linux/arch/riscv/kvm/aia_aplic.c
Anup Patel 289a007b98 RISC-V: KVM: Expose APLIC registers as attributes of AIA irqchip
We expose APLIC registers as KVM device attributes of the in-kernel
AIA irqchip device. This will allow KVM user-space to save/restore
APLIC state using KVM device ioctls().

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-06-18 21:24:50 +05:30

620 lines
15 KiB
C

// 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/kvm_host.h>
#include <linux/math.h>
#include <linux/spinlock.h>
#include <linux/swab.h>
#include <kvm/iodev.h>
#include <asm/kvm_aia_aplic.h>
struct aplic_irq {
raw_spinlock_t lock;
u32 sourcecfg;
u32 state;
#define APLIC_IRQ_STATE_PENDING BIT(0)
#define APLIC_IRQ_STATE_ENABLED BIT(1)
#define APLIC_IRQ_STATE_ENPEND (APLIC_IRQ_STATE_PENDING | \
APLIC_IRQ_STATE_ENABLED)
#define APLIC_IRQ_STATE_INPUT BIT(8)
u32 target;
};
struct aplic {
struct kvm_io_device iodev;
u32 domaincfg;
u32 genmsi;
u32 nr_irqs;
u32 nr_words;
struct aplic_irq *irqs;
};
static u32 aplic_read_sourcecfg(struct aplic *aplic, u32 irq)
{
u32 ret;
unsigned long flags;
struct aplic_irq *irqd;
if (!irq || aplic->nr_irqs <= irq)
return 0;
irqd = &aplic->irqs[irq];
raw_spin_lock_irqsave(&irqd->lock, flags);
ret = irqd->sourcecfg;
raw_spin_unlock_irqrestore(&irqd->lock, flags);
return ret;
}
static void aplic_write_sourcecfg(struct aplic *aplic, u32 irq, u32 val)
{
unsigned long flags;
struct aplic_irq *irqd;
if (!irq || aplic->nr_irqs <= irq)
return;
irqd = &aplic->irqs[irq];
if (val & APLIC_SOURCECFG_D)
val = 0;
else
val &= APLIC_SOURCECFG_SM_MASK;
raw_spin_lock_irqsave(&irqd->lock, flags);
irqd->sourcecfg = val;
raw_spin_unlock_irqrestore(&irqd->lock, flags);
}
static u32 aplic_read_target(struct aplic *aplic, u32 irq)
{
u32 ret;
unsigned long flags;
struct aplic_irq *irqd;
if (!irq || aplic->nr_irqs <= irq)
return 0;
irqd = &aplic->irqs[irq];
raw_spin_lock_irqsave(&irqd->lock, flags);
ret = irqd->target;
raw_spin_unlock_irqrestore(&irqd->lock, flags);
return ret;
}
static void aplic_write_target(struct aplic *aplic, u32 irq, u32 val)
{
unsigned long flags;
struct aplic_irq *irqd;
if (!irq || aplic->nr_irqs <= irq)
return;
irqd = &aplic->irqs[irq];
val &= APLIC_TARGET_EIID_MASK |
(APLIC_TARGET_HART_IDX_MASK << APLIC_TARGET_HART_IDX_SHIFT) |
(APLIC_TARGET_GUEST_IDX_MASK << APLIC_TARGET_GUEST_IDX_SHIFT);
raw_spin_lock_irqsave(&irqd->lock, flags);
irqd->target = val;
raw_spin_unlock_irqrestore(&irqd->lock, flags);
}
static bool aplic_read_pending(struct aplic *aplic, u32 irq)
{
bool ret;
unsigned long flags;
struct aplic_irq *irqd;
if (!irq || aplic->nr_irqs <= irq)
return false;
irqd = &aplic->irqs[irq];
raw_spin_lock_irqsave(&irqd->lock, flags);
ret = (irqd->state & APLIC_IRQ_STATE_PENDING) ? true : false;
raw_spin_unlock_irqrestore(&irqd->lock, flags);
return ret;
}
static void aplic_write_pending(struct aplic *aplic, u32 irq, bool pending)
{
unsigned long flags, sm;
struct aplic_irq *irqd;
