diff options
Diffstat (limited to 'arch/riscv/kvm/aia.c')
| -rw-r--r-- | arch/riscv/kvm/aia.c | 658 |
1 files changed, 658 insertions, 0 deletions
diff --git a/arch/riscv/kvm/aia.c b/arch/riscv/kvm/aia.c new file mode 100644 index 000000000000..a944294f6f23 --- /dev/null +++ b/arch/riscv/kvm/aia.c @@ -0,0 +1,658 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2021 Western Digital Corporation or its affiliates. + * Copyright (C) 2022 Ventana Micro Systems Inc. + * + * Authors: + * Anup Patel <apatel@ventanamicro.com> + */ + +#include <linux/kernel.h> +#include <linux/bitops.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/kvm_host.h> +#include <linux/percpu.h> +#include <linux/spinlock.h> +#include <asm/cpufeature.h> +#include <asm/kvm_aia_imsic.h> + +struct aia_hgei_control { + raw_spinlock_t lock; + unsigned long free_bitmap; + struct kvm_vcpu *owners[BITS_PER_LONG]; +}; +static DEFINE_PER_CPU(struct aia_hgei_control, aia_hgei); +static int hgei_parent_irq; + +unsigned int kvm_riscv_aia_nr_hgei; +unsigned int kvm_riscv_aia_max_ids; +DEFINE_STATIC_KEY_FALSE(kvm_riscv_aia_available); + +static int aia_find_hgei(struct kvm_vcpu *owner) +{ + int i, hgei; + unsigned long flags; + struct aia_hgei_control *hgctrl = get_cpu_ptr(&aia_hgei); + + raw_spin_lock_irqsave(&hgctrl->lock, flags); + + hgei = -1; + for (i = 1; i <= kvm_riscv_aia_nr_hgei; i++) { + if (hgctrl->owners[i] == owner) { + hgei = i; + break; + } + } + + raw_spin_unlock_irqrestore(&hgctrl->lock, flags); + + put_cpu_ptr(&aia_hgei); + return hgei; +} + +static void aia_set_hvictl(bool ext_irq_pending) +{ + unsigned long hvictl; + + /* + * HVICTL.IID == 9 and HVICTL.IPRIO == 0 represents + * no interrupt in HVICTL. + */ + + hvictl = (IRQ_S_EXT << HVICTL_IID_SHIFT) & HVICTL_IID; + hvictl |= ext_irq_pending; + csr_write(CSR_HVICTL, hvictl); +} + +#ifdef CONFIG_32BIT +void kvm_riscv_vcpu_aia_flush_interrupts(struct kvm_vcpu *vcpu) +{ + struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr; + unsigned long mask, val; + + if (!kvm_riscv_aia_available()) + return; + + if (READ_ONCE(vcpu->arch.irqs_pending_mask[1])) { + mask = xchg_acquire(&vcpu->arch.irqs_pending_mask[1], 0); + val = READ_ONCE(vcpu->arch.irqs_pending[1]) & mask; + + csr->hviph &= ~mask; + csr->hviph |= val; + } +} + +void kvm_riscv_vcpu_aia_sync_interrupts(struct kvm_vcpu *vcpu) +{ + struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr; + + if (kvm_riscv_aia_available()) + csr->vsieh = csr_read(CSR_VSIEH); +} +#endif + +bool kvm_riscv_vcpu_aia_has_interrupts(struct kvm_vcpu *vcpu, u64 mask) +{ + int hgei; + unsigned long seip; + + if (!kvm_riscv_aia_available()) + return false; + +#ifdef CONFIG_32BIT + if (READ_ONCE(vcpu->arch.irqs_pending[1]) & + (vcpu->arch.aia_context.guest_csr.vsieh & upper_32_bits(mask))) + return true; +#endif + + seip = vcpu->arch.guest_csr.vsie; + seip &= (unsigned long)mask; + seip &= BIT(IRQ_S_EXT); + + if (!kvm_riscv_aia_initialized(vcpu->kvm) || !seip) + return false; + + hgei = aia_find_hgei(vcpu); + if (hgei > 0) + return !!