arm: apple: Add RTKit support

Most Apple IOPs run a firmware that is based on what Apple calls
RTKit. RTKit implements a common mailbox protocol.  This code
provides an implementation of the AP side of this protocol,
providing a function to initialize RTKit-based firmwares as well
as a function to do a clean shutdown of this firmware.

Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested on: Macbook Air M1
Tested-by: Simon Glass <sjg@chromium.org>

diff --git a/arch/arm/include/asm/arch-apple/rtkit.h b/arch/arm/include/asm/arch-apple/rtkit.h
new file mode 100644 (file)
index 0000000..51f77f2
--- /dev/null
+++ b/arch/arm/include/asm/arch-apple/rtkit.h
@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2021 Mark Kettenis <kettenis@openbsd.org>
+ */
+
+#define APPLE_RTKIT_PWR_STATE_SLEEP    0x01
+#define APPLE_RTKIT_PWR_STATE_QUIESCED 0x10
+#define APPLE_RTKIT_PWR_STATE_ON       0x20
+
+int apple_rtkit_init(struct mbox_chan *);
+int apple_rtkit_shutdown(struct mbox_chan *, int);

diff --git a/arch/arm/mach-apple/Makefile b/arch/arm/mach-apple/Makefile
index e74a8c9df108c0daec33f22dbde040038cea47b4..52f30a777b2cc36c456ed7213a8a0362bd9e8d4a 100644 (file)
--- a/arch/arm/mach-apple/Makefile
+++ b/arch/arm/mach-apple/Makefile
@@ -2,3 +2,4 @@
 
