nvme-apple: Add initial Apple SoC NVMe driver

Apple SoCs such as the M1 come with an embedded NVMe controller that
is not attached to any PCIe bus. Additionally, it doesn't conform
to the NVMe specification and requires a bunch of changes to command
submission and IOMMU configuration to work.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sven Peter <sven@svenpeter.dev>

1 files changed, 1593 insertions, 0 deletions

diff --git a/drivers/nvme/host/apple.c b/drivers/nvme/host/apple.c
new file mode 100644
index 000000000000..b321f5c0563f
--- /dev/null
+++ b/drivers/nvme/host/apple.c
@@ -0,0 +1,1593 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Apple ANS NVM Express device driver
+ * Copyright The Asahi Linux Contributors
+ *
+ * Based on the pci.c NVM Express device driver
+ * Copyright (c) 2011-2014, Intel Corporation.
+ * and on the rdma.c NVMe over Fabrics RDMA host code.
+ * Copyright (c) 2015-2016 HGST, a Western Digital Company.
+ */
+
+#include <linux/async.h>
+#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/interrupt.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/jiffies.h>
+#include <linux/mempool.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/once.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/soc/apple/rtkit.h>
+#include <linux/soc/apple/sart.h>
+#include <linux/reset.h>
+#include <linux/time64.h>
+
+#include "nvme.h"
+
+#define APPLE_ANS_BOOT_TIMEOUT	  USEC_PER_SEC
+#define APPLE_ANS_MAX_QUEUE_DEPTH 64
+
+#define APPLE_ANS_COPROC_CPU_CONTROL	 0x44
+#define APPLE_ANS_COPROC_CPU_CONTROL_RUN BIT(4)
+
+#define APPLE_ANS_ACQ_DB  0x1004
+#define APPLE_ANS_IOCQ_DB 0x100c
+
+#define APPLE_ANS_MAX_PEND_CMDS_CTRL 0x1210
+
+#define APPLE_ANS_BOOT_STATUS	 0x1300
+#define APPLE_ANS_BOOT_STATUS_OK 0xde71ce55
+
+#define APPLE_ANS_UNKNOWN_CTRL	 0x24008
+#define APPLE_ANS_PRP_NULL_CHECK BIT(11)
+
+#define APPLE_ANS_LINEAR_SQ_CTRL 0x24908
+#define APPLE_ANS_LINEAR_SQ_EN	 BIT(0)
+
+#define APPLE_ANS_LINEAR_ASQ_DB	 0x2490c
+#define APPLE_ANS_LINEAR_IOSQ_DB 0x24910
+
+#define APPLE_NVMMU_NUM_TCBS	  0x28100
+#define APPLE_NVMMU_ASQ_TCB_BASE  0x28108
+#define APPLE_NVMMU_IOSQ_TCB_BASE 0x28110
+#define APPLE_NVMMU_TCB_INVAL	  0x28118
+#define APPLE_NVMMU_TCB_STAT	  0x28120
+
+/*
+ * This controller is a bit weird in the way command tags works: Both the
+ * admin and the IO queue share the same tag space. Additionally, tags
+ * cannot be higher than 0x40 which effectively limits the combined
+ * queue depth to 0x40. Instead of wasting half of that on the admin queue
+ * which gets much less traffic we instead reduce its size here.
+ * The controller also doesn't support async event such that no space must
+ * be reserved for NVME_NR_AEN_COMMANDS.
+ */
+#define APPLE_NVME_AQ_DEPTH	   2
+#define APPLE_NVME_AQ_MQ_TAG_DEPTH (APPLE_NVME_AQ_DEPTH - 1)
+
+/*
+ * These can be higher, but we need to ensure that any command doesn't
+ * require an sg allocation that needs more than a page of data.
+ */
+#define NVME_MAX_KB_SZ 4096
+#define NVME_MAX_SEGS  127
+
+/*
+ * This controller comes with an embedded IOMMU known as NVMMU.
+ * The NVMMU is pointed to an array of TCBs indexed by the command tag.
+ * Each command must be configured inside this structure before it's allowed
+ * to execute, including commands that don't require DMA transfers.
+ *
+ * An exception to this are Apple's vendor-specific commands (opcode 0xD8 on the
+ * admin queue): Those commands must still be added to the NVMMU but the DMA
+ * buffers cannot be represented as PRPs and must instead be allowed using SART.
+ *
+ * Programming the PRPs to the same values as those in the submission queue
+ * looks rather silly at first. This hardware is however designed for a kernel
+ * that runs the NVMMU code in a higher exception level than the NVMe driver.
+ * In that setting the NVMe driver first programs the submission queue entry
+ * and then executes a hypercall to the code that is allowed to program the
+ * NVMMU. The NVMMU driver then creates a shadow copy of the PRPs while
+ * verifying that they don't point to kernel text, data, pagetables, or similar
+ * protected areas before programming the TCB to point to this shadow copy.
+ * Since Linux doesn't do any of that we may as well just point both the queue
+ * and the TCB PRP pointer to the same memory.
+ */
+struct apple_nvmmu_tcb {
+	u8 opcode;
+
+#define APPLE_ANS_TCB_DMA_FROM_DEVICE BIT(0)
+#define APPLE_ANS_TCB_DMA_TO_DEVICE   BIT(1)
+	u8 dma_flags;
+
+	u8 command_id;
+	u8 _unk0;
+	u32 length;
+	u8 _unk1[16];
+	u64 prp1;
+	u64 prp2;
+	u8 _unk2[16];
+	u8 aes_iv[8];
+	u8 _aes_unk[64];
+};
+
+/*
+ * The Apple NVMe controller only supports a single admin and a single IO queue
+ * which are both limited to 64 entries and share a single interrupt.
+ *
+ * The completion queue works as usual. The submission "queue" instead is
+ * an array indexed by the command tag on this hardware. Commands must also be
+ * present in the NVMMU's tcb array. They are triggered by writing their tag to
+ * a MMIO register.
+ */
+struct apple_nvme_queue {
+	struct nvme_command *sqes;
+	struct nvme_completion *cqes;
+	struct apple_nvmmu_tcb *tcbs;
+
+	dma_addr_t sq_dma_addr;
+	dma_addr_t cq_dma_addr;
+	dma_addr_t tcb_dma_addr;
+
+	u32 __iomem *sq_db;
+	u32 __iomem *cq_db;
+
+	u16 cq_head;
+	u8 cq_phase;
+
+	bool is_adminq;
+	bool enabled;
+};
+
+/*
+ * The apple_nvme_iod describes the data in an I/O.
+ *
+ * The sg pointer contains the list of PRP chunk allocations in addition
+ * to the actual struct scatterlist.