if (!irq || aplic->nr_irqs <= irq)
return;
irqd = &aplic->irqs[irq];
raw_spin_lock_irqsave(&irqd->lock, flags);
sm = irqd->sourcecfg & APLIC_SOURCECFG_SM_MASK;
if (!pending &&
((sm == APLIC_SOURCECFG_SM_LEVEL_HIGH) ||
(sm == APLIC_SOURCECFG_SM_LEVEL_LOW)))
goto skip_write_pending;
if (pending)
irqd->state |= APLIC_IRQ_STATE_PENDING;
else
irqd->state &= ~APLIC_IRQ_STATE_PENDING;
skip_write_pending:
raw_spin_unlock_irqrestore(&irqd->lock, flags);
}
static bool aplic_read_enabled(struct aplic *aplic, u32 irq)
{
bool ret;
unsigned long flags;
struct aplic_irq *irqd;
if (!irq || aplic->nr_irqs <= irq)
return false;
irqd = &aplic->irqs[irq];
raw_spin_lock_irqsave(&irqd->lock, flags);
ret = (irqd->state & APLIC_IRQ_STATE_ENABLED) ? true : false;
raw_spin_unlock_irqrestore(&irqd->lock, flags);
return ret;
}
static void aplic_write_enabled(struct aplic *aplic, u32 irq, bool enabled)
{
unsigned long flags;
struct aplic_irq *irqd;
if (!irq || aplic->nr_irqs <= irq)
return;
irqd = &aplic->irqs[irq];
raw_spin_lock_irqsave(&irqd->lock, flags);
if (enabled)
irqd->state |= APLIC_IRQ_STATE_ENABLED;
else
irqd->state &= ~APLIC_IRQ_STATE_ENABLED;
raw_spin_unlock_irqrestore(&irqd->lock, flags);
}
static bool aplic_read_input(struct aplic *aplic, u32 irq)
{
bool ret;
unsigned long flags;
struct aplic_irq *irqd;
if (!irq || aplic->nr_irqs <= irq)
return false;
irqd = &aplic->irqs[irq];
raw_spin_lock_irqsave(&irqd->lock, flags);
ret = (irqd->state & APLIC_IRQ_STATE_INPUT) ? true : false;
raw_spin_unlock_irqrestore(&irqd->lock, flags);
return ret;
}
static void aplic_inject_msi(struct kvm *kvm, u32 irq, u32 target)
{
u32 hart_idx, guest_idx, eiid;
hart_idx = target >> APLIC_TARGET_HART_IDX_SHIFT;
hart_idx &= APLIC_TARGET_HART_IDX_MASK;
guest_idx = target >> APLIC_TARGET_GUEST_IDX_SHIFT;
guest_idx &= APLIC_TARGET_GUEST_IDX_MASK;
eiid = target & APLIC_TARGET_EIID_MASK;
kvm_riscv_aia_inject_msi_by_id(kvm, hart_idx, guest_idx, eiid);
}
static void aplic_update_irq_range(struct kvm *kvm, u32 first, u32 last)
{
bool inject;
u32 irq, target;
unsigned long flags;
struct aplic_irq *irqd;
struct aplic *aplic = kvm->arch.aia.aplic_state;
if (!(aplic->domaincfg & APLIC_DOMAINCFG_IE))
return;
for (irq = first; irq <= last; irq++) {
if (!irq || aplic->nr_irqs <= irq)
continue;
irqd = &aplic->irqs[irq];
raw_spin_lock_irqsave(&irqd->lock, flags);
inject = false;
target = irqd->target;
if ((irqd->state & APLIC_IRQ_STATE_ENPEND) ==
APLIC_IRQ_STATE_ENPEND) {
irqd->state &= ~APLIC_IRQ_STATE_PENDING;
inject = true;
}
raw_spin_unlock_irqrestore(&irqd->lock, flags);
if (inject)
aplic_inject_msi(kvm, irq, target);
}
}
int kvm_riscv_aia_aplic_inject(struct kvm *kvm, u32 source, bool level)
{
u32 target;
bool inject = false, ie;
unsigned long flags;
struct aplic_irq *irqd;
struct aplic *aplic = kvm->arch.aia.aplic_state;
if (!aplic || !source || (aplic->nr_irqs <= source))
return -ENODEV;
irqd = &aplic->irqs[source];
