diff options
Diffstat (limited to 'drivers/iommu/amd_iommu.c')
| -rw-r--r-- | drivers/iommu/amd_iommu.c | 90 |
1 files changed, 89 insertions, 1 deletions
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 7ccfc80ceb7..db9b788c28b 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -17,6 +17,7 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#include <linux/ratelimit.h> #include <linux/pci.h> #include <linux/pci-ats.h> #include <linux/bitmap.h> @@ -28,6 +29,8 @@ #include <linux/iommu.h> #include <linux/delay.h> #include <linux/amd-iommu.h> +#include <linux/notifier.h> +#include <linux/export.h> #include <asm/msidef.h> #include <asm/proto.h> #include <asm/iommu.h> @@ -59,6 +62,8 @@ static struct protection_domain *pt_domain; static struct iommu_ops amd_iommu_ops; +static ATOMIC_NOTIFIER_HEAD(ppr_notifier); + /* * general struct to manage commands send to an IOMMU */ @@ -488,12 +493,82 @@ static void iommu_poll_events(struct amd_iommu *iommu) spin_unlock_irqrestore(&iommu->lock, flags); } +static void iommu_handle_ppr_entry(struct amd_iommu *iommu, u32 head) +{ + struct amd_iommu_fault fault; + volatile u64 *raw; + int i; + + raw = (u64 *)(iommu->ppr_log + head); + + /* + * Hardware bug: Interrupt may arrive before the entry is written to + * memory. If this happens we need to wait for the entry to arrive. + */ + for (i = 0; i < LOOP_TIMEOUT; ++i) { + if (PPR_REQ_TYPE(raw[0]) != 0) + break; + udelay(1); + } + + if (PPR_REQ_TYPE(raw[0]) != PPR_REQ_FAULT) { + pr_err_ratelimited("AMD-Vi: Unknown PPR request received\n"); + return; + } + + fault.address = raw[1]; + fault.pasid = PPR_PASID(raw[0]); + fault.device_id = PPR_DEVID(raw[0]); + fault.tag = PPR_TAG(raw[0]); + fault.flags = PPR_FLAGS(raw[0]); + + /* + * To detect the hardware bug we need to clear the entry + * to back to zero. + */ + raw[0] = raw[1] = 0; + + atomic_notifier_call_chain(&ppr_notifier, 0, &fault); +} + +static void iommu_poll_ppr_log(struct amd_iommu *iommu) +{ + unsigned long flags; + u32 head, tail; + + if (iommu->ppr_log == NULL) + return; + + spin_lock_irqsave(&iommu->lock, flags); + + head = readl(iommu->mmio_base + MMIO_PPR_HEAD_OFFSET); + tail = readl(iommu->mmio_base + MMIO_PPR_TAIL_OFFSET); + + while (head != tail) { + + /* Handle PPR entry */ + iommu_handle_ppr_entry(iommu, head); + + /* Update and refresh ring-buffer state*/ + head = (head + PPR_ENTRY_SIZE) % PPR_LOG_SIZE; + writel(head, iommu->mmio_base + MMIO_PPR_HEAD_OFFSET); + tail = readl(iommu->mmio_base + MMIO_PPR_TAIL_OFFSET); + } + + /* enable ppr interrupts again */ + writel(MMIO_STATUS_PPR_INT_MASK, iommu->mmio_base + MMIO_STATUS_OFFSET); + + spin_unlock_irqrestore(&iommu->lock, flags); +} + irqreturn_t amd_iommu_int_thread(int irq, void *data) { struct amd_iommu *iommu; - for_each_iommu(iommu) + for_each_iommu(iommu) { iommu_poll_events(iommu); + iommu_poll_ppr_log(iommu); + } return IRQ_HANDLED; } @@ -2888,3 +2963,16 @@ int __init amd_iommu_init_passthrough(void) return 0; } + +/* IOMMUv2 specific functions */ +int amd_iommu_register_ppr_notifier(struct notifier_block *nb) +{ + return atomic_notifier_chain_register(&ppr_notifier, nb); +} +EXPORT_SYMBOL(amd_iommu_register_ppr_notifier); + +int amd_iommu_unregister_ppr_notifier(struct notifier_block *nb) +{ + return atomic_notifier_chain_unregister(&ppr_notifier, nb); +} +EXPORT_SYMBOL(amd_iommu_unregister_ppr_notifier); |