[Linux-ia64] Re: [Pcihpd-discuss] Re: PCI Hotplug Drivers for 2.5

Ivan Kokshaysky
2002-10-25T15:37:25Z

On Thu, Oct 24, 2002 at 06:22:44PM -0400, Scott Murray wrote:
> I hopefully will have something working against 2.5.44 tomorrow. I think
> the only potentially contentious piece that I'd like to get reviewed and
> maybe integrated before the feature freeze is the resource reservation
> stuff. There seemed to be no serious objections to the 2.4.x version I
> posted a while back, so maybe this won't be a big deal. Everything else
> is either __devinit/export tweaks or driver code.

The setup-bus code already does resource reservation, but only for
cardbus. It can be easily extended for any type of hotplug
controller though. Other enhancements (like configurable amount
of reserved IO/memory) also shouldn't be a problem.

Also I have a patch (appended) that allows to use pbus_size_bridges()
for cardbus bridges (which have different resource layout vs. PCI-to-PCI
ones).

BTW, 2.5 setup-* stuff went into 2.4 recently. :-)

Ivan.

--- 2.5.36/drivers/pci/setup-res.c Wed Sep 18 04:59:13 2002
+++ linux/drivers/pci/setup-res.c Thu Sep 19 19:31:45 2002
@@ -137,7 +137,7 @@ pci_assign_resource(struct pci_dev *dev,
}

/* Sort resources by alignment */
-void __init
+void __devinit
pdev_sort_resources(struct pci_dev *dev, struct resource_list *head)
{
int i;
--- 2.5.36/drivers/pci/setup-bus.c Wed Sep 18 04:58:56 2002
+++ linux/drivers/pci/setup-bus.c Thu Sep 19 19:29:04 2002
@@ -35,7 +35,7 @@

#define ROUND_UP(x, a) (((x) + (a) - 1) & ~((a) - 1))

-static int __init
+static int __devinit
pbus_assign_resources_sorted(struct pci_bus *bus)
{
struct list_head *ln;
@@ -85,7 +85,7 @@ pbus_assign_resources_sorted(struct pci_
requires that if there is no I/O ports or memory behind the
bridge, corresponding range must be turned off by writing base
value greater than limit to the bridge's base/limit registers. */
-static void __init
+static void __devinit
pci_setup_bridge(struct pci_bus *bus)
{
struct pbus_set_ranges_data ranges;
@@ -168,7 +168,7 @@ pci_setup_bridge(struct pci_bus *bus)
/* Check whether the bridge supports optional I/O and
prefetchable memory ranges. If not, the respective
base/limit registers must be read-only and read as 0. */
-static void __init
+static void __devinit
pci_bridge_check_ranges(struct pci_bus *bus)
{
u16 io;
@@ -206,20 +206,38 @@ pci_bridge_check_ranges(struct pci_bus *
b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
}

+/* Find first free bus resource of a given type */
+static struct resource * __devinit
+pbus_find_resource(struct pci_bus *bus, unsigned long type)
+{
+ int i;
+ struct resource *r;
+
+ for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
+ r = bus->resource[i];
+ if (r && !((r->flags ^ type) & type) && !r->parent)
+ return r;
+ }
+ return NULL;
+}
+
/* Sizing the IO windows of the PCI-PCI bridge is trivial,
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 __init
+static void __devinit
pbus_size_io(struct pci_bus *bus)
{
struct list_head *ln;
- struct resource *b_res = bus->resource[0];
+ struct resource *b_res = pbus_find_resource(bus, IORESOURCE_IO);
unsigned long size = 0, size1 = 0;

- if (!(b_res->flags & IORESOURCE_IO))
+ if (!b_res)
return;

+ DBGC((KERN_INFO "PCI: found %s resource %ld for IO\n",
+ bus->name, b_res - bus->resource[0]));
+
for (ln=bus->devices.next; ln != &bus->devices; ln=ln->next) {
struct pci_dev *dev = pci_dev_b(ln);
int i;
@@ -259,15 +277,21 @@ 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 void __init
+static int __devinit
pbus_size_mem(struct pci_bus *bus, unsigned long mask, unsigned long type)
{
struct list_head *ln;
unsigned long min_align, align, size;
unsigned long aligns[12]; /* Alignments from 1Mb to 2Gb */
int order, max_order;
- struct resource *b_res = (type & IORESOURCE_PREFETCH) ?
- bus->resource[2] : bus->resource[1];
+ struct resource *b_res = pbus_find_resource(bus, type);
+
+ if (!b_res)
+ return 0;
+
+ DBGC((KERN_INFO "PCI: found %s resource %ld for %s\n",
+ bus->name, b_res - bus->resource[0],
+ type & IORESOURCE_PREFETCH ? "PREF" : "MEM"));

memset(aligns, 0, sizeof(aligns));
max_order = 0;
@@ -325,17 +349,18 @@ pbus_size_mem(struct pci_bus *bus, unsig
size = ROUND_UP(size, min_align);
if (!size) {
b_res->flags = 0;
- return;
+ return 1;
}
b_res->start = min_align;
b_res->end = size + min_align - 1;
+ return 1;
}

-void __init
+void __devinit
pbus_size_bridges(struct pci_bus *bus)
{
struct list_head *ln;
- unsigned long mask, type;
+ unsigned long mask, prefetch;

for (ln=bus->children.next; ln != &bus->children; ln=ln->next)
pbus_size_bridges(pci_bus_b(ln));
@@ -348,17 +373,15 @@ pbus_size_bridges(struct pci_bus *bus)

pbus_size_io(bus);

- mask = type = IORESOURCE_MEM;
+ mask = IORESOURCE_MEM;
+ prefetch = IORESOURCE_MEM | IORESOURCE_PREFETCH;
/* If the bridge supports prefetchable range, size it separately. */
- if (bus->resource[2] &&
- bus->resource[2]->flags & IORESOURCE_PREFETCH) {
- pbus_size_mem(bus, IORESOURCE_PREFETCH, IORESOURCE_PREFETCH);
- mask |= IORESOURCE_PREFETCH; /* Size non-prefetch only. */
- }
- pbus_size_mem(bus, mask, type);
+ if (pbus_size_mem(bus, prefetch, prefetch))
+ mask = prefetch; /* Size non-prefetch only. */
+ pbus_size_mem(bus, mask, IORESOURCE_MEM);
}

-void __init
+void __devinit
pbus_assign_resources(struct pci_bus *bus)
{
struct list_head *ln;
@@ -367,7 +390,8 @@ pbus_assign_resources(struct pci_bus *bu
if (found_vga) {
struct pci_bus *b;

- /* Propagate presence of the VGA to upstream bridges */
+ /* Propagate presence of the VGA to upstream bridges.
+ This hack eventually will go away. */
for (b = bus; b->parent; b = b->parent) {
b->resource[0]->flags |= IORESOURCE_BUS_HAS_VGA;
}