Commit 08b1c196 authored by Bjorn Helgaas's avatar Bjorn Helgaas Committed by Bjorn Helgaas
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arm64: PCI: Search ACPI namespace to ensure ECAM space is reserved 



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.

Use acpi_resource_consumer() 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: default avatarBjorn Helgaas <bhelgaas@google.com>
Acked-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
parent dfd1972c

arch/arm64/kernel/pci.c

+11 −1
Original line number Original line Diff line number Diff line
@@ -124,8 +124,9 @@ pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root) 
	struct device *dev = &root->device->dev;

	struct device *dev = &root->device->dev;

	struct resource *bus_res = &root->secondary;

	struct resource *bus_res = &root->secondary;

	u16 seg = root->segment;

	u16 seg = root->segment;

	struct pci_config_window *cfg;

	struct resource cfgres;

	struct resource cfgres;

	struct acpi_device *adev;

	struct pci_config_window *cfg;

	unsigned int bsz;

	unsigned int bsz;





	/* Use address from _CBA if present, otherwise lookup MCFG */

	/* Use address from _CBA if present, otherwise lookup MCFG */
@@ -141,6 +142,15 @@ pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root) 
	cfgres.start = root->mcfg_addr + bus_res->start * bsz;

	cfgres.start = root->mcfg_addr + bus_res->start * bsz;

	cfgres.end = cfgres.start + resource_size(bus_res) * bsz - 1;

	cfgres.end = cfgres.start + resource_size(bus_res) * bsz - 1;

	cfgres.flags = IORESOURCE_MEM;

	cfgres.flags = IORESOURCE_MEM;



	adev = acpi_resource_consumer(&cfgres);

	if (adev)

		dev_info(dev, "ECAM area %pR reserved by %s\n", &cfgres,

			 dev_name(&adev->dev));

	else

		dev_warn(dev, FW_BUG "ECAM area %pR not reserved in ACPI namespace\n",

			 &cfgres);



	cfg = pci_ecam_create(dev, &cfgres, bus_res, &pci_generic_ecam_ops);

	cfg = pci_ecam_create(dev, &cfgres, bus_res, &pci_generic_ecam_ops);

	if (IS_ERR(cfg)) {

	if (IS_ERR(cfg)) {

		dev_err(dev, "%04x:%pR error %ld mapping ECAM\n", seg, bus_res,

		dev_err(dev, "%04x:%pR error %ld mapping ECAM\n", seg, bus_res,

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