ie = (aplic->domaincfg & APLIC_DOMAINCFG_IE) ? true : false;
raw_spin_lock_irqsave(&irqd->lock, flags);
if (irqd->sourcecfg & APLIC_SOURCECFG_D)
goto skip_unlock;
switch (irqd->sourcecfg & APLIC_SOURCECFG_SM_MASK) {
case APLIC_SOURCECFG_SM_EDGE_RISE:
if (level && !(irqd->state & APLIC_IRQ_STATE_INPUT) &&
!(irqd->state & APLIC_IRQ_STATE_PENDING))
irqd->state |= APLIC_IRQ_STATE_PENDING;
break;
case APLIC_SOURCECFG_SM_EDGE_FALL:
if (!level && (irqd->state & APLIC_IRQ_STATE_INPUT) &&
!(irqd->state & APLIC_IRQ_STATE_PENDING))
irqd->state |= APLIC_IRQ_STATE_PENDING;
break;
case APLIC_SOURCECFG_SM_LEVEL_HIGH:
if (level && !(irqd->state & APLIC_IRQ_STATE_PENDING))
irqd->state |= APLIC_IRQ_STATE_PENDING;
break;
case APLIC_SOURCECFG_SM_LEVEL_LOW:
if (!level && !(irqd->state & APLIC_IRQ_STATE_PENDING))
irqd->state |= APLIC_IRQ_STATE_PENDING;
break;
}
if (level)
irqd->state |= APLIC_IRQ_STATE_INPUT;
else
irqd->state &= ~APLIC_IRQ_STATE_INPUT;
target = irqd->target;
if (ie && ((irqd->state & APLIC_IRQ_STATE_ENPEND) ==
APLIC_IRQ_STATE_ENPEND)) {
irqd->state &= ~APLIC_IRQ_STATE_PENDING;
inject = true;
}
skip_unlock:
raw_spin_unlock_irqrestore(&irqd->lock, flags);
if (inject)
aplic_inject_msi(kvm, source, target);
return 0;
}
static u32 aplic_read_input_word(struct aplic *aplic, u32 word)
{
u32 i, ret = 0;
for (i = 0; i < 32; i++)
ret |= aplic_read_input(aplic, word * 32 + i) ? BIT(i) : 0;
return ret;
}
static u32 aplic_read_pending_word(struct aplic *aplic, u32 word)
{
u32 i, ret = 0;
for (i = 0; i < 32; i++)
ret |= aplic_read_pending(aplic, word * 32 + i) ? BIT(i) : 0;
return ret;
}
static void aplic_write_pending_word(struct aplic *aplic, u32 word,
u32 val, bool pending)
{
u32 i;
for (i = 0; i < 32; i++) {
if (val & BIT(i))
aplic_write_pending(aplic, word * 32 + i, pending);
}
}
static u32 aplic_read_enabled_word(struct aplic *aplic, u32 word)
{
u32 i, ret = 0;
for (i = 0; i < 32; i++)
ret |= aplic_read_enabled(aplic, word * 32 + i) ? BIT(i) : 0;
return ret;
}
static void aplic_write_enabled_word(struct aplic *aplic, u32 word,
u32 val, bool enabled)
{
u32 i;
for (i = 0; i < 32; i++) {
if (val & BIT(i))
aplic_write_enabled(aplic, word * 32 + i, enabled);
}
}
static int aplic_mmio_read_offset(struct kvm *kvm, gpa_t off, u32 *val32)
{
u32 i;
struct aplic *aplic = kvm->arch.aia.aplic_state;
if ((off & 0x3) != 0)
return -EOPNOTSUPP;
if (off == APLIC_DOMAINCFG) {
*val32 = APLIC_DOMAINCFG_RDONLY |
aplic->domaincfg | APLIC_DOMAINCFG_DM;
} else if ((off >= APLIC_SOURCECFG_BASE) &&
(off < (APLIC_SOURCECFG_BASE + (aplic->nr_irqs - 1) * 4))) {
i = ((off - APLIC_SOURCECFG_BASE) >> 2) + 1;
*val32 = aplic_read_sourcecfg(aplic, i);
} else if ((off >= APLIC_SETIP_BASE) &&
(off < (APLIC_SETIP_BASE + aplic->nr_words * 4))) {
i = (off - APLIC_SETIP_BASE) >> 2;
*val32 = aplic_read_pending_word(aplic, i);
} else if (off == APLIC_SETIPNUM) {
*val32 = 0;
} else if ((off >= APLIC_CLRIP_BASE) &&
(off < (APLIC_CLRIP_BASE + aplic->nr_words * 4))) {
