4 files changed, 151 insertions, 0 deletions

diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index b1aacfc62b1f..90265ab4437a 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -50,6 +50,7 @@ acpi-$(CONFIG_ACPI_REDUCED_HARDWARE_ONLY) += evged.o
 acpi-y                          += sysfs.o
 acpi-y                          += property.o
 acpi-$(CONFIG_X86)              += acpi_cmos_rtc.o
+acpi-$(CONFIG_X86)              += x86/apple.o
 acpi-$(CONFIG_X86)              += x86/utils.o
 acpi-$(CONFIG_DEBUG_FS)         += debugfs.o
 acpi-$(CONFIG_ACPI_NUMA)        += numa.o
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 58dd7ab3c653..ee066d74f5bf 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -233,6 +233,12 @@ static inline void suspend_nvs_restore(void) {}
 void acpi_init_properties(struct acpi_device *adev);
 void acpi_free_properties(struct acpi_device *adev);
 
+#ifdef CONFIG_X86
+void acpi_extract_apple_properties(struct acpi_device *adev);
+#else
+static inline void acpi_extract_apple_properties(struct acpi_device *adev) {}
+#endif
+
 /*--------------------------------------------------------------------------
                                 Watchdog
   -------------------------------------------------------------------------- */
diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 116bfc1937b5..fc1bb083f5f0 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -376,6 +376,9 @@ void acpi_init_properties(struct acpi_device *adev)
         if (acpi_of && !adev->flags.of_compatible_ok)
                 acpi_handle_info(adev->handle,
                          ACPI_DT_NAMESPACE_HID " requires 'compatible' property\n");
+
+        if (!adev->data.pointer)
+                acpi_extract_apple_properties(adev);
 }
 
 static void acpi_destroy_nondev_subnodes(struct list_head *list)
diff --git a/drivers/acpi/x86/apple.c b/drivers/acpi/x86/apple.c
new file mode 100644
index 000000000000..51b4cf9f25da
--- /dev/null
+++ b/drivers/acpi/x86/apple.c
@@ -0,0 +1,141 @@
+/*
+ * apple.c - Apple ACPI quirks
+ * Copyright (C) 2017 Lukas Wunner <lukas@wunner.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2) as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/bitmap.h>
+#include <linux/platform_data/x86/apple.h>
+#include <linux/uuid.h>
+
+/* Apple _DSM device properties GUID */
+static const guid_t apple_prp_guid =
+        GUID_INIT(0xa0b5b7c6, 0x1318, 0x441c,
+                  0xb0, 0xc9, 0xfe, 0x69, 0x5e, 0xaf, 0x94, 0x9b);
+
+/**
+ * acpi_extract_apple_properties - retrieve and convert Apple _DSM properties
+ * @adev: ACPI device for which to retrieve the properties
+ *
+ * Invoke Apple's custom _DSM once to check the protocol version and once more
+ * to retrieve the properties.  They are marshalled up in a single package as
+ * alternating key/value elements, unlike _DSD which stores them as a package
+ * of 2-element packages.  Convert to _DSD format and make them available under
+ * the primary fwnode.
+ */
+void acpi_extract_apple_properties(struct acpi_device *adev)
+{
+        unsigned int i, j = 0, newsize = 0, numprops, numvalid;
+        union acpi_object *props, *newprops;
+        unsigned long *valid = NULL;
+        void *free_space;
+
+        if (!x86_apple_machine)
+                return;
+
+        props = acpi_evaluate_dsm_typed(adev->handle, &apple_prp_guid, 1, 0,
+                                        NULL, ACPI_TYPE_BUFFER);
+        if (!props)
+                return;
+
+        if (!props->buffer.length)
+                goto out_free;
+
+        if (props->buffer.pointer[0] != 3) {
+                acpi_handle_info(adev->handle, FW_INFO
+                                 "unsupported properties version %*ph\n",
+                                 props->buffer.length, props->buffer.pointer);
+                goto out_free;
+        }
+
+        ACPI_FREE(props);
+        props = acpi_evaluate_dsm_typed(adev->handle, &apple_prp_guid, 1, 1,
+                                        NULL, ACPI_TYPE_PACKAGE);
+        if (!props)
+                return;
+
+        numprops = props->package.count / 2;
+        if (!numprops)
+                goto out_free;
+
+        valid = kcalloc(BITS_TO_LONGS(numprops), sizeof(long), GFP_KERNEL);
+        if (!valid)
+                goto out_free;
+
+        /* newsize = key length + value length of each tuple */
+        for (i = 0; i < numprops; i++) {
+                union acpi_object *key = &props->package.elements[i * 2];
+                union acpi_object *val = &props->package.elements[i * 2 + 1];
+
+                if ( key->type != ACPI_TYPE_STRING ||
+                    (val->type != ACPI_TYPE_INTEGER &&
+                     val->type != ACPI_TYPE_BUFFER))
+                        continue; /* skip invalid properties */
+
+                __set_bit(i, valid);
+                newsize += key->string.length + 1;
+                if ( val->type == ACPI_TYPE_BUFFER)
+                        newsize += val->buffer.length;
+        }
+
+        numvalid = bitmap_weight(valid, numprops);
+        if (numprops > numvalid)
+                acpi_handle_info(adev->handle, FW_INFO
+                                 "skipped %u properties: wrong type\n",
+                                 numprops - numvalid);
+        if (numvalid == 0)
+                goto out_free;
+
+        /* newsize += top-level package + 3 objects for each key/value tuple */
+        newsize += (1 + 3 * numvalid) * sizeof(union acpi_object);
+        newprops = ACPI_ALLOCATE_ZEROED(newsize);
+        if (!newprops)
+                goto out_free;
+
+        /* layout: top-level package | packages | key/value tuples | strings */
+        newprops->type = ACPI_TYPE_PACKAGE;
+        newprops->package.count = numvalid;
+        newprops->package.elements = &newprops[1];
+        free_space = &newprops[1 + 3 * numvalid];
+
+        for_each_set_bit(i, valid, numprops) {
+                union acpi_object *key = &props->package.elements[i * 2];
+                union acpi_object *val = &props->package.elements[i * 2 + 1];
+                unsigned int k = 1 + numvalid + j * 2; /* index into newprops */
+                unsigned int v = k + 1;
+
+                newprops[1 + j].type = ACPI_TYPE_PACKAGE;
+                newprops[1 + j].package.count = 2;
+                newprops[1 + j].package.elements = &newprops[k];
+
+                newprops[k].type = ACPI_TYPE_STRING;
+                newprops[k].string.length = key->string.length;
+                newprops[k].string.pointer = free_space;
+                memcpy(free_space, key->string.pointer, key->string.length);
+                free_space += key->string.length + 1;
+
+                newprops[v].type = val->type;
+                if (val->type == ACPI_TYPE_INTEGER) {
+                        newprops[v].integer.value = val->integer.value;
+                } else {
+                        newprops[v].buffer.length = val->buffer.length;
+                        newprops[v].buffer.pointer = free_space;
+                        memcpy(free_space, val->buffer.pointer,
+                               val->buffer.length);
+                        free_space += val->buffer.length;
+                }
+                j++; /* count valid properties */
+        }
+        WARN_ON(free_space != (void *)newprops + newsize);
+
+        adev->data.properties = newprops;
+        adev->data.pointer = newprops;
+
+out_free:
+        ACPI_FREE(props);
+        kfree(valid);
+}