(csr_read(CSR_HGEIP) & BIT(hgei)); + + return false; +} + +void kvm_riscv_vcpu_aia_update_hvip(struct kvm_vcpu *vcpu) +{ + struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; + + if (!kvm_riscv_aia_available()) + return; + +#ifdef CONFIG_32BIT + csr_write(CSR_HVIPH, vcpu->arch.aia_context.guest_csr.hviph); +#endif + aia_set_hvictl(!!(csr->hvip & BIT(IRQ_VS_EXT))); +} + +void kvm_riscv_vcpu_aia_load(struct kvm_vcpu *vcpu, int cpu) +{ + struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr; + + if (!kvm_riscv_aia_available()) + return; + + csr_write(CSR_VSISELECT, csr->vsiselect); + csr_write(CSR_HVIPRIO1, csr->hviprio1); + csr_write(CSR_HVIPRIO2, csr->hviprio2); +#ifdef CONFIG_32BIT + csr_write(CSR_VSIEH, csr->vsieh); + csr_write(CSR_HVIPH, csr->hviph); + csr_write(CSR_HVIPRIO1H, csr->hviprio1h); + csr_write(CSR_HVIPRIO2H, csr->hviprio2h); +#endif +} + +void kvm_riscv_vcpu_aia_put(struct kvm_vcpu *vcpu) +{ + struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr; + + if (!kvm_riscv_aia_available()) + return; + + csr->vsiselect = csr_read(CSR_VSISELECT); + csr->hviprio1 = csr_read(CSR_HVIPRIO1); + csr->hviprio2 = csr_read(CSR_HVIPRIO2); +#ifdef CONFIG_32BIT + csr->vsieh = csr_read(CSR_VSIEH); + csr->hviph = csr_read(CSR_HVIPH); + csr->hviprio1h = csr_read(CSR_HVIPRIO1H); + csr->hviprio2h = csr_read(CSR_HVIPRIO2H); +#endif +} + +int kvm_riscv_vcpu_aia_get_csr(struct kvm_vcpu *vcpu, + unsigned long reg_num, + unsigned long *out_val) +{ + struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr; + + if (reg_num >= sizeof(struct kvm_riscv_aia_csr) / sizeof(unsigned long)) + return -ENOENT; + + *out_val = 0; + if (kvm_riscv_aia_available()) + *out_val = ((unsigned long *)csr)[reg_num]; + + return 0; +} + +int kvm_riscv_vcpu_aia_set_csr(struct kvm_vcpu *vcpu, + unsigned long reg_num, + unsigned long val) +{ + struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr; + + if (reg_num >= sizeof(struct kvm_riscv_aia_csr) / sizeof(unsigned long)) + return -ENOENT; + + if (kvm_riscv_aia_available()) { + ((unsigned long *)csr)[reg_num] = val; + +#ifdef CONFIG_32BIT + if (reg_num == KVM_REG_RISCV_CSR_AIA_REG(siph)) + WRITE_ONCE(vcpu->arch.irqs_pending_mask[1], 0); +#endif + } + + return 0; +} + +int kvm_riscv_vcpu_aia_rmw_topei(struct kvm_vcpu *vcpu, + unsigned int csr_num, + unsigned long *val, + unsigned long new_val, + unsigned long wr_mask) +{ + /* If AIA not available then redirect trap */ + if (!kvm_riscv_aia_available()) + return KVM_INSN_ILLEGAL_TRAP; + + /* If AIA not initialized then forward to user space */ + if (!kvm_riscv_aia_initialized(vcpu->kvm)) + return KVM_INSN_EXIT_TO_USER_SPACE; + + return kvm_riscv_vcpu_aia_imsic_rmw(vcpu, KVM_RISCV_AIA_IMSIC_TOPEI, + val, new_val, wr_mask); +} + +/* + * External IRQ priority always read-only zero. This means default + * priority order is always preferred for external IRQs unless + * HVICTL.IID == 9 and HVICTL.IPRIO != 0 + */ +static int aia_irq2bitpos[] = { +0, 8, -1, -1, 16, 24, -1, -1, /* 0 - 7 */ +32, -1, -1, -1, -1, 40, 48, 56, /* 8 - 15 */ +64, 72, 80, 88, 96, 104, 112, 120, /* 16 - 23 */ +-1, -1, -1, -1, -1, -1, -1, -1, /* 24 - 31 */ +-1, -1, -1, -1, -1, -1, -1, -1, /* 32 - 39 */ +-1, -1, -1, -1, -1, -1, -1, -1, /* 