i = (off - APLIC_CLRIP_BASE) >> 2;
*val32 = aplic_read_input_word(aplic, i);
} else if (off == APLIC_CLRIPNUM) {
*val32 = 0;
} else if ((off >= APLIC_SETIE_BASE) &&
(off < (APLIC_SETIE_BASE + aplic->nr_words * 4))) {
i = (off - APLIC_SETIE_BASE) >> 2;
*val32 = aplic_read_enabled_word(aplic, i);
} else if (off == APLIC_SETIENUM) {
*val32 = 0;
} else if ((off >= APLIC_CLRIE_BASE) &&
(off < (APLIC_CLRIE_BASE + aplic->nr_words * 4))) {
*val32 = 0;
} else if (off == APLIC_CLRIENUM) {
*val32 = 0;
} else if (off == APLIC_SETIPNUM_LE) {
*val32 = 0;
} else if (off == APLIC_SETIPNUM_BE) {
*val32 = 0;
} else if (off == APLIC_GENMSI) {
*val32 = aplic->genmsi;
} else if ((off >= APLIC_TARGET_BASE) &&
(off < (APLIC_TARGET_BASE + (aplic->nr_irqs - 1) * 4))) {
i = ((off - APLIC_TARGET_BASE) >> 2) + 1;
*val32 = aplic_read_target(aplic, i);
} else
return -ENODEV;
return 0;
}
static int aplic_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
gpa_t addr, int len, void *val)
{
if (len != 4)
return -EOPNOTSUPP;
return aplic_mmio_read_offset(vcpu->kvm,
addr - vcpu->kvm->arch.aia.aplic_addr,
val);
}
static int aplic_mmio_write_offset(struct kvm *kvm, gpa_t off, u32 val32)
{
u32 i;
struct aplic *aplic = kvm->arch.aia.aplic_state;
if ((off & 0x3) != 0)
return -EOPNOTSUPP;
if (off == APLIC_DOMAINCFG) {
/* Only IE bit writeable */
aplic->domaincfg = val32 & APLIC_DOMAINCFG_IE;
} else if ((off >= APLIC_SOURCECFG_BASE) &&
(off < (APLIC_SOURCECFG_BASE + (aplic->nr_irqs - 1) * 4))) {
i = ((off - APLIC_SOURCECFG_BASE) >> 2) + 1;
aplic_write_sourcecfg(aplic, i, val32);
} else if ((off >= APLIC_SETIP_BASE) &&
(off < (APLIC_SETIP_BASE + aplic->nr_words * 4))) {
i = (off - APLIC_SETIP_BASE) >> 2;
aplic_write_pending_word(aplic, i, val32, true);
} else if (off == APLIC_SETIPNUM) {
aplic_write_pending(aplic, val32, true);
} else if ((off >= APLIC_CLRIP_BASE) &&
(off < (APLIC_CLRIP_BASE + aplic->nr_words * 4))) {
i = (off - APLIC_CLRIP_BASE) >> 2;
aplic_write_pending_word(aplic, i, val32, false);
} else if (off == APLIC_CLRIPNUM) {
aplic_write_pending(aplic, val32, false);
} else if ((off >= APLIC_SETIE_BASE) &&
(off < (APLIC_SETIE_BASE + aplic->nr_words * 4))) {
i = (off - APLIC_SETIE_BASE) >> 2;
aplic_write_enabled_word(aplic, i, val32, true);
} else if (off == APLIC_SETIENUM) {
aplic_write_enabled(aplic, val32, true);
} else if ((off >= APLIC_CLRIE_BASE) &&
(off < (APLIC_CLRIE_BASE + aplic->nr_words * 4))) {
i = (off - APLIC_CLRIE_BASE) >> 2;
aplic_write_enabled_word(aplic, i, val32, false);
} else if (off == APLIC_CLRIENUM) {
aplic_write_enabled(aplic, val32, false);
} else if (off == APLIC_SETIPNUM_LE) {
aplic_write_pending(aplic, val32, true);
} else if (off == APLIC_SETIPNUM_BE) {
aplic_write_pending(aplic, __swab32(val32), true);
} else if (off == APLIC_GENMSI) {
aplic->genmsi = val32 & ~(APLIC_TARGET_GUEST_IDX_MASK <<
APLIC_TARGET_GUEST_IDX_SHIFT);
kvm_riscv_aia_inject_msi_by_id(kvm,
val32 >> APLIC_TARGET_HART_IDX_SHIFT, 0,
