HACK compat mailbox shim

drivers/mailbox/Makefile

@@ -59,4 +59,4 @@ obj-$(CONFIG_SPRD_MBOX)		+= sprd-mailbox.o
 
 obj-$(CONFIG_QCOM_IPCC)		+= qcom-ipcc.o
 
-obj-$(CONFIG_APPLE_MBOX)	+= apple-asc-mailbox.o
+obj-$(CONFIG_APPLE_MBOX)	+= apple-asc-mailbox.o apple-mailbox-compat-shim.o

drivers/mailbox/apple-mailbox-compat-shim.c

@@ -0,0 +1,247 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/apple-mailbox.h>
+#include <linux/apple-rtkit.h>
+#include <linux/bitfield.h>
+#include <linux/bitmap.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/debugfs.h>
+#include <linux/dma-mapping.h>
+#include <linux/device.h>
+#include <linux/gfp.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kfifo.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+
+struct apple_compat_mbox;
+
+struct apple_compat_mbox_priv {
+                u8 ep;
+                struct apple_compat_mbox *mbox;
+                bool enabled;
+};
+
+struct apple_compat_mbox {
+	struct device *dev;
+
+	struct mbox_chan chan[0x100];
+        struct apple_compat_mbox_priv chan_priv[0x100];
+
+	struct mbox_controller controller;
+        struct mbox_client client;
+        struct mbox_chan *hw_chan;
+
+        struct apple_rtkit *rtk;
+
+        void __iomem *sart_regs;
+};
+
+
+static struct mbox_chan *apple_compat_mbox_of_xlate(struct mbox_controller *mbox,
+					     const struct of_phandle_args *spec)
+{
+	struct apple_compat_mbox *apple_mbox = dev_get_drvdata(mbox->dev);
+	u8 ep;
+
+	if (spec->args_count != 1)
+		return ERR_PTR(-EINVAL);
+
+	ep = spec->args[0];
+	apple_mbox->chan[ep].con_priv = &apple_mbox->chan_priv[ep];
+
+	return &apple_mbox->chan[ep];
+}
+
+static int apple_compat_mbox_chan_send_data(struct mbox_chan *chan, void *data)
+{
+	struct apple_compat_mbox_priv *priv = chan->con_priv;
+	struct apple_compat_mbox *apple_mbox = priv->mbox;
+	struct apple_mbox_msg msg;
+
+	msg.msg0 = (u64)data;
+	msg.msg1 = priv->ep;
+
+	return mbox_send_message(apple_mbox->hw_chan, &msg);
+}
+
+static int apple_compat_mbox_chan_startup(struct mbox_chan *chan)
+{
+	struct apple_compat_mbox_priv *priv = chan->con_priv;
+	priv->enabled = true;
+        apple_rtkit_start_ep(priv->mbox->rtk, priv->ep);
+	return 0;
+}
+
+static void apple_compat_mbox_chan_shutdown(struct mbox_chan *chan)
+{
+	struct apple_compat_mbox_priv *priv = chan->con_priv;
+	priv->enabled = false;
+}
+
+static bool apple_compat_mbox_chan_last_txdone(struct mbox_chan *chan)
+{
+	return true;
+}
+
+static const struct mbox_chan_ops apple_compat_mbox_ops = {
+	.send_data = &apple_compat_mbox_chan_send_data,
+	.last_tx_done = apple_compat_mbox_chan_last_txdone,
+	.startup = &apple_compat_mbox_chan_startup,
+	.shutdown = &apple_compat_mbox_chan_shutdown,
+};
+
+static int dummy_shmem_verify(void *cookie, dma_addr_t addr, size_t len)
+{
+        return 0;
+}
+
+static void rtk_got_msg(void *cookie, u8 endpoint, u64 message)
+{
+        struct apple_compat_mbox *mbox = cookie;
+
+        if (!mbox->chan_priv[endpoint].enabled)
+                return;
+
+        mbox_chan_received_data(&mbox->chan[endpoint], (void *)message);
+}
+
+#define APPLE_SART_CONFIG(idx) (0x00 + 4 * (idx))
+#define APPLE_SART_CONFIG_FLAGS GENMASK(31, 24)
+#define APPLE_SART_CONFIG_SIZE GENMASK(23, 0)
+#define APPLE_SART_CONFIG_SIZE_SHIFT 12
+
+#define APPLE_SART_PADDR(idx) (0x40 + 4 * (idx))
+#define APPLE_SART_PADDR_SHIFT 12
+
+#define APPLE_SART_MAX_ENTRIES 16
+
+static void *sart_alloc(void *cookie, size_t size, dma_addr_t *dma_handle,
+			    gfp_t flag)
