[PATCH RESEND 21/27] drivers:hv: Allow for MMIO claims that span ACPI _CRS records

From: K. Y. Srinivasan
Date: Fri Dec 11 2015 - 21:49:27 EST


From: Jake Oshins <jakeo@xxxxxxxxxxxxx>

This patch makes 16GB GPUs work in Hyper-V VMs, since, for
compatibility reasons, the Hyper-V BIOS lists MMIO ranges in 2GB
chunks in its root bus's _CRS object.

Signed-off-by: Jake Oshins <jakeo@xxxxxxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
---
drivers/hv/vmbus_drv.c | 16 ++++++++++++++++
1 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index f123bca..328e4c3 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1063,12 +1063,28 @@ static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
new_res->start = start;
new_res->end = end;

+ /*
+ * Stick ranges from higher in address space at the front of the list.
+ * If two ranges are adjacent, merge them.
+ */
do {
if (!*old_res) {
*old_res = new_res;
break;
}

+ if (((*old_res)->end + 1) == new_res->start) {
+ (*old_res)->end = new_res->end;
+ kfree(new_res);
+ break;
+ }
+
+ if ((*old_res)->start == new_res->end + 1) {
+ (*old_res)->start = new_res->start;
+ kfree(new_res);
+ break;
+ }
+
if ((*old_res)->end < new_res->start) {
new_res->sibling = *old_res;
if (prev_res)
--
1.7.4.1

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