Jan Beulich
2008-Sep-04 07:29 UTC
[Xen-devel] [PATCH] linux/pci-msi: translate Xen-provided PIRQs
Previously, the kernel depended upon Xen''s NR_IRQS to be no larger than
the kernel''s NR_PIRQS.
As usual, written and tested on 2.6.27-rc5 and made apply to the 2.6.18
tree without further testing.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Index: head-2008-09-01/arch/i386/kernel/io_apic-xen.c
==================================================================---
head-2008-09-01.orig/arch/i386/kernel/io_apic-xen.c 2008-08-22
15:28:26.000000000 +0200
+++ head-2008-09-01/arch/i386/kernel/io_apic-xen.c 2008-09-03 10:47:24.000000000
+0200
@@ -52,6 +52,7 @@
#include <xen/interface/xen.h>
#include <xen/interface/physdev.h>
+#include <xen/evtchn.h>
/* Fake i8259 */
#define make_8259A_irq(_irq) (io_apic_irqs &= ~(1UL<<(_irq)))
@@ -1275,7 +1276,7 @@ static void ioapic_register_intr(int irq
set_intr_gate(vector, interrupt[idx]);
}
#else
-#define ioapic_register_intr(_irq,_vector,_trigger) ((void)0)
+#define ioapic_register_intr(irq, vector, trigger) evtchn_register_pirq(irq)
#endif
static void __init setup_IO_APIC_irqs(void)
Index: head-2008-09-01/arch/x86_64/kernel/io_apic-xen.c
==================================================================---
head-2008-09-01.orig/arch/x86_64/kernel/io_apic-xen.c 2008-08-22
15:28:26.000000000 +0200
+++ head-2008-09-01/arch/x86_64/kernel/io_apic-xen.c 2008-09-03
10:47:28.000000000 +0200
@@ -81,6 +81,7 @@ int sis_apic_bug; /* not actually suppor
#include <xen/interface/xen.h>
#include <xen/interface/physdev.h>
+#include <xen/evtchn.h>
/* Fake i8259 */
#define make_8259A_irq(_irq) (io_apic_irqs &= ~(1UL<<(_irq)))
@@ -840,7 +841,7 @@ static void ioapic_register_intr(int irq
set_intr_gate(vector, interrupt[idx]);
}
#else
-#define ioapic_register_intr(_irq,_vector,_trigger) ((void)0)
+#define ioapic_register_intr(irq, vector, trigger) evtchn_register_pirq(irq)
#endif /* !CONFIG_XEN */
static void __init setup_IO_APIC_irqs(void)
Index: head-2008-09-01/drivers/pci/msi-xen.c
==================================================================---
head-2008-09-01.orig/drivers/pci/msi-xen.c 2008-09-03 13:17:09.000000000 +0200
+++ head-2008-09-01/drivers/pci/msi-xen.c 2008-09-03 14:38:24.000000000 +0200
@@ -17,6 +17,8 @@
#include <linux/pci.h>
#include <linux/proc_fs.h>
+#include <xen/evtchn.h>
+
#include <asm/errno.h>
#include <asm/io.h>
#include <asm/smp.h>
@@ -231,13 +233,15 @@ static int msi_unmap_pirq(struct pci_dev
int rc;
unmap.domid = msi_get_dev_owner(dev);
- unmap.pirq = pirq;
+ unmap.pirq = evtchn_get_xen_pirq(pirq);
if ((rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap)))
printk(KERN_WARNING "unmap irq %x failed\n", pirq);
if (rc < 0)
return rc;
+
+ evtchn_map_pirq(pirq, 0);
return 0;
}
@@ -272,7 +276,7 @@ static int msi_map_pirq_to_vector(struct
map_irq.domid = domid;
map_irq.type = MAP_PIRQ_TYPE_MSI;
map_irq.index = -1;
- map_irq.pirq = pirq;
+ map_irq.pirq = pirq < 0 ? -1 : evtchn_get_xen_pirq(pirq);
