[kvmtool PATCH 3/6] riscv: Make irqchip support pluggable
Anup Patel
apatel at ventanamicro.com
Tue Jul 25 08:24:27 PDT 2023
We will be having different types of irqchip:
1) PLIC emulated by user-space
2) AIA APLIC and IMSIC provided by in-kernel KVM module
To support above, we de-couple PLIC specific code from generic
RISC-V code (such as FDT generation) so that we can easily add
other types of irqchip.
Signed-off-by: Anup Patel <apatel at ventanamicro.com>
---
riscv/fdt.c | 14 ++++++--
riscv/include/kvm/kvm-arch.h | 25 ++++++++++++---
riscv/irq.c | 62 ++++++++++++++++++++++++++++++++++--
riscv/kvm.c | 2 ++
riscv/pci.c | 32 +++++++++++++------
riscv/plic.c | 61 +++++++++++++++++------------------
6 files changed, 147 insertions(+), 49 deletions(-)
diff --git a/riscv/fdt.c b/riscv/fdt.c
index 2724c6e..9af71b5 100644
--- a/riscv/fdt.c
+++ b/riscv/fdt.c
@@ -209,19 +209,26 @@ static int setup_fdt(struct kvm *kvm)
/* CPUs */
generate_cpu_nodes(fdt, kvm);
+ /* IRQCHIP */
+ if (!riscv_irqchip_generate_fdt_node)
+ die("No way to generate IRQCHIP FDT node\n");
+ riscv_irqchip_generate_fdt_node(fdt, kvm);
+
/* Simple Bus */
_FDT(fdt_begin_node(fdt, "smb"));
_FDT(fdt_property_string(fdt, "compatible", "simple-bus"));
_FDT(fdt_property_cell(fdt, "#address-cells", 0x2));
_FDT(fdt_property_cell(fdt, "#size-cells", 0x2));
- _FDT(fdt_property_cell(fdt, "interrupt-parent", PHANDLE_PLIC));
+ _FDT(fdt_property_cell(fdt, "interrupt-parent",
+ riscv_irqchip_phandle));
_FDT(fdt_property(fdt, "ranges", NULL, 0));
/* Virtio MMIO devices */
dev_hdr = device__first_dev(DEVICE_BUS_MMIO);
while (dev_hdr) {
generate_mmio_fdt_nodes = dev_hdr->data;
- generate_mmio_fdt_nodes(fdt, dev_hdr, plic__generate_irq_prop);
+ generate_mmio_fdt_nodes(fdt, dev_hdr,
+ riscv__generate_irq_prop);
dev_hdr = device__next_dev(dev_hdr);
}
@@ -229,7 +236,8 @@ static int setup_fdt(struct kvm *kvm)
dev_hdr = device__first_dev(DEVICE_BUS_IOPORT);
while (dev_hdr) {
generate_mmio_fdt_nodes = dev_hdr->data;
- generate_mmio_fdt_nodes(fdt, dev_hdr, plic__generate_irq_prop);
+ generate_mmio_fdt_nodes(fdt, dev_hdr,
+ riscv__generate_irq_prop);
dev_hdr = device__next_dev(dev_hdr);
}
diff --git a/riscv/include/kvm/kvm-arch.h b/riscv/include/kvm/kvm-arch.h
index 660355b..cd37fc6 100644
--- a/riscv/include/kvm/kvm-arch.h
+++ b/riscv/include/kvm/kvm-arch.h
@@ -10,8 +10,8 @@
#define RISCV_IOPORT 0x00000000ULL
#define RISCV_IOPORT_SIZE SZ_64K
-#define RISCV_PLIC 0x0c000000ULL
-#define RISCV_PLIC_SIZE SZ_64M
+#define RISCV_IRQCHIP 0x08000000ULL
+#define RISCV_IRQCHIP_SIZE SZ_128M
#define RISCV_MMIO 0x10000000ULL
#define RISCV_MMIO_SIZE SZ_512M
#define RISCV_PCI 0x30000000ULL
@@ -84,10 +84,27 @@ static inline bool riscv_addr_in_ioport_region(u64 phys_addr)
enum irq_type;
-void plic__generate_irq_prop(void *fdt, u8 irq, enum irq_type irq_type);
+enum irqchip_type {
+ IRQCHIP_UNKNOWN = 0,
+ IRQCHIP_PLIC,
+ IRQCHIP_AIA
+};
+
+extern enum irqchip_type riscv_irqchip;
+extern bool riscv_irqchip_inkernel;
+extern void (*riscv_irqchip_trigger)(struct kvm *kvm, int irq,
