From b07f2ebc109b607789f648dedcff4b125f9afec6 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Thu, 23 Feb 2012 19:23:32 -0800 Subject: [PATCH] PCI: add a PCI resource reallocation config option Add a new config option, PCI_REALLOC_ENABLE_AUTO, which will automatically try to re-allocate PCI resources if PCI_IOV support is enabled and the SR-IOV resources are unassigned. Behavior can still be controlled using the pci=realloc= parameter. -v2: According to Jesse, adding one CONFIG option for distribution to disable it or enable it. -v3: update Kconfig text (jbarnes) Signed-off-by: Yinghai Lu Signed-off-by: Jesse Barnes --- drivers/pci/Kconfig | 13 +++++++++++++ drivers/pci/setup-bus.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+) diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index 37856f7c778..848bfb84c04 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -31,6 +31,19 @@ config PCI_DEBUG When in doubt, say N. +config PCI_REALLOC_ENABLE_AUTO + bool "Enable PCI resource re-allocation detection" + depends on PCI + help + Say Y here if you want the PCI core to detect if PCI resource + re-allocation needs to be enabled. You can always use pci=realloc=on + or pci=realloc=off to override it. Note this feature is a no-op + unless PCI_IOV support is also enabled; in that case it will + automatically re-allocate PCI resources if SR-IOV BARs have not + been allocated by the BIOS. + + When in doubt, say N. + config PCI_STUB tristate "PCI Stub driver" depends on PCI diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index e21e1c23730..c9214a14b49 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1294,6 +1294,31 @@ static bool __init pci_realloc_enabled(void) return pci_realloc_enable >= user_enabled; } +static void __init pci_realloc_detect(void) +{ +#if defined(CONFIG_PCI_IOV) && defined(CONFIG_PCI_REALLOC_ENABLE_AUTO) + struct pci_dev *dev = NULL; + + if (pci_realloc_enable != undefined) + return; + + for_each_pci_dev(dev) { + int i; + + for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++) { + struct resource *r = &dev->resource[i]; + + /* Not assigned, or rejected by kernel ? */ + if (r->flags && !r->start) { + pci_realloc_enable = auto_enabled; + + return; + } + } + } +#endif +} + /* * first try will not touch pci bridge res * second and later try will clear small leaf bridge res @@ -1315,6 +1340,7 @@ pci_assign_unassigned_resources(void) int pci_try_num = 1; /* don't realloc if asked to do so */ + pci_realloc_detect(); if (pci_realloc_enabled()) { int max_depth = pci_get_max_depth(); @@ -1349,6 +1375,8 @@ again: if (tried_times >= pci_try_num) { if (pci_realloc_enable == undefined) printk(KERN_INFO "Some PCI device resources are unassigned, try booting with pci=realloc\n"); + else if (pci_realloc_enable == auto_enabled) + printk(KERN_INFO "Automatically enabled pci realloc, if you have problem, try booting with pci=realloc=off\n"); free_list(&fail_head); goto enable_and_dump; -- 2.39.5