--- /dev/null
+/*
+ * 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.
+ *
+ * Generation of main entry point for the guest, exception handling.
+ *
+ * Copyright (C) 2012 MIPS Technologies, Inc.
+ * Authors: Sanjay Lal <sanjayl@kymasys.com>
+ *
+ * Copyright (C) 2016 Imagination Technologies Ltd.
+ */
+
+#include <linux/kvm_host.h>
+#include <asm/msa.h>
+#include <asm/setup.h>
+#include <asm/uasm.h>
+
+/* Register names */
+#define ZERO 0
+#define AT 1
+#define V0 2
+#define V1 3
+#define A0 4
+#define A1 5
+
+#if _MIPS_SIM == _MIPS_SIM_ABI32
+#define T0 8
+#define T1 9
+#define T2 10
+#define T3 11
+#endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */
+
+#if _MIPS_SIM == _MIPS_SIM_ABI64 || _MIPS_SIM == _MIPS_SIM_NABI32
+#define T0 12
+#define T1 13
+#define T2 14
+#define T3 15
+#endif /* _MIPS_SIM == _MIPS_SIM_ABI64 || _MIPS_SIM == _MIPS_SIM_NABI32 */
+
+#define S0 16
+#define S1 17
+#define T9 25
+#define K0 26
+#define K1 27
+#define GP 28
+#define SP 29
+#define RA 31
+
+/* Some CP0 registers */
+#define C0_HWRENA 7, 0
+#define C0_BADVADDR 8, 0
+#define C0_ENTRYHI 10, 0
+#define C0_STATUS 12, 0
+#define C0_CAUSE 13, 0
+#define C0_EPC 14, 0
+#define C0_EBASE 15, 1
+#define C0_CONFIG3 16, 3
+#define C0_CONFIG5 16, 5
+#define C0_DDATA_LO 28, 3
+#define C0_ERROREPC 30, 0
+
+#define CALLFRAME_SIZ 32
+
+enum label_id {
+ label_fpu_1 = 1,
+ label_msa_1,
+ label_return_to_host,
+ label_kernel_asid,
+};
+
+UASM_L_LA(_fpu_1)
+UASM_L_LA(_msa_1)
+UASM_L_LA(_return_to_host)
+UASM_L_LA(_kernel_asid)
+
+static void *kvm_mips_build_enter_guest(void *addr);
+static void *kvm_mips_build_ret_from_exit(void *addr);
+static void *kvm_mips_build_ret_to_guest(void *addr);
+static void *kvm_mips_build_ret_to_host(void *addr);
+
+/**
+ * kvm_mips_build_vcpu_run() - Assemble function to start running a guest VCPU.
+ * @addr: Address to start writing code.
+ *
+ * Assemble the start of the vcpu_run function to run a guest VCPU. The function
+ * conforms to the following prototype:
+ *
+ * int vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu);
+ *
+ * The exit from the guest and return to the caller is handled by the code
+ * generated by kvm_mips_build_ret_to_host().
+ *
+ * Returns: Next address after end of written function.
+ */
+void *kvm_mips_build_vcpu_run(void *addr)
+{
+ u32 *p = addr;
+ unsigned int i;
+
+ /*
+ * A0: run
+ * A1: vcpu
+ */
+
+ /* k0/k1 not being used in host kernel context */
+ uasm_i_addiu(&p, K1, SP, -(int)sizeof(struct pt_regs));
+ for (i = 16; i < 32; ++i) {
+ if (i == 24)
+ i = 28;
+ UASM_i_SW(&p, i, offsetof(struct pt_regs, regs[i]), K1);
+ }
+
+ /* Save hi/lo */
+ uasm_i_mflo(&p, V0);
+ UASM_i_SW(&p, V0, offsetof(struct pt_regs, lo), K1);
+ uasm_i_mfhi(&p, V1);
+ UASM_i_SW(&p, V1, offsetof(struct pt_regs, hi), K1);
+
+ /* Save host status */
+ uasm_i_mfc0(&p, V0, C0_STATUS);
+ UASM_i_SW(&p, V0, offsetof(struct pt_regs, cp0_status), K1);
+
+ /* Save DDATA_LO, will be used to store pointer to vcpu */
+ uasm_i_mfc0(&p, V1, C0_DDATA_LO);
+ UASM_i_SW(&p, V1, offsetof(struct pt_regs, cp0_epc), K1);
+
+ /* DDATA_LO has pointer to vcpu */
+ uasm_i_mtc0(&p, A1, C0_DDATA_LO);
+
+ /* Offset into vcpu->arch */
+ uasm_i_addiu(&p, K1, A1, offsetof(struct kvm_vcpu, arch));
+
+ /*
+ * Save the host stack to VCPU, used for exception processing
+ * when we exit from the Guest
+ */
+ UASM_i_SW(&p, SP, offsetof(struct kvm_vcpu_arch, host_stack), K1);
+
+ /* Save the kernel gp as well */
+ UASM_i_SW(&p, GP, offsetof(struct kvm_vcpu_arch, host_gp), K1);
+
+ /*
+ * Setup status register for running the guest in UM, interrupts
+ * are disabled
+ */
+ UASM_i_LA(&p, K0, ST0_EXL | KSU_USER | ST0_BEV);
+ uasm_i_mtc0(&p, K0, C0_STATUS);
+ uasm_i_ehb(&p);
+
+ /* load up the new EBASE */
+ UASM_i_LW(&p, K0, offsetof(struct kvm_vcpu_arch, guest_ebase), K1);
+ uasm_i_mtc0(&p, K0, C0_EBASE);
+
+ /*
+ * Now that the new EBASE has been loaded, unset BEV, set
+ * interrupt mask as it was but make sure that timer interrupts
+ * are enabled
+ */
+ uasm_i_addiu(&p, K0, ZERO, ST0_EXL | KSU_USER | ST0_IE);
+ uasm_i_andi(&p, V0, V0, ST0_IM);
+ uasm_i_or(&p, K0, K0, V0);
+ uasm_i_mtc0(&p, K0, C0_STATUS);
+ uasm_i_ehb(&p);
+
+ p = kvm_mips_build_enter_guest(p);
+
+ return p;
+}
+
+/**
+ * kvm_mips_build_enter_guest() - Assemble code to resume guest execution.
