When do pci remove/rescan on system that have more iommus, got

[  894.089745] Set context mapping for c4:00.0
[  894.110890] mpt2sas3: Allocated physical memory: size(4293 kB)
[  894.112556] mpt2sas3: Current Controller Queue Depth(1883), Max Controller Queue Depth(2144)
[  894.127278] mpt2sas3: Scatter Gather Elements per IO(128)
[  894.361295] DRHD: handling fault status reg 2
[  894.364053] DMAR:[DMA Read] Request device [c4:00.0] fault addr fffbe000
[  894.364056] DMAR:[fault reason 02] Present bit in context entry is cl

it turns out when remove/rescan, pci dev will be freed and will get
another new dev.  but drhd units still keep old one...  so
dmar_find_matched_drhd_unit will return wrong drhd and iommu for the
device that is not on first iommu.

So need to update devices in drhd_units during pci remove/rescan.

Could save domain/bus/device/function aside in the list and according that
info restore new dev to drhd_units later.  Then
dmar_find_matched_drdh_unit and device_to_iommu could return right drhd
and iommu.

Add remove_dev_from_drhd/restore_dev_to_drhd functions to do the real
work.  call them in device ADD_DEVICE and UNBOUND_DRIVER

Need to do the samething to atsr.  (expose dmar_atsr_units and add
atsru->segment)

After patch, will right iommu for the new dev and will not get DMAR error
any more.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 3dc9befa5aec06343691474420ad203963119bdb..f0db877d71e6043133a373f7776a27292f10676c 100644 (file)
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -263,7 +263,7 @@ rmrr_parse_dev(struct dmar_rmrr_unit *rmrru)
        return ret;
 }
 
-static LIST_HEAD(dmar_atsr_units);
+LIST_HEAD(dmar_atsr_units);
 
 static int __init dmar_parse_one_atsr(struct acpi_dmar_header *hdr)
 {
@@ -277,6 +277,7 @@ static int __init dmar_parse_one_atsr(struct acpi_dmar_header *hdr)
 
        atsru->hdr = hdr;
        atsru->include_all = atsr->flags & 0x1;
+       atsru->segment = atsr->segment;
 
        list_add(&atsru->list, &dmar_atsr_units);
 
@@ -308,14 +309,12 @@ int dmar_find_matched_atsr_unit(struct pci_dev *dev)
 {
        int i;
        struct pci_bus *bus;
-       struct acpi_dmar_atsr *atsr;
        struct dmar_atsr_unit *atsru;
 
        dev = pci_physfn(dev);
 
        list_for_each_entry(atsru, &dmar_atsr_units, list) {
-               atsr = container_of(atsru->hdr, struct acpi_dmar_atsr, header);
-               if (atsr->segment == pci_domain_nr(dev->bus))
+               if (atsru->segment == pci_domain_nr(dev->bus))
                        goto found;
        }
 

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index c621c98c99da00886931b3aed1b8364c7de6b958..1d85ed6615ab2c8e0ebf5f63811feb1c2be70d15 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -633,6 +633,157 @@ static struct intel_iommu *device_to_iommu(int segment, u8 bus, u8 devfn)
        return NULL;
 }
 
