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.
Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxxxxxxxx>
---
drivers/pci/pci.c | 10 ++++++++++
drivers/pci/setup-bus.c | 43 ++++++++++++++++++++++++++++++++++++++-----
include/linux/pci.h | 3 +++
3 files changed, 51 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 7b70312..36efcf3 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
@@ -2672,6 +2678,10 @@ 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);
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index b636e24..5ab90ec 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -309,7 +309,7 @@ static struct resource *find_free_bus_resource(struct pci_bus *bus, unsigned lon
since these windows have 4K granularity and the IO ranges
of non-bridge PCI devices are limited to 256 bytes.
We must be careful with the ISA aliasing though. */
-static void pbus_size_io(struct pci_bus *bus)
+static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size)
{
struct pci_dev *dev;
struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO);
@@ -336,6 +336,8 @@ static void pbus_size_io(struct pci_bus *bus)
size1 += r_size;
}
}
+ if (size < min_size)
+ size = min_size;
/* To be fixed in 2.5: we should have sort of HAVE_ISA
flag in the struct pci_bus. */
#if defined(CONFIG_ISA) || defined(CONFIG_EISA)
@@ -354,7 +356,8 @@ static void pbus_size_io(struct pci_bus *bus)
/* Calculate the size of the bus and minimal alignment which
guarantees that all child resources fit in this size. */
-static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, unsigned long type)
+static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
+ unsigned long type, resource_size_t min_size)
{
struct pci_dev *dev;
resource_size_t min_align, align, size;
@@ -404,6 +407,8 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, unsigned long
mem64_mask &= r->flags & IORESOURCE_MEM_64;
}
}
+ if (size < min_size)
+ size = min_size;
align = 0;
min_align = 0;
@@ -479,10 +484,32 @@ static void pci_bus_size_cardbus(struct pci_bus *bus)
}
}
+static int is_pci_hotplug_bridge(struct pci_bus *bus)
+{
+ struct pci_dev *bridge = bus->self;
+ int pos;
+
+ /* Test for a generic pci hotplug bridge */
+ pos = pci_find_capability(bridge, PCI_CAP_ID_EXP);
+ if (pos) {
+ u32 reg32;
+ u16 reg16;
+ pci_read_config_word(bridge, pos + PCI_EXP_FLAGS, ®16);
+ if (reg16 & PCI_EXP_FLAGS_SLOT) {
+ pci_read_config_dword(bridge,
+ pos + PCI_EXP_SLTCAP, ®32);
+ if (reg32 & PCI_EXP_SLTCAP_HPC)
+ return 1;
+ }
+ }
+ return 0;
+}
+
void __ref pci_bus_size_bridges(struct pci_bus *bus)
{
struct pci_dev *dev;
unsigned long mask, prefmask;
+ resource_size_t min_mem_size = 0, min_io_size = 0;
list_for_each_entry(dev, &bus->devices, bus_list) {
struct pci_bus *b = dev->subordinate;
@@ -512,8 +539,12 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus)
case PCI_CLASS_BRIDGE_PCI:
pci_bridge_check_ranges(bus);
+ if (is_pci_hotplug_bridge(bus)) {
+ min_io_size = pci_hotplug_io_size;
+ min_mem_size = pci_hotplug_mem_size;
+ }
default:
- pbus_size_io(bus);
+ pbus_size_io(bus, min_io_size);
/* If the bridge supports prefetchable range, size it
separately. If it doesn't, or its prefetchable window
has already been allocated by arch code, try
@@ -521,9 +552,11 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus)
resources. */
mask = IORESOURCE_MEM;
prefmask = IORESOURCE_MEM | IORESOURCE_PREFETCH;
- if (pbus_size_mem(bus, prefmask, prefmask))
+ if (pbus_size_mem(bus, prefmask, prefmask, min_mem_size))
mask = prefmask; /* Success, size non-prefetch only. */
- pbus_size_mem(bus, mask, IORESOURCE_MEM);
+ else
+ min_mem_size += min_mem_size;
+ pbus_size_mem(bus, mask, IORESOURCE_MEM, min_mem_size);
break;
}
}
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 115fb7b..d6e57b0 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1236,6 +1236,9 @@ extern int pci_pci_problems;
extern unsigned long pci_cardbus_io_size;
extern unsigned long pci_cardbus_mem_size;
+extern unsigned long pci_hotplug_io_size;
+extern unsigned long pci_hotplug_mem_size;
+
int pcibios_add_platform_entries(struct pci_dev *dev);
void pcibios_disable_device(struct pci_dev *dev);
int pcibios_set_pcie_reset_state(struct pci_dev *dev,
--
1.6.2.5
--
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