+ * @addr: Address to start writing code.
+ *
+ * Assemble the code to resume guest execution. This code is common between the
+ * initial entry into the guest from the host, and returning from the exit
+ * handler back to the guest.
+ *
+ * Returns: Next address after end of written function.
+ */
+static void *kvm_mips_build_enter_guest(void *addr)
+{
+ u32 *p = addr;
+ unsigned int i;
+ struct uasm_label labels[2];
+ struct uasm_reloc relocs[2];
+ struct uasm_label *l = labels;
+ struct uasm_reloc *r = relocs;
+
+ memset(labels, 0, sizeof(labels));
+ memset(relocs, 0, sizeof(relocs));
+
+ /* Set Guest EPC */
+ UASM_i_LW(&p, T0, offsetof(struct kvm_vcpu_arch, pc), K1);
+ uasm_i_mtc0(&p, T0, C0_EPC);
+
+ /* Set the ASID for the Guest Kernel */
+ UASM_i_LW(&p, T0, offsetof(struct kvm_vcpu_arch, cop0), K1);
+ UASM_i_LW(&p, T0, offsetof(struct mips_coproc, reg[MIPS_CP0_STATUS][0]),
+ T0);
+ uasm_i_andi(&p, T0, T0, KSU_USER | ST0_ERL | ST0_EXL);
+ uasm_i_xori(&p, T0, T0, KSU_USER);
+ uasm_il_bnez(&p, &r, T0, label_kernel_asid);
+ uasm_i_addiu(&p, T1, K1,
+ offsetof(struct kvm_vcpu_arch, guest_kernel_asid));
+ /* else user */
+ uasm_i_addiu(&p, T1, K1,
+ offsetof(struct kvm_vcpu_arch, guest_user_asid));
+ uasm_l_kernel_asid(&l, p);
+
+ /* t1: contains the base of the ASID array, need to get the cpu id */
+ /* smp_processor_id */
+ UASM_i_LW(&p, T2, offsetof(struct thread_info, cpu), GP);
+ /* x4 */
+ uasm_i_sll(&p, T2, T2, 2);
+ UASM_i_ADDU(&p, T3, T1, T2);
+ UASM_i_LW(&p, K0, 0, T3);
+#ifdef CONFIG_MIPS_ASID_BITS_VARIABLE
+ /* x sizeof(struct cpuinfo_mips)/4 */
+ uasm_i_addiu(&p, T3, ZERO, sizeof(struct cpuinfo_mips)/4);
+ uasm_i_mul(&p, T2, T2, T3);
+
+ UASM_i_LA_mostly(&p, AT, (long)&cpu_data[0].asid_mask);
+ UASM_i_ADDU(&p, AT, AT, T2);
+ UASM_i_LW(&p, T2, uasm_rel_lo((long)&cpu_data[0].asid_mask), AT);
+ uasm_i_and(&p, K0, K0, T2);
+#else
+ uasm_i_andi(&p, K0, K0, MIPS_ENTRYHI_ASID);
+#endif
+ uasm_i_mtc0(&p, K0, C0_ENTRYHI);
+ uasm_i_ehb(&p);
+
+ /* Disable RDHWR access */
+ uasm_i_mtc0(&p, ZERO, C0_HWRENA);
+
+ /* load the guest context from VCPU and return */
+ for (i = 1; i < 32; ++i) {
+ /* Guest k0/k1 loaded later */
+ if (i == K0 || i == K1)
+ continue;
+ UASM_i_LW(&p, i, offsetof(struct kvm_vcpu_arch, gprs[i]), K1);
+ }
+
+ /* Restore hi/lo */
+ UASM_i_LW(&p, K0, offsetof(struct kvm_vcpu_arch, hi), K1);
+ uasm_i_mthi(&p, K0);
+
+ UASM_i_LW(&p, K0, offsetof(struct kvm_vcpu_arch, lo), K1);
+ uasm_i_mtlo(&p, K0);
+
+ /* Restore the guest's k0/k1 registers */
+ UASM_i_LW(&p, K0, offsetof(struct kvm_vcpu_arch, gprs[K0]), K1);
+ UASM_i_LW(&p, K1, offsetof(struct kvm_vcpu_arch, gprs[K1]), K1);
+
+ /* Jump to guest */
+ uasm_i_eret(&p);
+
+ uasm_resolve_relocs(relocs, labels);
+
+ return p;
+}
+
+/**
+ * kvm_mips_build_exception() - Assemble first level guest exception handler.
+ * @addr: Address to start writing code.
+ *
+ * Assemble exception vector code for guest execution. The generated vector will
+ * jump to the common exception handler generated by kvm_mips_build_exit().
+ *
+ * Returns: Next address after end of written function.
+ */
+void *kvm_mips_build_exception(void *addr)
+{
+ u32 *p = addr;
+
+ /* Save guest k0 */
+ uasm_i_mtc0(&p, K0, C0_ERROREPC);
+ uasm_i_ehb(&p);
+
+ /* Get EBASE */
+ uasm_i_mfc0(&p, K0, C0_EBASE);
+ /* Get rid of CPUNum */
+ uasm_i_srl(&p, K0, K0, 10);
+ uasm_i_sll(&p, K0, K0, 10);
+ /* Save k1 @ offset 0x3000 */
+ UASM_i_SW(&p, K1, 0x3000, K0);
+
+ /* Exception handler is installed @ offset 0x2000 */
+ uasm_i_addiu(&p, K0, K0, 0x2000);
+ /* Jump to the function */
+ uasm_i_jr(&p, K0);
+ uasm_i_nop(&p);
+
+ return p;
+}
+
+/**
+ * kvm_mips_build_exit() - Assemble common guest exit handler.
+ * @addr: Address to start writing code.
+ *
+ * Assemble the generic guest exit handling code. This is called by the
+ * exception vectors (generated by kvm_mips_build_exception()), and calls
+ * kvm_mips_handle_exit(), then either resumes the guest or returns to the host
+ * depending on the return value.
+ *
+ * Returns: Next address after end of written function.
