[PATCH 4/4] platform/x86/intel/vsec: Plumb ACPI PMT discovery tables through vsec

David E. Box
2026-01-07T00:22:12Z

Newer platform will optionally expose PMT discovery via ACPI instead of PCI
BARs. Add a generic discovery source flag and carry ACPI discovery entries
alongside the existing PCI resource path so PMT clients can consume either.

Changes:
- Add enum intel_vsec_disc_source { _PCI, _ACPI }.
- Extend intel_vsec_platform_info and intel_vsec_device with source enum
and ACPI discovery table pointer/
- When src==ACPI, skip BAR resource setup and copy the ACPI discovery
entries into the aux device.

No user-visible behavior change yet; this only wires ACPI data through vsec
in preparation for ACPI-enumerated PMT clients.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>
---
drivers/platform/x86/intel/vsec.c | 16 ++++++++++++++++
include/linux/intel_vsec.h | 20 +++++++++++++++++++-
2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/x86/intel/vsec.c b/drivers/platform/x86/intel/vsec.c
index 42471fd609b1..705672dcdd11 100644
--- a/drivers/platform/x86/intel/vsec.c
+++ b/drivers/platform/x86/intel/vsec.c
@@ -109,6 +109,7 @@ static void intel_vsec_dev_release(struct device *dev)

ida_free(intel_vsec_dev->ida, intel_vsec_dev->auxdev.id);

+ kfree(intel_vsec_dev->acpi_disc);
kfree(intel_vsec_dev->resource);
kfree(intel_vsec_dev);
}
@@ -321,6 +322,10 @@ static int intel_vsec_add_dev(struct device *dev, struct intel_vsec_header *head
* auxiliary device driver.
*/
for (i = 0, tmp = res; i < header->num_entries; i++, tmp++) {
+ /* This check doesn't apply to ACPI based discovery */
+ if (info->src == INTEL_VSEC_DISC_ACPI)
+ break;
+
tmp->start = base_addr + header->offset + i * (header->entry_size * sizeof(u32));
tmp->end = tmp->start + (header->entry_size * sizeof(u32)) - 1;
tmp->flags = IORESOURCE_MEM;
@@ -339,6 +344,17 @@ static int intel_vsec_add_dev(struct device *dev, struct intel_vsec_header *head
intel_vsec_dev->base_addr = info->base_addr;
intel_vsec_dev->priv_data = info->priv_data;
intel_vsec_dev->cap_id = cap_id;
+ intel_vsec_dev->src = info->src;
+
+ if (info->src == INTEL_VSEC_DISC_ACPI) {
+ size_t bytes;
+
+ bytes = intel_vsec_dev->num_resources * sizeof(info->acpi_disc[0]);
+
+ intel_vsec_dev->acpi_disc = kmemdup(info->acpi_disc, bytes, GFP_KERNEL);
+ if (!intel_vsec_dev->acpi_disc)
+ return -ENOMEM;
+ }

if (header->id == VSEC_ID_SDSI)
intel_vsec_dev->ida = &intel_vsec_sdsi_ida;
diff --git a/include/linux/intel_vsec.h b/include/linux/intel_vsec.h
index 931ff42361a9..9d7795480c49 100644
--- a/include/linux/intel_vsec.h
+++ b/include/linux/intel_vsec.h
@@ -32,6 +32,11 @@
struct resource;
struct pci_dev;

+enum intel_vsec_disc_source {
+ INTEL_VSEC_DISC_PCI, /* PCI, default */
+ INTEL_VSEC_DISC_ACPI, /* ACPI */
+};
+
enum intel_vsec_id {
VSEC_ID_TELEMETRY = 2,
VSEC_ID_WATCHER = 3,
@@ -102,6 +107,10 @@ struct vsec_feature_dependency {
* @parent: parent device in the auxbus chain
* @headers: list of headers to define the PMT client devices to create
* @deps: array of feature dependencies
+ * @acpi_disc: ACPI discovery tables, each entry is two QWORDs
+ * in little-endian format as defined by the PMT ACPI spec.
+ * Valid only when @provider == INTEL_VSEC_PROV_ACPI.
+ * @src: source of discovery table data
* @priv_data: private data, usable by parent devices, currently a callback
* @caps: bitmask of PMT capabilities for the given headers
* @quirks: bitmask of VSEC device quirks
@@ -112,6 +121,8 @@ struct intel_vsec_platform_info {
struct device *parent;
struct intel_vsec_header **headers;
const struct vsec_feature_dependency *deps;
+ u32 (*acpi_disc)[4];
+ enum intel_vsec_disc_source src;
void *priv_data;
unsigned long caps;
unsigned long quirks;
@@ -123,7 +134,12 @@ struct intel_vsec_platform_info {
* struct intel_sec_device - Auxbus specific device information
* @auxdev: auxbus device struct for auxbus access
* @dev: struct device associated with the device
- * @resource: any resources shared by the parent
+ * @resource: PCI discovery resources (BAR windows), one per discovery
+ * instance. Valid only when @src == INTEL_VSEC_PROV_PCI
+ * @acpi_disc: ACPI discovery tables, each entry is two QWORDs
+ * in little-endian format as defined by the PMT ACPI spec.
+ * Valid only when @src == INTEL_VSEC_PROV_ACPI.
+ * @src: source of discovery table data
* @ida: id reference
* @num_resources: number of resources
* @id: xarray id
@@ -136,6 +152,8 @@ struct intel_vsec_device {
struct auxiliary_device auxdev;
struct device *dev;
struct resource *resource;
+ u32 (*acpi_disc)[4];
+ enum intel_vsec_disc_source src;
struct ida *ida;
int num_resources;
int id; /* xa */
--
2.43.0