val32 & APLIC_TARGET_EIID_MASK);
} else if ((off >= APLIC_TARGET_BASE) &&
(off < (APLIC_TARGET_BASE + (aplic->nr_irqs - 1) * 4))) {
i = ((off - APLIC_TARGET_BASE) >> 2) + 1;
aplic_write_target(aplic, i, val32);
} else
return -ENODEV;
aplic_update_irq_range(kvm, 1, aplic->nr_irqs - 1);
return 0;
}
static int aplic_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
gpa_t addr, int len, const void *val)
{
if (len != 4)
return -EOPNOTSUPP;
return aplic_mmio_write_offset(vcpu->kvm,
addr - vcpu->kvm->arch.aia.aplic_addr,
*((const u32 *)val));
}
static struct kvm_io_device_ops aplic_iodoev_ops = {
.read = aplic_mmio_read,
.write = aplic_mmio_write,
};
int kvm_riscv_aia_aplic_set_attr(struct kvm *kvm, unsigned long type, u32 v)
{
int rc;
if (!kvm->arch.aia.aplic_state)
return -ENODEV;
rc = aplic_mmio_write_offset(kvm, type, v);
if (rc)
return rc;
return 0;
}
int kvm_riscv_aia_aplic_get_attr(struct kvm *kvm, unsigned long type, u32 *v)
{
int rc;
if (!kvm->arch.aia.aplic_state)
return -ENODEV;
rc = aplic_mmio_read_offset(kvm, type, v);
if (rc)
return rc;
return 0;
}
int kvm_riscv_aia_aplic_has_attr(struct kvm *kvm, unsigned long type)
{
int rc;
u32 val;
if (!kvm->arch.aia.aplic_state)
return -ENODEV;
rc = aplic_mmio_read_offset(kvm, type, &val);
if (rc)
return rc;
return 0;
}
int kvm_riscv_aia_aplic_init(struct kvm *kvm)
{
int i, ret = 0;
struct aplic *aplic;
/* Do nothing if we have zero sources */
if (!kvm->arch.aia.nr_sources)
return 0;
/* Allocate APLIC global state */
aplic = kzalloc(sizeof(*aplic), GFP_KERNEL);
if (!aplic)
return -ENOMEM;
kvm->arch.aia.aplic_state = aplic;
/* Setup APLIC IRQs */
aplic->nr_irqs = kvm->arch.aia.nr_sources + 1;
aplic->nr_words = DIV_ROUND_UP(aplic->nr_irqs, 32);
aplic->irqs = kcalloc(aplic->nr_irqs,
sizeof(*aplic->irqs), GFP_KERNEL);
if (!aplic->irqs) {
ret = -ENOMEM;
goto fail_free_aplic;
}
for (i = 0; i < aplic->nr_irqs; i++)
raw_spin_lock_init(&aplic->irqs[i].lock);
/* Setup IO device */
kvm_iodevice_init(&aplic->iodev, &aplic_iodoev_ops);
mutex_lock(&kvm->slots_lock);
ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS,
kvm->arch.aia.aplic_addr,
KVM_DEV_RISCV_APLIC_SIZE,
&aplic->iodev);
mutex_unlock(&kvm->slots_lock);
if (ret)
goto fail_free_aplic_irqs;
/* Setup default IRQ routing */
ret = kvm_riscv_setup_default_irq_routing(kvm, aplic->nr_irqs);
if (ret)
goto fail_unreg_iodev;
return 0;
fail_unreg_iodev:
mutex_lock(&kvm->slots_lock);
kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &aplic->iodev);
mutex_unlock(&kvm->slots_lock);
fail_free_aplic_irqs:
kfree(aplic->irqs);
fail_free_aplic:
kvm->arch.aia.aplic_state = NULL;
kfree(aplic);
return ret;
}
void kvm_riscv_aia_aplic_cleanup(struct kvm *kvm)
{
struct aplic *aplic = kvm->arch.aia.aplic_state;
if (!aplic)
return;
mutex_lock(&kvm->slots_lock);
kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &aplic->iodev);
mutex_unlock(&kvm->slots_lock);
kfree(aplic->irqs);
kvm->arch.aia.aplic_state = NULL;
kfree(aplic);
}