+#ifdef CONFIG_HOTPLUG
+struct dev_dmaru {
+       struct list_head list;
+       void *dmaru;
+       int index;
+       int segment;
+       unsigned char bus;
+       unsigned int devfn;
+};
+
+static int
+save_dev_dmaru(int segment, unsigned char bus, unsigned int devfn,
+                void *dmaru, int index, struct list_head *lh)
+{
+       struct dev_dmaru *m;
+
+       m = kzalloc(sizeof(*m), GFP_KERNEL);
+       if (!m)
+               return -ENOMEM;
+
+       m->segment = segment;
+       m->bus     = bus;
+       m->devfn   = devfn;
+       m->dmaru   = dmaru;
+       m->index   = index;
+
+       list_add(&m->list, lh);
+
+       return 0;
+}
+
+static void
+*get_dev_dmaru(int segment, unsigned char bus, unsigned int devfn,
+               int *index, struct list_head *lh)
+{
+       struct dev_dmaru *m;
+       void *dmaru = NULL;
+
+       list_for_each_entry(m, lh, list) {
+               if (m->segment == segment &&
+                   m->bus == bus && m->devfn == devfn) {
+                       *index = m->index;
+                       dmaru  = m->dmaru;
+                       list_del(&m->list);
+                       kfree(m);
+                       break;
+               }
+       }
+
+       return dmaru;
+}
+
+static LIST_HEAD(saved_dev_drhd_list);
+
+static void remove_dev_from_drhd(struct pci_dev *dev)
+{
+       struct dmar_drhd_unit *drhd = NULL;
+       int segment = pci_domain_nr(dev->bus);
+       int i;
+
+       for_each_drhd_unit(drhd) {
+               if (drhd->ignored)
+                       continue;
+               if (segment != drhd->segment)
+                       continue;
+
+               for (i = 0; i < drhd->devices_cnt; i++) {
+                       if (drhd->devices[i] == dev) {
+                               /* save it at first if it is in drhd */
+                               save_dev_dmaru(segment, dev->bus->number,
+                                               dev->devfn, drhd, i,
+                                               &saved_dev_drhd_list);
+                               /* always remove it */
+                               drhd->devices[i] = NULL;
+                               return;
+                       }
+               }
+       }
+}
+
+static void restore_dev_to_drhd(struct pci_dev *dev)
+{
+       struct dmar_drhd_unit *drhd = NULL;
+       int i;
+
+       /* find the stored drhd */
+       drhd = get_dev_dmaru(pci_domain_nr(dev->bus), dev->bus->number,
+                                dev->devfn, &i, &saved_dev_drhd_list);
+       /* restore that into drhd */
+       if (drhd)
+               drhd->devices[i] = dev;
+}
+#else
+static void remove_dev_from_drhd(struct pci_dev *dev)
+{
+}
+
+static void restore_dev_to_drhd(struct pci_dev *dev)
+{
+}
+#endif
+
+#if defined(CONFIG_DMAR) && defined(CONFIG_HOTPLUG)
+static LIST_HEAD(saved_dev_atsr_list);
+
+static void remove_dev_from_atsr(struct pci_dev *dev)
+{
+       struct dmar_atsr_unit *atsr = NULL;
+       int segment = pci_domain_nr(dev->bus);
+       int i;
+
+       for_each_atsr_unit(atsr) {
+               if (segment != atsr->segment)
+                       continue;
+
+               for (i = 0; i < atsr->devices_cnt; i++) {
+                       if (atsr->devices[i] == dev) {
+                               /* save it at first if it is in drhd */
+                               save_dev_dmaru(segment, dev->bus->number,
+                                               dev->devfn, atsr, i,
+                                               &saved_dev_atsr_list);
+                               /* always remove it */
+                               atsr->devices[i] = NULL;
+                               return;
+                       }
+               }
+       }
+}
+
+static void restore_dev_to_atsr(struct pci_dev *dev)
+{
+       struct dmar_atsr_unit *atsr = NULL;
+       int i;
+
+       /* find the stored atsr */
+       atsr = get_dev_dmaru(pci_domain_nr(dev->bus), dev->bus->number,
+                                dev->devfn, &i, &saved_dev_atsr_list);
+       /* restore that into atsr */
+       if (atsr)
+               atsr->devices[i] = dev;
+}
+#else
+static void remove_dev_from_atsr(struct pci_dev *dev)
+{
+}
+
+static void restore_dev_to_atsr(struct pci_dev *dev)
+{
+}
+#endif
+
 static void domain_flush_cache(struct dmar_domain *domain,
                               void *addr, int size)
 {
@@ -3403,20 +3554,36 @@ static int device_notifier(struct notifier_block *nb,
        struct pci_dev *pdev = to_pci_dev(dev);
        struct dmar_domain *domain;
 
-       if (iommu_no_mapping(dev))
+       if (unlikely(dev->bus != &pci_bus_type))
                return 0;
 
-       domain = find_domain(pdev);
-       if (!domain)
-               return 0;
+       switch (action) {
+       case BUS_NOTIFY_UNBOUND_DRIVER:
+               if (iommu_no_mapping(dev))
+                       goto out;
+
+               if (iommu_pass_through)
+                       goto out;
+
+               domain = find_domain(pdev);
+               if (!domain)
+                       goto out;
 
-       if (action == BUS_NOTIFY_UNBOUND_DRIVER && !iommu_pass_through) {
                domain_remove_one_dev_info(domain, pdev);
 
                if (!(domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE) &&
                    !(domain->flags & DOMAIN_FLAG_STATIC_IDENTITY) &&
                    list_empty(&domain->devices))
                        domain_exit(domain);
+out:
+               remove_dev_from_drhd(pdev);
+               remove_dev_from_atsr(pdev);
+
+               break;
+       case BUS_NOTIFY_ADD_DEVICE:
+               restore_dev_to_drhd(pdev);
+               restore_dev_to_atsr(pdev);
+               break;
        }
 
        return 0;

diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index 7b776d71d36d0e465dfb4b6384899026253540cc..6701d9432f0bc89d4f935b861fc1b5a9b8bd3d77 100644 (file)
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -219,14 +219,19 @@ struct dmar_rmrr_unit {
 #define for_each_rmrr_units(rmrr) \
        list_for_each_entry(rmrr, &dmar_rmrr_units, list)
 
+extern struct list_head dmar_atsr_units;
 struct dmar_atsr_unit {
        struct list_head list;          /* list of ATSR units */
        struct acpi_dmar_header *hdr;   /* ACPI header */
        struct pci_dev **devices;       /* target devices */
        int devices_cnt;                /* target device count */
+       u16     segment;                /* PCI domain           */
        u8 include_all:1;               /* include all ports */
 };
 
+#define for_each_atsr_unit(atsr) \
+       list_for_each_entry(atsr, &dmar_atsr_units, list)
+
 extern int intel_iommu_init(void);
 #else /* !CONFIG_DMAR: */
 static inline int intel_iommu_init(void) { return -ENODEV; }