+ */
+struct apple_nvme_iod {
+	struct nvme_request req;
+	struct nvme_command cmd;
+	struct apple_nvme_queue *q;
+	int npages; /* In the PRP list. 0 means small pool in use */
+	int nents; /* Used in scatterlist */
+	dma_addr_t first_dma;
+	unsigned int dma_len; /* length of single DMA segment mapping */
+	struct scatterlist *sg;
+};
+
+struct apple_nvme {
+	struct device *dev;
+
+	void __iomem *mmio_coproc;
+	void __iomem *mmio_nvme;
+
+	struct device **pd_dev;
+	struct device_link **pd_link;
+	int pd_count;
+
+	struct apple_sart *sart;
+	struct apple_rtkit *rtk;
+	struct reset_control *reset;
+
+	struct dma_pool *prp_page_pool;
+	struct dma_pool *prp_small_pool;
+	mempool_t *iod_mempool;
+
+	struct nvme_ctrl ctrl;
+	struct work_struct remove_work;
+
+	struct apple_nvme_queue adminq;
+	struct apple_nvme_queue ioq;
+
+	struct blk_mq_tag_set admin_tagset;
+	struct blk_mq_tag_set tagset;
+
+	int irq;
+	spinlock_t lock;
+};
+
+static_assert(sizeof(struct nvme_command) == 64);
+static_assert(sizeof(struct apple_nvmmu_tcb) == 128);
+
+static inline struct apple_nvme *ctrl_to_apple_nvme(struct nvme_ctrl *ctrl)
+{
+	return container_of(ctrl, struct apple_nvme, ctrl);
+}
+
+static inline struct apple_nvme *queue_to_apple_nvme(struct apple_nvme_queue *q)
+{
+	if (q->is_adminq)
+		return container_of(q, struct apple_nvme, adminq);
+	else
+		return container_of(q, struct apple_nvme, ioq);
+}
+
+static unsigned int apple_nvme_queue_depth(struct apple_nvme_queue *q)
+{
+	if (q->is_adminq)
+		return APPLE_NVME_AQ_DEPTH;
+	else
+		return APPLE_ANS_MAX_QUEUE_DEPTH;
+}
+
+static void apple_nvme_rtkit_crashed(void *cookie)
+{
+	struct apple_nvme *anv = cookie;
+
+	dev_warn(anv->dev, "RTKit crashed; unable to recover without a reboot");
+	nvme_reset_ctrl(&anv->ctrl);
+}
+
+static int apple_nvme_sart_dma_setup(void *cookie,
+				     struct apple_rtkit_shmem *bfr)
+{
+	struct apple_nvme *anv = cookie;
+	int ret;
+
+	if (bfr->iova)
+		return -EINVAL;
+	if (!bfr->size)
+		return -EINVAL;
+
+	bfr->buffer =
+		dma_alloc_coherent(anv->dev, bfr->size, &bfr->iova, GFP_KERNEL);
+	if (!bfr->buffer)
+		return -ENOMEM;
+
+	ret = apple_sart_add_allowed_region(anv->sart, bfr->iova, bfr->size);
+	if (ret) {
+		dma_free_coherent(anv->dev, bfr->size, bfr->buffer, bfr->iova);
+		bfr->buffer = NULL;
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void apple_nvme_sart_dma_destroy(void *cookie,
+					struct apple_rtkit_shmem *bfr)
+{
+	struct apple_nvme *anv = cookie;
+
+	apple_sart_remove_allowed_region(anv->sart, bfr->iova, bfr->size);
+	dma_free_coherent(anv->dev, bfr->size, bfr->buffer, bfr->iova);
+}
+
+static const struct apple_rtkit_ops apple_nvme_rtkit_ops = {
+	.crashed = apple_nvme_rtkit_crashed,
+	.shmem_setup = apple_nvme_sart_dma_setup,
+	.shmem_destroy = apple_nvme_sart_dma_destroy,
+};
+
+static void apple_nvmmu_inval(struct apple_nvme_queue *q, unsigned int tag)
+{
+	struct apple_nvme *anv = queue_to_apple_nvme(q);
+
+	writel(tag, anv->mmio_nvme + APPLE_NVMMU_TCB_INVAL);
+	if (readl(anv->mmio_nvme + APPLE_NVMMU_TCB_STAT))
+		dev_warn_ratelimited(anv->dev,
+				     "NVMMU TCB invalidation failed\n");
+}
+
+static void apple_nvme_submit_cmd(struct apple_nvme_queue *q,
+				  struct nvme_command *cmd)
+{
+	struct apple_nvme *anv = queue_to_apple_nvme(q);
+	u32 tag = nvme_tag_from_cid(cmd->common.command_id);
+	struct apple_nvmmu_tcb *tcb = &q->tcbs[tag];
+
+	tcb->opcode = cmd->common.opcode;
+	tcb->prp1 = cmd->common.dptr.prp1;
+	tcb->prp2 = cmd->common.dptr.prp2;
+	tcb->length = cmd->rw.length;
+	tcb->command_id = tag;
+
+	if (nvme_is_write(cmd))
+		tcb->dma_flags = APPLE_ANS_TCB_DMA_TO_DEVICE;
+	else
+		tcb->dma_flags = APPLE_ANS_TCB_DMA_FROM_DEVICE;
+
+	memcpy(&q->sqes[tag], cmd, sizeof(*cmd));
+
+	/*
+	 * This lock here doesn't make much sense at a first glace but
+	 * removing it will result in occasional missed completetion
+	 * interrupts even though the commands still appear on the CQ.
+	 * It's unclear why this happens but our best guess is that
+	 * there is a bug in the firmware triggered when a new command
+	 * is issued while we're inside the irq handler between the
+	 * NVMMU invalidation (and making the tag available again)
+	 * and the final CQ update.
+	 */
+	spin_lock_irq(&anv->lock);
+	writel(tag, q->sq_db);
+	spin_unlock_irq(&anv->lock);
+}
+
+/*
+ * From pci.c:
+ * Will slightly overestimate the number of pages needed.  This is OK
+ * as it only leads to a small amount of wasted memory for the lifetime of
+ * the I/O.
