ACPI: OSL: Change the type of acpi_os_map_generic_address() return value

Modify acpi_os_map_generic_address() to return the pointer returned
by acpi_os_map_iomem() which represents the logical address
corresponding to the struct acpi_generic_address argument passed to
it or NULL if that address cannot be obtained (for example, the
argument does not represent an address in system memory or it could
not be mapped by the OS).

Among other things, that will allow the ACPI OS layer to pass the
logical addresses of the FADT GPE blocks 0 and 1 to ACPICA going
forward.

Signed-off-by: Rafael J. Wysocki <[e-mail]>

drivers/acpi/apei/apei-base.c

···
 	rc = apei_check_gar(reg, &address, &access_bit_width);
 	if (rc)
 		return rc;
-	return acpi_os_map_generic_address(reg);
+
+	if (!acpi_os_map_generic_address(reg))
+		return -ENXIO;
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(apei_map_generic_address);
 

drivers/acpi/osl.c

···
 }
 EXPORT_SYMBOL_GPL(acpi_os_unmap_memory);
 
-int acpi_os_map_generic_address(struct acpi_generic_address *gas)
+void __iomem *acpi_os_map_generic_address(struct acpi_generic_address *gas)
 {
 	u64 addr;
-	void __iomem *virt;
 
 	if (gas->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
-		return 0;
+		return NULL;
 
 	/* Handle possible alignment issues */
 	memcpy(&addr, &gas->address, sizeof(addr));
 	if (!addr || !gas->bit_width)
-		return -EINVAL;
+		return NULL;
 
-	virt = acpi_os_map_iomem(addr, gas->bit_width / 8);
-	if (!virt)
-		return -EIO;
-
-	return 0;
+	return acpi_os_map_iomem(addr, gas->bit_width / 8);
 }
 EXPORT_SYMBOL(acpi_os_map_generic_address);
 
···
 		 * Use acpi_os_map_generic_address to pre-map the reset
 		 * register if it's in system memory.
 		 */
-		int rv;
+		void *rv;
 
 		rv = acpi_os_map_generic_address(&acpi_gbl_FADT.reset_register);
-		pr_debug(PREFIX "%s: map reset_reg status %d\n", __func__, rv);
+		pr_debug(PREFIX "%s: map reset_reg %s\n", __func__,
+			 rv ? "successful" : "failed");
 	}
 	acpi_os_initialized = true;
 

include/acpi/acpi_io.h

···
 void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size);
 void __iomem *acpi_os_get_iomem(acpi_physical_address phys, unsigned int size);
 
-int acpi_os_map_generic_address(struct acpi_generic_address *addr);
+void __iomem *acpi_os_map_generic_address(struct acpi_generic_address *addr);
 void acpi_os_unmap_generic_address(struct acpi_generic_address *addr);
 
 #endif