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[WIP] virtio: detect PIIX4 and attempt to power off via PIIX4 (broken) #500

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[WIP] virtio: detect PIIX4 and attempt to power off via PIIX4 (broken) #500

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ef4ffb6
debug
mbacarella Nov 12, 2021
044774e
implement piix4 poweroff
mbacarella Nov 12, 2021
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7 changes: 6 additions & 1 deletion bindings/virtio/bindings.h
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Original file line number Diff line number Diff line change
Expand Up @@ -48,17 +48,22 @@ int tscclock_init(void);
uint64_t tscclock_monotonic(void);
uint64_t tscclock_epochoffset(void);
void cpu_block(uint64_t until);
void cpu_wasteful_milli_sleep(uint64_t millis);

/* pci.c: only enumerate for now */
/* pci.c: only enumerate for now (except with a hack for poweroff). */
struct pci_config_info {
uint8_t bus;
uint8_t dev;
uint8_t fun;
uint16_t vendor_id;
uint16_t device_id;
uint16_t subsys_id;
uint16_t base;
uint8_t irq;
};

extern void (*pci_acpi_poweroff)(void);

void pci_enumerate(void);

/* virtio.c: mostly net for now */
Expand Down
169 changes: 142 additions & 27 deletions bindings/virtio/pci.c
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Original file line number Diff line number Diff line change
Expand Up @@ -23,12 +23,14 @@
#define PCI_CONFIG_ADDR 0xCF8
#define PCI_CONFIG_DATA 0xCFC

/* 8 bits for bus number, 5 bits for devices */
/* 8 bits for bus number, 5 bits for devices, 3 bits for functions */
#define PCI_MAX_BUSES (1 << 8)
#define PCI_MAX_DEVICES (1 << 5)
#define PCI_MAX_FUNCTIONS (1 << 3)

#define PCI_BUS_SHIFT (16)
#define PCI_DEVICE_SHIFT (11)
#define PCI_FUNCTION_SHIFT (8)
#define PCI_ENABLE_BIT (1 << 31)

#define PCI_CONF_SUBSYS_ID 0x2c
Expand All @@ -43,6 +45,7 @@
#define PCI_CONF_IOBAR_SHFT 0x0
#define PCI_CONF_IOBAR_MASK ~0x3

void (*pci_acpi_power_off)(void) = NULL;

#define PCI_CONF_READ(type, ret, a, s) do { \
uint32_t _conf_data; \
Expand All @@ -52,7 +55,6 @@
*(ret) = (type) _conf_data; \
} while (0)


static uint32_t net_devices_found;
static uint32_t blk_devices_found;

Expand All @@ -64,59 +66,172 @@ static void virtio_config(struct pci_config_info *pci)
/* we only support one net device and one blk device */
switch (pci->subsys_id) {
case PCI_CONF_SUBSYS_NET:
log(INFO, "Solo5: PCI:%02x:%02x: virtio-net device, base=0x%x, irq=%u\n",
pci->bus, pci->dev, pci->base, pci->irq);
log(INFO, "Solo5: PCI:%02x:%02x.%02x: virtio-net device, base=0x%x, irq=%u\n",
pci->bus, pci->dev, pci->fun, pci->base, pci->irq);
if (!net_devices_found++)
virtio_config_network(pci);
else
log(WARN, "Solo5: PCI:%02x:%02x: not configured\n", pci->bus,
pci->dev);
log(WARN, "Solo5: PCI:%02x:%02x.%02x: not configured\n", pci->bus,
pci->dev, pci->fun);
break;
case PCI_CONF_SUBSYS_BLK:
log(INFO, "Solo5: PCI:%02x:%02x: virtio-block device, base=0x%x, irq=%u\n",
pci->bus, pci->dev, pci->base, pci->irq);
log(INFO, "Solo5: PCI:%02x:%02x.%02x: virtio-block device, base=0x%x, irq=%u\n",
pci->bus, pci->dev, pci->fun, pci->base, pci->irq);
if (!blk_devices_found++)
virtio_config_block(pci);
else
log(WARN, "Solo5: PCI:%02x:%02x: not configured\n", pci->bus,
pci->dev);
log(WARN, "Solo5: PCI:%02x:%02x.%02x: not configured\n", pci->bus,
pci->dev, pci->fun);
break;
default:
log(WARN, "Solo5: PCI:%02x:%02x: unknown virtio device (0x%x)\n",
pci->bus, pci->dev, pci->subsys_id);
log(WARN, "Solo5: PCI:%02x:%02x.%02x: unknown virtio device (0x%x)\n",
pci->bus, pci->dev, pci->fun, pci->subsys_id);
return;
}
}

static void poweroff_noop(void) { }

/* According to the Google Compute Engine docs, guest OSes can gain access to
ACPI features by supporting the Intel PIIX4. We use it to implement power off. */