+ */
+static inline size_t apple_nvme_iod_alloc_size(void)
+{
+	const unsigned int nprps = DIV_ROUND_UP(
+		NVME_MAX_KB_SZ + NVME_CTRL_PAGE_SIZE, NVME_CTRL_PAGE_SIZE);
+	const int npages = DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
+	const size_t alloc_size = sizeof(__le64 *) * npages +
+				  sizeof(struct scatterlist) * NVME_MAX_SEGS;
+
+	return alloc_size;
+}
+
+static void **apple_nvme_iod_list(struct request *req)
+{
+	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
+
+	return (void **)(iod->sg + blk_rq_nr_phys_segments(req));
+}
+
+static void apple_nvme_free_prps(struct apple_nvme *anv, struct request *req)
+{
+	const int last_prp = NVME_CTRL_PAGE_SIZE / sizeof(__le64) - 1;
+	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	dma_addr_t dma_addr = iod->first_dma;
+	int i;
+
+	for (i = 0; i < iod->npages; i++) {
+		__le64 *prp_list = apple_nvme_iod_list(req)[i];
+		dma_addr_t next_dma_addr = prp_list[last_prp];
+
+		dma_pool_free(anv->prp_page_pool, prp_list, dma_addr);
+		dma_addr = next_dma_addr;
+	}
+}
+
+static void apple_nvme_unmap_data(struct apple_nvme *anv, struct request *req)
+{
+	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
+
+	if (iod->dma_len) {
+		dma_unmap_page(anv->dev, iod->first_dma, iod->dma_len,
+			       rq_dma_dir(req));
+		return;
+	}
+
+	WARN_ON_ONCE(!iod->nents);
+
+	dma_unmap_sg(anv->dev, iod->sg, iod->nents, rq_dma_dir(req));
+	if (iod->npages == 0)
+		dma_pool_free(anv->prp_small_pool, apple_nvme_iod_list(req)[0],
+			      iod->first_dma);
+	else
+		apple_nvme_free_prps(anv, req);
+	mempool_free(iod->sg, anv->iod_mempool);
+}
+
+static void apple_nvme_print_sgl(struct scatterlist *sgl, int nents)
+{
+	int i;
+	struct scatterlist *sg;
+
+	for_each_sg(sgl, sg, nents, i) {
+		dma_addr_t phys = sg_phys(sg);
+
+		pr_warn("sg[%d] phys_addr:%pad offset:%d length:%d dma_address:%pad dma_length:%d\n",
+			i, &phys, sg->offset, sg->length, &sg_dma_address(sg),
+			sg_dma_len(sg));
+	}
+}
+
+static blk_status_t apple_nvme_setup_prps(struct apple_nvme *anv,
+					  struct request *req,
+					  struct nvme_rw_command *cmnd)
+{
+	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	struct dma_pool *pool;
+	int length = blk_rq_payload_bytes(req);
+	struct scatterlist *sg = iod->sg;
+	int dma_len = sg_dma_len(sg);
+	u64 dma_addr = sg_dma_address(sg);
+	int offset = dma_addr & (NVME_CTRL_PAGE_SIZE - 1);
+	__le64 *prp_list;
+	void **list = apple_nvme_iod_list(req);
+	dma_addr_t prp_dma;
+	int nprps, i;
+
+	length -= (NVME_CTRL_PAGE_SIZE - offset);
+	if (length <= 0) {
+		iod->first_dma = 0;
+		goto done;
+	}
+
+	dma_len -= (NVME_CTRL_PAGE_SIZE - offset);
+	if (dma_len) {
+		dma_addr += (NVME_CTRL_PAGE_SIZE - offset);
+	} else {
+		sg = sg_next(sg);
+		dma_addr = sg_dma_address(sg);
+		dma_len = sg_dma_len(sg);
+	}
+
+	if (length <= NVME_CTRL_PAGE_SIZE) {
+		iod->first_dma = dma_addr;
+		goto done;
+	}
+
+	nprps = DIV_ROUND_UP(length, NVME_CTRL_PAGE_SIZE);
+	if (nprps <= (256 / 8)) {
+		pool = anv->prp_small_pool;
+		iod->npages = 0;
+	} else {
+		pool = anv->prp_page_pool;
+		iod->npages = 1;
+	}
+
+	prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
+	if (!prp_list) {
+		iod->first_dma = dma_addr;
+		iod->npages = -1;
+		return BLK_STS_RESOURCE;
+	}
+	list[0] = prp_list;
+	iod->first_dma = prp_dma;
+	i = 0;
+	for (;;) {
+		if (i == NVME_CTRL_PAGE_SIZE >> 3) {
+			__le64 *old_prp_list = prp_list;
+
+			prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
+			if (!prp_list)
+				goto free_prps;
+			list[iod->npages++] = prp_list;
+			prp_list[0] = old_prp_list[i - 1];
+			old_prp_list[i - 1] = prp_dma;
+			i = 1;
+		}
+		prp_list[i++] = dma_addr;
+		dma_len -= NVME_CTRL_PAGE_SIZE;
+		dma_addr += NVME_CTRL_PAGE_SIZE;
+		length -= NVME_CTRL_PAGE_SIZE;
+		if (length <= 0)
+			break;
+		if (dma_len > 0)
+			continue;
+		if (unlikely(dma_len < 0))
+			goto bad_sgl;
+		sg = sg_next(sg);
+		dma_addr = sg_dma_address(sg);
+		dma_len = sg_dma_len(sg);
+	}
+done:
+	cmnd->dptr.prp1 = sg_dma_address(iod->sg);
+	cmnd->dptr.prp2 = iod->first_dma;
+	return BLK_STS_OK;
+free_prps:
+	apple_nvme_free_prps(anv, req);
+	return BLK_STS_RESOURCE;
+bad_sgl:
+	WARN(DO_ONCE(apple_nvme_print_sgl, iod->sg, iod->nents),
+	     "Invalid SGL for payload:%d nents:%d\n", blk_rq_payload_bytes(req),
+	     iod->nents);
+	return BLK_STS_IOERR;
+}
+
+static blk_status_t apple_nvme_setup_prp_simple(struct apple_nvme *anv,
+						struct request *req,
+						struct nvme_rw_command *cmnd,
+						struct bio_vec *bv)
+{
+	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	unsigned int offset = bv->bv_offset & (NVME_CTRL_PAGE_SIZE - 1);
+	unsigned int first_prp_len = NVME_CTRL_PAGE_SIZE - offset;
+
+	iod->first_dma = dma_map_bvec(anv->dev, bv, rq_dma_dir(req), 0);
+	if (dma_mapping_error(anv->dev, iod->first_dma))
+		return BLK_STS_RESOURCE;
+	iod->dma_len = bv->bv_len;
+
+	cmnd->dptr.prp1 = iod->first_dma;
+	if (bv->bv_len > first_prp_len)
+		cmnd->dptr.prp2 = iod->first_dma + first_prp_len;
+	return BLK_STS_OK;
+}
+
+static blk_status_t apple_nvme_map_data(struct apple_nvme *anv,
+					struct request *req,
+					struct nvme_command *cmnd)
+{
+	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	blk_status_t ret = BLK_STS_RESOURCE;
+	int nr_mapped;
+
+	if (blk_rq_nr_phys_segments(req) == 1) {
+		struct bio_vec bv = req_bvec(req);
+
+		if (bv.bv_offset + bv.bv_len <= NVME_CTRL_PAGE_SIZE * 2)
+			return apple_nvme_setup_prp_simple(anv, req, &cmnd->rw,
+							   &bv);
+	}
+
+	iod->dma_len = 0;
+	iod->sg = mempool_alloc(anv->iod_mempool, GFP_ATOMIC);
+	if (!iod->sg)
+		return BLK_STS_RESOURCE;
+	sg_init_table(iod->sg, blk_rq_nr_phys_segments(req));
