From 3f068aae7a958555533847af88705b5629f31600 Mon Sep 17 00:00:00 2001 From: Sam Bobroff Date: Fri, 16 Aug 2019 14:48:05 +1000 Subject: [PATCH] powerpc/64: Adjust order in pcibios_init() The pcibios_init() function for PowerPC 64 currently calls pci_bus_add_devices() before pcibios_resource_survey(). This means that at boot time, when the pcibios_bus_add_device() hooks are called by pci_bus_add_devices(), device resources have not been allocated and they are unable to perform EEH setup, so a separate pass is needed. This patch adjusts that order so that it will become possible to consolidate the EEH setup work into a single location. The only functional change is to execute pcibios_resource_survey() (excepting ppc_md.pcibios_fixup(), see below) before pci_bus_add_devices() instead of after it. Because pcibios_scan_phb() and pci_bus_add_devices() are called together in a loop, this must be broken into one loop for each call. Then the call to pcibios_resource_survey() is moved up in between them. This changes the ordering but because pcibios_resource_survey() also calls ppc_md.pcibios_fixup(), that call is extracted out into pcibios_init() to where pcibios_resource_survey() was, so that it is not moved. The only other caller of pcibios_resource_survey() is the PowerPC 32 version of pcibios_init(), and therefore, that is modified to call ppc_md.pcibios_fixup() right after pcibios_resource_survey() so that there is no functional change there at all. The re-arrangement will cause very few side-effects because at this stage in the boot, pci_bus_add_devices() does very little: - pci_create_sysfs_dev_files() does nothing (no sysfs yet) - pci_proc_attach_device() does nothing (no proc yet) - device_attach() does nothing (no drivers yet) This leaves only the pci_final_fixup calls, D3 support, and marking the device as added. Of those, only the pci_final_fixup calls have the potential to be affected by resource allocation. The only pci_final_fixup handlers that touch resources seem to be one for x86 (pci_amd_enable_64bit_bar()), and a PowerPC 32 platform driver (quirk_final_uli1575()), neither of which use this pcibios_init() function. Even if they did, it would almost certainly be a bug, under the current ordering, to rely on or make changes to resources before they were allocated. Signed-off-by: Sam Bobroff Reviewed-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/4506b0489eabd0921a3587d90bd44c7683f3472d.1565930772.git.sbobroff@linux.ibm.com --- arch/powerpc/kernel/pci-common.c | 4 ---- arch/powerpc/kernel/pci_32.c | 4 ++++ arch/powerpc/kernel/pci_64.c | 12 +++++++++--- 3 files changed, 13 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c index f627e15bb43c..1c448cf25506 100644 --- a/arch/powerpc/kernel/pci-common.c +++ b/arch/powerpc/kernel/pci-common.c @@ -1379,10 +1379,6 @@ void __init pcibios_resource_survey(void) pr_debug("PCI: Assigning unassigned resources...\n"); pci_assign_unassigned_resources(); } - - /* Call machine dependent fixup */ - if (ppc_md.pcibios_fixup) - ppc_md.pcibios_fixup(); } /* This is used by the PCI hotplug driver to allocate resource diff --git a/arch/powerpc/kernel/pci_32.c b/arch/powerpc/kernel/pci_32.c index 50942a1d1a5f..b49e1060a3bf 100644 --- a/arch/powerpc/kernel/pci_32.c +++ b/arch/powerpc/kernel/pci_32.c @@ -263,6 +263,10 @@ static int __init pcibios_init(void) /* Call common code to handle resource allocation */ pcibios_resource_survey(); + /* Call machine dependent fixup */ + if (ppc_md.pcibios_fixup) + ppc_md.pcibios_fixup(); + /* Call machine dependent post-init code */ if (ppc_md.pcibios_after_init) ppc_md.pcibios_after_init(); diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c index b7030b1189d0..f83d1f69b1dd 100644 --- a/arch/powerpc/kernel/pci_64.c +++ b/arch/powerpc/kernel/pci_64.c @@ -54,14 +54,20 @@ static int __init pcibios_init(void) pci_add_flags(PCI_ENABLE_PROC_DOMAINS | PCI_COMPAT_DOMAIN_0); /* Scan all of the recorded PCI controllers. */ - list_for_each_entry_safe(hose, tmp, &hose_list, list_node) { + list_for_each_entry_safe(hose, tmp, &hose_list, list_node) pcibios_scan_phb(hose); - pci_bus_add_devices(hose->bus); - } /* Call common code to handle resource allocation */ pcibios_resource_survey(); + /* Add devices. */ + list_for_each_entry_safe(hose, tmp, &hose_list, list_node) + pci_bus_add_devices(hose->bus); + + /* Call machine dependent fixup */ + if (ppc_md.pcibios_fixup) + ppc_md.pcibios_fixup(); + printk(KERN_DEBUG "PCI: Probing PCI hardware done\n"); return 0;