platform/x86/intel/pmt: Use PMT callbacks

PMT providers may require device specific actions before their telemetry
may be read. If the read_telem() is assigned, call it instead of
memcpy_fromio() and return. Since this needs to be done in multiple
locations, add pmt_telem_read_mmio() as a wrapper function to perform this
and any other needed checks.
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Link: https://lore.kernel.org/r/20240725122346.4063913-4-michael.j.ruhl@intel.comSigned-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/x86/intel/pmt/class.c

@@ -58,6 +58,22 @@ pmt_memcpy64_fromio(void *to, const u64 __iomem *from, size_t count)
 	return count;
 }
 
+int pmt_telem_read_mmio(struct pci_dev *pdev, struct pmt_callbacks *cb, u32 guid, void *buf,
+			void __iomem *addr, u32 count)
+{
+	if (cb && cb->read_telem)
+		return cb->read_telem(pdev, guid, buf, count);
+
+	if (guid == GUID_SPR_PUNIT)
+		/* PUNIT on SPR only supports aligned 64-bit read */
+		return pmt_memcpy64_fromio(buf, addr, count);
+
+	memcpy_fromio(buf, addr, count);
+
+	return count;
+}
+EXPORT_SYMBOL_NS_GPL(pmt_telem_read_mmio, INTEL_PMT);
+
 /*
  * sysfs
  */
@@ -79,11 +95,8 @@ intel_pmt_read(struct file *filp, struct kobject *kobj,
 	if (count > entry->size - off)
 		count = entry->size - off;
 
-	if (entry->guid == GUID_SPR_PUNIT)
-		/* PUNIT on SPR only supports aligned 64-bit read */
-		count = pmt_memcpy64_fromio(buf, entry->base + off, count);
-	else
-		memcpy_fromio(buf, entry->base + off, count);
+	count = pmt_telem_read_mmio(entry->ep->pcidev, entry->cb, entry->header.guid, buf,
+				    entry->base + off, count);
 
 	return count;
 }
@@ -239,6 +252,7 @@ static int intel_pmt_populate_entry(struct intel_pmt_entry *entry,
 
 	entry->guid = header->guid;
 	entry->size = header->size;
+	entry->cb = ivdev->priv_data;
 
 	return 0;
 }
@@ -300,7 +314,7 @@ static int intel_pmt_dev_register(struct intel_pmt_entry *entry,
 		goto fail_ioremap;
 
 	if (ns->pmt_add_endpoint) {
-		ret = ns->pmt_add_endpoint(entry, ivdev->pcidev);
+		ret = ns->pmt_add_endpoint(ivdev, entry);
 		if (ret)
 			goto fail_add_endpoint;
 	}

drivers/platform/x86/intel/pmt/class.h

@@ -24,6 +24,7 @@ struct pci_dev;
 struct telem_endpoint {
 	struct pci_dev		*pcidev;
 	struct telem_header	header;
+	struct pmt_callbacks	*cb;
 	void __iomem		*base;
 	bool			present;
 	struct kref		kref;
@@ -43,6 +44,7 @@ struct intel_pmt_entry {
 	struct kobject		*kobj;
 	void __iomem		*disc_table;
 	void __iomem		*base;
+	struct pmt_callbacks	*cb;
 	unsigned long		base_addr;
 	size_t			size;
 	u32			guid;
@@ -55,10 +57,12 @@ struct intel_pmt_namespace {
 	const struct attribute_group *attr_grp;
 	int (*pmt_header_decode)(struct intel_pmt_entry *entry,
 				 struct device *dev);
-	int (*pmt_add_endpoint)(struct intel_pmt_entry *entry,
-				struct pci_dev *pdev);
+	int (*pmt_add_endpoint)(struct intel_vsec_device *ivdev,
+				struct intel_pmt_entry *entry);
 };
 
+int pmt_telem_read_mmio(struct pci_dev *pdev, struct pmt_callbacks *cb, u32 guid, void *buf,
+			void __iomem *addr, u32 count);
 bool intel_pmt_is_early_client_hw(struct device *dev);
 int intel_pmt_dev_create(struct intel_pmt_entry *entry,
 			 struct intel_pmt_namespace *ns,

drivers/platform/x86/intel/pmt/telemetry.c

@@ -93,8 +93,8 @@ static int pmt_telem_header_decode(struct intel_pmt_entry *entry,
 	return 0;
 }
 
-static int pmt_telem_add_endpoint(struct intel_pmt_entry *entry,
-				  struct pci_dev *pdev)
+static int pmt_telem_add_endpoint(struct intel_vsec_device *ivdev,
+				  struct intel_pmt_entry *entry)
 {
 	struct telem_endpoint *ep;
 
@@ -104,13 +104,14 @@ static int pmt_telem_add_endpoint(struct intel_pmt_entry *entry,
 		return -ENOMEM;
 
 	ep = entry->ep;
-	ep->pcidev = pdev;
+	ep->pcidev = ivdev->pcidev;
 	ep->header.access_type = entry->header.access_type;
 	ep->header.guid = entry->header.guid;
 	ep->header.base_offset = entry->header.base_offset;
 	ep->header.size = entry->header.size;
 	ep->base = entry->base;
 	ep->present = true;
+	ep->cb = ivdev->priv_data;
 
 	kref_init(&ep->kref);
 
@@ -218,7 +219,8 @@ int pmt_telem_read(struct telem_endpoint *ep, u32 id, u64 *data, u32 count)
 	if (offset + NUM_BYTES_QWORD(count) > size)
 		return -EINVAL;
 
-	memcpy_fromio(data, ep->base + offset, NUM_BYTES_QWORD(count));
+	pmt_telem_read_mmio(ep->pcidev, ep->cb, ep->header.guid, data, ep->base + offset,
+			    NUM_BYTES_QWORD(count));
 
 	return ep->present ? 0 : -EPIPE;
 }