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authorJoerg Roedel <joerg.roedel@amd.com>2011-11-10 19:13:51 +0100
committerJoerg Roedel <joerg.roedel@amd.com>2011-12-12 14:55:04 +0100
commit72e1dcc4192288ad5e37888aa1dbb23b3ef4aa9a (patch)
tree7e06c2f6ddf2f03dfd6c845f05cf9ce092ceacc2 /drivers/iommu/amd_iommu.c
parent5abcdba4fa535c29f736455e37229ee97e0e7f5d (diff)
iommu/amd: Implement notifier for PPR faults
Add a notifer at which a module can attach to get informed about incoming PPR faults. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Diffstat (limited to 'drivers/iommu/amd_iommu.c')
-rw-r--r--drivers/iommu/amd_iommu.c90
1 files changed, 89 insertions, 1 deletions
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 7ccfc80ceb7a..db9b788c28ba 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);