+	iod->nents = blk_rq_map_sg(req->q, req, iod->sg);
+	if (!iod->nents)
+		goto out_free_sg;
+
+	nr_mapped = dma_map_sg_attrs(anv->dev, iod->sg, iod->nents,
+				     rq_dma_dir(req), DMA_ATTR_NO_WARN);
+	if (!nr_mapped)
+		goto out_free_sg;
+
+	ret = apple_nvme_setup_prps(anv, req, &cmnd->rw);
+	if (ret != BLK_STS_OK)
+		goto out_unmap_sg;
+	return BLK_STS_OK;
+
+out_unmap_sg:
+	dma_unmap_sg(anv->dev, iod->sg, iod->nents, rq_dma_dir(req));
+out_free_sg:
+	mempool_free(iod->sg, anv->iod_mempool);
+	return ret;
+}
+
+static __always_inline void apple_nvme_unmap_rq(struct request *req)
+{
+	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	struct apple_nvme *anv = queue_to_apple_nvme(iod->q);
+
+	if (blk_rq_nr_phys_segments(req))
+		apple_nvme_unmap_data(anv, req);
+}
+
+static void apple_nvme_complete_rq(struct request *req)
+{
+	apple_nvme_unmap_rq(req);
+	nvme_complete_rq(req);
+}
+
+static void apple_nvme_complete_batch(struct io_comp_batch *iob)
+{
+	nvme_complete_batch(iob, apple_nvme_unmap_rq);
+}
+
+static inline bool apple_nvme_cqe_pending(struct apple_nvme_queue *q)
+{
+	struct nvme_completion *hcqe = &q->cqes[q->cq_head];
+
+	return (READ_ONCE(hcqe->status) & 1) == q->cq_phase;
+}
+
+static inline struct blk_mq_tags *
+apple_nvme_queue_tagset(struct apple_nvme *anv, struct apple_nvme_queue *q)
+{
+	if (q->is_adminq)
+		return anv->admin_tagset.tags[0];
+	else
+		return anv->tagset.tags[0];
+}
+
+static inline void apple_nvme_handle_cqe(struct apple_nvme_queue *q,
+					 struct io_comp_batch *iob, u16 idx)
+{
+	struct apple_nvme *anv = queue_to_apple_nvme(q);
+	struct nvme_completion *cqe = &q->cqes[idx];
+	__u16 command_id = READ_ONCE(cqe->command_id);
+	struct request *req;
+
+	apple_nvmmu_inval(q, command_id);
+
+	req = nvme_find_rq(apple_nvme_queue_tagset(anv, q), command_id);
+	if (unlikely(!req)) {
+		dev_warn(anv->dev, "invalid id %d completed", command_id);
+		return;
+	}
+
+	if (!nvme_try_complete_req(req, cqe->status, cqe->result) &&
+	    !blk_mq_add_to_batch(req, iob, nvme_req(req)->status,
+				 apple_nvme_complete_batch))
+		apple_nvme_complete_rq(req);
+}
+
+static inline void apple_nvme_update_cq_head(struct apple_nvme_queue *q)
+{
+	u32 tmp = q->cq_head + 1;
+
+	if (tmp == apple_nvme_queue_depth(q)) {
+		q->cq_head = 0;
+		q->cq_phase ^= 1;
+	} else {
+		q->cq_head = tmp;
+	}
+}
+
+static bool apple_nvme_poll_cq(struct apple_nvme_queue *q,
+			       struct io_comp_batch *iob)
+{
+	bool found = false;
+
+	while (apple_nvme_cqe_pending(q)) {
+		found = true;
+
+		/*
+		 * load-load control dependency between phase and the rest of
+		 * the cqe requires a full read memory barrier
+		 */
+		dma_rmb();
+		apple_nvme_handle_cqe(q, iob, q->cq_head);
+		apple_nvme_update_cq_head(q);
+	}
+
+	if (found)
+		writel(q->cq_head, q->cq_db);
+
+	return found;
+}
+
+static bool apple_nvme_handle_cq(struct apple_nvme_queue *q, bool force)
+{
+	bool found;
+	DEFINE_IO_COMP_BATCH(iob);
+
+	if (!READ_ONCE(q->enabled) && !force)
+		return false;
+
+	found = apple_nvme_poll_cq(q, &iob);
+
+	if (!rq_list_empty(iob.req_list))
+		apple_nvme_complete_batch(&iob);
+
+	return found;
+}
+
+static irqreturn_t apple_nvme_irq(int irq, void *data)
+{
+	struct apple_nvme *anv = data;
+	bool handled = false;
+	unsigned long flags;
+
+	spin_lock_irqsave(&anv->lock, flags);
+	if (apple_nvme_handle_cq(&anv->ioq, false))
+		handled = true;
+	if (apple_nvme_handle_cq(&anv->adminq, false))
+		handled = true;
+	spin_unlock_irqrestore(&anv->lock, flags);
+
+	if (handled)
+		return IRQ_HANDLED;
+	return IRQ_NONE;
+}
+
+static int apple_nvme_create_cq(struct apple_nvme *anv)
+{
+	struct nvme_command c = {};
+
+	/*
+	 * Note: we (ab)use the fact that the prp fields survive if no data
+	 * is attached to the request.
+	 */
+	c.create_cq.opcode = nvme_admin_create_cq;
+	c.create_cq.prp1 = anv->ioq.cq_dma_addr;
+	c.create_cq.cqid = 1;
+	c.create_cq.qsize = APPLE_ANS_MAX_QUEUE_DEPTH - 1;
+	c.create_cq.cq_flags = NVME_QUEUE_PHYS_CONTIG | NVME_CQ_IRQ_ENABLED;
+	c.create_cq.irq_vector = 0;
+
+	return nvme_submit_sync_cmd(anv->ctrl.admin_q, &c, NULL, 0);
+}
+
+static int apple_nvme_remove_cq(struct apple_nvme *anv)
+{
+	struct nvme_command c = {};
+
+	c.delete_queue.opcode = nvme_admin_delete_cq;
+	c.delete_queue.qid = 1;
+
+	return nvme_submit_sync_cmd(anv->ctrl.admin_q, &c, NULL, 0);
+}
+
+static int apple_nvme_create_sq(struct apple_nvme *anv)
+{
+	struct nvme_command c = {};
+
+	/*
+	 * Note: we (ab)use the fact that the prp fields survive if no data
+	 * is attached to the request.
+	 */
+	c.create_sq.opcode = nvme_admin_create_sq;
+	c.create_sq.prp1 = anv->ioq.sq_dma_addr;
+	c.create_sq.sqid = 1;
+	c.create_sq.qsize = APPLE_ANS_MAX_QUEUE_DEPTH - 1;
+	c.create_sq.sq_flags = NVME_QUEUE_PHYS_CONTIG;
+	c.create_sq.cqid = 1;
+
+	return nvme_submit_sync_cmd(anv->ctrl.admin_q, &c, NULL, 0);
+}
+
+static int apple_nvme_remove_sq(struct apple_nvme *anv)
+{
+	struct nvme_command c = {};
+
+	c.delete_queue.opcode = nvme_admin_delete_sq;
+	c.delete_queue.qid = 1;
+
+	return nvme_submit_sync_cmd(anv->ctrl.admin_q, &c, NULL, 0);
+}
+
+static blk_status_t apple_nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
+					const struct blk_mq_queue_data *bd)
+{
+	struct nvme_ns *ns = hctx->queue->queuedata;
+	struct apple_nvme_queue *q = hctx->driver_data;
+	struct apple_nvme *anv = queue_to_apple_nvme(q);
+	struct request *req = bd->rq;
+	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	struct nvme_command *cmnd = &iod->cmd;
+	blk_status_t ret;
+
+	iod->npages = -1;
+	iod->nents = 0;
+
+	/*
+	 * We should not need to do this, but we're still using this to
+	 * ensure we can drain requests on a dying queue.
