diff options
Diffstat (limited to 'arch/powerpc/kernel/pci-common.c')
| -rw-r--r-- | arch/powerpc/kernel/pci-common.c | 54 |
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); |