[PATCH] piix: fix mtrr setup

[Gerd Hoffmann]

Add a piix4 memory setup function to make the control flow more clear.

Set the new mtrr_base variable (added by q35 patch set) to the start of
the 32bit pci window to make sure the mtrr entry added covers the I/O
window.

Make the 32bit pci window start at 0x80000000, 0xc0000000 or 0xe000000
(depending on the memory installed) so we can cover the whole window
with a single mtrr entry.

Signed-off-by: Gerd Hoffmann 
---
 src/pciinit.c |   18 +++++++++++++++---
 1 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/pciinit.c b/src/pciinit.c
index 93a53e8..28c77ed 100644
--- a/src/pciinit.c
+++ b/src/pciinit.c
@@ -660,6 +660,18 @@ static void pci_region_map_entries(struct pci_bus *busses, struct pci_region *r)
     }
 }

+void i440fx_mem_addr_init(struct pci_device *dev, void *arg)
+{
+    u64 *start = (u64 *)arg;
+
+    if (RamSize <= 0x80000000)
+        *start = 0x80000000;
+    else if (RamSize <= 0xc0000000)
+        *start = 0xc0000000;
+
+    mtrr_base = *start;
+}
+
 void mch_mem_addr_init(struct pci_device *dev, void *arg)
 {
     u64 *start = (u64 *)arg; 
@@ -670,6 +682,8 @@ void mch_mem_addr_init(struct pci_device *dev, void *arg)
 }

static const struct pci_device_id pci_mem_addr_tbl[] = {
+    PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82441,
+               i440fx_mem_addr_init),
     PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_Q35_MCH,
                mch_mem_addr_init),
     PCI_DEVICE_END,
@@ -677,9 +691,7 @@ static const struct pci_device_id pci_mem_addr_tbl[] = {

static void pci_bios_map_devices(struct pci_bus *busses)
 {
-    pcimem_start = RamSize;
-
-    /* let's add in mmconfig space on q35 */
+    /* chipset specific memory setup */
     pci_find_init_device(pci_mem_addr_tbl, &pcimem_start);

if (pci_bios_init_root_regions(busses)) {

[Kevin O'Connor]

On Mon, Oct 22, 2012 at 10:12:03AM +0200, Gerd Hoffmann wrote:
> Add a piix4 memory setup function to make the control flow more clear.
>
> Set the new mtrr_base variable (added by q35 patch set) to the start of
> the 32bit pci window to make sure the mtrr entry added covers the I/O
> window.
>
> Make the 32bit pci window start at 0x80000000, 0xc0000000 or 0xe000000
> (depending on the memory installed) so we can cover the whole window
> with a single mtrr entry.

Patch looks okay to me.  However, as noted in the q35 patch series,
I'd prefer to see the scan moved out of pci_bios_map_devices() and the
global pcimem_start assigned directly instead of via a pointer.

-Kevin