PCI: pcie: Ensure hotplug ports have a minimum number of resources

In general a BIOS may goof or we may hotplug in a hotplug controller.
In either case the kernel needs to reserve resources for plugging
in more devices in the future instead of creating a minimal resource
assignment.

We already do this for cardbus bridges I am just adding a variant
for pcie bridges.

v2: Make testing for pcie hotplug bridges based on a flag.

    So far we only set the flag for pcie but a header_quirk
    could easily be added for the non-standard pci hotplug
    bridges.

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index bd993351db45..8c663d628d03 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -41,6 +41,12 @@ int pci_domains_supported = 1;
 unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE;
 unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
 
+#define DEFAULT_HOTPLUG_IO_SIZE         (256)
+#define DEFAULT_HOTPLUG_MEM_SIZE        (2*1024*1024)
+/* pci=hpmemsize=nnM,hpiosize=nn can override this */
+unsigned long pci_hotplug_io_size  = DEFAULT_HOTPLUG_IO_SIZE;
+unsigned long pci_hotplug_mem_size = DEFAULT_HOTPLUG_MEM_SIZE;
+
 /**
  * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
  * @bus: pointer to PCI bus structure to search
@@ -2732,6 +2738,10 @@ static int __init pci_setup(char *str)
                                                         strlen(str + 19));
                         } else if (!strncmp(str, "ecrc=", 5)) {
                                 pcie_ecrc_get_policy(str + 5);
+                        } else if (!strncmp(str, "hpiosize=", 9)) {
+                                pci_hotplug_io_size = memparse(str + 9, &str);
+                        } else if (!strncmp(str, "hpmemsize=", 10)) {
+                                pci_hotplug_mem_size = memparse(str + 10, &str);
                         } else {
                                 printk(KERN_ERR "PCI: Unknown option `%s'\n",
                                                 str);