+ */
+void *kvm_mips_build_exit(void *addr)
+{
+ u32 *p = addr;
+ unsigned int i;
+ struct uasm_label labels[3];
+ struct uasm_reloc relocs[3];
+ struct uasm_label *l = labels;
+ struct uasm_reloc *r = relocs;
+
+ memset(labels, 0, sizeof(labels));
+ memset(relocs, 0, sizeof(relocs));
+
+ /*
+ * Generic Guest exception handler. We end up here when the guest
+ * does something that causes a trap to kernel mode.
+ */
+
+ /* Get the VCPU pointer from DDATA_LO */
+ uasm_i_mfc0(&p, K1, C0_DDATA_LO);
+ uasm_i_addiu(&p, K1, K1, offsetof(struct kvm_vcpu, arch));
+
+ /* Start saving Guest context to VCPU */
+ for (i = 0; i < 32; ++i) {
+ /* Guest k0/k1 saved later */
+ if (i == K0 || i == K1)
+ continue;
+ UASM_i_SW(&p, i, offsetof(struct kvm_vcpu_arch, gprs[i]), K1);
+ }
+
+ /* We need to save hi/lo and restore them on the way out */
+ uasm_i_mfhi(&p, T0);
+ UASM_i_SW(&p, T0, offsetof(struct kvm_vcpu_arch, hi), K1);
+
+ uasm_i_mflo(&p, T0);
+ UASM_i_SW(&p, T0, offsetof(struct kvm_vcpu_arch, lo), K1);
+
+ /* Finally save guest k0/k1 to VCPU */
+ uasm_i_mfc0(&p, T0, C0_ERROREPC);
+ UASM_i_SW(&p, T0, offsetof(struct kvm_vcpu_arch, gprs[K0]), K1);
+
+ /* Get GUEST k1 and save it in VCPU */
+ uasm_i_addiu(&p, T1, ZERO, ~0x2ff);
+ uasm_i_mfc0(&p, T0, C0_EBASE);
+ uasm_i_and(&p, T0, T0, T1);
+ UASM_i_LW(&p, T0, 0x3000, T0);
+ UASM_i_SW(&p, T0, offsetof(struct kvm_vcpu_arch, gprs[K1]), K1);
+
+ /* Now that context has been saved, we can use other registers */
+
+ /* Restore vcpu */
+ uasm_i_mfc0(&p, A1, C0_DDATA_LO);
+ uasm_i_move(&p, S1, A1);
+
+ /* Restore run (vcpu->run) */
+ UASM_i_LW(&p, A0, offsetof(struct kvm_vcpu, run), A1);
+ /* Save pointer to run in s0, will be saved by the compiler */
+ uasm_i_move(&p, S0, A0);
+
+ /*
+ * Save Host level EPC, BadVaddr and Cause to VCPU, useful to process
+ * the exception
+ */
+ uasm_i_mfc0(&p, K0, C0_EPC);
+ UASM_i_SW(&p, K0, offsetof(struct kvm_vcpu_arch, pc), K1);
+
+ uasm_i_mfc0(&p, K0, C0_BADVADDR);
+ UASM_i_SW(&p, K0, offsetof(struct kvm_vcpu_arch, host_cp0_badvaddr),
+ K1);
+
+ uasm_i_mfc0(&p, K0, C0_CAUSE);
+ uasm_i_sw(&p, K0, offsetof(struct kvm_vcpu_arch, host_cp0_cause), K1);
+
+ /* Now restore the host state just enough to run the handlers */
+
+ /* Switch EBASE to the one used by Linux */
+ /* load up the host EBASE */
+ uasm_i_mfc0(&p, V0, C0_STATUS);
+
+ uasm_i_lui(&p, AT, ST0_BEV >> 16);
+ uasm_i_or(&p, K0, V0, AT);
+
+ uasm_i_mtc0(&p, K0, C0_STATUS);
+ uasm_i_ehb(&p);
+
+ UASM_i_LA_mostly(&p, K0, (long)&ebase);
+ UASM_i_LW(&p, K0, uasm_rel_lo((long)&ebase), K0);
+ uasm_i_mtc0(&p, K0, C0_EBASE);
+
+ /*
+ * If FPU is enabled, save FCR31 and clear it so that later ctc1's don't
+ * trigger FPE for pending exceptions.
+ */
+ uasm_i_lui(&p, AT, ST0_CU1 >> 16);
+ uasm_i_and(&p, V1, V0, AT);
+ uasm_il_beqz(&p, &r, V1, label_fpu_1);
+ uasm_i_nop(&p);
+ uasm_i_cfc1(&p, T0, 31);
+ uasm_i_sw(&p, T0, offsetof(struct kvm_vcpu_arch, fpu.fcr31), K1);
+ uasm_i_ctc1(&p, ZERO, 31);
+ uasm_l_fpu_1(&l, p);
+
+#ifdef CONFIG_CPU_HAS_MSA
+ /*
+ * If MSA is enabled, save MSACSR and clear it so that later
+ * instructions don't trigger MSAFPE for pending exceptions.
+ */
+ uasm_i_mfc0(&p, T0, C0_CONFIG3);
+ uasm_i_ext(&p, T0, T0, 28, 1); /* MIPS_CONF3_MSAP */
+ uasm_il_beqz(&p, &r, T0, label_msa_1);
+ uasm_i_nop(&p);
+ uasm_i_mfc0(&p, T0, C0_CONFIG5);
+ uasm_i_ext(&p, T0, T0, 27, 1); /* MIPS_CONF5_MSAEN */
+ uasm_il_beqz(&p, &r, T0, label_msa_1);
+ uasm_i_nop(&p);
+ uasm_i_cfcmsa(&p, T0, MSA_CSR);
+ uasm_i_sw(&p, T0, offsetof(struct kvm_vcpu_arch, fpu.msacsr),
+ K1);
+ uasm_i_ctcmsa(&p, MSA_CSR, ZERO);
+ uasm_l_msa_1(&l, p);
+#endif
+
+ /* Now that the new EBASE has been loaded, unset BEV and KSU_USER */
+ uasm_i_addiu(&p, AT, ZERO, ~(ST0_EXL | KSU_USER | ST0_IE));
+ uasm_i_and(&p, V0, V0, AT);
+ uasm_i_lui(&p, AT, ST0_CU0 >> 16);
+ uasm_i_or(&p, V0, V0, AT);
+ uasm_i_mtc0(&p, V0, C0_STATUS);
+ uasm_i_ehb(&p);
+
+ /* Load up host GP */
+ UASM_i_LW(&p, GP, offsetof(struct kvm_vcpu_arch, host_gp), K1);
+
+ /* Need a stack before we can jump to "C" */
+ UASM_i_LW(&p, SP, offsetof(struct kvm_vcpu_arch, host_stack), K1);
+
+ /* Saved host state */
+ uasm_i_addiu(&p, SP, SP, -(int)sizeof(struct pt_regs));
+
+ /*
+ * XXXKYMA do we need to load the host ASID, maybe not because the
+ * kernel entries are marked GLOBAL, need to verify
+ */
+
+ /* Restore host DDATA_LO */
+ UASM_i_LW(&p, K0, offsetof(struct pt_regs, cp0_epc), SP);
+ uasm_i_mtc0(&p, K0, C0_DDATA_LO);
+
+ /* Restore RDHWR access */
+ UASM_i_LA_mostly(&p, K0, (long)&hwrena);
+ uasm_i_lw(&p, K0, uasm_rel_lo((long)&hwrena), K0);
+ uasm_i_mtc0(&p, K0, C0_HWRENA);
+
+ /* Jump to handler */
+ /*
+ * XXXKYMA: not sure if this is safe, how large is the stack??
