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iommu/vt-d: Copy IR table from old kernel when in kdump mode

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When we are booting into a kdump kernel and find IR enabled,
copy over the contents of the previous IR table so that
spurious interrupts will not be target aborted.

Tested-by: ZhenHua Li <zhen-hual@hp.com>
Tested-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Joerg Roedel 2015-06-12 15:00:21 +02:00
parent d4d1c0f3d6
commit af3b358e48
2 changed files with 71 additions and 0 deletions
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70
drivers/iommu/intel_irq_remapping.c
View File

@ -11,6 +11,7 @@
#include <linux/irq.h>
#include <linux/intel-iommu.h>
#include <linux/acpi.h>
#include <linux/crash_dump.h>
#include <asm/io_apic.h>
#include <asm/smp.h>
#include <asm/cpu.h>
@ -54,8 +55,28 @@ static struct hpet_scope ir_hpet[MAX_HPET_TBS];
*/
static DEFINE_RAW_SPINLOCK(irq_2_ir_lock);
static void iommu_disable_irq_remapping(struct intel_iommu *iommu);
static int __init parse_ioapics_under_ir(void);
static bool ir_pre_enabled(struct intel_iommu *iommu)
{
return (iommu->flags & VTD_FLAG_IRQ_REMAP_PRE_ENABLED);
}
static void clear_ir_pre_enabled(struct intel_iommu *iommu)
{
iommu->flags &= ~VTD_FLAG_IRQ_REMAP_PRE_ENABLED;
}
static void init_ir_status(struct intel_iommu *iommu)
{
u32 gsts;
gsts = readl(iommu->reg + DMAR_GSTS_REG);
if (gsts & DMA_GSTS_IRES)
iommu->flags |= VTD_FLAG_IRQ_REMAP_PRE_ENABLED;
}
static struct irq_2_iommu *irq_2_iommu(unsigned int irq)
{
struct irq_cfg *cfg = irq_cfg(irq);
@ -426,6 +447,44 @@ static int set_msi_sid(struct irte *irte, struct pci_dev *dev)
return 0;
}
static int iommu_load_old_irte(struct intel_iommu *iommu)
{
struct irte *old_ir_table;
phys_addr_t irt_phys;
size_t size;
u64 irta;
if (!is_kdump_kernel()) {
pr_warn("IRQ remapping was enabled on %s but we are not in kdump mode\n",
iommu->name);
clear_ir_pre_enabled(iommu);
iommu_disable_irq_remapping(iommu);
return -EINVAL;
}
/* Check whether the old ir-table has the same size as ours */
irta = dmar_readq(iommu->reg + DMAR_IRTA_REG);
if ((irta & INTR_REMAP_TABLE_REG_SIZE_MASK)
!= INTR_REMAP_TABLE_REG_SIZE)
return -EINVAL;
irt_phys = irta & VTD_PAGE_MASK;
size = INTR_REMAP_TABLE_ENTRIES*sizeof(struct irte);
/* Map the old IR table */
old_ir_table = ioremap_cache(irt_phys, size);
if (!old_ir_table)
return -ENOMEM;
/* Copy data over */
memcpy(iommu->ir_table->base, old_ir_table, size);
__iommu_flush_cache(iommu, iommu->ir_table->base, size);
return 0;
}
static void iommu_set_irq_remapping(struct intel_iommu *iommu, int mode)
{
unsigned long flags;
@ -531,6 +590,17 @@ static int intel_setup_irq_remapping(struct intel_iommu *iommu)
}
}
init_ir_status(iommu);
if (ir_pre_enabled(iommu)) {
if (iommu_load_old_irte(iommu))
pr_err("Failed to copy IR table for %s from previous kernel\n",
iommu->name);
else
pr_info("Copied IR table for %s from previous kernel\n",
iommu->name);
}
iommu_set_irq_remapping(iommu, eim_mode);
return 0;

1
include/linux/intel-iommu.h
View File

@ -296,6 +296,7 @@ struct q_inval {
/* 1MB - maximum possible interrupt remapping table size */
#define INTR_REMAP_PAGE_ORDER 8
#define INTR_REMAP_TABLE_REG_SIZE 0xf
#define INTR_REMAP_TABLE_REG_SIZE_MASK 0xf
#define INTR_REMAP_TABLE_ENTRIES 65536