+	 */
+	if (unlikely(!READ_ONCE(q->enabled)))
+		return BLK_STS_IOERR;
+
+	if (!nvme_check_ready(&anv->ctrl, req, true))
+		return nvme_fail_nonready_command(&anv->ctrl, req);
+
+	ret = nvme_setup_cmd(ns, req);
+	if (ret)
+		return ret;
+
+	if (blk_rq_nr_phys_segments(req)) {
+		ret = apple_nvme_map_data(anv, req, cmnd);
+		if (ret)
+			goto out_free_cmd;
+	}
+
+	blk_mq_start_request(req);
+	apple_nvme_submit_cmd(q, cmnd);
+	return BLK_STS_OK;
+
+out_free_cmd:
+	nvme_cleanup_cmd(req);
+	return ret;
+}
+
+static int apple_nvme_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+				unsigned int hctx_idx)
+{
+	hctx->driver_data = data;
+	return 0;
+}
+
+static int apple_nvme_init_request(struct blk_mq_tag_set *set,
+				   struct request *req, unsigned int hctx_idx,
+				   unsigned int numa_node)
+{
+	struct apple_nvme_queue *q = set->driver_data;
+	struct apple_nvme *anv = queue_to_apple_nvme(q);
+	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	struct nvme_request *nreq = nvme_req(req);
+
+	iod->q = q;
+	nreq->ctrl = &anv->ctrl;
+	nreq->cmd = &iod->cmd;
+
+	return 0;
+}
+
+static void apple_nvme_disable(struct apple_nvme *anv, bool shutdown)
+{
+	u32 csts = readl(anv->mmio_nvme + NVME_REG_CSTS);
+	bool dead = false, freeze = false;
+	unsigned long flags;
+
+	if (apple_rtkit_is_crashed(anv->rtk))
+		dead = true;
+	if (!(csts & NVME_CSTS_RDY))
+		dead = true;
+	if (csts & NVME_CSTS_CFS)
+		dead = true;
+
+	if (anv->ctrl.state == NVME_CTRL_LIVE ||
+	    anv->ctrl.state == NVME_CTRL_RESETTING) {
+		freeze = true;
+		nvme_start_freeze(&anv->ctrl);
+	}
+
+	/*
+	 * Give the controller a chance to complete all entered requests if
+	 * doing a safe shutdown.
+	 */
+	if (!dead && shutdown && freeze)
+		nvme_wait_freeze_timeout(&anv->ctrl, NVME_IO_TIMEOUT);
+
+	nvme_stop_queues(&anv->ctrl);
+
+	if (!dead) {
+		if (READ_ONCE(anv->ioq.enabled)) {
+			apple_nvme_remove_sq(anv);
+			apple_nvme_remove_cq(anv);
+		}
+
+		if (shutdown)
+			nvme_shutdown_ctrl(&anv->ctrl);
+		nvme_disable_ctrl(&anv->ctrl);
+	}
+
+	WRITE_ONCE(anv->ioq.enabled, false);
+	WRITE_ONCE(anv->adminq.enabled, false);
+	mb(); /* ensure that nvme_queue_rq() sees that enabled is cleared */
+	nvme_stop_admin_queue(&anv->ctrl);
+
+	/* last chance to complete any requests before nvme_cancel_request */
+	spin_lock_irqsave(&anv->lock, flags);
+	apple_nvme_handle_cq(&anv->ioq, true);
+	apple_nvme_handle_cq(&anv->adminq, true);
+	spin_unlock_irqrestore(&anv->lock, flags);
+
+	blk_mq_tagset_busy_iter(&anv->tagset, nvme_cancel_request, &anv->ctrl);
+	blk_mq_tagset_busy_iter(&anv->admin_tagset, nvme_cancel_request,
+				&anv->ctrl);
+	blk_mq_tagset_wait_completed_request(&anv->tagset);
+	blk_mq_tagset_wait_completed_request(&anv->admin_tagset);
+
+	/*
+	 * The driver will not be starting up queues again if shutting down so
+	 * must flush all entered requests to their failed completion to avoid
+	 * deadlocking blk-mq hot-cpu notifier.
+	 */
+	if (shutdown) {
+		nvme_start_queues(&anv->ctrl);
+		nvme_start_admin_queue(&anv->ctrl);
+	}
+}
+
+static enum blk_eh_timer_return apple_nvme_timeout(struct request *req,
+						   bool reserved)
+{
+	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
+	struct apple_nvme_queue *q = iod->q;
+	struct apple_nvme *anv = queue_to_apple_nvme(q);
+	unsigned long flags;
+	u32 csts = readl(anv->mmio_nvme + NVME_REG_CSTS);
+
+	if (anv->ctrl.state != NVME_CTRL_LIVE) {
+		/*
+		 * From rdma.c:
+		 * If we are resetting, connecting or deleting we should
+		 * complete immediately because we may block controller
+		 * teardown or setup sequence
+		 * - ctrl disable/shutdown fabrics requests
+		 * - connect requests
+		 * - initialization admin requests
+		 * - I/O requests that entered after unquiescing and
+		 *   the controller stopped responding
+		 *
+		 * All other requests should be cancelled by the error
+		 * recovery work, so it's fine that we fail it here.