 obj-y += board.o
 obj-y += lowlevel_init.o
+obj-y += rtkit.o

diff --git a/arch/arm/mach-apple/rtkit.c b/arch/arm/mach-apple/rtkit.c
new file mode 100644 (file)
index 0000000..dff475c
--- /dev/null
+++ b/arch/arm/mach-apple/rtkit.c
@@ -0,0 +1,231 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2021 Mark Kettenis <kettenis@openbsd.org>
+ * (C) Copyright 2021 Copyright The Asahi Linux Contributors
+ */
+
+#include <common.h>
+#include <mailbox.h>
+#include <malloc.h>
+
+#include <asm/arch/rtkit.h>
+#include <linux/apple-mailbox.h>
+#include <linux/bitfield.h>
+
+#define APPLE_RTKIT_EP_MGMT 0
+#define APPLE_RTKIT_EP_CRASHLOG        1
+#define APPLE_RTKIT_EP_SYSLOG 2
+#define APPLE_RTKIT_EP_DEBUG 3
+#define APPLE_RTKIT_EP_IOREPORT 4
+
+/* Messages for management endpoint. */
+#define APPLE_RTKIT_MGMT_TYPE GENMASK(59, 52)
+
+#define APPLE_RTKIT_MGMT_PWR_STATE GENMASK(15, 0)
+
+#define APPLE_RTKIT_MGMT_HELLO 1
+#define APPLE_RTKIT_MGMT_HELLO_REPLY 2
+#define APPLE_RTKIT_MGMT_HELLO_MINVER GENMASK(15, 0)
+#define APPLE_RTKIT_MGMT_HELLO_MAXVER GENMASK(31, 16)
+
+#define APPLE_RTKIT_MGMT_STARTEP 5
+#define APPLE_RTKIT_MGMT_STARTEP_EP GENMASK(39, 32)
+#define APPLE_RTKIT_MGMT_STARTEP_FLAG BIT(1)
+
+#define APPLE_RTKIT_MGMT_SET_IOP_PWR_STATE 6
+#define APPLE_RTKIT_MGMT_SET_IOP_PWR_STATE_ACK 7
+
+#define APPLE_RTKIT_MGMT_EPMAP 8
+#define APPLE_RTKIT_MGMT_EPMAP_LAST BIT(51)
+#define APPLE_RTKIT_MGMT_EPMAP_BASE GENMASK(34, 32)
+#define APPLE_RTKIT_MGMT_EPMAP_BITMAP GENMASK(31, 0)
+
+#define APPLE_RTKIT_MGMT_EPMAP_REPLY 8
+#define APPLE_RTKIT_MGMT_EPMAP_REPLY_MORE BIT(0)
+
+#define APPLE_RTKIT_MIN_SUPPORTED_VERSION 11
+#define APPLE_RTKIT_MAX_SUPPORTED_VERSION 12
+
+/* Messages for internal endpoints. */
+#define APPLE_RTKIT_BUFFER_REQUEST 1
+#define APPLE_RTKIT_BUFFER_REQUEST_SIZE GENMASK(51, 44)
+#define APPLE_RTKIT_BUFFER_REQUEST_IOVA GENMASK(41, 0)
+
+int apple_rtkit_init(struct mbox_chan *chan)
+{
+       struct apple_mbox_msg msg;
+       int endpoints[256];
+       int nendpoints = 0;
+       int endpoint;
+       int min_ver, max_ver, want_ver;
+       int msgtype, pwrstate;
+       u64 reply;
+       u32 bitmap, base;
+       int i, ret;
+
+       /* Wakup the IOP. */
+       msg.msg0 = FIELD_PREP(APPLE_RTKIT_MGMT_TYPE, APPLE_RTKIT_MGMT_SET_IOP_PWR_STATE) |
+               FIELD_PREP(APPLE_RTKIT_MGMT_PWR_STATE, APPLE_RTKIT_PWR_STATE_ON);
+       msg.msg1 = APPLE_RTKIT_EP_MGMT;
+       ret = mbox_send(chan, &msg);
+       if (ret < 0)
+               return ret;
+
+       /* Wait for protocol version negotiation message. */
+       ret = mbox_recv(chan, &msg, 10000);
+       if (ret < 0)
+               return ret;
+
+       endpoint = msg.msg1;
+       msgtype = FIELD_GET(APPLE_RTKIT_MGMT_TYPE, msg.msg0);
+       if (endpoint != APPLE_RTKIT_EP_MGMT) {
+               printf("%s: unexpected endpoint %d\n", __func__, endpoint);
+               return -EINVAL;
+       }
+       if (msgtype != APPLE_RTKIT_MGMT_HELLO) {
+               printf("%s: unexpected message type %d\n", __func__, msgtype);
+               return -EINVAL;
+       }
+
+       min_ver = FIELD_GET(APPLE_RTKIT_MGMT_HELLO_MINVER, msg.msg0);
+       max_ver = FIELD_GET(APPLE_RTKIT_MGMT_HELLO_MAXVER, msg.msg0);
+       want_ver = min(APPLE_RTKIT_MAX_SUPPORTED_VERSION, max_ver);
+
+       if (min_ver > APPLE_RTKIT_MAX_SUPPORTED_VERSION) {
+               printf("%s: firmware min version %d is too new\n",
+                      __func__, min_ver);
+               return -ENOTSUPP;
+       }
+
+       if (max_ver < APPLE_RTKIT_MIN_SUPPORTED_VERSION) {
+               printf("%s: firmware max version %d is too old\n",
+                      __func__, max_ver);
+               return -ENOTSUPP;
+       }
+
+       /* Ack version. */
+       msg.msg0 = FIELD_PREP(APPLE_RTKIT_MGMT_TYPE, APPLE_RTKIT_MGMT_HELLO_REPLY) |
+               FIELD_PREP(APPLE_RTKIT_MGMT_HELLO_MINVER, want_ver) |
+               FIELD_PREP(APPLE_RTKIT_MGMT_HELLO_MAXVER, want_ver);
+       msg.msg1 = APPLE_RTKIT_EP_MGMT;
+       ret = mbox_send(chan, &msg);
+       if (ret < 0)
+               return ret;
+
+wait_epmap:
+       /* Wait for endpoint map message. */
+       ret = mbox_recv(chan, &msg, 10000);
+       if (ret < 0)
+               return ret;
+
+       endpoint = msg.msg1;
