platform/x86/intel/vsec: Plumb ACPI PMT discovery tables through vsec

Some platforms 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>
Link: https://patch.msgid.link/20260313015202.3660072-7-david.e.box@linux.intel.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

diff --git a/drivers/platform/x86/intel/vsec.c b/drivers/platform/x86/intel/vsec.c
index 34b2c19ecff05c4f75aca3acfd296c77d4395e1f..7d5dbc1c1d05a8be698a2262eb6e932c90a085e1 100644 (file)
--- a/drivers/platform/x86/intel/vsec.c
+++ b/drivers/platform/x86/intel/vsec.c
@@ -24,7 +24,9 @@
 #include <linux/intel_vsec.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/overflow.h>
 #include <linux/pci.h>
+#include <linux/string.h>
 #include <linux/types.h>
 
 #define PMT_XA_START                   0
@@ -109,6 +111,7 @@ 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);
 }
@@ -320,6 +323,13 @@ 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++) {
+               /*
+                * Skip resource mapping check for ACPI-based discovery
+                * since those tables are read from _DSD, not MMIO.
+                */
+               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;
@@ -338,6 +348,19 @@ 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;
+
+               if (check_mul_overflow(intel_vsec_dev->num_resources,
+                                      sizeof(*info->acpi_disc), &bytes))
+                       return -EOVERFLOW;
+
+               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 4eecb2a6bac4ff2651521a5578e0eb71a1ba3918..1fe5665a9d02a849d066bccf72d087fd6507eb10 100644 (file)
--- a/include/linux/intel_vsec.h
+++ b/include/linux/intel_vsec.h
@@ -33,6 +33,11 @@ struct device;
 struct pci_dev;
 struct resource;
 
+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,
@@ -103,6 +108,10 @@ 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_DISC_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
@@ -113,6 +122,8 @@ 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;
@@ -124,7 +135,12 @@ struct intel_vsec_platform_info {
  * struct intel_vsec_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_DISC_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_DISC_ACPI.
+ * @src:           source of discovery table data
  * @ida:           id reference
  * @num_resources: number of resources
  * @id:            xarray id
@@ -138,6 +154,8 @@ 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 */