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-rw-r--r--arch/ppc64/kernel/pSeries_iommu.c169
1 files changed, 89 insertions, 80 deletions
diff --git a/arch/ppc64/kernel/pSeries_iommu.c b/arch/ppc64/kernel/pSeries_iommu.c
index f0fd7fbd653..8c6313e7e14 100644
--- a/arch/ppc64/kernel/pSeries_iommu.c
+++ b/arch/ppc64/kernel/pSeries_iommu.c
@@ -265,8 +265,10 @@ static void iommu_table_setparms(struct pci_controller *phb,
tbl->it_offset = phb->dma_window_base_cur >> PAGE_SHIFT;
/* Test if we are going over 2GB of DMA space */
- if (phb->dma_window_base_cur + phb->dma_window_size > (1L << 31))
+ if (phb->dma_window_base_cur + phb->dma_window_size > 0x80000000ul) {
+ udbg_printf("PCI_DMA: Unexpected number of IOAs under this PHB.\n");
panic("PCI_DMA: Unexpected number of IOAs under this PHB.\n");
+ }
phb->dma_window_base_cur += phb->dma_window_size;
@@ -310,92 +312,84 @@ static void iommu_table_setparms_lpar(struct pci_controller *phb,
static void iommu_bus_setup_pSeries(struct pci_bus *bus)
{
- struct device_node *dn, *pdn;
- struct pci_dn *pci;
+ struct device_node *dn;
struct iommu_table *tbl;
+ struct device_node *isa_dn, *isa_dn_orig;
+ struct device_node *tmp;
+ struct pci_dn *pci;
+ int children;
DBG("iommu_bus_setup_pSeries, bus %p, bus->self %p\n", bus, bus->self);
- /* For each (root) bus, we carve up the available DMA space in 256MB
- * pieces. Since each piece is used by one (sub) bus/device, that would
- * give a maximum of 7 devices per PHB. In most cases, this is plenty.
- *
- * The exception is on Python PHBs (pre-POWER4). Here we don't have EADS
- * bridges below the PHB to allocate the sectioned tables to, so instead
- * we allocate a 1GB table at the PHB level.
+ dn = pci_bus_to_OF_node(bus);
+ pci = PCI_DN(dn);
+
+ if (bus->self) {
+ /* This is not a root bus, any setup will be done for the
+ * device-side of the bridge in iommu_dev_setup_pSeries().
+ */
+ return;
+ }
+
+ /* Check if the ISA bus on the system is under
+ * this PHB.
*/
+ isa_dn = isa_dn_orig = of_find_node_by_type(NULL, "isa");
- dn = pci_bus_to_OF_node(bus);
- pci = dn->data;
-
- if (!bus->self) {
- /* Root bus */
- if (is_python(dn)) {
- unsigned int *iohole;
-
- DBG("Python root bus %s\n", bus->name);
-
- iohole = (unsigned int *)get_property(dn, "io-hole", 0);
-
- if (iohole) {
- /* On first bus we need to leave room for the
- * ISA address space. Just skip the first 256MB
- * alltogether. This leaves 768MB for the window.
- */
- DBG("PHB has io-hole, reserving 256MB\n");
- pci->phb->dma_window_size = 3 << 28;
- pci->phb->dma_window_base_cur = 1 << 28;
- } else {
- /* 1GB window by default */
- pci->phb->dma_window_size = 1 << 30;
- pci->phb->dma_window_base_cur = 0;
- }
-
- tbl = kmalloc(sizeof(struct iommu_table), GFP_KERNEL);
-
- iommu_table_setparms(pci->phb, dn, tbl);
- pci->iommu_table = iommu_init_table(tbl);
- } else {
- /* Do a 128MB table at root. This is used for the IDE
- * controller on some SMP-mode POWER4 machines. It
- * doesn't hurt to allocate it on other machines
- * -- it'll just be unused since new tables are
- * allocated on the EADS level.
- *
- * Allocate at offset 128MB to avoid having to deal
- * with ISA holes; 128MB table for IDE is plenty.
