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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
commitb4b7ff4b08e691656c9d77c758fc355833128ac0 (patch)
tree82fcb00e6b918026dc9f2d1f05ed8eee83874cc0 /arch/s390/pci
parent35acfa0fc609f2a2cd95cef4a6a9c3a5c38f1778 (diff)
Linux-libre 4.4-gnupck-4.4-gnu
Diffstat (limited to 'arch/s390/pci')
-rw-r--r--arch/s390/pci/pci_dma.c111
1 files changed, 76 insertions, 35 deletions
diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index 37505b8b4..d348f2c09 100644
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -24,7 +24,7 @@ static int zpci_refresh_global(struct zpci_dev *zdev)
zdev->iommu_pages * PAGE_SIZE);
}
-static unsigned long *dma_alloc_cpu_table(void)
+unsigned long *dma_alloc_cpu_table(void)
{
unsigned long *table, *entry;
@@ -33,7 +33,7 @@ static unsigned long *dma_alloc_cpu_table(void)
return NULL;
for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
- *entry = ZPCI_TABLE_INVALID | ZPCI_TABLE_PROTECTED;
+ *entry = ZPCI_TABLE_INVALID;
return table;
}
@@ -51,7 +51,7 @@ static unsigned long *dma_alloc_page_table(void)
return NULL;
for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
- *entry = ZPCI_PTE_INVALID | ZPCI_TABLE_PROTECTED;
+ *entry = ZPCI_PTE_INVALID;
return table;
}
@@ -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;
@@ -114,20 +114,10 @@ static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr
return &pto[px];
}
-static void dma_update_cpu_trans(struct zpci_dev *zdev, 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(zdev->dma_table, dma_addr);
- if (!entry) {
- WARN_ON_ONCE(1);
- return;
- }
-
if (flags & ZPCI_PTE_INVALID) {
invalidate_pt_entry(entry);
- return;
} else {
set_pt_pfaa(entry, page_addr);
validate_pt_entry(entry);
@@ -146,17 +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, 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;
}
@@ -175,13 +173,25 @@ 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);
return rc;
}
-static void dma_free_seg_table(unsigned long entry)
+void dma_free_seg_table(unsigned long entry)
{
unsigned long *sto = get_rt_sto(entry);
int sx;
@@ -193,21 +203,18 @@ static void dma_free_seg_table(unsigned long entry)
dma_free_cpu_table(sto);
}
-static void dma_cleanup_tables(struct zpci_dev *zdev)
+void dma_cleanup_tables(unsigned long *table)
{
- unsigned long *table;
int rtx;
- if (!zdev || !zdev->dma_table)
+ if (!table)
return;
- table = zdev->dma_table;
for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
if (reg_entry_isvalid(table[rtx]))
dma_free_seg_table(table[rtx]);
dma_free_cpu_table(table);
- zdev->dma_table = NULL;
}
static unsigned long __dma_alloc_iommu(struct zpci_dev *zdev,
@@ -262,6 +269,16 @@ out:
spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
}
+static inline void zpci_err_dma(unsigned long rc, unsigned long addr)
+{
+ struct {
+ unsigned long rc;
+ unsigned long addr;
+ } __packed data = {rc, addr};
+
+ zpci_err_hex(&data, sizeof(data));
+}
+
static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction direction,
@@ -272,33 +289,40 @@ static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
unsigned long pa = page_to_phys(page) + offset;
int flags = ZPCI_PTE_VALID;
dma_addr_t dma_addr;
+ int ret;
/* This rounds up number of pages based on size and offset */
nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
iommu_page_index = dma_alloc_iommu(zdev, nr_pages);
- if (iommu_page_index == -1)
+ if (iommu_page_index == -1) {
+ ret = -ENOSPC;
goto out_err;
+ }
/* Use rounded up size */
size = nr_pages * PAGE_SIZE;
dma_addr = zdev->start_dma + iommu_page_index * PAGE_SIZE;
- if (dma_addr + size > zdev->end_dma)
+ if (dma_addr + size > zdev->end_dma) {
+ ret = -ERANGE;
goto out_free;
+ }
if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
flags |= ZPCI_TABLE_PROTECTED;
- if (!dma_update_trans(zdev, pa, dma_addr, size, flags)) {
- atomic64_add(nr_pages, &zdev->mapped_pages);
- return dma_addr + (offset & ~PAGE_MASK);
- }
+ ret = dma_update_trans(zdev, pa, dma_addr, size, flags);
+ if (ret)
+ goto out_free;
+
+ atomic64_add(nr_pages, &zdev->mapped_pages);
+ return dma_addr + (offset & ~PAGE_MASK);
out_free:
dma_free_iommu(zdev, iommu_page_index, nr_pages);
out_err:
zpci_err("map error:\n");
- zpci_err_hex(&pa, sizeof(pa));
+ zpci_err_dma(ret, pa);
return DMA_ERROR_CODE;
}
@@ -308,14 +332,16 @@ static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
{
struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
unsigned long iommu_page_index;
- int npages;
+ int npages, ret;
npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
dma_addr = dma_addr & PAGE_MASK;
- if (dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
- ZPCI_TABLE_PROTECTED | ZPCI_PTE_INVALID)) {
+ ret = dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
+ ZPCI_PTE_INVALID);
+ if (ret) {
zpci_err("unmap error:\n");
- zpci_err_hex(&dma_addr, sizeof(dma_addr));
+ zpci_err_dma(ret, dma_addr);
+ return;
}
atomic64_add(npages, &zdev->unmapped_pages);
@@ -416,6 +442,13 @@ int zpci_dma_init_device(struct zpci_dev *zdev)
{
int rc;
+ /*
+ * At this point, if the device is part of an IOMMU domain, this would
+ * be a strong hint towards a bug in the IOMMU API (common) code and/or
+ * simultaneous access via IOMMU and DMA API. So let's issue a warning.
+ */
+ WARN_ON(zdev->s390_domain);
+
spin_lock_init(&zdev->iommu_bitmap_lock);
spin_lock_init(&zdev->dma_table_lock);
@@ -450,8 +483,16 @@ out_clean:
void zpci_dma_exit_device(struct zpci_dev *zdev)
{
+ /*
+ * At this point, if the device is part of an IOMMU domain, this would
+ * be a strong hint towards a bug in the IOMMU API (common) code and/or
+ * simultaneous access via IOMMU and DMA API. So let's issue a warning.
+ */
+ WARN_ON(zdev->s390_domain);
+
zpci_unregister_ioat(zdev, 0);
- dma_cleanup_tables(zdev);
+ dma_cleanup_tables(zdev->dma_table);
+ zdev->dma_table = NULL;
vfree(zdev->iommu_bitmap);
zdev->iommu_bitmap = NULL;
zdev->next_bit = 0;