From: Keir Fraser Date: Fri, 23 May 2008 10:15:19 +0000 (+0100) Subject: x86: Fix Xen boot on 8-node AMD machines X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14207^2~49 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=2b2408c9871d6b77b09969c09e7c80af4130893a;p=xen.git x86: Fix Xen boot on 8-node AMD machines In xen/arch/x86/cpu/amd.c the function disable_c1_ramping iterates over the northbridges using NR_CPUS as an upper bound for the number of nodes. If there are no more northbridges found, it stops iterating. Sadly it just adds the northbridge number to 0x18 and uses this as a PCI device number, so probing the 9th northbridge on an 8 node system will be caught by the newly inserted assertion in pci_conf_read in current unstable. We fix this by first querying the number of nodes from the first northbridge to avoid the overflow. Signed-off-by: Andre Przywara Verified by Mark.Johnson@sun.com --- diff --git a/xen/arch/x86/cpu/amd.c b/xen/arch/x86/cpu/amd.c index f0253152bc..766d645f90 100644 --- a/xen/arch/x86/cpu/amd.c +++ b/xen/arch/x86/cpu/amd.c @@ -74,9 +74,11 @@ static int c1_ramping_may_cause_clock_drift(struct cpuinfo_x86 *c) static void disable_c1_ramping(void) { u8 pmm7; - int node; + int node, nr_nodes; - for (node=0; node < NR_CPUS; node++) { + /* Read the number of nodes from the first Northbridge. */ + nr_nodes = ((pci_conf_read32(0, 0x18, 0x0, 0x60)>>4)&0x07)+1; + for (node = 0; node < nr_nodes; node++) { /* PMM7: bus=0, dev=0x18+node, function=0x3, register=0x87. */ pmm7 = pci_conf_read8(0, 0x18+node, 0x3, 0x87); /* Invalid read means we've updated every Northbridge. */