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-rw-r--r--arch/powerpc/kernel/pci-common.c54
1 files changed, 51 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index d1f91e1a813b..c6ac4f01dd56 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -41,11 +41,18 @@
#include <asm/ppc-pci.h>
#include <asm/eeh.h>
+/* hose_spinlock protects accesses to the the phb_bitmap. */
static DEFINE_SPINLOCK(hose_spinlock);
LIST_HEAD(hose_list);
-/* XXX kill that some day ... */
-static int global_phb_number; /* Global phb counter */
+/* For dynamic PHB numbering on get_phb_number(): max number of PHBs. */
+#define MAX_PHBS 0x10000
+
+/*
+ * For dynamic PHB numbering: used/free PHBs tracking bitmap.
+ * Accesses to this bitmap should be protected by hose_spinlock.
+ */
+static DECLARE_BITMAP(phb_bitmap, MAX_PHBS);
/* ISA Memory physical address */
resource_size_t isa_mem_base;
@@ -64,6 +71,42 @@ struct dma_map_ops *get_pci_dma_ops(void)
}
EXPORT_SYMBOL(get_pci_dma_ops);
+/*
+ * This function should run under locking protection, specifically
+ * hose_spinlock.
+ */
+static int get_phb_number(struct device_node *dn)
+{
+ int ret, phb_id = -1;
+ u64 prop;
+
+ /*
+ * Try fixed PHB numbering first, by checking archs and reading
+ * the respective device-tree properties. Firstly, try powernv by
+ * reading "ibm,opal-phbid", only present in OPAL environment.
+ */
+ ret = of_property_read_u64(dn, "ibm,opal-phbid", &prop);
+ if (ret)
+ ret = of_property_read_u32_index(dn, "reg", 1, (u32 *)&prop);
+
+ if (!ret)
+ phb_id = (int)(prop & (MAX_PHBS - 1));
+
+ /* We need to be sure to not use the same PHB number twice. */
+ if ((phb_id >= 0) && !test_and_set_bit(phb_id, phb_bitmap))
+ return phb_id;
+
+ /*
+ * If not pseries nor powernv, or if fixed PHB numbering tried to add
+ * the same PHB number twice, then fallback to dynamic PHB numbering.
+ */
+ phb_id = find_first_zero_bit(phb_bitmap, MAX_PHBS);
+ BUG_ON(phb_id >= MAX_PHBS);
+ set_bit(phb_id, phb_bitmap);
+
+ return phb_id;
+}
+
struct pci_controller *pcibios_alloc_controller(struct device_node *dev)
{
struct pci_controller *phb;
@@ -72,7 +115,7 @@ struct pci_controller *pcibios_alloc_controller(struct device_node *dev)
if (phb == NULL)
return NULL;
spin_lock(&hose_spinlock);
- phb->global_number = global_phb_number++;
+ phb->global_number = get_phb_number(dev);
list_add_tail(&phb->list_node, &hose_list);
spin_unlock(&hose_spinlock);
phb->dn = dev;
@@ -94,6 +137,11 @@ EXPORT_SYMBOL_GPL(pcibios_alloc_controller);
void pcibios_free_controller(struct pci_controller *phb)
{
spin_lock(&hose_spinlock);
+
+ /* Clear bit of phb_bitmap to allow reuse of this PHB number. */
+ if (phb->global_number < MAX_PHBS)
+ clear_bit(phb->global_number, phb_bitmap);
+
list_del(&phb->list_node);
spin_unlock(&hose_spinlock);