Merge tag 'asahi-soc-rtkit-sart-nvme-for-5.19' of https://github.com/AsahiLinux/linux into arm/drivers

Apple SoC NVMe driver and dependencies:

  - RTKit IPC library required to boot and communicate with
    co-processors embedded inside Apple SoCs
  - SART DMA address filter required to allow some DMA transactions for
    the NVMe co-processor
  - NVMe platform driver

The following minor changes since v3 on the mailing list have been
folded in:

  - sart: %llx -> %pa for a phys_addr_t
  - rtkit:/sart: Drop IS_ENABLED inside headers
  - rtkit: Use EXPORT_SYMBOL_GPL instead of EXPORT_SYMBOL
  - nvme: Set NVME_REQ_CANCELLED in the timeout handler
  - nvme: Use DEFINE_SIMPLE_DEV_PM_OPS instead of #ifdef CONFIG_PM_SLEEP

* tag 'asahi-soc-rtkit-sart-nvme-for-5.19' of https://github.com/AsahiLinux/linux:
  nvme-apple: Add initial Apple SoC NVMe driver
  dt-bindings: nvme: Add Apple ANS NVMe
  soc: apple: Add SART driver
  dt-bindings: iommu: Add Apple SART DMA address filter
  soc: apple: Add RTKit IPC library
  soc: apple: Always include Makefile

Link: https://lore.kernel.org/r/20220505154020.84638-1-sven@svenpeter.dev
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

