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Commit af3b358e authored by Joerg Roedel's avatar Joerg Roedel
Browse files

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



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: default avatarZhenHua Li <zhen-hual@hp.com>
Tested-by: default avatarBaoquan He <bhe@redhat.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent d4d1c0f3

drivers/iommu/intel_irq_remapping.c

+70 −0
Original line number Original line Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/irq.h>

#include <linux/irq.h>

#include <linux/intel-iommu.h>

#include <linux/intel-iommu.h>

#include <linux/acpi.h>

#include <linux/acpi.h>

#include <linux/crash_dump.h>

#include <asm/io_apic.h>

#include <asm/io_apic.h>

#include <asm/smp.h>

#include <asm/smp.h>

#include <asm/cpu.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 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 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)

static struct irq_2_iommu *irq_2_iommu(unsigned int irq)

{

{

	struct irq_cfg *cfg = irq_cfg(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;

	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)

static void iommu_set_irq_remapping(struct intel_iommu *iommu, int mode)

{

{

	unsigned long flags;

	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);

	iommu_set_irq_remapping(iommu, eim_mode);





	return 0;

	return 0;

include/linux/intel-iommu.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -296,6 +296,7 @@ struct q_inval { 
/* 1MB - maximum possible interrupt remapping table size */

/* 1MB - maximum possible interrupt remapping table size */

#define INTR_REMAP_PAGE_ORDER	8

#define INTR_REMAP_PAGE_ORDER	8

#define INTR_REMAP_TABLE_REG_SIZE	0xf

#define INTR_REMAP_TABLE_REG_SIZE	0xf

#define INTR_REMAP_TABLE_REG_SIZE_MASK  0xf





#define INTR_REMAP_TABLE_ENTRIES	65536

#define INTR_REMAP_TABLE_ENTRIES	65536