blob: c1453a2895a59d6df8536c713447c7204a34b33d [file] [log] [blame]
From: Alex Deucher <alexander.deucher@amd.com>
Date: Mon, 13 Jun 2016 15:37:34 -0400
Subject: drm/radeon: fix asic initialization for virtualized environments
commit 05082b8bbd1a0ffc74235449c4b8930a8c240f85 upstream.
When executing in a PCI passthrough based virtuzliation environment, the
hypervisor will usually attempt to send a PCIe bus reset signal to the
ASIC when the VM reboots. In this scenario, the card is not correctly
initialized, but we still consider it to be posted. Therefore, in a
passthrough based environemnt we should always post the card to guarantee
it is in a good state for driver initialization.
Ported from amdgpu commit:
amdgpu: fix asic initialization for virtualized environments
Cc: Andres Rodriguez <andres.rodriguez@amd.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/gpu/drm/radeon/radeon_device.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -350,10 +350,31 @@ void radeon_gtt_location(struct radeon_d
/*
* GPU helpers function.
*/
+
+/**
+ * radeon_device_is_virtual - check if we are running is a virtual environment
+ *
+ * Check if the asic has been passed through to a VM (all asics).
+ * Used at driver startup.
+ * Returns true if virtual or false if not.
+ */
+static bool radeon_device_is_virtual(void)
+{
+#ifdef CONFIG_X86
+ return boot_cpu_has(X86_FEATURE_HYPERVISOR);
+#else
+ return false;
+#endif
+}
+
bool radeon_card_posted(struct radeon_device *rdev)
{
uint32_t reg;
+ /* for pass through, always force asic_init */
+ if (radeon_device_is_virtual())
+ return false;
+
if (efi_enabled(EFI_BOOT) &&
rdev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE)
return false;