From 0e4c2eeb758a91e68b9eaf7a4bee9bd5ed97ff2b Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Mon, 31 Jul 2017 17:37:51 +0100 Subject: [PATCH] alpha/PCI: Replace pci_fixup_irqs() call with host bridge IRQ mapping hooks The pci_fixup_irqs() function allocates IRQs for all PCI devices present in a system; those PCI devices possibly belong to different PCI bus trees (and possibly rooted at different host bridges) and may well be enabled (ie probed and bound to a driver) by the time pci_fixup_irqs() is called when probing a given host bridge driver. Furthermore, current kernel code relying on pci_fixup_irqs() to assign legacy PCI IRQs to devices does not work at all for hotplugged devices in that the code carrying out the IRQ fixup is called at host bridge driver probe time, which just cannot take into account devices hotplugged after the system has booted. The introduction of map/swizzle function hooks in struct pci_host_bridge allows us to define per-bridge map/swizzle functions that can be used at device probe time in PCI core code to allocate IRQs for a given device (through pci_assign_irq()). Convert PCI host bridge initialization code to the pci_scan_root_bus_bridge() API (that allows to pass a struct pci_host_bridge with initialized map/swizzle pointers) and remove the pci_fixup_irqs() call from arch code. Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Cc: Richard Henderson Cc: Ivan Kokshaysky --- arch/alpha/kernel/pci.c | 27 ++++++++++++++++++++------- arch/alpha/kernel/sys_nautilus.c | 31 +++++++++++++++++++++++++++---- 2 files changed, 47 insertions(+), 11 deletions(-) diff --git a/arch/alpha/kernel/pci.c b/arch/alpha/kernel/pci.c index 5f387ee5b5c5..d558287c6133 100644 --- a/arch/alpha/kernel/pci.c +++ b/arch/alpha/kernel/pci.c @@ -312,8 +312,9 @@ common_init_pci(void) { struct pci_controller *hose; struct list_head resources; + struct pci_host_bridge *bridge; struct pci_bus *bus; - int next_busno; + int ret, next_busno; int need_domain_info = 0; u32 pci_mem_end; u32 sg_base; @@ -336,11 +337,25 @@ common_init_pci(void) pci_add_resource_offset(&resources, hose->mem_space, hose->mem_space->start); - bus = pci_scan_root_bus(NULL, next_busno, alpha_mv.pci_ops, - hose, &resources); - if (!bus) + bridge = pci_alloc_host_bridge(0); + if (!bridge) continue; - hose->bus = bus; + + list_splice_init(&resources, &bridge->windows); + bridge->dev.parent = NULL; + bridge->sysdata = hose; + bridge->busnr = next_busno; + bridge->ops = alpha_mv.pci_ops; + bridge->swizzle_irq = alpha_mv.pci_swizzle; + bridge->map_irq = alpha_mv.pci_map_irq; + + ret = pci_scan_root_bus_bridge(bridge); + if (ret) { + pci_free_host_bridge(bridge); + continue; + } + + bus = hose->bus = bridge->bus; hose->need_domain_info = need_domain_info; next_busno = bus->busn_res.end + 1; /* Don't allow 8-bit bus number overflow inside the hose - @@ -354,7 +369,6 @@ common_init_pci(void) pcibios_claim_console_setup(); pci_assign_unassigned_resources(); - pci_fixup_irqs(alpha_mv.pci_swizzle, alpha_mv.pci_map_irq); for (hose = hose_head; hose; hose = hose->next) { bus = hose->bus; if (bus) @@ -362,7 +376,6 @@ common_init_pci(void) } } - struct pci_controller * __init alloc_pci_controller(void) { diff --git a/arch/alpha/kernel/sys_nautilus.c b/arch/alpha/kernel/sys_nautilus.c index 2cfaa0e5c577..8ae04a121186 100644 --- a/arch/alpha/kernel/sys_nautilus.c +++ b/arch/alpha/kernel/sys_nautilus.c @@ -194,22 +194,46 @@ static struct resource irongate_mem = { .name = "Irongate PCI MEM", .flags = IORESOURCE_MEM, }; +static struct resource busn_resource = { + .name = "PCI busn", + .start = 0, + .end = 255, + .flags = IORESOURCE_BUS, +}; void __init nautilus_init_pci(void) { struct pci_controller *hose = hose_head; + struct pci_host_bridge *bridge; struct pci_bus *bus; struct pci_dev *irongate; unsigned long bus_align, bus_size, pci_mem; unsigned long memtop = max_low_pfn << PAGE_SHIFT; + int ret; + + bridge = pci_alloc_host_bridge(0); + if (!bridge) + return; + + pci_add_resource(&bridge->windows, &ioport_resource); + pci_add_resource(&bridge->windows, &iomem_resource); + pci_add_resource(&bridge->windows, &busn_resource); + bridge->dev.parent = NULL; + bridge->sysdata = hose; + bridge->busnr = 0; + bridge->ops = alpha_mv.pci_ops; + bridge->swizzle_irq = alpha_mv.pci_swizzle; + bridge->map_irq = alpha_mv.pci_map_irq; /* Scan our single hose. */ - bus = pci_scan_bus(0, alpha_mv.pci_ops, hose); - if (!bus) + ret = pci_scan_root_bus_bridge(bridge); + if (ret) { + pci_free_host_bridge(bridge); return; + } - hose->bus = bus; + bus = hose->bus = bridge->bus; pcibios_claim_one_bus(bus); irongate = pci_get_bus_and_slot(0, 0); @@ -254,7 +278,6 @@ nautilus_init_pci(void) /* pci_common_swizzle() relies on bus->self being NULL for the root bus, so just clear it. */ bus->self = NULL; - pci_fixup_irqs(alpha_mv.pci_swizzle, alpha_mv.pci_map_irq); pci_bus_add_devices(bus); } -- 2.20.1