Merge tag 'iommu-fixes-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull IOMMU fixes from Joerg Roedel:
"Two patches are in here which fix AMD IOMMU specific issues. One
patch fixes a long-standing warning on resume because the
amd_iommu_resume function enabled interrupts. The other patch fixes a
deadlock in an error-path of the page-fault request handling code of
the IOMMU driver.
* tag 'iommu-fixes-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
iommu/amd: Fix deadlock in ppr-handling error path
iommu/amd: Cache pdev pointer to root-bridge
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index d90a421..a2e418c 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -547,26 +547,12 @@
spin_unlock_irqrestore(&iommu->lock, flags);
}
-static void iommu_handle_ppr_entry(struct amd_iommu *iommu, u32 head)
+static void iommu_handle_ppr_entry(struct amd_iommu *iommu, u64 *raw)
{
struct amd_iommu_fault fault;
- volatile u64 *raw;
- int i;
INC_STATS_COUNTER(pri_requests);
- 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;
@@ -578,12 +564,6 @@
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);
}
@@ -595,25 +575,62 @@
if (iommu->ppr_log == NULL)
return;
+ /* enable ppr interrupts again */
+ writel(MMIO_STATUS_PPR_INT_MASK, iommu->mmio_base + MMIO_STATUS_OFFSET);
+
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) {
+ volatile u64 *raw;
+ u64 entry[2];
+ int i;
- /* Handle PPR entry */
- iommu_handle_ppr_entry(iommu, head);
+ raw = (u64 *)(iommu->ppr_log + head);
- /* Update and refresh ring-buffer state*/
+ /*
+ * 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);
+ }
+
+ /* Avoid memcpy function-call overhead */
+ entry[0] = raw[0];
+ entry[1] = raw[1];
+
+ /*
+ * To detect the hardware bug we need to clear the entry
+ * back to zero.
+ */
+ raw[0] = raw[1] = 0UL;
+
+ /* Update head pointer of hardware ring-buffer */
head = (head + PPR_ENTRY_SIZE) % PPR_LOG_SIZE;
writel(head, iommu->mmio_base + MMIO_PPR_HEAD_OFFSET);
+
+ /*
+ * Release iommu->lock because ppr-handling might need to
+ * re-aquire it
+ */
+ spin_unlock_irqrestore(&iommu->lock, flags);
+
+ /* Handle PPR entry */
+ iommu_handle_ppr_entry(iommu, entry);
+
+ spin_lock_irqsave(&iommu->lock, flags);
+
+ /* Refresh ring-buffer information */
+ head = readl(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);
}
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index c567903..542024b 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -1029,6 +1029,9 @@
if (!iommu->dev)
return 1;
+ iommu->root_pdev = pci_get_bus_and_slot(iommu->dev->bus->number,
+ PCI_DEVFN(0, 0));
+
iommu->cap_ptr = h->cap_ptr;
iommu->pci_seg = h->pci_seg;
iommu->mmio_phys = h->mmio_phys;
@@ -1323,20 +1326,16 @@
{
int i, j;
u32 ioc_feature_control;
- struct pci_dev *pdev = NULL;
+ struct pci_dev *pdev = iommu->root_pdev;
/* RD890 BIOSes may not have completely reconfigured the iommu */
- if (!is_rd890_iommu(iommu->dev))
+ if (!is_rd890_iommu(iommu->dev) || !pdev)
return;
/*
* First, we need to ensure that the iommu is enabled. This is
* controlled by a register in the northbridge
*/
- pdev = pci_get_bus_and_slot(iommu->dev->bus->number, PCI_DEVFN(0, 0));
-
- if (!pdev)
- return;
/* Select Northbridge indirect register 0x75 and enable writing */
pci_write_config_dword(pdev, 0x60, 0x75 | (1 << 7));
@@ -1346,8 +1345,6 @@
if (!(ioc_feature_control & 0x1))
pci_write_config_dword(pdev, 0x64, ioc_feature_control | 1);
- pci_dev_put(pdev);
-
/* Restore the iommu BAR */
pci_write_config_dword(iommu->dev, iommu->cap_ptr + 4,
iommu->stored_addr_lo);
diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index 2452f3b..2435555 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -481,6 +481,9 @@
/* Pointer to PCI device of this IOMMU */
struct pci_dev *dev;
+ /* Cache pdev to root device for resume quirks */
+ struct pci_dev *root_pdev;
+
/* physical address of MMIO space */
u64 mmio_phys;
/* virtual address of MMIO space */