/* This PIIX4 poweroff technique is learned from the Linux kernel.
https://github.com/torvalds/linux/blob/master/drivers/power/reset/piix4-poweroff.c */

#define DEVICE_ID_INTEL_PIIX4 0x7113

static struct pci_config_info piix4_pci_dev;
#define PIIX4_SUSPEND_MAGIC 0x00120002

enum piix4_pm_io_reg {
PIIX4_FUNC3IO_PMSTS = 0x00,
#define PIIX4_FUNC3IO_PMSTS_PWRBTN_STS (1 << 8)
PIIX4_FUNC3IO_PMCNTRL = 0x04,
#define PIIX4_FUNC3IO_PMCNTRL_SUS_EN (1 << 13)
#define PIIX4_FUNC3IO_PMCNTRL_SUS_TYP_SOFF (0x0 << 10)
};

/*
#define PCI_OP_WRITE(size, type, len) \
int noinline pci_bus_write_config_##size \
(struct pci_bus *bus, unsigned int devfn, int pos, type value) \
{ \
int res; \
unsigned long flags; \
if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
pci_lock_config(flags); \
res = bus->ops->write(bus, devfn, pos, len, value); \
pci_unlock_config(flags); \
return res; \
}
*/

static void poweroff_piix4(void)
{
uint16_t sts;

/* In a full PCI implementation we would calculate this stuff on enumeration,
but rather than introduce potential bugs at startup probing for these
features, lets leave it for poweroff. */
log(WARN, "Solo5: initiating PIIX4 ACPI poweroff\n");

/* Ensure the power button status is clear */
while (1) {
sts = inw(piix4_pci_dev.base + PIIX4_FUNC3IO_PMSTS);
if (!(sts & PIIX4_FUNC3IO_PMSTS_PWRBTN_STS))
break;
outw(piix4_pci_dev.base + PIIX4_FUNC3IO_PMSTS, sts);
}
log(WARN, "Solo5: button status is clear\n");

/* Enable entry to suspend */
outw(
piix4_pci_dev.base + PIIX4_FUNC3IO_PMCNTRL,
PIIX4_FUNC3IO_PMCNTRL_SUS_TYP_SOFF | PIIX4_FUNC3IO_PMCNTRL_SUS_EN
);

/* If the special cycle occurs too soon this doesn't work... */
cpu_wasteful_milli_sleep(10);

log(WARN, "Solo5: milli_sleep 10 complete\n");

/* The PIIX4 will enter the suspend state only after seeing a special cycle
with the correct magic data on the PCI bus. Generate that cycle now. */
/*
pci_bus_write_config_dword(
piix4_pci_dev,
(0x1f << 3 | 0x7),
0,
PIIX4_SUSPEND_MAGIC);
*/
/* Give the system some time to power down, then error */
cpu_wasteful_milli_sleep(1000);
log(WARN, "Solo5: PIIX4 ACPI poweroff failed!\n");
}


void (*pci_acpi_poweroff)(void) = poweroff_noop;

static void intel_config(struct pci_config_info *pci)
{
switch (pci->device_id) {
case DEVICE_ID_INTEL_PIIX4:
log(INFO, "Solo5: PCI:%02x:%02x.%02x: Intel 82371AB/EB/MB PIIX4 ACPI, irq=%u, base=0x%x\n",
pci->bus, pci->dev, pci->fun, pci->irq, pci->base);
memcpy(&piix4_pci_dev, pci, sizeof(struct pci_config_info));
pci_acpi_poweroff = poweroff_piix4;
break;
default:
log(WARN, "Solo5: PCI:%02x:%02x.%02x: unknown Intel device; device_id:0x%x, subsys_id: 0x%x\n",
pci->bus, pci->dev, pci->fun, pci->device_id, pci->subsys_id);
break;
}
}

