvm/tlb.c')
| -rw-r--r-- | arch/mips/kvm/tlb.c | 525 |
1 files changed, 525 insertions, 0 deletions
diff --git a/arch/mips/kvm/tlb.c b/arch/mips/kvm/tlb.c new file mode 100644 index 0000000000..4e91971daa --- /dev/null +++ b/arch/mips/kvm/tlb.c @@ -0,0 +1,525 @@ +/* + * 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/mipsregs.h> +#include <asm/mmu_context.h> +#include <asm/cacheflush.h> +#include <asm/tlb.h> +#include <asm/tlbdebug.h> + +#undef CONFIG_MIPS_MT +#include <asm/r4kcache.h> +#define CONFIG_MIPS_MT + +unsigned long GUESTID_MASK; +EXPORT_SYMBOL_GPL(GUESTID_MASK); +unsigned long GUESTID_FIRST_VERSION; +EXPORT_SYMBOL_GPL(GUESTID_FIRST_VERSION); +unsigned long GUESTID_VERSION_MASK; +EXPORT_SYMBOL_GPL(GUESTID_VERSION_MASK); + +static u32 kvm_mips_get_root_asid(struct kvm_vcpu *vcpu) +{ + struct mm_struct *gpa_mm = &vcpu->kvm->arch.gpa_mm; + + if (cpu_has_guestid) + return 0; + else + return cpu_asid(smp_processor_id(), gpa_mm); +} + +static int _kvm_mips_host_tlb_inv(unsigned long entryhi) +{ + int idx; + + write_c0_entryhi(entryhi); + mtc0_tlbw_hazard(); + + tlb_probe(); + tlb_probe_hazard(); + idx = read_c0_index(); + + BUG_ON(idx >= current_cpu_data.tlbsize); + + 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(); + } + + return idx; +} + +/* GuestID management */ + +/** + * clear_root_gid() - Set GuestCtl1.RID for normal root operation. + */ +static inline void clear_root_gid(void) +{ + if (cpu_has_guestid) { + clear_c0_guestctl1(MIPS_GCTL1_RID); + mtc0_tlbw_hazard(); + } +} + +/** + * set_root_gid_to_guest_gid() - Set GuestCtl1.RID to match GuestCtl1.ID. + * + * Sets the root GuestID to match the current guest GuestID, for TLB operation + * on the GPA->RPA mappings in the root TLB. + * + * The caller must be sure to disable HTW while the root GID is set, and + * possibly longer if TLB registers are modified. + */ +static inline void set_root_gid_to_guest_gid(void) +{ + unsigned int guestctl1; + + if (cpu_has_guestid) { + back_to_back_c0_hazard(); + guestctl1 = read_c0_guestctl1(); + guestctl1 = (guestctl1 & ~MIPS_GCTL1_RID) | + ((guestctl1 & MIPS_GCTL1_ID) >> MIPS_GCTL1_ID_SHIFT) + << MIPS_GCTL1_RID_SHIFT; + write_c0_guestctl1(guestctl1); + mtc0_tlbw_hazard(); + } +} + +int kvm_vz_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long va) +{ + int idx; + unsigned long flags, old_entryhi; + + local_irq_save(flags); + htw_stop(); + + /* Set root GuestID for root probe and write of guest TLB entry */ + set_root_gid_to_guest_gid(); + + old_entryhi = read_c0_entryhi(); + + idx = _kvm_mips_host_tlb_inv((va & VPN2_MASK) | + kvm_mips_get_root_asid(vcpu)); + + write_c0_entryhi(old_entryhi); + clear_root_gid(); + mtc0_tlbw_hazard(); + + htw_start(); + local_irq_restore(flags); + + /* + * We don't want to get reserved instruction exceptions for missing tlb + * entries. + */ + if (cpu_has_vtag_icache) + flush_icache_all(); + + if (idx > 0) + kvm_debug("%s: Invalidated root entryhi %#lx @ idx %d\n", + __func__, (va & VPN2_MASK) | + kvm_mips_get_root_asid(vcpu), idx); + + return 0; +} +EXPORT_SYMBOL_GPL(kvm_vz_host_tlb_inv); + +/** + * kvm_vz_guest_tlb_lookup() - Lookup a guest VZ TLB mapping. + * @vcpu: KVM VCPU pointer. + * @gpa: Guest virtual address in a TLB mapped guest