+ * Now jump to the kvm_mips_handle_exit() to see if we can deal
+ * with this in the kernel
+ */
+ UASM_i_LA(&p, T9, (unsigned long)kvm_mips_handle_exit);
+ uasm_i_jalr(&p, RA, T9);
+ uasm_i_addiu(&p, SP, SP, -CALLFRAME_SIZ);
+
+ uasm_resolve_relocs(relocs, labels);
+
+ p = kvm_mips_build_ret_from_exit(p);
+
+ return p;
+}
+
+/**
+ * kvm_mips_build_ret_from_exit() - Assemble guest exit return handler.
+ * @addr: Address to start writing code.
+ *
+ * Assemble the code to handle the return from kvm_mips_handle_exit(), either
+ * resuming the guest or returning to the host depending on the return value.
+ *
+ * Returns: Next address after end of written function.
+ */
+static void *kvm_mips_build_ret_from_exit(void *addr)
+{
+ u32 *p = addr;
+ struct uasm_label labels[2];
+ struct uasm_reloc relocs[2];
+ struct uasm_label *l = labels;
+ struct uasm_reloc *r = relocs;
+
+ memset(labels, 0, sizeof(labels));
+ memset(relocs, 0, sizeof(relocs));
+
+ /* Return from handler Make sure interrupts are disabled */
+ uasm_i_di(&p, ZERO);
+ uasm_i_ehb(&p);
+
+ /*
+ * XXXKYMA: k0/k1 could have been blown away if we processed
+ * an exception while we were handling the exception from the
+ * guest, reload k1
+ */
+
+ uasm_i_move(&p, K1, S1);
+ uasm_i_addiu(&p, K1, K1, offsetof(struct kvm_vcpu, arch));
+
+ /*
+ * Check return value, should tell us if we are returning to the
+ * host (handle I/O etc)or resuming the guest
+ */
+ uasm_i_andi(&p, T0, V0, RESUME_HOST);
+ uasm_il_bnez(&p, &r, T0, label_return_to_host);
+ uasm_i_nop(&p);
+
+ p = kvm_mips_build_ret_to_guest(p);
+
+ uasm_l_return_to_host(&l, p);
+ p = kvm_mips_build_ret_to_host(p);
+
+ uasm_resolve_relocs(relocs, labels);
+
+ return p;
+}
+
+/**
+ * kvm_mips_build_ret_to_guest() - Assemble code to return to the guest.
+ * @addr: Address to start writing code.
+ *
+ * Assemble the code to handle return from the guest exit handler
+ * (kvm_mips_handle_exit()) back to the guest.
+ *
+ * Returns: Next address after end of written function.
+ */
+static void *kvm_mips_build_ret_to_guest(void *addr)
+{
+ u32 *p = addr;
+
+ /* Put the saved pointer to vcpu (s1) back into the DDATA_LO Register */
+ uasm_i_mtc0(&p, S1, C0_DDATA_LO);
+
+ /* Load up the Guest EBASE to minimize the window where BEV is set */
+ UASM_i_LW(&p, T0, offsetof(struct kvm_vcpu_arch, guest_ebase), K1);
+
+ /* Switch EBASE back to the one used by KVM */
+ uasm_i_mfc0(&p, V1, C0_STATUS);
+ uasm_i_lui(&p, AT, ST0_BEV >> 16);
+ uasm_i_or(&p, K0, V1, AT);
+ uasm_i_mtc0(&p, K0, C0_STATUS);
+ uasm_i_ehb(&p);
+ uasm_i_mtc0(&p, T0, C0_EBASE);
+
+ /* Setup status register for running guest in UM */
+ uasm_i_ori(&p, V1, V1, ST0_EXL | KSU_USER | ST0_IE);
+ UASM_i_LA(&p, AT, ~(ST0_CU0 | ST0_MX));
+ uasm_i_and(&p, V1, V1, AT);
+ uasm_i_mtc0(&p, V1, C0_STATUS);
+ uasm_i_ehb(&p);
+
+ p = kvm_mips_build_enter_guest(p);
+
+ return p;
+}
+
+/**
+ * kvm_mips_build_ret_to_host() - Assemble code to return to the host.
+ * @addr: Address to start writing code.
+ *
+ * Assemble the code to handle return from the guest exit handler
+ * (kvm_mips_handle_exit()) back to the host, i.e. to the caller of the vcpu_run
+ * function generated by kvm_mips_build_vcpu_run().
+ *
+ * Returns: Next address after end of written function.