+ int level, bool edge);
+extern void (*riscv_irqchip_generate_fdt_node)(void *fdt, struct kvm *kvm);
+extern u32 riscv_irqchip_phandle;
+extern u32 riscv_irqchip_msi_phandle;
+extern bool riscv_irqchip_line_sensing;
-void plic__irq_trig(struct kvm *kvm, int irq, int level, bool edge);
+void plic__create(struct kvm *kvm);
void pci__generate_fdt_nodes(void *fdt);
+void riscv__generate_irq_prop(void *fdt, u8 irq, enum irq_type irq_type);
+
+void riscv__irqchip_create(struct kvm *kvm);
+
#endif /* KVM__KVM_ARCH_H */
diff --git a/riscv/irq.c b/riscv/irq.c
index 78a582d..b608a2f 100644
--- a/riscv/irq.c
+++ b/riscv/irq.c
@@ -1,13 +1,71 @@
#include "kvm/kvm.h"
#include "kvm/kvm-cpu.h"
#include "kvm/irq.h"
+#include "kvm/fdt.h"
+#include "kvm/virtio.h"
+
+enum irqchip_type riscv_irqchip = IRQCHIP_UNKNOWN;
+bool riscv_irqchip_inkernel = false;
+void (*riscv_irqchip_trigger)(struct kvm *kvm, int irq, int level, bool edge)
+ = NULL;
+void (*riscv_irqchip_generate_fdt_node)(void *fdt, struct kvm *kvm) = NULL;
+u32 riscv_irqchip_phandle = PHANDLE_RESERVED;
+u32 riscv_irqchip_msi_phandle = PHANDLE_RESERVED;
+bool riscv_irqchip_line_sensing = false;
void kvm__irq_line(struct kvm *kvm, int irq, int level)
{
- plic__irq_trig(kvm, irq, level, false);
+ struct kvm_irq_level irq_level;
+
+ if (riscv_irqchip_inkernel) {
+ irq_level.irq = irq;
+ irq_level.level = !!level;
+ if (ioctl(kvm->vm_fd, KVM_IRQ_LINE, &irq_level) < 0)
+ pr_warning("%s: Could not KVM_IRQ_LINE for irq %d\n",
+ __func__, irq);
+ } else {
+ if (riscv_irqchip_trigger)
+ riscv_irqchip_trigger(kvm, irq, level, false);
+ else
+ pr_warning("%s: Can't change level for irq %d\n",
+ __func__, irq);
+ }
}
void kvm__irq_trigger(struct kvm *kvm, int irq)
{
- plic__irq_trig(kvm, irq, 1, true);
+ if (riscv_irqchip_inkernel) {
+ kvm__irq_line(kvm, irq, VIRTIO_IRQ_HIGH);
+ kvm__irq_line(kvm, irq, VIRTIO_IRQ_LOW);
+ } else {
+ if (riscv_irqchip_trigger)
+ riscv_irqchip_trigger(kvm, irq, 1, true);
+ else
+ pr_warning("%s: Can't trigger irq %d\n",
+ __func__, irq);
+ }
+}
+
+void riscv__generate_irq_prop(void *fdt, u8 irq, enum irq_type irq_type)
+{
+ u32 prop[2], size;
+
+ prop[0] = cpu_to_fdt32(irq);
+ size = sizeof(u32);
+ if (riscv_irqchip_line_sensing) {
+ prop[1] = cpu_to_fdt32(irq_type);
+ size += sizeof(u32);
+ }
+
+ _FDT(fdt_property(fdt, "interrupts", prop, size));
+}
+
+void riscv__irqchip_create(struct kvm *kvm)
+{
+ /* Try PLIC irqchip */
+ plic__create(kvm);
+
+ /* Fail if irqchip unknown */
+ if (riscv_irqchip == IRQCHIP_UNKNOWN)
+ die("No IRQCHIP found\n");
}
diff --git a/riscv/kvm.c b/riscv/kvm.c
index 8daad94..1d49479 100644
--- a/riscv/kvm.c
+++ b/riscv/kvm.c
@@ -96,6 +96,8 @@ void kvm__arch_init(struct kvm *kvm)
madvise(kvm->arch.ram_alloc_start, kvm->arch.ram_alloc_size,
MADV_HUGEPAGE);
+
+ riscv__irqchip_create(kvm);
}
#define FDT_ALIGN SZ_4M
diff --git a/riscv/pci.c b/riscv/pci.c
index 604fd20..61dee06 100644
--- a/riscv/pci.c
+++ b/riscv/pci.c
@@ -7,20 +7,21 @@
/*