+		 */
+		dev_warn(anv->dev,
+			 "I/O %d(aq:%d) timeout while not in live state\n",
+			 req->tag, q->is_adminq);
+		if (blk_mq_request_started(req) &&
+		    !blk_mq_request_completed(req)) {
+			nvme_req(req)->status = NVME_SC_HOST_ABORTED_CMD;
+			nvme_req(req)->flags |= NVME_REQ_CANCELLED;
+			blk_mq_complete_request(req);
+		}
+		return BLK_EH_DONE;
+	}
+
+	/* check if we just missed an interrupt if we're still alive */
+	if (!apple_rtkit_is_crashed(anv->rtk) && !(csts & NVME_CSTS_CFS)) {
+		spin_lock_irqsave(&anv->lock, flags);
+		apple_nvme_handle_cq(q, false);
+		spin_unlock_irqrestore(&anv->lock, flags);
+		if (blk_mq_request_completed(req)) {
+			dev_warn(anv->dev,
+				 "I/O %d(aq:%d) timeout: completion polled\n",
+				 req->tag, q->is_adminq);
+			return BLK_EH_DONE;
+		}
+	}
+
+	/*
+	 * aborting commands isn't supported which leaves a full reset as our
+	 * only option here
+	 */
+	dev_warn(anv->dev, "I/O %d(aq:%d) timeout: resetting controller\n",
+		 req->tag, q->is_adminq);
+	nvme_req(req)->flags |= NVME_REQ_CANCELLED;
+	apple_nvme_disable(anv, false);
+	nvme_reset_ctrl(&anv->ctrl);
+	return BLK_EH_DONE;
+}
+
+static int apple_nvme_poll(struct blk_mq_hw_ctx *hctx,
+			   struct io_comp_batch *iob)
+{
+	struct apple_nvme_queue *q = hctx->driver_data;
+	struct apple_nvme *anv = queue_to_apple_nvme(q);
+	bool found;
+	unsigned long flags;
+
+	spin_lock_irqsave(&anv->lock, flags);
+	found = apple_nvme_poll_cq(q, iob);
+	spin_unlock_irqrestore(&anv->lock, flags);
+
+	return found;
+}
+
+static const struct blk_mq_ops apple_nvme_mq_admin_ops = {
+	.queue_rq = apple_nvme_queue_rq,
+	.complete = apple_nvme_complete_rq,
+	.init_hctx = apple_nvme_init_hctx,
+	.init_request = apple_nvme_init_request,
+	.timeout = apple_nvme_timeout,
+};
+
+static const struct blk_mq_ops apple_nvme_mq_ops = {
+	.queue_rq = apple_nvme_queue_rq,
+	.complete = apple_nvme_complete_rq,
+	.init_hctx = apple_nvme_init_hctx,
+	.init_request = apple_nvme_init_request,
+	.timeout = apple_nvme_timeout,
+	.poll = apple_nvme_poll,
+};
+
+static void apple_nvme_init_queue(struct apple_nvme_queue *q)
+{
+	unsigned int depth = apple_nvme_queue_depth(q);
+
+	q->cq_head = 0;
+	q->cq_phase = 1;
+	memset(q->tcbs, 0,
+	       APPLE_ANS_MAX_QUEUE_DEPTH * sizeof(struct apple_nvmmu_tcb));
+	memset(q->cqes, 0, depth * sizeof(struct nvme_completion));
+	WRITE_ONCE(q->enabled, true);
+	wmb(); /* ensure the first interrupt sees the initialization */
+}
+
+static void apple_nvme_reset_work(struct work_struct *work)
+{
+	unsigned int nr_io_queues = 1;
+	int ret;
+	u32 boot_status, aqa;
+	struct apple_nvme *anv =
+		container_of(work, struct apple_nvme, ctrl.reset_work);
+
+	if (anv->ctrl.state != NVME_CTRL_RESETTING) {
+		dev_warn(anv->dev, "ctrl state %d is not RESETTING\n",
+			 anv->ctrl.state);
+		ret = -ENODEV;
+		goto out;
+	}
+
+	/* there's unfortunately no known way to recover if RTKit crashed :( */
+	if (apple_rtkit_is_crashed(anv->rtk)) {
+		dev_err(anv->dev,
+			"RTKit has crashed without any way to recover.");
+		ret = -EIO;
+		goto out;
+	}
+
+	if (anv->ctrl.ctrl_config & NVME_CC_ENABLE)
+		apple_nvme_disable(anv, false);
+
+	/* RTKit must be shut down cleanly for the (soft)-reset to work */
+	if (apple_rtkit_is_running(anv->rtk)) {
+		dev_dbg(anv->dev, "Trying to shut down RTKit before reset.");
+		ret = apple_rtkit_shutdown(anv->rtk);
+		if (ret)
+			goto out;
+	}
+
+	writel(0, anv->mmio_coproc + APPLE_ANS_COPROC_CPU_CONTROL);
+
+	ret = reset_control_assert(anv->reset);
+	if (ret)
+		goto out;
+
+	ret = apple_rtkit_reinit(anv->rtk);
+	if (ret)
+		goto out;
+
+	ret = reset_control_deassert(anv->reset);
+	if (ret)
+		goto out;
+
+	writel(APPLE_ANS_COPROC_CPU_CONTROL_RUN,
+	       anv->mmio_coproc + APPLE_ANS_COPROC_CPU_CONTROL);
+	ret = apple_rtkit_boot(anv->rtk);
+	if (ret) {
+		dev_err(anv->dev, "ANS did not boot");
+		goto out;
+	}
+
+	ret = readl_poll_timeout(anv->mmio_nvme + APPLE_ANS_BOOT_STATUS,
+				 boot_status,
+				 boot_status == APPLE_ANS_BOOT_STATUS_OK,
+				 USEC_PER_MSEC, APPLE_ANS_BOOT_TIMEOUT);
+	if (ret) {
+		dev_err(anv->dev, "ANS did not initialize");
+		goto out;
+	}
+
+	dev_dbg(anv->dev, "ANS booted successfully.");
+
+	/*
+	 * Limit the max command size to prevent iod->sg allocations going
+	 * over a single page.
+	 */
+	anv->ctrl.max_hw_sectors = min_t(u32, NVME_MAX_KB_SZ << 1,
+					 dma_max_mapping_size(anv->dev) >> 9);
+	anv->ctrl.max_segments = NVME_MAX_SEGS;
+
+	/*
+	 * Enable NVMMU and linear submission queues.
+	 * While we could keep those disabled and pretend this is slightly
+	 * more common NVMe controller we'd still need some quirks (e.g.
+	 * sq entries will be 128 bytes) and Apple might drop support for
+	 * that mode in the future.
+	 */
+	writel(APPLE_ANS_LINEAR_SQ_EN,
+	       anv->mmio_nvme + APPLE_ANS_LINEAR_SQ_CTRL);
+
+	/* Allow as many pending command as possible for both queues */
+	writel(APPLE_ANS_MAX_QUEUE_DEPTH | (APPLE_ANS_MAX_QUEUE_DEPTH << 16),
+	       anv->mmio_nvme + APPLE_ANS_MAX_PEND_CMDS_CTRL);
+
+	/* Setup the NVMMU for the maximum admin and IO queue depth */
+	writel(APPLE_ANS_MAX_QUEUE_DEPTH - 1,
+	       anv->mmio_nvme + APPLE_NVMMU_NUM_TCBS);
+
+	/*
+	 * This is probably a chicken bit: without it all commands where any PRP
+	 * is set to zero (including those that don't use that field) fail and