map_irq.bus = dev->bus->number;
map_irq.devfn = dev->devfn;
map_irq.entry_nr = entry_nr;
@@ -283,8 +287,12 @@ static int msi_map_pirq_to_vector(struct
if (rc < 0)
return rc;
+ /* This happens when MSI support is not enabled in Xen. */
+ if (rc == 0 && map_irq.pirq < 0)
+ return -ENOSYS;
- return map_irq.pirq;
+ BUG_ON(map_irq.pirq <= 0);
+ return evtchn_map_pirq(pirq, map_irq.pirq);
}
static int msi_map_vector(struct pci_dev *dev, int entry_nr, u64 table_base)
Index: head-2008-09-01/drivers/xen/core/evtchn.c
==================================================================---
head-2008-09-01.orig/drivers/xen/core/evtchn.c 2008-09-03 13:17:09.000000000
+0200
+++ head-2008-09-01/drivers/xen/core/evtchn.c 2008-09-03 16:05:34.000000000
+0200
@@ -83,13 +83,27 @@ enum {
IRQT_VIRQ,
IRQT_IPI,
IRQT_LOCAL_PORT,
- IRQT_CALLER_PORT
+ IRQT_CALLER_PORT,
+ _IRQT_COUNT
};
+#define _IRQT_BITS 4
+#define _EVTCHN_BITS 12
+#define _INDEX_BITS (32 - _IRQT_BITS - _EVTCHN_BITS)
+
/* Constructor for packed IRQ information. */
static inline u32 mk_irq_info(u32 type, u32 index, u32 evtchn)
{
- return ((type << 24) | (index << 16) | evtchn);
+ BUILD_BUG_ON(_IRQT_COUNT > (1U << _IRQT_BITS));
+
+ BUILD_BUG_ON(NR_PIRQS > (1U << _INDEX_BITS));
+ BUILD_BUG_ON(NR_VIRQS > (1U << _INDEX_BITS));
+ BUILD_BUG_ON(NR_IPIS > (1U << _INDEX_BITS));
+ BUG_ON(index >> _INDEX_BITS);
+
+ BUILD_BUG_ON(NR_EVENT_CHANNELS > (1U << _EVTCHN_BITS));
+
+ return ((type << (32 - _IRQT_BITS)) | (index << _EVTCHN_BITS) |
evtchn);
}
/* Convenient shorthand for packed representation of an unbound IRQ. */
@@ -102,17 +116,17 @@ static inline u32 mk_irq_info(u32 type,
static inline unsigned int evtchn_from_irq(int irq)
{
- return (u16)(irq_info[irq]);
+ return irq_info[irq] & ((1U << _EVTCHN_BITS) - 1);
}
static inline unsigned int index_from_irq(int irq)
{
- return (u8)(irq_info[irq] >> 16);
+ return (irq_info[irq] >> _EVTCHN_BITS) & ((1U << _INDEX_BITS)
- 1);
}
static inline unsigned int type_from_irq(int irq)
{
- return (u8)(irq_info[irq] >> 24);
+ return irq_info[irq] >> (32 - _IRQT_BITS);
}
/* IRQ <-> VIRQ mapping. */
@@ -882,6 +896,60 @@ static struct irq_chip dynirq_chip = {
.retrigger = resend_irq_on_evtchn,
};
+void evtchn_register_pirq(int irq)
+{
+ irq_info[irq] = mk_irq_info(IRQT_PIRQ, irq, 0);
+}
+
+#ifndef CONFIG_X86_IO_APIC
+#undef IO_APIC_IRQ
+#define IO_APIC_IRQ(irq) ((irq) >= pirq_to_irq(16))
+#endif
+
+int evtchn_map_pirq(int irq, int xen_pirq)
+{
+ if (irq < 0) {
+ static DEFINE_SPINLOCK(irq_alloc_lock);
+
+ irq = pirq_to_irq(NR_PIRQS - 1);
+ spin_lock(&irq_alloc_lock);
+ do {
+ if (!IO_APIC_IRQ(irq))
+ continue;
+ if (!index_from_irq(irq)) {
+ BUG_ON(type_from_irq(irq) != IRQT_UNBOUND);
+ irq_info[irq] = mk_irq_info(IRQT_PIRQ,
+ xen_pirq, 0);
+ break;
+ }
+ } while (--irq);
+ spin_unlock(&irq_alloc_lock);
+ if (irq < pirq_to_irq(16))
+ return -ENOSPC;
+ } else if (!xen_pirq) {
+ if (unlikely(type_from_irq(irq) != IRQT_PIRQ))
+ return -EINVAL;
