I can not kexec RHEL 5.1 from 2.6.25-rc3 later
caused by:
commit 89d694b9dbe769ca1004e01db0ca43964806a611
Author: Thomas Gleixner <tglx@linutronix.de>
Date: Mon Feb 18 18:25:17 2008 +0100
genirq: do not leave interupts enabled on free_irq
The default_disable() function was changed in commit:
76d2160147f43f982dfe881404cfde9fd0a9da21
genirq: do not mask interrupts by default
It removed the mask function in favour of the default delayed
interrupt disabling. Unfortunately this also broke the shutdown in
free_irq() when the last handler is removed from the interrupt for
those architectures which rely on the default implementations. Now we
can end up with a enabled interrupt line after the last handler was
removed, which can result in spurious interrupts.
Fix this by adding a default_shutdown function, which is only
installed, when the irqchip implementation does provide neither a
shutdown nor a disable function.
[@stable: affected versions: .21 - .24 ]
for MSI, default_shutdown will call mask_bit for msi device. so all mask bits will
left disabled after free_irq.
then if kexec next kernel that only can use msi_enable bit.
all device's MSI can not be used.
So try to restore MSI mask bits that is saved before using msi in first kernel.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Index: linux-2.6/arch/x86/kernel/io_apic_64.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/io_apic_64.c
+++ linux-2.6/arch/x86/kernel/io_apic_64.c
@@ -2003,6 +2003,14 @@ static void set_msi_irq_affinity(unsigne
}
#endif /* CONFIG_SMP */
+static void msi_shutdown(unsigned int irq)
+{
+ struct irq_desc *desc = irq_desc + irq;
+
+ msi_restore_mask_bits(irq);
+ desc->status |= IRQ_MASKED;
+}
+
/*
* IRQ Chip for MSI PCI/PCI-X/PCI-Express Devices,
* which implement the MSI or MSI-X Capability Structure.
@@ -2012,6 +2020,7 @@ static struct irq_chip msi_chip = {
.unmask = unmask_msi_irq,
.mask = mask_msi_irq,
.ack = ack_apic_edge,
+ .shutdown = msi_shutdown,
#ifdef CONFIG_SMP
.set_affinity = set_msi_irq_affinity,
#endif
Index: linux-2.6/drivers/pci/msi.c
===================================================================
--- linux-2.6.orig/drivers/pci/msi.c
+++ linux-2.6/drivers/pci/msi.c
@@ -123,6 +123,31 @@ static void msix_flush_writes(unsigned i
}
}
+void msi_restore_mask_bits(unsigned int irq)
+{
+ struct msi_desc *entry;
+
+ entry = get_irq_msi(irq);
+ BUG_ON(!entry || !entry->dev);
+ switch (entry->msi_attrib.type) {
+ case PCI_CAP_ID_MSI:
+ if (entry->msi_attrib.maskbit) {
+ int pos;
+ u32 mask_bits;
+
+ pos = (long)entry->mask_base;
+ mask_bits = entry->orig_mask_bits;
+ pci_write_config_dword(entry->dev, pos, mask_bits);
+ }
+ break;
+ case PCI_CAP_ID_MSIX:
+ break;
+ default:
+ BUG();
+ break;
+ }
+}
+
static void msi_set_mask_bit(unsigned int irq, int flag)
{
struct msi_desc *entry;
@@ -376,6 +401,7 @@ static int msi_capability_init(struct pc
pci_read_config_dword(dev,
msi_mask_bits_reg(pos, is_64bit_address(control)),
&maskbits);
+ entry->orig_mask_bits = maskbits;
temp = (1 << multi_msi_capable(control));
temp = ((temp - 1) & ~temp);
maskbits |= temp;
Index: linux-2.6/include/linux/msi.h
===================================================================
--- linux-2.6.orig/include/linux/msi.h
+++ linux-2.6/include/linux/msi.h
@@ -14,6 +14,7 @@ extern void mask_msi_irq(unsigned int ir
extern void unmask_msi_irq(unsigned int irq);
extern void read_msi_msg(unsigned int irq, struct msi_msg *msg);
extern void write_msi_msg(unsigned int irq, struct msi_msg *msg);
+extern void msi_restore_mask_bits(unsigned int irq);
struct msi_desc {
struct {
@@ -30,6 +31,7 @@ struct msi_desc {
struct list_head list;
void __iomem *mask_base;
+ u32 orig_mask_bits; /* restoring it for freeing */
struct pci_dev *dev;
/* Last set MSI message */
--