+       msgtype = FIELD_GET(APPLE_RTKIT_MGMT_TYPE, msg.msg0);
+       if (endpoint != APPLE_RTKIT_EP_MGMT) {
+               printf("%s: unexpected endpoint %d\n", __func__, endpoint);
+               return -EINVAL;
+       }
+       if (msgtype != APPLE_RTKIT_MGMT_EPMAP) {
+               printf("%s: unexpected message type %d\n", __func__, msgtype);
+               return -EINVAL;
+       }
+
+       bitmap = FIELD_GET(APPLE_RTKIT_MGMT_EPMAP_BITMAP, msg.msg0);
+       base = FIELD_GET(APPLE_RTKIT_MGMT_EPMAP_BASE, msg.msg0);
+       for (i = 0; i < 32; i++) {
+               if (bitmap & (1U << i))
+                       endpoints[nendpoints++] = base * 32 + i;
+       }
+
+       /* Ack endpoint map. */
+       reply = FIELD_PREP(APPLE_RTKIT_MGMT_TYPE, APPLE_RTKIT_MGMT_EPMAP_REPLY) |
+               FIELD_PREP(APPLE_RTKIT_MGMT_EPMAP_BASE, base);
+       if (msg.msg0 & APPLE_RTKIT_MGMT_EPMAP_LAST)
+               reply |= APPLE_RTKIT_MGMT_EPMAP_LAST;
+       else
+               reply |= APPLE_RTKIT_MGMT_EPMAP_REPLY_MORE;
+       msg.msg0 = reply;
+       msg.msg1 = APPLE_RTKIT_EP_MGMT;
+       ret = mbox_send(chan, &msg);
+       if (ret < 0)
+               return ret;
+
+       if (reply & APPLE_RTKIT_MGMT_EPMAP_REPLY_MORE)
+               goto wait_epmap;
+
+       for (i = 0; i < nendpoints; i++) {
+               /* Don't start the syslog endpoint since we can't
+                  easily handle its messages in U-Boot. */
+               if (endpoints[i] == APPLE_RTKIT_EP_SYSLOG)
+                       continue;
+
+               /* Request endpoint. */
+               msg.msg0 = FIELD_PREP(APPLE_RTKIT_MGMT_TYPE, APPLE_RTKIT_MGMT_STARTEP) |
+                       FIELD_PREP(APPLE_RTKIT_MGMT_STARTEP_EP, endpoints[i]) |
+                       APPLE_RTKIT_MGMT_STARTEP_FLAG;
+               msg.msg1 = APPLE_RTKIT_EP_MGMT;
+               ret = mbox_send(chan, &msg);
+               if (ret < 0)
+                       return ret;
+       }
+
+       pwrstate = APPLE_RTKIT_PWR_STATE_SLEEP;
+       while (pwrstate != APPLE_RTKIT_PWR_STATE_ON) {
+               ret = mbox_recv(chan, &msg, 100000);
+               if (ret < 0)
+                       return ret;
+
+               endpoint = msg.msg1;
+               msgtype = FIELD_GET(APPLE_RTKIT_MGMT_TYPE, msg.msg0);
+
+               if (endpoint == APPLE_RTKIT_EP_CRASHLOG ||
+                   endpoint == APPLE_RTKIT_EP_SYSLOG ||
+                   endpoint == APPLE_RTKIT_EP_IOREPORT) {
+                       u64 addr = FIELD_GET(APPLE_RTKIT_BUFFER_REQUEST_IOVA, msg.msg0);
+                       u64 size = FIELD_GET(APPLE_RTKIT_BUFFER_REQUEST_SIZE, msg.msg0);
+
+                       if (msgtype == APPLE_RTKIT_BUFFER_REQUEST && addr != 0)
+                               continue;
+
+                       msg.msg0 = FIELD_PREP(APPLE_RTKIT_MGMT_TYPE, APPLE_RTKIT_BUFFER_REQUEST) |
+                               FIELD_PREP(APPLE_RTKIT_BUFFER_REQUEST_SIZE, size) |
+                               FIELD_PREP(APPLE_RTKIT_BUFFER_REQUEST_IOVA, addr);
+                       msg.msg1 = endpoint;
+                       ret = mbox_send(chan, &msg);
+                       if (ret < 0)
+                               return ret;
+                       continue;
+               }
+
+               if (endpoint != APPLE_RTKIT_EP_MGMT) {
+                       printf("%s: unexpected endpoint %d\n", __func__, endpoint);
+                       return -EINVAL;
+               }
+               if (msgtype != APPLE_RTKIT_MGMT_SET_IOP_PWR_STATE_ACK) {
+                       printf("%s: unexpected message type %d\n", __func__, msgtype);
+                       return -EINVAL;
+               }
+
+               pwrstate = FIELD_GET(APPLE_RTKIT_MGMT_PWR_STATE, msg.msg0);
+       }
+
+       return 0;
+}
+
+int apple_rtkit_shutdown(struct mbox_chan *chan, int pwrstate)
+{
+       struct apple_mbox_msg msg;
+       int ret;
+
+       msg.msg0 = FIELD_PREP(APPLE_RTKIT_MGMT_TYPE, APPLE_RTKIT_MGMT_SET_IOP_PWR_STATE) |
+               FIELD_PREP(APPLE_RTKIT_MGMT_PWR_STATE, pwrstate);
+       msg.msg1 = APPLE_RTKIT_EP_MGMT;
+       ret = mbox_send(chan, &msg);
+       if (ret < 0)
+               return ret;
+
+       ret = mbox_recv(chan, &msg, 100000);
+       if (ret < 0)
+               return ret;
+
+       return 0;
+}