- */
- pci->phb->dma_window_size = 1 << 27;
- pci->phb->dma_window_base_cur = 1 << 27;
-
- tbl = kmalloc(sizeof(struct iommu_table), GFP_KERNEL);
-
- iommu_table_setparms(pci->phb, dn, tbl);
- pci->iommu_table = iommu_init_table(tbl);
-
- /* All child buses have 256MB tables */
- pci->phb->dma_window_size = 1 << 28;
- }
- } else {
- pdn = pci_bus_to_OF_node(bus->parent);
+ while (isa_dn && isa_dn != dn)
+ isa_dn = isa_dn->parent;
+
+ if (isa_dn_orig)
+ of_node_put(isa_dn_orig);
- if (!bus->parent->self && !is_python(pdn)) {
- struct iommu_table *tbl;
- /* First child and not python means this is the EADS
- * level. Allocate new table for this slot with 256MB
- * window.
- */
+ /* Count number of direct PCI children of the PHB.
+ * All PCI device nodes have class-code property, so it's
+ * an easy way to find them.
+ */
+ for (children = 0, tmp = dn->child; tmp; tmp = tmp->sibling)
+ if (get_property(tmp, "class-code", NULL))
+ children++;
- tbl = kmalloc(sizeof(struct iommu_table), GFP_KERNEL);
+ DBG("Children: %d\n", children);
- iommu_table_setparms(pci->phb, dn, tbl);
+ /* Calculate amount of DMA window per slot. Each window must be
+ * a power of two (due to pci_alloc_consistent requirements).
+ *
+ * Keep 256MB aside for PHBs with ISA.
+ */
- pci->iommu_table = iommu_init_table(tbl);
- } else {
- /* Lower than first child or under python, use parent table */
- pci->iommu_table = PCI_DN(pdn)->iommu_table;
- }
+ if (!isa_dn) {
+ /* No ISA/IDE - just set window size and return */
+ pci->phb->dma_window_size = 0x80000000ul; /* To be divided */
+
+ while (pci->phb->dma_window_size * children > 0x80000000ul)
+ pci->phb->dma_window_size >>= 1;
+ DBG("No ISA/IDE, window size is %x\n", pci->phb->dma_window_size);
+ pci->phb->dma_window_base_cur = 0;
+
+ return;
}
+
+ /* If we have ISA, then we probably have an IDE
+ * controller too. Allocate a 128MB table but
+ * skip the first 128MB to avoid stepping on ISA
+ * space.
+ */
+ pci->phb->dma_window_size = 0x8000000ul;
+ pci->phb->dma_window_base_cur = 0x8000000ul;
+
+ tbl = kmalloc(sizeof(struct iommu_table), GFP_KERNEL);
+
+ iommu_table_setparms(pci->phb, dn, tbl);
+ pci->iommu_table = iommu_init_table(tbl);
+
+ /* Divide the rest (1.75GB) among the children */
+ pci->phb->dma_window_size = 0x80000000ul;
+ while (pci->phb->dma_window_size * children > 0x70000000ul)
+ pci->phb->dma_window_size >>= 1;
+
+ DBG("ISA/IDE, window size is %x\n", pci->phb->dma_window_size);
+
}
@@ -446,14 +440,29 @@ static void iommu_bus_setup_pSeriesLP(struct pci_bus *bus)
static void iommu_dev_setup_pSeries(struct pci_dev *dev)
{
struct device_node *dn, *mydn;
+ struct iommu_table *tbl;
DBG("iommu_dev_setup_pSeries, dev %p (%s)\n", dev, dev->pretty_name);
- /* Now copy the iommu_table ptr from the bus device down to the
- * pci device_node. This means get_iommu_table() won't need to search
- * up the device tree to find it.
- */
+
mydn = dn = pci_device_to_OF_node(dev);
+ /* If we're the direct child of a root bus, then we need to allocate
+ * an iommu table ourselves. The bus setup code should have setup
+ * the window sizes already.
+ */
+ if (!dev->bus->self) {
+ DBG(" --> first child, no bridge. Allocating iommu table.\n");
+ tbl = kmalloc(sizeof(struct iommu_table), GFP_KERNEL);
+ iommu_table_setparms(PCI_DN(dn)->phb, dn, tbl);
+ PCI_DN(mydn)->iommu_table = iommu_init_table(tbl);
+
+ return;
+ }
+
+ /* If this device is further down the bus tree, search upwards until
+ * an already allocated iommu table is found and use that.
+ */
+
while (dn && dn->data && PCI_DN(dn)->iommu_table == NULL)
dn = dn->parent;