segment. + * @gpa: Pointer to output guest physical address it maps to. + * + * Converts a guest virtual address in a guest TLB mapped segment to a guest + * physical address, by probing the guest TLB. + * + * Returns: 0 if guest TLB mapping exists for @gva. *@gpa will have been + * written. + * -EFAULT if no guest TLB mapping exists for @gva. *@gpa may not + * have been written. + */ +int kvm_vz_guest_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long gva, + unsigned long *gpa) +{ + unsigned long o_entryhi, o_entrylo[2], o_pagemask; + unsigned int o_index; + unsigned long entrylo[2], pagemask, pagemaskbit, pa; + unsigned long flags; + int index; + + /* Probe the guest TLB for a mapping */ + local_irq_save(flags); + /* Set root GuestID for root probe of guest TLB entry */ + htw_stop(); + set_root_gid_to_guest_gid(); + + o_entryhi = read_gc0_entryhi(); + o_index = read_gc0_index(); + + write_gc0_entryhi((o_entryhi & 0x3ff) | (gva & ~0xfffl)); + mtc0_tlbw_hazard(); + guest_tlb_probe(); + tlb_probe_hazard(); + + index = read_gc0_index(); + if (index < 0) { + /* No match, fail */ + write_gc0_entryhi(o_entryhi); + write_gc0_index(o_index); + + clear_root_gid(); + htw_start(); + local_irq_restore(flags); + return -EFAULT; + } + + /* Match! read the TLB entry */ + o_entrylo[0] = read_gc0_entrylo0(); + o_entrylo[1] = read_gc0_entrylo1(); + o_pagemask = read_gc0_pagemask(); + + mtc0_tlbr_hazard(); + guest_tlb_read(); + tlb_read_hazard(); + + entrylo[0] = read_gc0_entrylo0(); + entrylo[1] = read_gc0_entrylo1(); + pagemask = ~read_gc0_pagemask() & ~0x1fffl; + + write_gc0_entryhi(o_entryhi); + write_gc0_index(o_index); + write_gc0_entrylo0(o_entrylo[0]); + write_gc0_entrylo1(o_entrylo[1]); + write_gc0_pagemask(o_pagemask); + + clear_root_gid(); + htw_start(); + local_irq_restore(flags); + + /* Select one of the EntryLo values and interpret the GPA */ + pagemaskbit = (pagemask ^ (pagemask & (pagemask - 1))) >> 1; + pa = entrylo[!!(gva & pagemaskbit)]; + + /* + * TLB entry may have become invalid since TLB probe if physical FTLB + * entries are shared between threads (e.g. I6400). + */ + if (!(pa & ENTRYLO_V)) + return -EFAULT; + + /* + * Note, this doesn't take guest MIPS32 XPA into account, where PFN is + * split with XI/RI in the middle. + */ + pa = (pa << 6) & ~0xfffl; + pa |= gva & ~(pagemask | pagemaskbit); + + *gpa = pa; + return 0; +} +EXPORT_SYMBOL_GPL(kvm_vz_guest_tlb_lookup); + +/** + * kvm_vz_local_flush_roottlb_all_guests() - Flush all root TLB entries for + * guests. + * + * Invalidate all entries in root tlb which are GPA mappings. + */ +void kvm_vz_local_flush_roottlb_all_guests(void) +{ + unsigned long flags; + unsigned long old_entryhi, old_pagemask, old_guestctl1; + int entry; + + if (WARN_ON(!cpu_has_guestid)) + return; + + local_irq_save(flags); + htw_stop(); + + /* TLBR may clobber EntryHi.ASID, PageMask, and GuestCtl1.RID */ + old_entryhi = read_c0_entryhi(); + old_pagemask = read_c0_pagemask(); + old_guestctl1 = read_c0_guestctl1(); + + /* + * Invalidate guest entries in root TLB while leaving root entries + * intact when possible. + */ + for (entry = 0; entry < current_cpu_data.tlbsize; entry++) { + write_c0_index(entry); + mtc0_tlbw_hazard(); + tlb_read(); + tlb_read_hazard(); + + /* Don't invalidate non-guest (RVA) mappings in the root TLB */ + if (!