From: Joerg Roedel <[email protected]> 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.
Signed-off-by: Joerg Roedel <[email protected]> --- drivers/iommu/intel_irq_remapping.c | 70 +++++++++++++++++++++++++++++++++++++ include/linux/intel-iommu.h | 1 + 2 files changed, 71 insertions(+) diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c index 8497028..2a90121 100644 --- a/drivers/iommu/intel_irq_remapping.c +++ b/drivers/iommu/intel_irq_remapping.c @@ -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; diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index fff87f1..9aedf21 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -295,6 +295,7 @@ 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 -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
