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authorBjorn Helgaas <bhelgaas@google.com>2017-06-19 15:26:57 -0500
committerBjorn Helgaas <bhelgaas@google.com>2017-07-02 18:47:15 -0500
commit575a144e7b3006c1b583ccecc4ede8b180d00d0c (patch)
tree3fb8d4ebafd55b6376f0aa9a6e2cb5206132ab84 /drivers/pci
parent769b461fc0c0451bacf75826d5830fc07c5a57e4 (diff)
downloadlinux-575a144e7b3006c1b583ccecc4ede8b180d00d0c.tar.bz2
PCI: vmd: Correct comment: VMD domains start at 0x10000, not 0x1000
VMD domains are allocated starting at 0x10000, not 0x1000 as the comment said. Correct the comment and add a reference to the ACPI spec for _SEG. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Keith Busch <keith.busch@intel.com>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/host/vmd.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/pci/host/vmd.c b/drivers/pci/host/vmd.c
index e27ad2a3bd33..53aa1d4b17e8 100644
--- a/drivers/pci/host/vmd.c
+++ b/drivers/pci/host/vmd.c
@@ -539,7 +539,10 @@ static void vmd_detach_resources(struct vmd_dev *vmd)
}
/*
- * VMD domains start at 0x1000 to not clash with ACPI _SEG domains.
+ * VMD domains start at 0x10000 to not clash with ACPI _SEG domains.
+ * Per ACPI r6.0, sec 6.5.6, _SEG returns an integer, of which the lower
+ * 16 bits are the PCI Segment Group (domain) number. Other bits are
+ * currently reserved.
*/
static int vmd_find_free_domain(void)
{