From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
The static MCFG table tells us the base of ECAM space, but it does not
reserve the space -- the reservation should be done via a device in the
ACPI namespace whose _CRS includes the ECAM region.
Add pci_ecam_verify_reservation() to check whether the ECAM space is
reserved by an ACPI namespace device. If it is, emit a message showing
which device reserves it. If not, emit a "[Firmware Bug]" warning.
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/pci/ecam.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/drivers/pci/ecam.c b/drivers/pci/ecam.c
index 43ed08d..3805122 100644
--- a/drivers/pci/ecam.c
+++ b/drivers/pci/ecam.c
@@ -14,6 +14,7 @@
* version 2 (GPLv2) along with this source code.
*/
+#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/kernel.h>
@@ -29,6 +30,24 @@
*/
static const bool per_bus_mapping = !IS_ENABLED(CONFIG_64BIT);
+static void pci_ecam_verify_reservation(struct device *dev,
+ struct resource *ecam)
+{
+#ifdef CONFIG_ACPI
+ struct acpi_device *adev;
+
+ adev = acpi_resource_consumer(ecam);
+ if (!adev) {
+ dev_warn(dev, FW_BUG "ECAM area %pR not reserved in ACPI namespace\n",
+ ecam);
+ return;
+ }
+
+ dev_info(dev, "ECAM area %pR reserved by %s\n", ecam,
+ dev_name(&adev->dev));
+#endif
+}
+
/*
* Create a PCI config space window
* - reserve mem region
@@ -51,6 +70,8 @@ struct pci_config_window *pci_ecam_create(struct device *dev,
if (!cfg)
return ERR_PTR(-ENOMEM);
+ pci_ecam_verify_reservation(dev, cfgres);
+
cfg->parent = dev;
cfg->ops = ops;
cfg->busr.start = busr->start;
--
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