ocxl: Assign a register set to a Logical Partition

Platform specific function to assign a register set to a Logical Partition.
The "ibm,mmio-atsd" property, provided by the firmware, contains the 16
base ATSD physical addresses (ATSD0 through ATSD15) of the set of MMIO
registers (XTS MMIO ATSDx LPARID/AVA/launch/status register).

For the time being, the ATSD0 set of registers is used by default.
Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201125155013.39955-2-clombard@linux.vnet.ibm.com

arch/powerpc/include/asm/pnv-ocxl.h

@@ -28,4 +28,7 @@ int pnv_ocxl_spa_setup(struct pci_dev *dev, void *spa_mem, int PE_mask, void **p
 void pnv_ocxl_spa_release(void *platform_data);
 int pnv_ocxl_spa_remove_pe_from_cache(void *platform_data, int pe_handle);
 
+int pnv_ocxl_map_lpar(struct pci_dev *dev, uint64_t lparid,
+		      uint64_t lpcr, void __iomem **arva);
+void pnv_ocxl_unmap_lpar(void __iomem *arva);
 #endif /* _ASM_PNV_OCXL_H */

arch/powerpc/platforms/powernv/ocxl.c

@@ -483,3 +483,48 @@ int pnv_ocxl_spa_remove_pe_from_cache(void *platform_data, int pe_handle)
 	return rc;
 }
 EXPORT_SYMBOL_GPL(pnv_ocxl_spa_remove_pe_from_cache);
+
+int pnv_ocxl_map_lpar(struct pci_dev *dev, uint64_t lparid,
+		      uint64_t lpcr, void __iomem **arva)
+{
+	struct pci_controller *hose = pci_bus_to_host(dev->bus);
+	struct pnv_phb *phb = hose->private_data;
+	u64 mmio_atsd;
+	int rc;
+
+	/* ATSD physical address.
+	 * ATSD LAUNCH register: write access initiates a shoot down to
+	 * initiate the TLB Invalidate command.
+	 */
+	rc = of_property_read_u64_index(hose->dn, "ibm,mmio-atsd",
+					0, &mmio_atsd);
+	if (rc) {
+		dev_info(&dev->dev, "No available ATSD found\n");
+		return rc;
+	}
+
+	/* Assign a register set to a Logical Partition and MMIO ATSD
+	 * LPARID register to the required value.
+	 */
+	rc = opal_npu_map_lpar(phb->opal_id, pci_dev_id(dev),
+			       lparid, lpcr);
+	if (rc) {
+		dev_err(&dev->dev, "Error mapping device to LPAR: %d\n", rc);
+		return rc;
+	}
+
+	*arva = ioremap(mmio_atsd, 24);
+	if (!(*arva)) {
+		dev_warn(&dev->dev, "ioremap failed - mmio_atsd: %#llx\n", mmio_atsd);
+		rc = -ENOMEM;
+	}
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(pnv_ocxl_map_lpar);
+
+void pnv_ocxl_unmap_lpar(void __iomem *arva)
+{
+	iounmap(arva);
+}
+EXPORT_SYMBOL_GPL(pnv_ocxl_unmap_lpar);