在 2020/1/5 20:53, Michael S. Tsirkin 写道:
On Sun, Jan 05, 2020 at 07:34:01AM -0500, Michael S. Tsirkin wrote:On Thu, Dec 19, 2019 at 02:47:59PM +0800, Heyi Guo wrote:According to ACPI spec, _ADR should be used for device which is on a bus that has a standard enumeration algorithm. It does not make sense to have a _ADR object for devices which already have _HID and will be enumerated by OSPM. Signed-off-by: Heyi Guo <guoh...@huawei.com>Are you sure? I would think this depends on the ID and the device really. E.g. PCI devices all are expected to have _ADR and some of them have a _HID.To clarify I am not commenting on patches. The spec says this: 6.1.5 _HID (Hardware ID) This object is used to supply OSPM with the device’s PNP ID or ACPI ID. 1 When describing a platform, use of any _HID objects is optional. However, a _HID object must be used to describe any device that will be enumerated by OSPM. OSPM only enumerates a device when no bus enumerator can detect the device ID. For example, devices on an ISA bus are enumerated by OSPM. Use the _ADR object to describe devices enumerated by bus enumerators other than OSPM. Note: "detect the device ID" not "enumerate the device" which I think means there's a driver matching this vendor/device ID. So it seems fine to have _ADR so device is enumerated, and still have _HID e.g. so ACPI driver can be loaded as fallback if there's no bus driver. Note I am not saying the patch itself is not correct. Maybe these devices are not on any standard bus and that is why they should not have _ADR? I have not looked. I am just saying that spec does not seem to imply _HID and _ADR can't coexist.
More reading on the spec, I found a statement as below (https://uefi.org/sites/default/files/resources/ACPI_6_3_May16.pdf, section 6.1, on top of page 343):
A device object must contain either an _HID object or an _ADR object, but should not contain both
So I think it is at least not recomended to use both _HID and _ADR in a single device object.
Thanks, Heyi
CC Corey who added a device with both HID and ADR to x86 recenly. Apropos Corey, why was HID APP0005 chosen?--- Cc: Shannon Zhao <shannon.zha...@gmail.com> Cc: Peter Maydell <peter.mayd...@linaro.org> Cc: "Michael S. Tsirkin" <m...@redhat.com> Cc: Igor Mammedov <imamm...@redhat.com> Cc: qemu-...@nongnu.org Cc: qemu-devel@nongnu.org --- hw/arm/virt-acpi-build.c | 8 -------- tests/data/acpi/virt/DSDT | Bin 18449 -> 18426 bytes tests/data/acpi/virt/DSDT.memhp | Bin 19786 -> 19763 bytes tests/data/acpi/virt/DSDT.numamem | Bin 18449 -> 18426 bytes 4 files changed, 8 deletions(-) diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c index 9f4c7d1889..be752c0ad8 100644 --- a/hw/arm/virt-acpi-build.c +++ b/hw/arm/virt-acpi-build.c @@ -78,11 +78,6 @@ static void acpi_dsdt_add_uart(Aml *scope, const MemMapEntry *uart_memmap, AML_EXCLUSIVE, &uart_irq, 1)); aml_append(dev, aml_name_decl("_CRS", crs));- /* The _ADR entry is used to link this device to the UART described- * in the SPCR table, i.e. SPCR.base_address.address == _ADR. - */ - aml_append(dev, aml_name_decl("_ADR", aml_int(uart_memmap->base))); - aml_append(scope, dev); }@@ -170,7 +165,6 @@ static void acpi_dsdt_add_pci(Aml *scope, const MemMapEntry *memmap,aml_append(dev, aml_name_decl("_CID", aml_string("PNP0A03"))); aml_append(dev, aml_name_decl("_SEG", aml_int(0))); aml_append(dev, aml_name_decl("_BBN", aml_int(0))); - aml_append(dev, aml_name_decl("_ADR", aml_int(0))); aml_append(dev, aml_name_decl("_UID", aml_string("PCI0"))); aml_append(dev, aml_name_decl("_STR", aml_unicode("PCIe 0 Device"))); aml_append(dev, aml_name_decl("_CCA", aml_int(1))); @@ -334,7 +328,6 @@ static void acpi_dsdt_add_gpio(Aml *scope, const MemMapEntry *gpio_memmap, { Aml *dev = aml_device("GPO0"); aml_append(dev, aml_name_decl("_HID", aml_string("ARMH0061"))); - aml_append(dev, aml_name_decl("_ADR", aml_int(0))); aml_append(dev, aml_name_decl("_UID", aml_int(0)));Aml *crs = aml_resource_template();@@ -364,7 +357,6 @@ static void acpi_dsdt_add_power_button(Aml *scope) { Aml *dev = aml_device(ACPI_POWER_BUTTON_DEVICE); aml_append(dev, aml_name_decl("_HID", aml_string("PNP0C0C"))); - aml_append(dev, aml_name_decl("_ADR", aml_int(0))); aml_append(dev, aml_name_decl("_UID", aml_int(0))); aml_append(scope, dev); } diff --git a/tests/data/acpi/virt/DSDT b/tests/data/acpi/virt/DSDTPlease do not include binary changes in acpi patches. See comment at the top of tests/bios-tables-test.c for documentation on how to update these. -- MST.