+ */
+static void *kvm_mips_build_ret_to_host(void *addr)
+{
+ u32 *p = addr;
+ unsigned int i;
+
+ /* EBASE is already pointing to Linux */
+ UASM_i_LW(&p, K1, offsetof(struct kvm_vcpu_arch, host_stack), K1);
+ uasm_i_addiu(&p, K1, K1, -(int)sizeof(struct pt_regs));
+
+ /* Restore host DDATA_LO */
+ UASM_i_LW(&p, K0, offsetof(struct pt_regs, cp0_epc), K1);
+ uasm_i_mtc0(&p, K0, C0_DDATA_LO);
+
+ /*
+ * r2/v0 is the return code, shift it down by 2 (arithmetic)
+ * to recover the err code
+ */
+ uasm_i_sra(&p, K0, V0, 2);
+ uasm_i_move(&p, V0, K0);
+
+ /* Load context saved on the host stack */
+ for (i = 16; i < 31; ++i) {
+ if (i == 24)
+ i = 28;
+ UASM_i_LW(&p, i, offsetof(struct pt_regs, regs[i]), K1);
+ }
+
+ UASM_i_LW(&p, K0, offsetof(struct pt_regs, hi), K1);
+ uasm_i_mthi(&p, K0);
+
+ UASM_i_LW(&p, K0, offsetof(struct pt_regs, lo), K1);
+ uasm_i_mtlo(&p, K0);
+
+ /* Restore RDHWR access */
+ UASM_i_LA_mostly(&p, K0, (long)&hwrena);
+ uasm_i_lw(&p, K0, uasm_rel_lo((long)&hwrena), K0);
+ uasm_i_mtc0(&p, K0, C0_HWRENA);
+
+ /* Restore RA, which is the address we will return to */
+ UASM_i_LW(&p, RA, offsetof(struct pt_regs, regs[RA]), K1);
+ uasm_i_jr(&p, RA);
+ uasm_i_nop(&p);
+
+ return p;
+}
+
+++ /dev/null
-/*
- * 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.
- *
- * Main entry point for the guest, exception handling.
- *
- * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved.
- * Authors: Sanjay Lal <sanjayl@kymasys.com>
- */
-
-#include <asm/asm.h>
-#include <asm/asmmacro.h>
-#include <asm/regdef.h>
-#include <asm/mipsregs.h>
-#include <asm/stackframe.h>
-#include <asm/asm-offsets.h>
-
-#define _C_LABEL(x) x
-#define MIPSX(name) mips32_ ## name
-#define CALLFRAME_SIZ 32
-
-/*
- * VECTOR
- * exception vector entrypoint
- */
-#define VECTOR(x, regmask) \
- .ent _C_LABEL(x),0; \
- EXPORT(x);
-
-#define VECTOR_END(x) \
- EXPORT(x);
-
-/* Overload, Danger Will Robinson!! */
-#define PT_HOST_USERLOCAL PT_EPC
-
-#define CP0_DDATA_LO $28,3
-
-/* Resume Flags */
-#define RESUME_FLAG_HOST (1<<1) /* Resume host? */
-
-#define RESUME_GUEST 0
-#define RESUME_HOST RESUME_FLAG_HOST
-
-/*
- * __kvm_mips_vcpu_run: entry point to the guest
- * a0: run
- * a1: vcpu
- */
- .set noreorder
-
-FEXPORT(__kvm_mips_vcpu_run)
- /* k0/k1 not being used in host kernel context */
- INT_ADDIU k1, sp, -PT_SIZE
- LONG_S $16, PT_R16(k1)
- LONG_S $17, PT_R17(k1)
- LONG_S $18, PT_R18(k1)
- LONG_S $19, PT_R19(k1)
- LONG_S $20, PT_R20(k1)
- LONG_S $21, PT_R21(k1)
- LONG_S $22, PT_R22(k1)
- LONG_S $23, PT_R23(k1)
-
- LONG_S $28, PT_R28(k1)
- LONG_S $29, PT_R29(k1)
- LONG_S $30, PT_R30(k1)
- LONG_S $31, PT_R31(k1)
-
- /* Save hi/lo */
- mflo v0
- LONG_S v0, PT_LO(k1)
- mfhi v1
- LONG_S v1, PT_HI(k1)
-
- /* Save host status */
- mfc0 v0, CP0_STATUS
- LONG_S v0, PT_STATUS(k1)
-
- /* Save DDATA_LO, will be used to store pointer to vcpu */
- mfc0 v1, CP0_DDATA_LO
- LONG_S v1, PT_HOST_USERLOCAL(k1)
-
- /* DDATA_LO has pointer to vcpu */
- mtc0 a1, CP0_DDATA_LO
-
- /* Offset into vcpu->arch */
- INT_ADDIU k1, a1, VCPU_HOST_ARCH
-
- /*
- * Save the host stack to VCPU, used for exception processing
- * when we exit from the Guest
- */
- LONG_S sp, VCPU_HOST_STACK(k1)
-
- /* Save the kernel gp as well */
- LONG_S gp, VCPU_HOST_GP(k1)
-
- /*
- * Setup status register for running the guest in UM, interrupts
- * are disabled
- */
- li k0, (ST0_EXL | KSU_USER | ST0_BEV)
- mtc0 k0, CP0_STATUS
- ehb
-
- /* load up the new EBASE */
- LONG_L k0, VCPU_GUEST_EBASE(k1)
- mtc0 k0, CP0_EBASE
-
- /*
- * Now that the new EBASE has been loaded, unset BEV, set
- * interrupt mask as it was but make sure that timer interrupts
- * are enabled
- */
- li k0, (ST0_EXL | KSU_USER | ST0_IE)
- andi v0, v0, ST0_IM
- or k0, k0, v0
- mtc0 k0, CP0_STATUS
- ehb
-
- /* Set Guest EPC */
- LONG_L t0, VCPU_PC(k1)
- mtc0 t0, CP0_EPC
-
-FEXPORT(__kvm_mips_load_asid)
- /* Set the ASID for the Guest Kernel */
- PTR_L t0, VCPU_COP0(k1)
- LONG_L t0, COP0_STATUS(t0)
- andi t0, KSU_USER | ST0_ERL | ST0_EXL
- xori t0, KSU_USER
- bnez t0, 1f /* If kernel */
- INT_ADDIU t1, k1, VCPU_GUEST_KERNEL_ASID /* (BD) */
- INT_ADDIU t1, k1, VCPU_GUEST_USER_ASID /* else user */
-1:
- /* t1: contains the base of the ASID array, need to get the cpu id */
- LONG_L t2, TI_CPU($28) /* smp_processor_id */
- INT_SLL t2, t2, 2 /* x4 */
- REG_ADDU t3, t1, t2
- LONG_L k0, (t3)
-#ifdef CONFIG_MIPS_ASID_BITS_VARIABLE
