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 000000000..4e91971da
--- /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