40 - 47 */ +-1, -1, -1, -1, -1, -1, -1, -1, /* 48 - 55 */ +-1, -1, -1, -1, -1, -1, -1, -1, /* 56 - 63 */ +}; + +static u8 aia_get_iprio8(struct kvm_vcpu *vcpu, unsigned int irq) +{ + unsigned long hviprio; + int bitpos = aia_irq2bitpos[irq]; + + if (bitpos < 0) + return 0; + + switch (bitpos / BITS_PER_LONG) { + case 0: + hviprio = csr_read(CSR_HVIPRIO1); + break; + case 1: +#ifndef CONFIG_32BIT + hviprio = csr_read(CSR_HVIPRIO2); + break; +#else + hviprio = csr_read(CSR_HVIPRIO1H); + break; + case 2: + hviprio = csr_read(CSR_HVIPRIO2); + break; + case 3: + hviprio = csr_read(CSR_HVIPRIO2H); + break; +#endif + default: + return 0; + } + + return (hviprio >> (bitpos % BITS_PER_LONG)) & TOPI_IPRIO_MASK; +} + +static void aia_set_iprio8(struct kvm_vcpu *vcpu, unsigned int irq, u8 prio) +{ + unsigned long hviprio; + int bitpos = aia_irq2bitpos[irq]; + + if (bitpos < 0) + return; + + switch (bitpos / BITS_PER_LONG) { + case 0: + hviprio = csr_read(CSR_HVIPRIO1); + break; + case 1: +#ifndef CONFIG_32BIT + hviprio = csr_read(CSR_HVIPRIO2); + break; +#else + hviprio = csr_read(CSR_HVIPRIO1H); + break; + case 2: + hviprio = csr_read(CSR_HVIPRIO2); + break; + case 3: + hviprio = csr_read(CSR_HVIPRIO2H); + break; +#endif + default: + return; + } + + hviprio &= ~(TOPI_IPRIO_MASK << (bitpos % BITS_PER_LONG)); + hviprio |= (unsigned long)prio << (bitpos % BITS_PER_LONG); + + switch (bitpos / BITS_PER_LONG) { + case 0: + csr_write(CSR_HVIPRIO1, hviprio); + break; + case 1: +#ifndef CONFIG_32BIT + csr_write(CSR_HVIPRIO2, hviprio); + break; +#else + csr_write(CSR_HVIPRIO1H, hviprio); + break; + case 2: + csr_write(CSR_HVIPRIO2, hviprio); + break; + case 3: + csr_write(CSR_HVIPRIO2H, hviprio); + break; +#endif + default: + return; + } +} + +static int aia_rmw_iprio(struct kvm_vcpu *vcpu, unsigned int isel, + unsigned long *val, unsigned long new_val, + unsigned long wr_mask) +{ + int i, first_irq, nirqs; + unsigned long old_val; + u8 prio; + +#ifndef CONFIG_32BIT + if (isel & 0x1) + return KVM_INSN_ILLEGAL_TRAP; +#endif + + nirqs = 4 * (BITS_PER_LONG / 32); + first_irq = (isel - ISELECT_IPRIO0) * 4; + + old_val = 0; + for (i = 0; i < nirqs; i++) { + prio = aia_get_iprio8(vcpu, first_irq + i); + old_val |= (unsigned long)prio << (TOPI_IPRIO_BITS * i); + } + + if (val) + *val = old_val; + + if (wr_mask) { + new_val = (old_val & ~wr_mask) | (new_val & wr_mask); + for (i = 0; i < nirqs; i++) { + prio = (new_val >> (TOPI_IPRIO_BITS * i)) & + TOPI_IPRIO_MASK; + aia_set_iprio8(vcpu, first_irq + i, prio); + } + } + + return KVM_INSN_CONTINUE_NEXT_SEPC; +} + +int kvm_riscv_vcpu_aia_rmw_ireg(struct kvm_vcpu *vcpu, unsigned int csr_num, + unsigned long *val, unsigned long new_val, + unsigned long wr_mask) +{ + unsigned int isel; + + /* If AIA not available then redirect trap */ + if (!kvm_riscv_aia_available()) + return KVM_INSN_ILLEGAL_TRAP; + + /* First try to emulate in kernel space */ + isel = csr_read(CSR_VSISELECT) & ISELECT_MASK; + if (isel >= ISELECT_IPRIO0 && isel <= ISELECT_IPRIO15) + return aia_rmw_iprio(vcpu, isel, val, new_val, wr_mask); + else if (isel >= IMSIC_FIRST && isel <= IMSIC_LAST && + kvm_riscv_aia_initialized(vcpu->kvm)) + return kvm_riscv_vcpu_aia_imsic_rmw(vcpu, isel, val, new_val, + wr_mask); + + /* We can't handle it here so redirect to user space */ + return KVM_INSN_EXIT_TO_USER_SPACE; +} + +int kvm_riscv_aia_alloc_hgei(int cpu, struct kvm_vcpu *owner, + void __iomem **hgei_va, phys_addr_t *hgei_pa) +{ + int ret = -ENOENT; + unsigned long flags; + struct aia_hgei_control *hgctrl = per_cpu_ptr(&aia_hgei, cpu); + + if (!kvm_riscv_aia_available() || !hgctrl) + return -ENODEV; + + raw_spin_lock_irqsave(&hgctrl->lock, flags); + + if (hgctrl->free_bitmap) { + ret = __ffs(hgctrl->free_bitmap); + hgctrl->free_bitmap &= ~BIT(ret); + hgctrl->owners[ret] = owner; + } + + raw_spin_unlock_irqrestore(&hgctrl->lock, flags); + + /* TODO: To be updated later by AIA IMSIC HW guest file support */ + if (hgei_va) + *hgei_va = NULL; + if (hgei_pa) + *hgei_pa = 0; + + return ret; +} + +void kvm_riscv_aia_free_hgei(int cpu, int hgei) +{ + unsigned long flags; + struct aia_hgei_control *hgctrl = per_cpu_ptr(&aia_hgei, cpu); + + if (!kvm_riscv_aia_available() || !hgctrl) + return; + + raw_spin_lock_irqsave(&hgctrl->lock, flags); + + if (hgei > 0 && hgei <= kvm_riscv_aia_nr_hgei) { + if (!(hgctrl->free_bitmap & BIT(hgei))) { + hgctrl->free_bitmap |= BIT(hgei); + hgctrl->owners[hgei] = NULL; + } + } + + raw_spin_unlock_irqrestore(&hgctrl->lock, flags); +} + +void kvm_riscv_aia_wakeon_hgei(struct kvm_vcpu *owner, bool enable) +{ + int hgei; + + if (!kvm_riscv_aia_available()) + return; + + hgei = aia_find_hgei(owner); + if (hgei > 0) { + if (enable) + csr_set(CSR_HGEIE, BIT(hgei)); + else + csr_clear(CSR_HGEIE, BIT(hgei)); + } +} + +static irqreturn_t hgei_interrupt(int irq, void *dev_id) +{ + int i; + unsigned long hgei_mask, flags; + struct aia_hgei_control *hgctrl = get_cpu_ptr(&aia_hgei); + + hgei_mask = csr_read(CSR_HGEIP) & csr_read(CSR_HGEIE); + csr_clear(CSR_HGEIE, hgei_mask); + + raw_spin_lock_irqsave(&hgctrl->lock, flags); + + for_each_set_bit(i, &hgei_mask, BITS_PER_LONG) { + if (hgctrl->owners[i]) + kvm_vcpu_kick(hgctrl->owners[i]); + } + + raw_spin_unlock_irqrestore(&hgctrl->lock, flags); + + put_cpu_ptr(&aia_hgei); + return IRQ_HANDLED; +} + +static int aia_hgei_init(void) +{ + int cpu, rc; + struct irq_domain *domain; + struct aia_hgei_control *hgctrl; + + /* Initialize per-CPU guest external interrupt line management */ + for_each_possible_cpu(cpu) { + hgctrl = per_cpu_ptr(&aia_hgei, cpu); + raw_spin_lock_init(&hgctrl->lock); + if (kvm_riscv_aia_nr_hgei) { + hgctrl->free_bitmap = + BIT(kvm_riscv_aia_nr_hgei + 1) - 1; + hgctrl->free_bitmap &= ~BIT(0); + } else + hgctrl->free_bitmap = 0; + } + + /* Find INTC irq domain */ + domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(), + DOMAIN_BUS_ANY); + if (!domain) { + kvm_err("unable to find INTC domain\n"); + return -ENOENT; + } + + /* Map per-CPU SGEI interrupt from INTC domain */ + hgei_parent_irq = irq_create_mapping(domain, IRQ_S_GEXT); + if (!hgei_parent_irq) { + kvm_err("unable to map SGEI IRQ\n"); + return -ENOMEM; + } + + /* Request per-CPU SGEI interrupt */ + rc = request_percpu_irq(hgei_parent_irq, hgei_interrupt, + "riscv-kvm", &aia_hgei); + if (rc) { + kvm_err("failed to request SGEI IRQ\n"); + return rc; + } + + return 0; +} + +static void aia_hgei_exit(void) +{ + /* Free per-CPU SGEI interrupt */ + free_percpu_irq(hgei_parent_irq, &aia_hgei); +} + +void kvm_riscv_aia_enable(void) +{ + if (!kvm_riscv_aia_available()) + return; + + aia_set_hvictl(false); + csr_write(CSR_HVIPRIO1, 0x0); + csr_write(CSR_HVIPRIO2, 0x0); +#ifdef CONFIG_32BIT + csr_write(CSR_HVIPH, 0x0); + csr_write(CSR_HIDELEGH, 0x0); + csr_write(CSR_HVIPRIO1H, 0x0); + csr_write(CSR_HVIPRIO2H, 0x0); +#endif + + /* Enable per-CPU SGEI interrupt */ + enable_percpu_irq(hgei_parent_irq, + irq_get_trigger_type(hgei_parent_irq)); + csr_set(CSR_HIE, BIT(IRQ_S_GEXT)); +} + +void kvm_riscv_aia_disable(void) +{ + int i; + unsigned long flags; + struct kvm_vcpu *vcpu; + struct aia_hgei_control *hgctrl; + + if (!kvm_riscv_aia_available()) + return; + hgctrl = get_cpu_ptr(&aia_hgei); + + /* Disable per-CPU SGEI interrupt */ + csr_clear(CSR_HIE, BIT(IRQ_S_GEXT)); + disable_percpu_irq(hgei_parent_irq); + + aia_set_hvictl(false); + + raw_spin_lock_irqsave(&hgctrl->lock, flags); + + for (i = 0; i <= kvm_riscv_aia_nr_hgei; i++) { + vcpu = hgctrl->owners[i]; + if (!vcpu) + continue; + + /* + * We release hgctrl->lock before notifying IMSIC + * so that we don't have lock ordering issues. + */ + raw_spin_unlock_irqrestore(&hgctrl->lock, flags); + + /* Notify IMSIC */ + kvm_riscv_vcpu_aia_imsic_release(vcpu); + + /* + * Wakeup VCPU if it was blocked so that it can + * run on other HARTs + */ + if (csr_read(CSR_HGEIE) & BIT(i)) { + csr_clear(CSR_HGEIE, BIT(i)); + kvm_vcpu_kick(vcpu); + } + + raw_spin_lock_irqsave(&hgctrl->lock, flags); + } + + raw_spin_unlock_irqrestore(&hgctrl->lock, flags); + + put_cpu_ptr(&aia_hgei); +} + +int kvm_riscv_aia_init(void) +{ + int rc; + + if (!riscv_isa_extension_available(NULL, SxAIA)) + return -ENODEV; + + /* Figure-out number of bits in HGEIE */ + csr_write(CSR_HGEIE, -1UL); + kvm_riscv_aia_nr_hgei = fls_long(csr_read(CSR_HGEIE)); + csr_write(CSR_HGEIE, 0); + if (kvm_riscv_aia_nr_hgei) + kvm_riscv_aia_nr_hgei--; + + /* + * Number of usable HGEI lines should be minimum of per-HART + * IMSIC guest files and number of bits in HGEIE + * + * TODO: To be updated later by AIA IMSIC HW guest file support + */ + kvm_riscv_aia_nr_hgei = 0; + + /* + * Find number of guest MSI IDs + * + * TODO: To be updated later by AIA IMSIC HW guest file support + */ + kvm_riscv_aia_max_ids = IMSIC_MAX_ID; + + /* Initialize guest external interrupt line management */ + rc = aia_hgei_init(); + if (rc) + return rc; + + /* Register device operations */ + rc = kvm_register_device_ops(&kvm_riscv_aia_device_ops, + KVM_DEV_TYPE_RISCV_AIA); + if (rc) { + aia_hgei_exit(); + return rc; + } + + /* Enable KVM AIA support */ + static_branch_enable(&kvm_riscv_aia_available); + + return 0; +} + +void kvm_riscv_aia_exit(void) +{ + if (!kvm_riscv_aia_available()) + return; + + /* Unregister device operations */ + kvm_unregister_device_ops(KVM_DEV_TYPE_RISCV_AIA); + + /* Cleanup the HGEI state */ + aia_hgei_exit(); +} |