+	 * the co-processor complains about "completed with err BAD_CMD-" or
+	 * a "NULL_PRP_PTR_ERR" in the syslog
+	 */
+	writel(readl(anv->mmio_nvme + APPLE_ANS_UNKNOWN_CTRL) &
+		       ~APPLE_ANS_PRP_NULL_CHECK,
+	       anv->mmio_nvme + APPLE_ANS_UNKNOWN_CTRL);
+
+	/* Setup the admin queue */
+	aqa = APPLE_NVME_AQ_DEPTH - 1;
+	aqa |= aqa << 16;
+	writel(aqa, anv->mmio_nvme + NVME_REG_AQA);
+	writeq(anv->adminq.sq_dma_addr, anv->mmio_nvme + NVME_REG_ASQ);
+	writeq(anv->adminq.cq_dma_addr, anv->mmio_nvme + NVME_REG_ACQ);
+
+	/* Setup NVMMU for both queues */
+	writeq(anv->adminq.tcb_dma_addr,
+	       anv->mmio_nvme + APPLE_NVMMU_ASQ_TCB_BASE);
+	writeq(anv->ioq.tcb_dma_addr,
+	       anv->mmio_nvme + APPLE_NVMMU_IOSQ_TCB_BASE);
+
+	anv->ctrl.sqsize =
+		APPLE_ANS_MAX_QUEUE_DEPTH - 1; /* 0's based queue depth */
+	anv->ctrl.cap = readq(anv->mmio_nvme + NVME_REG_CAP);
+
+	dev_dbg(anv->dev, "Enabling controller now");
+	ret = nvme_enable_ctrl(&anv->ctrl);
+	if (ret)
+		goto out;
+
+	dev_dbg(anv->dev, "Starting admin queue");
+	apple_nvme_init_queue(&anv->adminq);
+	nvme_start_admin_queue(&anv->ctrl);
+
+	if (!nvme_change_ctrl_state(&anv->ctrl, NVME_CTRL_CONNECTING)) {
+		dev_warn(anv->ctrl.device,
+			 "failed to mark controller CONNECTING\n");
+		ret = -ENODEV;
+		goto out;
+	}
+
+	ret = nvme_init_ctrl_finish(&anv->ctrl);
+	if (ret)
+		goto out;
+
+	dev_dbg(anv->dev, "Creating IOCQ");
+	ret = apple_nvme_create_cq(anv);
+	if (ret)
+		goto out;
+	dev_dbg(anv->dev, "Creating IOSQ");
+	ret = apple_nvme_create_sq(anv);
+	if (ret)
+		goto out_remove_cq;
+
+	apple_nvme_init_queue(&anv->ioq);
+	nr_io_queues = 1;
+	ret = nvme_set_queue_count(&anv->ctrl, &nr_io_queues);
+	if (ret)
+		goto out_remove_sq;
+	if (nr_io_queues != 1) {
+		ret = -ENXIO;
+		goto out_remove_sq;
+	}
+
+	anv->ctrl.queue_count = nr_io_queues + 1;
+
+	nvme_start_queues(&anv->ctrl);
+	nvme_wait_freeze(&anv->ctrl);
+	blk_mq_update_nr_hw_queues(&anv->tagset, 1);
+	nvme_unfreeze(&anv->ctrl);
+
+	if (!nvme_change_ctrl_state(&anv->ctrl, NVME_CTRL_LIVE)) {
+		dev_warn(anv->ctrl.device,
+			 "failed to mark controller live state\n");
+		ret = -ENODEV;
+		goto out_remove_sq;
+	}
+
+	nvme_start_ctrl(&anv->ctrl);
+
+	dev_dbg(anv->dev, "ANS boot and NVMe init completed.");
+	return;
+
+out_remove_sq:
+	apple_nvme_remove_sq(anv);
+out_remove_cq:
+	apple_nvme_remove_cq(anv);
+out:
+	dev_warn(anv->ctrl.device, "Reset failure status: %d\n", ret);
+	nvme_change_ctrl_state(&anv->ctrl, NVME_CTRL_DELETING);
+	nvme_get_ctrl(&anv->ctrl);
+	apple_nvme_disable(anv, false);
+	nvme_kill_queues(&anv->ctrl);
+	if (!queue_work(nvme_wq, &anv->remove_work))
+		nvme_put_ctrl(&anv->ctrl);
+}
+
+static void apple_nvme_remove_dead_ctrl_work(struct work_struct *work)
+{
+	struct apple_nvme *anv =
+		container_of(work, struct apple_nvme, remove_work);
+
+	nvme_put_ctrl(&anv->ctrl);
+	device_release_driver(anv->dev);
+}
+
+static int apple_nvme_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val)
+{
+	*val = readl(ctrl_to_apple_nvme(ctrl)->mmio_nvme + off);
+	return 0;
+}
+
+static int apple_nvme_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val)
+{
+	writel(val, ctrl_to_apple_nvme(ctrl)->mmio_nvme + off);
+	return 0;
+}
+
+static int apple_nvme_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val)
+{
+	*val = readq(ctrl_to_apple_nvme(ctrl)->mmio_nvme + off);
+	return 0;
+}
+
+static int apple_nvme_get_address(struct nvme_ctrl *ctrl, char *buf, int size)
+{
+	struct device *dev = ctrl_to_apple_nvme(ctrl)->dev;
+
+	return snprintf(buf, size, "%s\n", dev_name(dev));
+}
+
+static void apple_nvme_free_ctrl(struct nvme_ctrl *ctrl)
+{
+	struct apple_nvme *anv = ctrl_to_apple_nvme(ctrl);
+
+	if (anv->ctrl.admin_q)
+		blk_put_queue(anv->ctrl.admin_q);
+	put_device(anv->dev);
+}
+
+static const struct nvme_ctrl_ops nvme_ctrl_ops = {
+	.name = "apple-nvme",
+	.module = THIS_MODULE,
+	.flags = 0,
+	.reg_read32 = apple_nvme_reg_read32,
+	.reg_write32 = apple_nvme_reg_write32,
+	.reg_read64 = apple_nvme_reg_read64,
+	.free_ctrl = apple_nvme_free_ctrl,
+	.get_address = apple_nvme_get_address,
+};
+
+static void apple_nvme_async_probe(void *data, async_cookie_t cookie)
+{
+	struct apple_nvme *anv = data;
+
+	flush_work(&anv->ctrl.reset_work);
+	flush_work(&anv->ctrl.scan_work);
+	nvme_put_ctrl(&anv->ctrl);
+}
+
+static int apple_nvme_alloc_tagsets(struct apple_nvme *anv)
+{
+	int ret;
+
+	anv->admin_tagset.ops = &apple_nvme_mq_admin_ops;
+	anv->admin_tagset.nr_hw_queues = 1;
+	anv->admin_tagset.queue_depth = APPLE_NVME_AQ_MQ_TAG_DEPTH;
+	anv->admin_tagset.timeout = NVME_ADMIN_TIMEOUT;
+	anv->admin_tagset.numa_node = NUMA_NO_NODE;
+	anv->admin_tagset.cmd_size = sizeof(struct apple_nvme_iod);
+	anv->admin_tagset.flags = BLK_MQ_F_NO_SCHED;
+	anv->admin_tagset.driver_data = &anv->adminq;
+
+	ret = blk_mq_alloc_tag_set(&anv->admin_tagset);
+	if (ret)
+		return ret;
+	ret = devm_add_action_or_reset(anv->dev,
+				       (void (*)(void *))blk_mq_free_tag_set,
+				       &anv->admin_tagset);
+	if (ret)
+		return ret;
+
+	anv->tagset.ops = &apple_nvme_mq_ops;
+	anv->tagset.nr_hw_queues = 1;
+	anv->tagset.nr_maps = 1;
+	/*
+	 * Tags are used as an index to the NVMMU and must be unique across
+	 * both queues. The admin queue gets the first APPLE_NVME_AQ_DEPTH which
+	 * must be marked as reserved in the IO queue.