- li t3, CPUINFO_SIZE/4
- mul t2, t2, t3 /* x sizeof(struct cpuinfo_mips)/4 */
- LONG_L t2, (cpu_data + CPUINFO_ASID_MASK)(t2)
- and k0, k0, t2
-#else
- andi k0, k0, MIPS_ENTRYHI_ASID
-#endif
- mtc0 k0, CP0_ENTRYHI
- ehb
-
- /* Disable RDHWR access */
- mtc0 zero, CP0_HWRENA
-
- .set noat
- /* Now load up the Guest Context from VCPU */
- LONG_L $1, VCPU_R1(k1)
- LONG_L $2, VCPU_R2(k1)
- LONG_L $3, VCPU_R3(k1)
-
- LONG_L $4, VCPU_R4(k1)
- LONG_L $5, VCPU_R5(k1)
- LONG_L $6, VCPU_R6(k1)
- LONG_L $7, VCPU_R7(k1)
-
- LONG_L $8, VCPU_R8(k1)
- LONG_L $9, VCPU_R9(k1)
- LONG_L $10, VCPU_R10(k1)
- LONG_L $11, VCPU_R11(k1)
- LONG_L $12, VCPU_R12(k1)
- LONG_L $13, VCPU_R13(k1)
- LONG_L $14, VCPU_R14(k1)
- LONG_L $15, VCPU_R15(k1)
- LONG_L $16, VCPU_R16(k1)
- LONG_L $17, VCPU_R17(k1)
- LONG_L $18, VCPU_R18(k1)
- LONG_L $19, VCPU_R19(k1)
- LONG_L $20, VCPU_R20(k1)
- LONG_L $21, VCPU_R21(k1)
- LONG_L $22, VCPU_R22(k1)
- LONG_L $23, VCPU_R23(k1)
- LONG_L $24, VCPU_R24(k1)
- LONG_L $25, VCPU_R25(k1)
-
- /* k0/k1 loaded up later */
-
- LONG_L $28, VCPU_R28(k1)
- LONG_L $29, VCPU_R29(k1)
- LONG_L $30, VCPU_R30(k1)
- LONG_L $31, VCPU_R31(k1)
-
- /* Restore hi/lo */
- LONG_L k0, VCPU_LO(k1)
- mtlo k0
-
- LONG_L k0, VCPU_HI(k1)
- mthi k0
-
-FEXPORT(__kvm_mips_load_k0k1)
- /* Restore the guest's k0/k1 registers */
- LONG_L k0, VCPU_R26(k1)
- LONG_L k1, VCPU_R27(k1)
-
- /* Jump to guest */
- eret
-EXPORT(__kvm_mips_vcpu_run_end)
-
-VECTOR(MIPSX(exception), unknown)
-/* Find out what mode we came from and jump to the proper handler. */
- mtc0 k0, CP0_ERROREPC #01: Save guest k0
- ehb #02:
-
- mfc0 k0, CP0_EBASE #02: Get EBASE
- INT_SRL k0, k0, 10 #03: Get rid of CPUNum
- INT_SLL k0, k0, 10 #04
- LONG_S k1, 0x3000(k0) #05: Save k1 @ offset 0x3000
- INT_ADDIU k0, k0, 0x2000 #06: Exception handler is
- # installed @ offset 0x2000
- j k0 #07: jump to the function
- nop #08: branch delay slot
-VECTOR_END(MIPSX(exceptionEnd))
-.end MIPSX(exception)
-
-/*
- * Generic Guest exception handler. We end up here when the guest
- * does something that causes a trap to kernel mode.
- */
-NESTED (MIPSX(GuestException), CALLFRAME_SIZ, ra)
- /* Get the VCPU pointer from DDTATA_LO */
- mfc0 k1, CP0_DDATA_LO
- INT_ADDIU k1, k1, VCPU_HOST_ARCH
-
- /* Start saving Guest context to VCPU */
- LONG_S $0, VCPU_R0(k1)
- LONG_S $1, VCPU_R1(k1)
- LONG_S $2, VCPU_R2(k1)
- LONG_S $3, VCPU_R3(k1)
- LONG_S $4, VCPU_R4(k1)
- LONG_S $5, VCPU_R5(k1)
- LONG_S $6, VCPU_R6(k1)
- LONG_S $7, VCPU_R7(k1)
- LONG_S $8, VCPU_R8(k1)
- LONG_S $9, VCPU_R9(k1)
- LONG_S $10, VCPU_R10(k1)
- LONG_S $11, VCPU_R11(k1)
- LONG_S $12, VCPU_R12(k1)
- LONG_S $13, VCPU_R13(k1)
- LONG_S $14, VCPU_R14(k1)
- LONG_S $15, VCPU_R15(k1)
- LONG_S $16, VCPU_R16(k1)
- LONG_S $17, VCPU_R17(k1)
- LONG_S $18, VCPU_R18(k1)
- LONG_S $19, VCPU_R19(k1)
- LONG_S $20, VCPU_R20(k1)
- LONG_S $21, VCPU_R21(k1)
- LONG_S $22, VCPU_R22(k1)
- LONG_S $23, VCPU_R23(k1)
- LONG_S $24, VCPU_R24(k1)
- LONG_S $25, VCPU_R25(k1)
-
- /* Guest k0/k1 saved later */
-
- LONG_S $28, VCPU_R28(k1)
- LONG_S $29, VCPU_R29(k1)
- LONG_S $30, VCPU_R30(k1)
- LONG_S $31, VCPU_R31(k1)
-
- .set at
-
- /* We need to save hi/lo and restore them on the way out */
- mfhi t0
- LONG_S t0, VCPU_HI(k1)
-
- mflo t0
- LONG_S t0, VCPU_LO(k1)
-
- /* Finally save guest k0/k1 to VCPU */
- mfc0 t0, CP0_ERROREPC
- LONG_S t0, VCPU_R26(k1)
-
- /* Get GUEST k1 and save it in VCPU */
- PTR_LI t1, ~0x2ff
- mfc0 t0, CP0_EBASE
- and t0, t0, t1
- LONG_L t0, 0x3000(t0)
- LONG_S t0, VCPU_R27(k1)
-
- /* Now that context has been saved, we can use other registers */
-
- /* Restore vcpu */
- mfc0 a1, CP0_DDATA_LO
- move s1, a1
-
- /* Restore run (vcpu->run) */
- LONG_L a0, VCPU_RUN(a1)
- /* Save pointer to run in s0, will be saved by the compiler */
- move s0, a0
-
- /*
- * Save Host level EPC, BadVaddr and Cause to VCPU, useful to
- * process the exception
- */
- mfc0 k0,CP0_EPC
- LONG_S k0, VCPU_PC(k1)
-
- mfc0 k0, CP0_BADVADDR
- LONG_S k0, VCPU_HOST_CP0_BADVADDR(k1)
-
- mfc0 k0, CP0_CAUSE
- sw k0, VCPU_HOST_CP0_CAUSE(k1)
-
- /* Now restore the host state just enough to run the handlers */
-
- /* Switch EBASE to the one used by Linux */
- /* load up the host EBASE */
- mfc0 v0, CP0_STATUS
-
- or k0, v0, ST0_BEV
-
- mtc0 k0, CP0_STATUS
- ehb
-
- LONG_L k0, ebase
- mtc0 k0,CP0_EBASE
-
- /*
- * If FPU is enabled, save FCR31 and clear it so that later ctc1's don't
- * trigger FPE for pending exceptions.