* An entry in the interrupt-map table looks like:
- * <pci unit address> <pci interrupt pin> <plic phandle> <plic interrupt>
+ * <pci unit address> <pci interrupt pin> <irqchip phandle> <irqchip line>
*/
struct of_interrupt_map_entry {
struct of_pci_irq_mask pci_irq_mask;
- u32 plic_phandle;
- u32 plic_irq;
+ u32 irqchip_phandle;
+ u32 irqchip_line;
+ u32 irqchip_sense;
} __attribute__((packed));
void pci__generate_fdt_nodes(void *fdt)
{
struct device_header *dev_hdr;
struct of_interrupt_map_entry irq_map[OF_PCI_IRQ_MAP_MAX];
- unsigned nentries = 0;
+ unsigned nentries = 0, nsize;
/* Bus range */
u32 bus_range[] = { cpu_to_fdt32(0), cpu_to_fdt32(1), };
/* Configuration Space */
@@ -48,6 +49,11 @@ void pci__generate_fdt_nodes(void *fdt)
},
};
+ /* Find size of each interrupt map entery */
+ nsize = sizeof(struct of_interrupt_map_entry);
+ if (!riscv_irqchip_line_sensing)
+ nsize -= sizeof(u32);
+
/* Boilerplate PCI properties */
_FDT(fdt_begin_node(fdt, "pci"));
_FDT(fdt_property_string(fdt, "device_type", "pci"));
@@ -64,12 +70,13 @@ void pci__generate_fdt_nodes(void *fdt)
/* Generate the interrupt map ... */
dev_hdr = device__first_dev(DEVICE_BUS_PCI);
while (dev_hdr && nentries < ARRAY_SIZE(irq_map)) {
- struct of_interrupt_map_entry *entry = &irq_map[nentries];
+ struct of_interrupt_map_entry *entry;
struct pci_device_header *pci_hdr = dev_hdr->data;
u8 dev_num = dev_hdr->dev_num;
u8 pin = pci_hdr->irq_pin;
u8 irq = pci_hdr->irq_line;
+ entry = ((void *)irq_map) + (nsize * nentries);
*entry = (struct of_interrupt_map_entry) {
.pci_irq_mask = {
.pci_addr = {
@@ -79,16 +86,18 @@ void pci__generate_fdt_nodes(void *fdt)
},
.pci_pin = cpu_to_fdt32(pin),
},
- .plic_phandle = cpu_to_fdt32(PHANDLE_PLIC),
- .plic_irq = cpu_to_fdt32(irq),
+ .irqchip_phandle = cpu_to_fdt32(riscv_irqchip_phandle),
+ .irqchip_line = cpu_to_fdt32(irq),
};
+ if (riscv_irqchip_line_sensing)
+ entry->irqchip_sense = cpu_to_fdt32(IRQ_TYPE_LEVEL_HIGH);
+
nentries++;
dev_hdr = device__next_dev(dev_hdr);
}
- _FDT(fdt_property(fdt, "interrupt-map", irq_map,
- sizeof(struct of_interrupt_map_entry) * nentries));
+ _FDT(fdt_property(fdt, "interrupt-map", irq_map, nsize * nentries));
/* ... and the corresponding mask. */
if (nentries) {
@@ -105,5 +114,10 @@ void pci__generate_fdt_nodes(void *fdt)
sizeof(irq_mask)));
}
+ /* Set MSI parent if available */
+ if (riscv_irqchip_msi_phandle != PHANDLE_RESERVED)
+ _FDT(fdt_property_cell(fdt, "msi-parent",
+ riscv_irqchip_msi_phandle));
+
_FDT(fdt_end_node(fdt));
}
diff --git a/riscv/plic.c b/riscv/plic.c
index 6242286..ab7c574 100644
--- a/riscv/plic.c
+++ b/riscv/plic.c
@@ -118,7 +118,6 @@ struct plic_context {
struct plic_state {
bool ready;
struct kvm *kvm;
- struct device_header dev_hdr;
/* Static Configuration */
u32 num_irq;
@@ -204,7 +203,7 @@ static u32 __plic_context_irq_claim(struct plic_state *s,
return best_irq;
}
-void plic__irq_trig(struct kvm *kvm, int irq, int level, bool edge)
+static void plic__irq_trig(struct kvm *kvm, int irq, int level, bool edge)
{