(read_c0_guestctl1() & MIPS_GCTL1_RID)) + continue; + + /* Make sure all entries differ. */ + write_c0_entryhi(UNIQUE_ENTRYHI(entry)); + write_c0_entrylo0(0); + write_c0_entrylo1(0); + write_c0_guestctl1(0); + mtc0_tlbw_hazard(); + tlb_write_indexed(); + } + + write_c0_entryhi(old_entryhi); + write_c0_pagemask(old_pagemask); + write_c0_guestctl1(old_guestctl1); + tlbw_use_hazard(); + + htw_start(); + local_irq_restore(flags); +} +EXPORT_SYMBOL_GPL(kvm_vz_local_flush_roottlb_all_guests); + +/** + * kvm_vz_local_flush_guesttlb_all() - Flush all guest TLB entries. + * + * Invalidate all entries in guest tlb irrespective of guestid. + */ +void kvm_vz_local_flush_guesttlb_all(void) +{ + unsigned long flags; + unsigned long old_index; + unsigned long old_entryhi; + unsigned long old_entrylo[2]; + unsigned long old_pagemask; + int entry; + u64 cvmmemctl2 = 0; + + local_irq_save(flags); + + /* Preserve all clobbered guest registers */ + old_index = read_gc0_index(); + old_entryhi = read_gc0_entryhi(); + old_entrylo[0] = read_gc0_entrylo0(); + old_entrylo[1] = read_gc0_entrylo1(); + old_pagemask = read_gc0_pagemask(); + + switch (current_cpu_type()) { + case CPU_CAVIUM_OCTEON3: + /* Inhibit machine check due to multiple matching TLB entries */ + cvmmemctl2 = read_c0_cvmmemctl2(); + cvmmemctl2 |= CVMMEMCTL2_INHIBITTS; + write_c0_cvmmemctl2(cvmmemctl2); + break; + } + + /* Invalidate guest entries in guest TLB */ + write_gc0_entrylo0(0); + write_gc0_entrylo1(0); + write_gc0_pagemask(0); + for (entry = 0; entry < current_cpu_data.guest.tlbsize; entry++) { + /* Make sure all entries differ. */ + write_gc0_index(entry); + write_gc0_entryhi(UNIQUE_GUEST_ENTRYHI(entry)); + mtc0_tlbw_hazard(); + guest_tlb_write_indexed(); + } + + if (cvmmemctl2) { + cvmmemctl2 &= ~CVMMEMCTL2_INHIBITTS; + write_c0_cvmmemctl2(cvmmemctl2); + } + + write_gc0_index(old_index); + write_gc0_entryhi(old_entryhi); + write_gc0_entrylo0(old_entrylo[0]); + write_gc0_entrylo1(old_entrylo[1]); + write_gc0_pagemask(old_pagemask); + tlbw_use_hazard(); + + local_irq_restore(flags); +} +EXPORT_SYMBOL_GPL(kvm_vz_local_flush_guesttlb_all); + +/** + * kvm_vz_save_guesttlb() - Save a range of guest TLB entries. + * @buf: Buffer to write TLB entries into. + * @index: Start index. + * @count: Number of entries to save. + * + * Save a range of guest TLB entries. The caller must ensure interrupts are + * disabled. + */ +void kvm_vz_save_guesttlb(struct kvm_mips_tlb *buf, unsigned int index, + unsigned int count) +{ + unsigned int end = index + count; + unsigned long old_entryhi, old_entrylo0, old_entrylo1, old_pagemask; + unsigned int guestctl1 = 0; + int old_index, i; + + /* Save registers we're about to clobber */ + old_index = read_gc0_index(); + old_entryhi = read_gc0_entryhi(); + old_entrylo0 = read_gc0_entrylo0(); + old_entrylo1 = read_gc0_entrylo1(); + old_pagemask = read_gc0_pagemask(); + + /* Set root GuestID for root probe */ + htw_stop(); + set_root_gid_to_guest_gid(); + if (cpu_has_guestid) + guestctl1 = read_c0_guestctl1(); + + /* Read each entry from guest TLB */ + for (i = index; i < end; ++i, ++buf) { + write_gc0_index(i); + + mtc0_tlbr_hazard(); + guest_tlb_read(); + tlb_read_hazard(); + + if (cpu_has_guestid && + (read_c0_guestctl1() ^ guestctl1) & MIPS_GCTL1_RID) { + /* Entry invalid or belongs to another guest */ + buf->tlb_hi = UNIQUE_GUEST_ENTRYHI(i); + buf->tlb_lo[0] = 0; + buf->tlb_lo[1] = 0; + buf->tlb_mask = 0; + } else { + /* Entry belongs to the right guest */ + buf->tlb_hi = read_gc0_entryhi(); + buf->tlb_lo[0] = read_gc0_entrylo0(); + buf->tlb_lo[1] = read_gc0_entrylo1(); + buf->tlb_mask = read_gc0_pagemask(); + } + } + + /* Clear root GuestID again */ + clear_root_gid(); + htw_start(); + + /* Restore clobbered registers */ + write_gc0_index(old_index); + write_gc0_entryhi(old_entryhi); + write_gc0_entrylo0(old_entrylo0); + write_gc0_entrylo1(old_entrylo1); + write_gc0_pagemask(old_pagemask); + + tlbw_use_hazard(); +} +EXPORT_SYMBOL_GPL(kvm_vz_save_guesttlb); + +/** + * kvm_vz_load_guesttlb() - Save a range of guest TLB entries. + * @buf: Buffer to read TLB entries from. + * @index: Start index. + * @count: Number of entries to load. + * + * Load a range of guest TLB entries. The caller must ensure interrupts are + * disabled. + */ +void kvm_vz_load_guesttlb(const struct kvm_mips_tlb *buf, unsigned int index, + unsigned int count) +{ + unsigned int end = index + count; + unsigned long old_entryhi, old_entrylo0, old_entrylo1, old_pagemask; + int old_index, i; + + /* Save registers we're about to clobber */ + old_index = read_gc0_index(); + old_entryhi = read_gc0_entryhi(); + old_entrylo0 = read_gc0_entrylo0(); + old_entrylo1 = read_gc0_entrylo1(); + old_pagemask = read_gc0_pagemask(); + + /* Set root GuestID for root probe */ + htw_stop(); + set_root_gid_to_guest_gid(); + + /* Write each entry to guest TLB */ + for (i = index; i < end; ++i, ++buf) { + write_gc0_index(i); + write_gc0_entryhi(buf->tlb_hi); + write_gc0_entrylo0(buf->tlb_lo[0]); + write_gc0_entrylo1(buf->tlb_lo[1]); + write_gc0_pagemask(buf->tlb_mask); + + mtc0_tlbw_hazard(); + guest_tlb_write_indexed(); + } + + /* Clear root GuestID again */ + clear_root_gid(); + htw_start(); + + /* Restore clobbered registers */ + write_gc0_index(old_index); + write_gc0_entryhi(old_entryhi); + write_gc0_entrylo0(old_entrylo0); + write_gc0_entrylo1(old_entrylo1); + write_gc0_pagemask(old_pagemask); + + tlbw_use_hazard(); +} +EXPORT_SYMBOL_GPL(kvm_vz_load_guesttlb); + +#ifdef CONFIG_CPU_LOONGSON64 +void kvm_loongson_clear_guest_vtlb(void) +{ + int idx = read_gc0_index(); + + /* Set root GuestID for root probe and write of guest TLB entry */ + set_root_gid_to_guest_gid(); + + write_gc0_index(0); + guest_tlbinvf(); + write_gc0_index(idx); + + clear_root_gid(); + set_c0_diag(LOONGSON_DIAG_ITLB | LOONGSON_DIAG_DTLB); +} +EXPORT_SYMBOL_GPL(kvm_loongson_clear_guest_vtlb); + +void kvm_loongson_clear_guest_ftlb(void) +{ + int i; + int idx = read_gc0_index(); + + /* Set root GuestID for root probe and write of guest TLB entry */ + set_root_gid_to_guest_gid(); + + for (i = current_cpu_data.tlbsizevtlb; + i < (current_cpu_data.tlbsizevtlb + + current_cpu_data.tlbsizeftlbsets); + i++) { + write_gc0_index(i); + guest_tlbinvf(); + } + write_gc0_index(idx); + + clear_root_gid(); + set_c0_diag(LOONGSON_DIAG_ITLB | LOONGSON_DIAG_DTLB); +} +EXPORT_SYMBOL_GPL(kvm_loongson_clear_guest_ftlb); +#endif |