- */
- and v1, v0, ST0_CU1
- beqz v1, 1f
- nop
- .set push
- SET_HARDFLOAT
- cfc1 t0, fcr31
- sw t0, VCPU_FCR31(k1)
- ctc1 zero,fcr31
- .set pop
-1:
-
-#ifdef CONFIG_CPU_HAS_MSA
- /*
- * If MSA is enabled, save MSACSR and clear it so that later
- * instructions don't trigger MSAFPE for pending exceptions.
- */
- mfc0 t0, CP0_CONFIG3
- ext t0, t0, 28, 1 /* MIPS_CONF3_MSAP */
- beqz t0, 1f
- nop
- mfc0 t0, CP0_CONFIG5
- ext t0, t0, 27, 1 /* MIPS_CONF5_MSAEN */
- beqz t0, 1f
- nop
- _cfcmsa t0, MSA_CSR
- sw t0, VCPU_MSA_CSR(k1)
- _ctcmsa MSA_CSR, zero
-1:
-#endif
-
- /* Now that the new EBASE has been loaded, unset BEV and KSU_USER */
- and v0, v0, ~(ST0_EXL | KSU_USER | ST0_IE)
- or v0, v0, ST0_CU0
- mtc0 v0, CP0_STATUS
- ehb
-
- /* Load up host GP */
- LONG_L gp, VCPU_HOST_GP(k1)
-
- /* Need a stack before we can jump to "C" */
- LONG_L sp, VCPU_HOST_STACK(k1)
-
- /* Saved host state */
- INT_ADDIU sp, sp, -PT_SIZE
-
- /*
- * XXXKYMA do we need to load the host ASID, maybe not because the
- * kernel entries are marked GLOBAL, need to verify
- */
-
- /* Restore host DDATA_LO */
- LONG_L k0, PT_HOST_USERLOCAL(sp)
- mtc0 k0, CP0_DDATA_LO
-
- /* Restore RDHWR access */
- INT_L k0, hwrena
- mtc0 k0, CP0_HWRENA
-
- /* Jump to handler */
-FEXPORT(__kvm_mips_jump_to_handler)
- /*
- * XXXKYMA: not sure if this is safe, how large is the stack??
- * Now jump to the kvm_mips_handle_exit() to see if we can deal
- * with this in the kernel
- */
- PTR_LA t9, kvm_mips_handle_exit
- jalr.hb t9
- INT_ADDIU sp, sp, -CALLFRAME_SIZ /* BD Slot */
-
- /* Return from handler Make sure interrupts are disabled */
- di
- ehb
-
- /*
- * XXXKYMA: k0/k1 could have been blown away if we processed
- * an exception while we were handling the exception from the
- * guest, reload k1
- */
-
- move k1, s1
- INT_ADDIU k1, k1, VCPU_HOST_ARCH
-
- /*
- * Check return value, should tell us if we are returning to the
- * host (handle I/O etc)or resuming the guest
- */
- andi t0, v0, RESUME_HOST
- bnez t0, __kvm_mips_return_to_host
- nop
-
-__kvm_mips_return_to_guest:
- /* Put the saved pointer to vcpu (s1) back into the DDATA_LO Register */
- mtc0 s1, CP0_DDATA_LO
-
- /* Load up the Guest EBASE to minimize the window where BEV is set */
- LONG_L t0, VCPU_GUEST_EBASE(k1)
-
- /* Switch EBASE back to the one used by KVM */
- mfc0 v1, CP0_STATUS
- or k0, v1, ST0_BEV
- mtc0 k0, CP0_STATUS
- ehb
- mtc0 t0, CP0_EBASE
-
- /* Setup status register for running guest in UM */
- or v1, v1, (ST0_EXL | KSU_USER | ST0_IE)
- and v1, v1, ~(ST0_CU0 | ST0_MX)
- mtc0 v1, CP0_STATUS
- ehb
-
- /* Set Guest EPC */
- LONG_L t0, VCPU_PC(k1)
- mtc0 t0, CP0_EPC
-
- /* Set the ASID for the Guest Kernel */
- PTR_L t0, VCPU_COP0(k1)
- LONG_L t0, COP0_STATUS(t0)
- andi t0, KSU_USER | ST0_ERL | ST0_EXL
- xori t0, KSU_USER
- bnez t0, 1f /* If kernel */
- INT_ADDIU t1, k1, VCPU_GUEST_KERNEL_ASID /* (BD) */
- INT_ADDIU t1, k1, VCPU_GUEST_USER_ASID /* else user */
-1:
- /* t1: contains the base of the ASID array, need to get the cpu id */
- LONG_L t2, TI_CPU($28) /* smp_processor_id */
- INT_SLL t2, t2, 2 /* x4 */
- REG_ADDU t3, t1, t2
- LONG_L k0, (t3)
-#ifdef CONFIG_MIPS_ASID_BITS_VARIABLE
- li t3, CPUINFO_SIZE/4
- mul t2, t2, t3 /* x sizeof(struct cpuinfo_mips)/4 */
- LONG_L t2, (cpu_data + CPUINFO_ASID_MASK)(t2)
- and k0, k0, t2
-#else
- andi k0, k0, MIPS_ENTRYHI_ASID
-#endif
- mtc0 k0, CP0_ENTRYHI
- ehb
-
- /* Disable RDHWR access */
- mtc0 zero, CP0_HWRENA
-
- .set noat
- /* load the guest context from VCPU and return */
- LONG_L $0, VCPU_R0(k1)