#define VENDOR_INTEL 0x8086
#define VENDOR_QUMRANET_VIRTIO 0x1af4

void pci_enumerate(void)
{
uint32_t bus;
uint8_t dev;
uint8_t fun;

for (bus = 0; bus < PCI_MAX_BUSES; bus++) {
for (dev = 0; dev < PCI_MAX_DEVICES; dev++) {
uint32_t config_addr, config_data;
struct pci_config_info pci;

config_addr = (PCI_ENABLE_BIT)
| (bus << PCI_BUS_SHIFT)
| (dev << PCI_DEVICE_SHIFT);

outl(PCI_CONFIG_ADDR, config_addr);
config_data = inl(PCI_CONFIG_DATA);

pci.bus = bus;
pci.dev = dev;
pci.vendor_id = config_data & 0xffff;
for (fun = 0; fun < PCI_MAX_FUNCTIONS; fun++) {
uint32_t config_addr, config_data;
uint16_t vendor_id;
struct pci_config_info pci;

config_addr = (PCI_ENABLE_BIT)
| (bus << PCI_BUS_SHIFT)
| (dev << PCI_DEVICE_SHIFT)
| (fun << PCI_FUNCTION_SHIFT);

outl(PCI_CONFIG_ADDR, config_addr);
config_data = inl(PCI_CONFIG_DATA);

vendor_id = config_data & 0xffff;
if (vendor_id == 0xffff) {
/* This means there's no device here. */
continue;
}
pci.bus = bus;
pci.dev = dev;
pci.fun = fun;
pci.vendor_id = vendor_id;
pci.device_id = (config_data >> 16) & 0xffff;

if (pci.vendor_id == VENDOR_QUMRANET_VIRTIO) {
PCI_CONF_READ(uint16_t, &pci.subsys_id, config_addr, SUBSYS_ID);
PCI_CONF_READ(uint16_t, &pci.base, config_addr, IOBAR);
PCI_CONF_READ(uint8_t, &pci.irq, config_addr, IRQ);

virtio_config(&pci);
if (pci.vendor_id == VENDOR_QUMRANET_VIRTIO) {
virtio_config(&pci);
} else if (pci.vendor_id == VENDOR_INTEL) {
intel_config(&pci);
}
}
}
}
Expand Down
7 changes: 3 additions & 4 deletions bindings/virtio/platform.c
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Original file line number Diff line number Diff line change
Expand Up @@ -107,10 +107,9 @@ void platform_exit(int status __attribute__((unused)),
*/
outw(0x501, 41);

/*
* If we got here, there is no way to initiate "shutdown" on virtio without
* ACPI, so just halt.
*/
pci_acpi_poweroff();

/* If we got here, ACPI poweroff wasn't supported. So just halt. */
platform_puts("Solo5: Halted\n", 14);
cpu_halt();
}
Expand Down
11 changes: 11 additions & 0 deletions bindings/virtio/tscclock.c
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Original file line number Diff line number Diff line change
Expand Up @@ -329,3 +329,14 @@ void cpu_block(uint64_t until) {
"cli;\n");
cpu_intr_depth = d;
}

/* This is only here for timing while configuring devices on either startup or
shutdown. Do not generally use. */
void cpu_wasteful_milli_sleep(uint64_t millis)
{
uint64_t now_ns = solo5_clock_monotonic();
uint64_t until_ns = now_ns + (millis * 1000000);
while (solo5_clock_monotonic() <= until_ns) {
/* Spin! */
}
}
4 changes: 2 additions & 2 deletions bindings/virtio/virtio_blk.c
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Original file line number Diff line number Diff line change
Expand Up @@ -162,9 +162,9 @@ void virtio_config_block(struct pci_config_info *pci)
outl(pci->base + VIRTIO_PCI_GUEST_FEATURES, guest_features);

virtio_blk_sectors = inq(pci->base + VIRTIO_PCI_CONFIG_OFF);
log(INFO, "Solo5: PCI:%02x:%02x: configured, capacity=%llu sectors, "
log(INFO, "Solo5: PCI:%02x:%02x.%02x: configured, capacity=%llu sectors, "
"features=0x%x\n",
pci->bus, pci->dev, (unsigned long long)virtio_blk_sectors,
pci->bus, pci->dev, pci->fun, (unsigned long long)virtio_blk_sectors,
host_features);

virtq_init_rings(pci->base, &blkq, 0);
Expand Down
4 changes: 2 additions & 2 deletions bindings/virtio/virtio_net.c
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Original file line number Diff line number Diff line change
Expand Up @@ -181,8 +181,8 @@ void virtio_config_network(struct pci_config_info *pci)
virtio_net_mac[3],
virtio_net_mac[4],
virtio_net_mac[5]);
log(INFO, "Solo5: PCI:%02x:%02x: configured, mac=%s, features=0x%x\n",
pci->bus, pci->dev, virtio_net_mac_str, host_features);
log(INFO, "Solo5: PCI:%02x:%02x.%02x: configured, mac=%s, features=0x%x\n",
pci->bus, pci->dev, pci->fun, virtio_net_mac_str, host_features);

/*
* 7. Perform device-specific setup, including discovery of virtqueues for
Expand Down