s390/pci_dma: handle dma table failures

We use lazy allocation for translation table entries but don't handle
allocation (and other) failures during translation table updates.

Handle these failures and undo translation table updates when it's
meaningful.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/include/asm/pci_dma.h b/arch/s390/include/asm/pci_dma.h
index 7a7abf1a5537242746b079bfb57dfe555a1e6b33..1aac41e83ea197121c5dd178c587323f9b875aa1 100644 (file)
--- a/arch/s390/include/asm/pci_dma.h
+++ b/arch/s390/include/asm/pci_dma.h
@@ -195,5 +195,7 @@ void zpci_dma_exit_device(struct zpci_dev *);
 void dma_free_seg_table(unsigned long);
 unsigned long *dma_alloc_cpu_table(void);
 void dma_cleanup_tables(unsigned long *);
-void dma_update_cpu_trans(unsigned long *, void *, dma_addr_t, int);
+unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr);
+void dma_update_cpu_trans(unsigned long *entry, void *page_addr, int flags);
+
 #endif

diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index e4a3a31fd59a2e6e4fc21843774b87d7f24c0112..f137949c9abf0fcc4415d33b7a5464013ab345f0 100644 (file)
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -95,7 +95,7 @@ static unsigned long *dma_get_page_table_origin(unsigned long *entry)
        return pto;
 }
 
-static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr)
+unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr)
 {
        unsigned long *sto, *pto;
        unsigned int rtx, sx, px;
@@ -114,17 +114,8 @@ static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr
        return &pto[px];
 }
 
-void dma_update_cpu_trans(unsigned long *dma_table, void *page_addr,
-                         dma_addr_t dma_addr, int flags)
+void dma_update_cpu_trans(unsigned long *entry, void *page_addr, int flags)
 {
-       unsigned long *entry;
-
-       entry = dma_walk_cpu_trans(dma_table, dma_addr);
-       if (!entry) {
-               WARN_ON_ONCE(1);
-               return;
-       }
-
        if (flags & ZPCI_PTE_INVALID) {
                invalidate_pt_entry(entry);
        } else {
@@ -145,18 +136,25 @@ static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
        u8 *page_addr = (u8 *) (pa & PAGE_MASK);
        dma_addr_t start_dma_addr = dma_addr;
        unsigned long irq_flags;
+       unsigned long *entry;
        int i, rc = 0;
 
        if (!nr_pages)
                return -EINVAL;
 
        spin_lock_irqsave(&zdev->dma_table_lock, irq_flags);
-       if (!zdev->dma_table)
+       if (!zdev->dma_table) {
+               rc = -EINVAL;
                goto no_refresh;
+       }
 
        for (i = 0; i < nr_pages; i++) {
-               dma_update_cpu_trans(zdev->dma_table, page_addr, dma_addr,
-                                    flags);
+               entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
+               if (!entry) {
+                       rc = -ENOMEM;
+                       goto undo_cpu_trans;
+               }
+               dma_update_cpu_trans(entry, page_addr, flags);
                page_addr += PAGE_SIZE;
                dma_addr += PAGE_SIZE;
        }
@@ -175,6 +173,18 @@ static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
 
        rc = zpci_refresh_trans((u64) zdev->fh << 32, start_dma_addr,
                                nr_pages * PAGE_SIZE);
+undo_cpu_trans:
+       if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) {
+               flags = ZPCI_PTE_INVALID;
+               while (i-- > 0) {
+                       page_addr -= PAGE_SIZE;
+                       dma_addr -= PAGE_SIZE;
+                       entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
+                       if (!entry)
+                               break;
+                       dma_update_cpu_trans(entry, page_addr, flags);
+               }
+       }
 
 no_refresh:
        spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);

diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
index cbe198cb36991d3970f5a0ce4fc3596ee85eb5a7..471ee36b9c6eea6d72ad74302fadfb97c28f8a7f 100644 (file)
--- a/drivers/iommu/s390-iommu.c
+++ b/drivers/iommu/s390-iommu.c
@@ -216,6 +216,7 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain,
        u8 *page_addr = (u8 *) (pa & PAGE_MASK);
        dma_addr_t start_dma_addr = dma_addr;
        unsigned long irq_flags, nr_pages, i;
+       unsigned long *entry;
        int rc = 0;
 
        if (dma_addr < s390_domain->domain.geometry.aperture_start ||
@@ -228,8 +229,12 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain,
 
        spin_lock_irqsave(&s390_domain->dma_table_lock, irq_flags);
        for (i = 0; i < nr_pages; i++) {
-               dma_update_cpu_trans(s390_domain->dma_table, page_addr,
-                                    dma_addr, flags);
+               entry = dma_walk_cpu_trans(s390_domain->dma_table, dma_addr);
+               if (!entry) {
+                       rc = -ENOMEM;
+                       goto undo_cpu_trans;
+               }
+               dma_update_cpu_trans(entry, page_addr, flags);
                page_addr += PAGE_SIZE;
                dma_addr += PAGE_SIZE;
        }
@@ -242,6 +247,20 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain,
                        break;
        }
        spin_unlock(&s390_domain->list_lock);
+
+undo_cpu_trans:
+       if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) {
+               flags = ZPCI_PTE_INVALID;
+               while (i-- > 0) {
+                       page_addr -= PAGE_SIZE;
+                       dma_addr -= PAGE_SIZE;
+                       entry = dma_walk_cpu_trans(s390_domain->dma_table,
+                                                  dma_addr);
+                       if (!entry)
+                               break;
+                       dma_update_cpu_trans(entry, page_addr, flags);
+               }
+       }
        spin_unlock_irqrestore(&s390_domain->dma_table_lock, irq_flags);
 
        return rc;