2 files changed, 208 insertions, 0 deletions

diff --git a/include/linux/soc/apple/rtkit.h b/include/linux/soc/apple/rtkit.h
new file mode 100644
index 000000000000..88eb832eac7b
--- /dev/null
+++ b/include/linux/soc/apple/rtkit.h
@@ -0,0 +1,155 @@
+/* SPDX-License-Identifier: GPL-2.0-only OR MIT */
+/*
+ * Apple RTKit IPC Library
+ * Copyright (C) The Asahi Linux Contributors
+ *
+ * Apple's SoCs come with various co-processors running their RTKit operating
+ * system. This protocol library is used by client drivers to use the
+ * features provided by them.
+ */
+#ifndef _LINUX_APPLE_RTKIT_H_
+#define _LINUX_APPLE_RTKIT_H_
+
+#include <linux/device.h>
+#include <linux/types.h>
+#include <linux/mailbox_client.h>
+
+/*
+ * Struct to represent implementation-specific RTKit operations.
+ *
+ * @buffer:    Shared memory buffer allocated inside normal RAM.
+ * @iomem:     Shared memory buffer controlled by the co-processors.
+ * @size:      Size of the shared memory buffer.
+ * @iova:      Device VA of shared memory buffer.
+ * @is_mapped: Shared memory buffer is managed by the co-processor.
+ */
+
+struct apple_rtkit_shmem {
+	void *buffer;
+	void __iomem *iomem;
+	size_t size;
+	dma_addr_t iova;
+	bool is_mapped;
+};
+
+/*
+ * Struct to represent implementation-specific RTKit operations.
+ *
+ * @crashed:       Called when the co-processor has crashed. Runs in process
+ *                 context.
+ * @recv_message:  Function called when a message from RTKit is received
+ *                 on a non-system endpoint. Called from a worker thread.
+ * @recv_message_early:
+ *                 Like recv_message, but called from atomic context. It
+ *                 should return true if it handled the message. If it
+ *                 returns false, the message will be passed on to the
+ *                 worker thread.
+ * @shmem_setup:   Setup shared memory buffer. If bfr.is_iomem is true the
+ *                 buffer is managed by the co-processor and needs to be mapped.
+ *                 Otherwise the buffer is managed by Linux and needs to be
+ *                 allocated. If not specified dma_alloc_coherent is used.
+ *                 Called in process context.
+ * @shmem_destroy: Undo the shared memory buffer setup in shmem_setup. If not
+ *                 specified dma_free_coherent is used. Called in process
+ *                 context.
+ */
+struct apple_rtkit_ops {
+	void (*crashed)(void *cookie);
+	void (*recv_message)(void *cookie, u8 endpoint, u64 message);
+	bool (*recv_message_early)(void *cookie, u8 endpoint, u64 message);
+	int (*shmem_setup)(void *cookie, struct apple_rtkit_shmem *bfr);
+	void (*shmem_destroy)(void *cookie, struct apple_rtkit_shmem *bfr);
+};
+
+struct apple_rtkit;
+
+/*
+ * Initializes the internal state required to handle RTKit. This
+ * should usually be called within _probe.
+ *
+ * @dev:         Pointer to the device node this coprocessor is assocated with
+ * @cookie:      opaque cookie passed to all functions defined in rtkit_ops
+ * @mbox_name:   mailbox name used to communicate with the co-processor
+ * @mbox_idx:    mailbox index to be used if mbox_name is NULL
+ * @ops:         pointer to rtkit_ops to be used for this co-processor
+ */
+struct apple_rtkit *devm_apple_rtkit_init(struct device *dev, void *cookie,
+					  const char *mbox_name, int mbox_idx,
+					  const struct apple_rtkit_ops *ops);
+
+/*
+ * Reinitialize internal structures. Must only be called with the co-processor
+ * is held in reset.
+ */
+int apple_rtkit_reinit(struct apple_rtkit *rtk);
+
+/*
+ * Handle RTKit's boot process. Should be called after the CPU of the
+ * co-processor has been started.
+ */
+int apple_rtkit_boot(struct apple_rtkit *rtk);
+
+/*
+ * Quiesce the co-processor.
+ */
+int apple_rtkit_quiesce(struct apple_rtkit *rtk);
+
+/*
+ * Wake the co-processor up from hibernation mode.
+ */
+int apple_rtkit_wake(struct apple_rtkit *rtk);
+
+/*
+ * Shutdown the co-processor
+ */
+int apple_rtkit_shutdown(struct apple_rtkit *rtk);
+
+/*
+ * Checks if RTKit is running and ready to handle messages.
+ */
+bool apple_rtkit_is_running(struct apple_rtkit *rtk);
+
+/*
+ * Checks if RTKit has crashed.
+ */
+bool apple_rtkit_is_crashed(struct apple_rtkit *rtk);
+
+/*
+ * Starts an endpoint. Must be called after boot but before any messages can be
+ * sent or received from that endpoint.
+ */
+int apple_rtkit_start_ep(struct apple_rtkit *rtk, u8 endpoint);
+
+/*
+ * Send a message to the given endpoint.
+ *
+ * @rtk:            RTKit reference
+ * @ep:             target endpoint
+ * @message:        message to be sent
+ * @completeion:    will be completed once the message has been submitted
+ *                  to the hardware FIFO. Can be NULL.
+ * @atomic:         if set to true this function can be called from atomic
+ *                  context.
+ */
+int apple_rtkit_send_message(struct apple_rtkit *rtk, u8 ep, u64 message,
+			     struct completion *completion, bool atomic);
+
+/*
+ * Send a message to the given endpoint and wait until it has been submitted
+ * to the hardware FIFO.
+ * Will return zero on success and a negative error code on failure
+ * (e.g. -ETIME when the message couldn't be written within the given
+ * timeout)
+ *
+ * @rtk:            RTKit reference
+ * @ep:             target endpoint
+ * @message:        message to be sent
+ * @timeout:        timeout in milliseconds to allow the message transmission
+ *                  to be completed
+ * @atomic:         if set to true this function can be called from atomic
+ *                  context.
+ */
+int apple_rtkit_send_message_wait(struct apple_rtkit *rtk, u8 ep, u64 message,
+				  unsigned long timeout, bool atomic);
+
+#endif /* _LINUX_APPLE_RTKIT_H_ */
diff --git a/include/linux/soc/apple/sart.h b/include/linux/soc/apple/sart.h
new file mode 100644
index 000000000000..2249bf6cde09
--- /dev/null
+++ b/include/linux/soc/apple/sart.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0-only OR MIT */
+/*
+ * Apple SART device driver
+ * Copyright (C) The Asahi Linux Contributors
+ *
+ * Apple SART is a simple address filter for DMA transactions.
+ * Regions of physical memory must be added to the SART's allow
+ * list before any DMA can target these. Unlike a proper
+ * IOMMU no remapping can be done.
+ */
+
+#ifndef _LINUX_SOC_APPLE_SART_H_
+#define _LINUX_SOC_APPLE_SART_H_
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/types.h>
+
+struct apple_sart;
+
+/*
+ * Get a reference to the SART attached to dev.
+ *
+ * Looks for the phandle reference in apple,sart and returns a pointer
+ * to the corresponding apple_sart struct to be used with
+ * apple_sart_add_allowed_region and apple_sart_remove_allowed_region.
+ */
+struct apple_sart *devm_apple_sart_get(struct device *dev);
+
+/*
+ * Adds the region [paddr, paddr+size] to the DMA allow list.
+ *
+ * @sart: SART reference
+ * @paddr: Start address of the region to be used for DMA
+ * @size: Size of the region to be used for DMA.
+ */
+int apple_sart_add_allowed_region(struct apple_sart *sart, phys_addr_t paddr,
+				  size_t size);
+
+/*
+ * Removes the region [paddr, paddr+size] from the DMA allow list.
+ *
+ * Note that exact same paddr and size used for apple_sart_add_allowed_region
+ * have to be passed.
+ *
+ * @sart: SART reference
+ * @paddr: Start address of the region no longer used for DMA
+ * @size: Size of the region no longer used for DMA.
+ */
+int apple_sart_remove_allowed_region(struct apple_sart *sart, phys_addr_t paddr,
+				     size_t size);
+
+#endif /* _LINUX_SOC_APPLE_SART_H_ */