+{
+        struct apple_compat_mbox *mbox = cookie;
+        u32 buffer_config;
+        int i;
+        void *cpu_addr = dma_alloc_coherent(mbox->dev, size, dma_handle, flag);
+
+	buffer_config = FIELD_PREP(APPLE_SART_CONFIG_FLAGS, 0xff);
+ 	buffer_config |=
+ 		FIELD_PREP(APPLE_SART_CONFIG_SIZE,
+ 			   size >> APPLE_SART_CONFIG_SIZE_SHIFT);
+
+ 	for (i = 0; i < APPLE_SART_MAX_ENTRIES; ++i) {
+ 		u32 config =
+ 			readl(mbox->sart_regs + APPLE_SART_CONFIG(i));
+ 		if (FIELD_GET(APPLE_SART_CONFIG_FLAGS, config) != 0)
+ 			continue;
+
+ 		writel((*dma_handle) >> APPLE_SART_PADDR_SHIFT,
+ 		       mbox->sart_regs + APPLE_SART_PADDR(i));
+ 		writel(buffer_config,
+ 		       mbox->sart_regs + APPLE_SART_CONFIG(i));
+ 		break;
+ 	}
+
+        return cpu_addr;
+}
+
+static struct apple_rtkit_ops shmem_rtkit_ops =
+{
+        .shmem_owner = APPLE_RTKIT_SHMEM_OWNER_RTKIT,
+        .shmem_verify = dummy_shmem_verify,
+        .recv_message = rtk_got_msg,
+};
+
+static struct apple_rtkit_ops sart_rtkit_ops =
+{
+        .shmem_owner = APPLE_RTKIT_SHMEM_OWNER_LINUX,
+        .shmem_alloc = sart_alloc,
+        .recv_message = rtk_got_msg,
+};
+
+static int apple_compat_mbox_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct apple_compat_mbox *mbox;
+	struct device *dev = &pdev->dev;
+        struct resource *res, *sart_res;
+
+        dev_err(dev, "this is a hack, please don't use it.");
+        add_taint(TAINT_CRAP, LOCKDEP_STILL_OK);
+
+	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, mbox);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "coproc");
+	if (!res)
+		return -EINVAL;
+
+        sart_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sart");
+        if (sart_res) {
+                mbox->sart_regs = devm_ioremap_resource(dev, sart_res);
+                if (IS_ERR(mbox->sart_regs))
+                        return PTR_ERR(mbox->sart_regs);
+        }
+
+	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
+	if (ret)
+		return ret;
+
+	mbox->dev = dev;
+
+        if (sart_res)
+                mbox->rtk = apple_rtkit_init(dev, mbox, res, "mbox", &sart_rtkit_ops);
+        else
+                mbox->rtk = apple_rtkit_init(dev, mbox, res, "mbox", &shmem_rtkit_ops);
+
+        apple_rtkit_boot_wait(mbox->rtk);
+
+	mbox->controller.dev = mbox->dev;
+	mbox->controller.num_chans = 0x100;
+	mbox->controller.chans = mbox->chan;
+	mbox->controller.ops = &apple_compat_mbox_ops;
+	mbox->controller.of_xlate = &apple_compat_mbox_of_xlate;
+	mbox->controller.txdone_poll = true;
+
+	return devm_mbox_controller_register(dev, &mbox->controller);
+}
+
+static const struct of_device_id apple_compat_mbox_of_match[] = {
+	{ .compatible = "apple,t8103-compat-mailbox", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, apple_compat_mbox_of_match);
+
+static int apple_compat_mbox_remove(struct platform_device *pdev)
+{
+	//struct apple_compat_mbox *apple_mbox = platform_get_drvdata(pdev);
+	return 0;
+}
+
+static void apple_compat_mbox_shutdown(struct platform_device *pdev)
+{
+	apple_compat_mbox_remove(pdev);
+}
+
+static struct platform_driver apple_compat_mbox_driver = {
+	.driver = {
+		.name = "apple-compat-mailbox",
+		.of_match_table = apple_compat_mbox_of_match,
+	},
+	.probe = apple_compat_mbox_probe,
+	.remove = apple_compat_mbox_remove,
+	.shutdown = apple_compat_mbox_shutdown,
+};
+module_platform_driver(apple_compat_mbox_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
+MODULE_DESCRIPTION("HACK: Apple mailbox compat layer");