+ irq_info[irq] = IRQ_UNBOUND;
+ return 0;
+ } else if (type_from_irq(irq) != IRQT_PIRQ
+ || index_from_irq(irq) != xen_pirq) {
+ printk(KERN_ERR "IRQ#%d is already mapped to %d:%u - "
+ "cannot map to PIRQ#%u\n",
+ irq, type_from_irq(irq), index_from_irq(irq), xen_pirq);
+ return -EINVAL;
+ }
+ return index_from_irq(irq) ? irq : -EINVAL;
+}
+
+int evtchn_get_xen_pirq(int irq)
+{
+ if (!IO_APIC_IRQ(irq))
+ return irq;
+ if (unlikely(type_from_irq(irq) != IRQT_PIRQ))
+ return 0;
+ return index_from_irq(irq);
+}
+
static inline void pirq_unmask_notify(int pirq)
{
struct physdev_eoi eoi = { .irq = pirq };
@@ -914,7 +982,7 @@ static unsigned int startup_pirq(unsigne
if (VALID_EVTCHN(evtchn))
goto out;
- bind_pirq.pirq = irq;
+ bind_pirq.pirq = evtchn_get_xen_pirq(irq);
/* NB. We are happy to share unless we are probing. */
bind_pirq.flags = probing_irq(irq) ? 0 : BIND_PIRQ__WILL_SHARE;
if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq) != 0) {
@@ -929,7 +997,7 @@ static unsigned int startup_pirq(unsigne
evtchn_to_irq[evtchn] = irq;
bind_evtchn_to_cpu(evtchn, 0);
- irq_info[irq] = mk_irq_info(IRQT_PIRQ, irq, evtchn);
+ irq_info[irq] = mk_irq_info(IRQT_PIRQ, bind_pirq.pirq, evtchn);
out:
unmask_evtchn(evtchn);
@@ -954,7 +1022,7 @@ static void shutdown_pirq(unsigned int i
bind_evtchn_to_cpu(evtchn, 0);
evtchn_to_irq[evtchn] = -1;
- irq_info[irq] = IRQ_UNBOUND;
+ irq_info[irq] = mk_irq_info(IRQT_PIRQ, index_from_irq(irq), 0);
}
static void enable_pirq(unsigned int irq)
Index: head-2008-09-01/include/asm-i386/mach-xen/irq_vectors.h
==================================================================---
head-2008-09-01.orig/include/asm-i386/mach-xen/irq_vectors.h 2008-09-03
13:17:09.000000000 +0200
+++ head-2008-09-01/include/asm-i386/mach-xen/irq_vectors.h 2008-09-03
11:09:40.000000000 +0200
@@ -37,7 +37,11 @@
*/
#define PIRQ_BASE 0
-#define NR_PIRQS 256
+#if NR_CPUS < MAX_IO_APICS
+# define NR_PIRQS (NR_VECTORS + 32 * NR_CPUS)
+#else
+# define NR_PIRQS (NR_VECTORS + 32 * MAX_IO_APICS)
+#endif
#define DYNIRQ_BASE (PIRQ_BASE + NR_PIRQS)
#define NR_DYNIRQS 256
Index: head-2008-09-01/include/xen/evtchn.h
==================================================================---
head-2008-09-01.orig/include/xen/evtchn.h 2008-09-03 13:17:09.000000000 +0200
+++ head-2008-09-01/include/xen/evtchn.h 2008-09-03 14:34:50.000000000 +0200
@@ -117,6 +117,13 @@ asmlinkage void evtchn_do_upcall(struct
/* Entry point for notifications into the userland character device. */
void evtchn_device_upcall(int port);
+/* Mark a PIRQ as unavailable for dynamic allocation. */
+void evtchn_register_pirq(int irq);
+/* Map a Xen-supplied PIRQ to a dynamically allocated one. */
+int evtchn_map_pirq(int irq, int xen_pirq);
+/* Look up a Xen-supplied PIRQ for a dynamically allocated one. */
+int evtchn_get_xen_pirq(int irq);
+
void mask_evtchn(int port);
void disable_all_local_evtchn(void);
void unmask_evtchn(int port);
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