#include <linux/virtio_console.h>
#include <linux/pm.h>
#include <linux/export.h>
+#include <linux/pci.h>
+#include <linux/virtio_pci.h>
+#include <asm/acpi.h>
#include <asm/apic.h>
#include <asm/lguest.h>
#include <asm/paravirt.h>
#include <asm/stackprotector.h>
#include <asm/reboot.h> /* for struct machine_ops */
#include <asm/kvm_para.h>
+#include <asm/pci_x86.h>
+#include <asm/pci-direct.h>
/*G:010
* Welcome to the Guest!
.irq_unmask = enable_lguest_irq,
};
+static int lguest_enable_irq(struct pci_dev *dev)
+{
+ u8 line = 0;
+
+ /* We literally use the PCI interrupt line as the irq number. */
+ pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &line);
+ irq_set_chip_and_handler_name(line, &lguest_irq_controller,
+ handle_level_irq, "level");
+ dev->irq = line;
+ return 0;
+}
+
+/* We don't do hotplug PCI, so this shouldn't be called. */
+static void lguest_disable_irq(struct pci_dev *dev)
+{
+ WARN_ON(1);
+}
+
/*
* This sets up the Interrupt Descriptor Table (IDT) entry for each hardware
* interrupt (except 128, which is used for system calls), and then tells the
{
unsigned int i;
- for (i = FIRST_EXTERNAL_VECTOR; i < NR_VECTORS; i++) {
+ for (i = FIRST_EXTERNAL_VECTOR; i < FIRST_SYSTEM_VECTOR; i++) {
/* Some systems map "vectors" to interrupts weirdly. Not us! */
__this_cpu_write(vector_irq[i], i - FIRST_EXTERNAL_VECTOR);
if (i != SYSCALL_VECTOR)
return "LGUEST";
}
+/* Offset within PCI config space of BAR access capability. */
+static int console_cfg_offset = 0;
+static int console_access_cap;
+
+/* Set up so that we access off in bar0 (on bus 0, device 1, function 0) */
+static void set_cfg_window(u32 cfg_offset, u32 off)
+{
+ write_pci_config_byte(0, 1, 0,
+ cfg_offset + offsetof(struct virtio_pci_cap, bar),
+ 0);
+ write_pci_config(0, 1, 0,
+ cfg_offset + offsetof(struct virtio_pci_cap, length),
+ 4);
+ write_pci_config(0, 1, 0,
+ cfg_offset + offsetof(struct virtio_pci_cap, offset),
+ off);
+}
+
+static u32 read_bar_via_cfg(u32 cfg_offset, u32 off)
+{
+ set_cfg_window(cfg_offset, off);
+ return read_pci_config(0, 1, 0,
+ cfg_offset + sizeof(struct virtio_pci_cap));
+}
+
+static void write_bar_via_cfg(u32 cfg_offset, u32 off, u32 val)
+{
+ set_cfg_window(cfg_offset, off);
+ write_pci_config(0, 1, 0,
+ cfg_offset + sizeof(struct virtio_pci_cap), val);
+}
+
+static void probe_pci_console(void)
+{
+ u8 cap, common_cap = 0, device_cap = 0;
+ /* Offsets within BAR0 */
+ u32 common_offset, device_offset;
+
+ /* Avoid recursive printk into here. */
+ console_cfg_offset = -1;
+
+ if (!early_pci_allowed()) {
+ printk(KERN_ERR "lguest: early PCI access not allowed!\n");
+ return;
+ }
+
+ /* We expect a console PCI device at BUS0, slot 1. */
+ if (read_pci_config(0, 1, 0, 0) != 0x10431AF4) {
+ printk(KERN_ERR "lguest: PCI device is %#x!\n",
+ read_pci_config(0, 1, 0, 0));
+ return;
+ }
+
+ /* Find the capabilities we need (must be in bar0) */
+ cap = read_pci_config_byte(0, 1, 0, PCI_CAPABILITY_LIST);
+ while (cap) {
+ u8 vndr = read_pci_config_byte(0, 1, 0, cap);
+ if (vndr == PCI_CAP_ID_VNDR) {
+ u8 type, bar;
+ u32 offset;
+
+ type = read_pci_config_byte(0, 1, 0,
+ cap + offsetof(struct virtio_pci_cap, cfg_type));
+ bar = read_pci_config_byte(0, 1, 0,
+ cap + offsetof(struct virtio_pci_cap, bar));
+ offset = read_pci_config(0, 1, 0,
+ cap + offsetof(struct virtio_pci_cap, offset));
+
+ switch (type) {