- LONG_L $1, VCPU_R1(k1)
- LONG_L $2, VCPU_R2(k1)
- LONG_L $3, VCPU_R3(k1)
- LONG_L $4, VCPU_R4(k1)
- LONG_L $5, VCPU_R5(k1)
- LONG_L $6, VCPU_R6(k1)
- LONG_L $7, VCPU_R7(k1)
- LONG_L $8, VCPU_R8(k1)
- LONG_L $9, VCPU_R9(k1)
- LONG_L $10, VCPU_R10(k1)
- LONG_L $11, VCPU_R11(k1)
- LONG_L $12, VCPU_R12(k1)
- LONG_L $13, VCPU_R13(k1)
- LONG_L $14, VCPU_R14(k1)
- LONG_L $15, VCPU_R15(k1)
- LONG_L $16, VCPU_R16(k1)
- LONG_L $17, VCPU_R17(k1)
- LONG_L $18, VCPU_R18(k1)
- LONG_L $19, VCPU_R19(k1)
- LONG_L $20, VCPU_R20(k1)
- LONG_L $21, VCPU_R21(k1)
- LONG_L $22, VCPU_R22(k1)
- LONG_L $23, VCPU_R23(k1)
- LONG_L $24, VCPU_R24(k1)
- LONG_L $25, VCPU_R25(k1)
-
- /* $/k1 loaded later */
- LONG_L $28, VCPU_R28(k1)
- LONG_L $29, VCPU_R29(k1)
- LONG_L $30, VCPU_R30(k1)
- LONG_L $31, VCPU_R31(k1)
-
-FEXPORT(__kvm_mips_skip_guest_restore)
- LONG_L k0, VCPU_HI(k1)
- mthi k0
-
- LONG_L k0, VCPU_LO(k1)
- mtlo k0
-
- LONG_L k0, VCPU_R26(k1)
- LONG_L k1, VCPU_R27(k1)
-
- eret
- .set at
-
-__kvm_mips_return_to_host:
- /* EBASE is already pointing to Linux */
- LONG_L k1, VCPU_HOST_STACK(k1)
- INT_ADDIU k1,k1, -PT_SIZE
-
- /* Restore host DDATA_LO */
- LONG_L k0, PT_HOST_USERLOCAL(k1)
- mtc0 k0, CP0_DDATA_LO
-
- /*
- * r2/v0 is the return code, shift it down by 2 (arithmetic)
- * to recover the err code
- */
- INT_SRA k0, v0, 2
- move $2, k0
-
- /* Load context saved on the host stack */
- LONG_L $16, PT_R16(k1)
- LONG_L $17, PT_R17(k1)
- LONG_L $18, PT_R18(k1)
- LONG_L $19, PT_R19(k1)
- LONG_L $20, PT_R20(k1)
- LONG_L $21, PT_R21(k1)
- LONG_L $22, PT_R22(k1)
- LONG_L $23, PT_R23(k1)
-
- LONG_L $28, PT_R28(k1)
- LONG_L $29, PT_R29(k1)
- LONG_L $30, PT_R30(k1)
-
- LONG_L k0, PT_HI(k1)
- mthi k0
-
- LONG_L k0, PT_LO(k1)
- mtlo k0
-
- /* Restore RDHWR access */
- INT_L k0, hwrena
- mtc0 k0, CP0_HWRENA
-
- /* Restore RA, which is the address we will return to */
- LONG_L ra, PT_R31(k1)
- j ra
- nop
-
-VECTOR_END(MIPSX(GuestExceptionEnd))
-.end MIPSX(GuestException)
-
-MIPSX(exceptions):
- ####
- ##### The exception handlers.
- #####
- .word _C_LABEL(MIPSX(GuestException)) # 0
- .word _C_LABEL(MIPSX(GuestException)) # 1
- .word _C_LABEL(MIPSX(GuestException)) # 2
- .word _C_LABEL(MIPSX(GuestException)) # 3
- .word _C_LABEL(MIPSX(GuestException)) # 4
- .word _C_LABEL(MIPSX(GuestException)) # 5
- .word _C_LABEL(MIPSX(GuestException)) # 6
- .word _C_LABEL(MIPSX(GuestException)) # 7
- .word _C_LABEL(MIPSX(GuestException)) # 8
- .word _C_LABEL(MIPSX(GuestException)) # 9
- .word _C_LABEL(MIPSX(GuestException)) # 10
- .word _C_LABEL(MIPSX(GuestException)) # 11
- .word _C_LABEL(MIPSX(GuestException)) # 12
- .word _C_LABEL(MIPSX(GuestException)) # 13
- .word _C_LABEL(MIPSX(GuestException)) # 14
- .word _C_LABEL(MIPSX(GuestException)) # 15
- .word _C_LABEL(MIPSX(GuestException)) # 16
- .word _C_LABEL(MIPSX(GuestException)) # 17
- .word _C_LABEL(MIPSX(GuestException)) # 18
- .word _C_LABEL(MIPSX(GuestException)) # 19
- .word _C_LABEL(MIPSX(GuestException)) # 20
- .word _C_LABEL(MIPSX(GuestException)) # 21
- .word _C_LABEL(MIPSX(GuestException)) # 22
- .word _C_LABEL(MIPSX(GuestException)) # 23
- .word _C_LABEL(MIPSX(GuestException)) # 24
- .word _C_LABEL(MIPSX(GuestException)) # 25
- .word _C_LABEL(MIPSX(GuestException)) # 26
- .word _C_LABEL(MIPSX(GuestException)) # 27
- .word _C_LABEL(MIPSX(GuestException)) # 28
- .word _C_LABEL(MIPSX(GuestException)) # 29
- .word _C_LABEL(MIPSX(GuestException)) # 30
- .word _C_LABEL(MIPSX(GuestException)) # 31
projects / cascardo / linux.git / commitdiff