bool irq_marked = false;
u8 i, irq_prio, irq_word;
@@ -425,7 +424,7 @@ static void plic__mmio_callback(struct kvm_cpu *vcpu,
die("plic: invalid len=%d", len);
addr &= ~0x3;
- addr -= RISCV_PLIC;
+ addr -= RISCV_IRQCHIP;
if (is_write) {
if (PRIORITY_BASE <= addr && addr < ENABLE_BASE) {
@@ -464,34 +463,23 @@ static void plic__mmio_callback(struct kvm_cpu *vcpu,
}
}
-void plic__generate_irq_prop(void *fdt, u8 irq, enum irq_type irq_type)
-{
- u32 irq_prop[] = {
- cpu_to_fdt32(irq)
- };
-
- _FDT(fdt_property(fdt, "interrupts", irq_prop, sizeof(irq_prop)));
-}
-
-static void plic__generate_fdt_node(void *fdt,
- struct device_header *dev_hdr,
- void (*generate_irq_prop)(void *fdt,
- u8 irq,
- enum irq_type))
+static void plic__generate_fdt_node(void *fdt, struct kvm *kvm)
{
u32 i;
+ char name[64];
u32 reg_cells[4], *irq_cells;
reg_cells[0] = 0;
- reg_cells[1] = cpu_to_fdt32(RISCV_PLIC);
+ reg_cells[1] = cpu_to_fdt32(RISCV_IRQCHIP);
reg_cells[2] = 0;
- reg_cells[3] = cpu_to_fdt32(RISCV_PLIC_SIZE);
+ reg_cells[3] = cpu_to_fdt32(RISCV_IRQCHIP_SIZE);
irq_cells = calloc(plic.num_context * 2, sizeof(u32));
if (!irq_cells)
die("Failed to alloc irq_cells");
- _FDT(fdt_begin_node(fdt, "interrupt-controller at 0c000000"));
+ sprintf(name, "interrupt-controller@%08x", (u32)RISCV_IRQCHIP);
+ _FDT(fdt_begin_node(fdt, name));
_FDT(fdt_property_string(fdt, "compatible", "riscv,plic0"));
_FDT(fdt_property(fdt, "reg", reg_cells, sizeof(reg_cells)));
_FDT(fdt_property_cell(fdt, "#interrupt-cells", 1));
@@ -518,12 +506,10 @@ static int plic__init(struct kvm *kvm)
int ret;
struct plic_context *c;
- plic.kvm = kvm;
- plic.dev_hdr = (struct device_header) {
- .bus_type = DEVICE_BUS_MMIO,
- .data = plic__generate_fdt_node,
- };
+ if (riscv_irqchip != IRQCHIP_PLIC)
+ return 0;
+ plic.kvm = kvm;
plic.num_irq = MAX_DEVICES;
plic.num_irq_word = plic.num_irq / 32;
if ((plic.num_irq_word * 32) < plic.num_irq)
@@ -544,15 +530,11 @@ static int plic__init(struct kvm *kvm)
mutex_init(&plic.irq_lock);
- ret = kvm__register_mmio(kvm, RISCV_PLIC, RISCV_PLIC_SIZE,
+ ret = kvm__register_mmio(kvm, RISCV_IRQCHIP, RISCV_IRQCHIP_SIZE,
false, plic__mmio_callback, &plic);
if (ret)
return ret;
- ret = device__register(&plic.dev_hdr);
- if (ret)
- return ret;
-
plic.ready = true;
return 0;
@@ -562,10 +544,27 @@ dev_init(plic__init);
static int plic__exit(struct kvm *kvm)
{
+ if (riscv_irqchip != IRQCHIP_PLIC)
+ return 0;
+
plic.ready = false;
- kvm__deregister_mmio(kvm, RISCV_PLIC);
+ kvm__deregister_mmio(kvm, RISCV_IRQCHIP);
free(plic.contexts);
return 0;
}
dev_exit(plic__exit);
+
+void plic__create(struct kvm *kvm)
+{
+ if (riscv_irqchip != IRQCHIP_UNKNOWN)
+ return;
+
+ riscv_irqchip = IRQCHIP_PLIC;
+ riscv_irqchip_inkernel = false;
+ riscv_irqchip_trigger = plic__irq_trig;
+ riscv_irqchip_generate_fdt_node = plic__generate_fdt_node;
+ riscv_irqchip_phandle = PHANDLE_PLIC;
+ riscv_irqchip_msi_phandle = PHANDLE_RESERVED;
+ riscv_irqchip_line_sensing = false;
+}
--
2.34.1
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