[SeaBIOS] [PATCH V2 2/2] fw/pci: map memory and IO regions for multiple pci root buses

[Kevin O'Connor]

On Mon, Feb 16, 2015 at 06:14:57PM +0200, Marcel Apfelbaum wrote:
> On 02/16/2015 06:07 PM, Kevin O'Connor wrote:
> >On Mon, Feb 16, 2015 at 05:43:31PM +0200, Marcel Apfelbaum wrote:
> >>On 02/16/2015 04:55 PM, Kevin O'Connor wrote:
> >>>On Mon, Feb 16, 2015 at 11:31:03AM +0200, Marcel Apfelbaum wrote:
> >>>>For resource sizing and mapping purposes treat devices on extra root
> >>>>buses as if they are on the default root bus (bus 0).
> >>>
> >>Hi Kevin,
> >>Thank you for the review.
> >>
> >>>Remind me - did you need the resources for each extra root bus to be
> >>>continuous (ie, not interspersed with resources allocated to devices
> >>>on the root bus)?  If I read your patch correctly, it wont segregate
> >>>resources on the extra buses.
> >>
> >>I did need them continuous for prev implementation.
> >>I modified the QEMU code to be generic allowing mem/IO
> >>regions not to be continuous (per PCI root bus).
> >>The ACPI and the Operating systems do not require this,
> >>so the correct way is to achieve better resources utilization.
> >
> >Okay, thanks.
> >
> >BTW, do you need the res_on_default_bus flag?  Would the below work
> >(totally untested)?
> I tried that already :)
> It will not work if you have a pci-bridge behind a pci-bridge (and so on...)

Okay - I'm missing something then.  The only place bus->bus_dev==NULL
is for root busses (busses[0] or extra root busses), and the only
place bus->res_on_default_bus is set is when bus->bus_dev==NULL.  So,
why can't bus->bus_dev==NULL be tested instead of
bus->res_on_default_bus?

If it can be done, the patch below is likely better (totally untested).

-Kevin


--- a/src/fw/pciinit.c
+++ b/src/fw/pciinit.c
@@ -601,7 +601,7 @@ static void pci_region_migrate_64bit_entries(struct pci_region *from,
 }
 
 static struct pci_region_entry *
-pci_region_create_entry(struct pci_bus *bus, struct pci_device *dev,
+pci_region_create_entry(struct pci_bus *busses, struct pci_device *dev,
                         int bar, u64 size, u64 align, int type, int is64)
 {
     struct pci_region_entry *entry = malloc_tmp(sizeof(*entry));
@@ -617,6 +617,10 @@ pci_region_create_entry(struct pci_bus *bus, struct pci_device *dev,
     entry->is64 = is64;
     entry->type = type;
     // Insert into list in sorted order.
+    struct pci_bus *bus = &busses[pci_bdf_to_bus(dev->bdf)];
+    if (!bus->bus_dev)
+        // Resources for all root busses go in busses[0]
+        bus = &busses[0];
     struct hlist_node **pprev;
     struct pci_region_entry *pos;
     hlist_for_each_entry_pprev(pos, pprev, &bus->r[type].list, node) {
@@ -667,7 +671,6 @@ static int pci_bios_check_devices(struct pci_bus *busses)
         if (pci->class == PCI_CLASS_BRIDGE_PCI)
             busses[pci->secondary_bus].bus_dev = pci;
 
-        struct pci_bus *bus = &busses[pci_bdf_to_bus(pci->bdf)];
         int i;
         for (i = 0; i < PCI_NUM_REGIONS; i++) {
             if ((pci->class == PCI_CLASS_BRIDGE_PCI) &&
@@ -682,7 +685,7 @@ static int pci_bios_check_devices(struct pci_bus *busses)
             if (type != PCI_REGION_TYPE_IO && size < PCI_DEVICE_MEM_MIN)
                 size = PCI_DEVICE_MEM_MIN;
             struct pci_region_entry *entry = pci_region_create_entry(
-                bus, pci, i, size, size, type, is64);
+                busses, pci, i, size, size, type, is64);
             if (!entry)
                 return -1;
 
@@ -697,7 +700,6 @@ static int pci_bios_check_devices(struct pci_bus *busses)
         struct pci_bus *s = &busses[secondary_bus];
         if (!s->bus_dev)
             continue;
-        struct pci_bus *parent = &busses[pci_bdf_to_bus(s->bus_dev->bdf)];
         int type;
         int hotplug_support = pci_bus_hotplug_support(s);
         for (type = 0; type < PCI_REGION_TYPE_COUNT; type++) {
@@ -715,7 +717,7 @@ static int pci_bios_check_devices(struct pci_bus *busses)
                                             s->bus_dev, type);
             // entry->bar is -1 if the entry represents a bridge region
             struct pci_region_entry *entry = pci_region_create_entry(
-                parent, s->bus_dev, -1, size, align, type, is64);
+                busses, s->bus_dev, -1, size, align, type, is64);
             if (!entry)
                 return -1;
             dprintf(1, "PCI: secondary bus %d size %08llx type %s\n",