+ case VIRTIO_PCI_CAP_COMMON_CFG:
+ if (bar == 0) {
+ common_cap = cap;
+ common_offset = offset;
+ }
+ break;
+ case VIRTIO_PCI_CAP_DEVICE_CFG:
+ if (bar == 0) {
+ device_cap = cap;
+ device_offset = offset;
+ }
+ break;
+ case VIRTIO_PCI_CAP_PCI_CFG:
+ console_access_cap = cap;
+ break;
+ }
+ }
+ cap = read_pci_config_byte(0, 1, 0, cap + PCI_CAP_LIST_NEXT);
+ }
+ if (!common_cap || !device_cap || !console_access_cap) {
+ printk(KERN_ERR "lguest: No caps (%u/%u/%u) in console!\n",
+ common_cap, device_cap, console_access_cap);
+ return;
+ }
+
+
+#define write_common_config(reg, val) \
+ write_bar_via_cfg(console_access_cap, \
+ common_offset+offsetof(struct virtio_pci_common_cfg,reg),\
+ val)
+
+#define read_common_config(reg) \
+ read_bar_via_cfg(console_access_cap, \
+ common_offset+offsetof(struct virtio_pci_common_cfg,reg))
+
+ /* Check features: they must offer EMERG_WRITE */
+ write_common_config(device_feature_select, 0);
+
+ if (!(read_common_config(device_feature)
+ & (1 << VIRTIO_CONSOLE_F_EMERG_WRITE))) {
+ printk(KERN_ERR "lguest: console missing EMERG_WRITE\n");
+ return;
+ }
+
+ console_cfg_offset = device_offset;
+}
+
/*
* We will eventually use the virtio console device to produce console output,
- * but before that is set up we use LHCALL_NOTIFY on normal memory to produce
- * console output.
+ * but before that is set up we use the virtio PCI console's backdoor mmio
+ * access and the "emergency" write facility (which is legal even before the
+ * device is configured).
*/
static __init int early_put_chars(u32 vtermno, const char *buf, int count)
{
- char scratch[17];
- unsigned int len = count;
+ /* If we couldn't find PCI console, forget it. */
+ if (console_cfg_offset < 0)
+ return count;
- /* We use a nul-terminated string, so we make a copy. Icky, huh? */
- if (len > sizeof(scratch) - 1)
- len = sizeof(scratch) - 1;
- scratch[len] = '\0';
- memcpy(scratch, buf, len);
- hcall(LHCALL_NOTIFY, __pa(scratch), 0, 0, 0);
+ if (unlikely(!console_cfg_offset)) {
+ probe_pci_console();
+ if (console_cfg_offset < 0)
+ return count;
+ }
- /* This routine returns the number of bytes actually written. */
- return len;
+ write_bar_via_cfg(console_access_cap,
+ console_cfg_offset
+ + offsetof(struct virtio_console_config, emerg_wr),
+ buf[0]);
+ return 1;
}
/*
/* Hook in our special panic hypercall code. */
atomic_notifier_chain_register(&panic_notifier_list, &paniced);
- /*
- * The IDE code spends about 3 seconds probing for disks: if we reserve
- * all the I/O ports up front it can't get them and so doesn't probe.
- * Other device drivers are similar (but less severe). This cuts the
- * kernel boot time on my machine from 4.1 seconds to 0.45 seconds.
- */
- paravirt_disable_iospace();
-
/*
* This is messy CPU setup stuff which the native boot code does before
* start_kernel, so we have to do, too:
/* Register our very early console. */
virtio_cons_early_init(early_put_chars);
+ /* Don't let ACPI try to control our PCI interrupts. */
+ disable_acpi();
+
+ /* We control them ourselves, by overriding these two hooks. */
+ pcibios_enable_irq = lguest_enable_irq;
+ pcibios_disable_irq = lguest_disable_irq;
+
/*
* Last of all, we set the power management poweroff hook to point to
* the Guest routine to power off, and the reboot hook to our restart
projects / mirror_ubuntu-artful-kernel.git / blobdiff