powerpc/powernv: Improve kexec reliability
We add a machine_shutdown hook that frees the OPAL interrupts
(so they get masked at the source and don't fire while kexec'ing)
and which triggers an IODA reset on all the PCIe host bridges
which will have the effect of blocking all DMAs and subsequent
PCIs interrupts.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index b6c8b58..b2906ad 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -563,6 +563,8 @@
extern int opal_machine_check(struct pt_regs *regs);
+extern void opal_shutdown(void);
+
#endif /* __ASSEMBLY__ */
#endif /* __OPAL_H */
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 12d9846..27907cb 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -15,6 +15,7 @@
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/interrupt.h>
+#include <linux/slab.h>
#include <asm/opal.h>
#include <asm/firmware.h>
@@ -28,6 +29,8 @@
static struct device_node *opal_node;
static DEFINE_SPINLOCK(opal_write_lock);
extern u64 opal_mc_secondary_handler[];
+static unsigned int *opal_irqs;
+static unsigned int opal_irq_count;
int __init early_init_dt_scan_opal(unsigned long node,
const char *uname, int depth, void *data)
@@ -323,6 +326,8 @@
irqs = of_get_property(opal_node, "opal-interrupts", &irqlen);
pr_debug("opal: Found %d interrupts reserved for OPAL\n",
irqs ? (irqlen / 4) : 0);
+ opal_irq_count = irqlen / 4;
+ opal_irqs = kzalloc(opal_irq_count * sizeof(unsigned int), GFP_KERNEL);
for (i = 0; irqs && i < (irqlen / 4); i++, irqs++) {
unsigned int hwirq = be32_to_cpup(irqs);
unsigned int irq = irq_create_mapping(NULL, hwirq);
@@ -334,7 +339,19 @@
if (rc)
pr_warning("opal: Error %d requesting irq %d"
" (0x%x)\n", rc, irq, hwirq);
+ opal_irqs[i] = irq;
}
return 0;
}
subsys_initcall(opal_init);
+
+void opal_shutdown(void)
+{
+ unsigned int i;
+
+ for (i = 0; i < opal_irq_count; i++) {
+ if (opal_irqs[i])
+ free_irq(opal_irqs[i], 0);
+ opal_irqs[i] = 0;
+ }
+}
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 1da578b..3937aaa 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1048,6 +1048,12 @@
return phb->ioda.pe_rmap[(bus->number << 8) | devfn];
}
+static void pnv_pci_ioda_shutdown(struct pnv_phb *phb)
+{
+ opal_pci_reset(phb->opal_id, OPAL_PCI_IODA_TABLE_RESET,
+ OPAL_ASSERT_RESET);
+}
+
void __init pnv_pci_init_ioda_phb(struct device_node *np, int ioda_type)
{
struct pci_controller *hose;
@@ -1178,6 +1184,9 @@
/* Setup TCEs */
phb->dma_dev_setup = pnv_pci_ioda_dma_dev_setup;
+ /* Setup shutdown function for kexec */
+ phb->shutdown = pnv_pci_ioda_shutdown;
+
/* Setup MSI support */
pnv_pci_init_ioda_msis(phb);
diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index 55dfca844..163bd74 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -450,6 +450,18 @@
pnv_pci_dma_fallback_setup(hose, pdev);
}
+void pnv_pci_shutdown(void)
+{
+ struct pci_controller *hose;
+
+ list_for_each_entry(hose, &hose_list, list_node) {
+ struct pnv_phb *phb = hose->private_data;
+
+ if (phb && phb->shutdown)
+ phb->shutdown(phb);
+ }
+}
+
/* Fixup wrong class code in p7ioc and p8 root complex */
static void pnv_p7ioc_rc_quirk(struct pci_dev *dev)
{
diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index 48dc4bb..25d76c4 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -86,6 +86,7 @@
void (*dma_dev_setup)(struct pnv_phb *phb, struct pci_dev *pdev);
void (*fixup_phb)(struct pci_controller *hose);
u32 (*bdfn_to_pe)(struct pnv_phb *phb, struct pci_bus *bus, u32 devfn);
+ void (*shutdown)(struct pnv_phb *phb);
union {
struct {
@@ -158,4 +159,5 @@
extern void pnv_pci_init_ioda2_phb(struct device_node *np);
extern void pnv_pci_ioda_tce_invalidate(struct iommu_table *tbl,
u64 *startp, u64 *endp);
+
#endif /* __POWERNV_PCI_H */
diff --git a/arch/powerpc/platforms/powernv/powernv.h b/arch/powerpc/platforms/powernv/powernv.h
index 8a9df7f..a1c6f83 100644
--- a/arch/powerpc/platforms/powernv/powernv.h
+++ b/arch/powerpc/platforms/powernv/powernv.h
@@ -9,8 +9,10 @@
#ifdef CONFIG_PCI
extern void pnv_pci_init(void);
+extern void pnv_pci_shutdown(void);
#else
static inline void pnv_pci_init(void) { }
+static inline void pnv_pci_shutdown(void) { }
#endif
#endif /* _POWERNV_H */
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index db1ad1c..c20381c 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -126,6 +126,17 @@
{
}
+static void pnv_shutdown(void)
+{
+ /* Let the PCI code clear up IODA tables */
+ pnv_pci_shutdown();
+
+ /* And unregister all OPAL interrupts so they don't fire
+ * up while we kexec
+ */
+ opal_shutdown();
+}
+
#ifdef CONFIG_KEXEC
static void pnv_kexec_cpu_down(int crash_shutdown, int secondary)
{
@@ -187,6 +198,7 @@
.init_IRQ = pnv_init_IRQ,
.show_cpuinfo = pnv_show_cpuinfo,
.progress = pnv_progress,
+ .machine_shutdown = pnv_shutdown,
.power_save = power7_idle,
.calibrate_decr = generic_calibrate_decr,
#ifdef CONFIG_KEXEC