+	 */
+	anv->tagset.reserved_tags = APPLE_NVME_AQ_DEPTH;
+	anv->tagset.queue_depth = APPLE_ANS_MAX_QUEUE_DEPTH - 1;
+	anv->tagset.timeout = NVME_IO_TIMEOUT;
+	anv->tagset.numa_node = NUMA_NO_NODE;
+	anv->tagset.cmd_size = sizeof(struct apple_nvme_iod);
+	anv->tagset.flags = BLK_MQ_F_SHOULD_MERGE;
+	anv->tagset.driver_data = &anv->ioq;
+
+	ret = blk_mq_alloc_tag_set(&anv->tagset);
+	if (ret)
+		return ret;
+	ret = devm_add_action_or_reset(
+		anv->dev, (void (*)(void *))blk_mq_free_tag_set, &anv->tagset);
+	if (ret)
+		return ret;
+
+	anv->ctrl.admin_tagset = &anv->admin_tagset;
+	anv->ctrl.tagset = &anv->tagset;
+
+	return 0;
+}
+
+static int apple_nvme_queue_alloc(struct apple_nvme *anv,
+				  struct apple_nvme_queue *q)
+{
+	unsigned int depth = apple_nvme_queue_depth(q);
+
+	q->cqes = dmam_alloc_coherent(anv->dev,
+				      depth * sizeof(struct nvme_completion),
+				      &q->cq_dma_addr, GFP_KERNEL);
+	if (!q->cqes)
+		return -ENOMEM;
+
+	q->sqes = dmam_alloc_coherent(anv->dev,
+				      depth * sizeof(struct nvme_command),
+				      &q->sq_dma_addr, GFP_KERNEL);
+	if (!q->sqes)
+		return -ENOMEM;
+
+	/*
+	 * We need the maximum queue depth here because the NVMMU only has a
+	 * single depth configuration shared between both queues.
+	 */
+	q->tcbs = dmam_alloc_coherent(anv->dev,
+				      APPLE_ANS_MAX_QUEUE_DEPTH *
+					      sizeof(struct apple_nvmmu_tcb),
+				      &q->tcb_dma_addr, GFP_KERNEL);
+	if (!q->tcbs)
+		return -ENOMEM;
+
+	/*
+	 * initialize phase to make sure the allocated and empty memory
+	 * doesn't look like a full cq already.
+	 */
+	q->cq_phase = 1;
+	return 0;
+}
+
+static void apple_nvme_detach_genpd(struct apple_nvme *anv)
+{
+	int i;
+
+	if (anv->pd_count <= 1)
+		return;
+
+	for (i = anv->pd_count - 1; i >= 0; i--) {
+		if (anv->pd_link[i])
+			device_link_del(anv->pd_link[i]);
+		if (!IS_ERR_OR_NULL(anv->pd_dev[i]))
+			dev_pm_domain_detach(anv->pd_dev[i], true);
+	}
+}
+
+static int apple_nvme_attach_genpd(struct apple_nvme *anv)
+{
+	struct device *dev = anv->dev;
+	int i;
+
+	anv->pd_count = of_count_phandle_with_args(
+		dev->of_node, "power-domains", "#power-domain-cells");
+	if (anv->pd_count <= 1)
+		return 0;
+
+	anv->pd_dev = devm_kcalloc(dev, anv->pd_count, sizeof(*anv->pd_dev),
+				   GFP_KERNEL);
+	if (!anv->pd_dev)
+		return -ENOMEM;
+
+	anv->pd_link = devm_kcalloc(dev, anv->pd_count, sizeof(*anv->pd_link),
+				    GFP_KERNEL);
+	if (!anv->pd_link)
+		return -ENOMEM;
+
+	for (i = 0; i < anv->pd_count; i++) {
+		anv->pd_dev[i] = dev_pm_domain_attach_by_id(dev, i);
+		if (IS_ERR(anv->pd_dev[i])) {
+			apple_nvme_detach_genpd(anv);
+			return PTR_ERR(anv->pd_dev[i]);
+		}
+
+		anv->pd_link[i] = device_link_add(dev, anv->pd_dev[i],
+						  DL_FLAG_STATELESS |
+						  DL_FLAG_PM_RUNTIME |
+						  DL_FLAG_RPM_ACTIVE);
+		if (!anv->pd_link[i]) {
+			apple_nvme_detach_genpd(anv);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int apple_nvme_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct apple_nvme *anv;
+	int ret;
+
+	anv = devm_kzalloc(dev, sizeof(*anv), GFP_KERNEL);
+	if (!anv)
+		return -ENOMEM;
+
+	anv->dev = get_device(dev);
+	anv->adminq.is_adminq = true;
+	platform_set_drvdata(pdev, anv);
+
+	ret = apple_nvme_attach_genpd(anv);
+	if (ret < 0) {
+		dev_err_probe(dev, ret, "Failed to attach power domains");
+		goto put_dev;
+	}
+	if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64))) {
+		ret = -ENXIO;
+		goto put_dev;
+	}
+
+	anv->irq = platform_get_irq(pdev, 0);
+	if (anv->irq < 0) {
+		ret = anv->irq;
+		goto put_dev;
+	}
+	if (!anv->irq) {
+		ret = -ENXIO;
+		goto put_dev;
+	}
+
+	anv->mmio_coproc = devm_platform_ioremap_resource_byname(pdev, "ans");
+	if (IS_ERR(anv->mmio_coproc)) {
+		ret = PTR_ERR(anv->mmio_coproc);
+		goto put_dev;
+	}
+	anv->mmio_nvme = devm_platform_ioremap_resource_byname(pdev, "nvme");
+	if (IS_ERR(anv->mmio_nvme)) {
+		ret = PTR_ERR(anv->mmio_nvme);
+		goto put_dev;
+	}
+
+	anv->adminq.sq_db = anv->mmio_nvme + APPLE_ANS_LINEAR_ASQ_DB;
+	anv->adminq.cq_db = anv->mmio_nvme + APPLE_ANS_ACQ_DB;
+	anv->ioq.sq_db = anv->mmio_nvme + APPLE_ANS_LINEAR_IOSQ_DB;
+	anv->ioq.cq_db = anv->mmio_nvme + APPLE_ANS_IOCQ_DB;
+
+	anv->sart = devm_apple_sart_get(dev);
+	if (IS_ERR(anv->sart)) {
+		ret = dev_err_probe(dev, PTR_ERR(anv->sart),
+				    "Failed to initialize SART");
+		goto put_dev;
+	}
+
+	anv->reset = devm_reset_control_array_get_exclusive(anv->dev);
+	if (IS_ERR(anv->reset)) {
+		ret = dev_err_probe(dev, PTR_ERR(anv->reset),
+				    "Failed to get reset control");
+		goto put_dev;
+	}
+
+	INIT_WORK(&anv->ctrl.reset_work, apple_nvme_reset_work);
+	INIT_WORK(&anv->remove_work, apple_nvme_remove_dead_ctrl_work);
+	spin_lock_init(&anv->lock);
+
+	ret = apple_nvme_queue_alloc(anv, &anv->adminq);
+	if (ret)
+		goto put_dev;
+	ret = apple_nvme_queue_alloc(anv, &anv->ioq);
+	if (ret)
+		goto put_dev;
+
+	anv->prp_page_pool = dmam_pool_create("prp list page", anv->dev,
+					      NVME_CTRL_PAGE_SIZE,
+					      NVME_CTRL_PAGE_SIZE, 0);
+	if (!anv->prp_page_pool) {
+		ret = -ENOMEM;
+		goto put_dev;
+	}
+
+	anv->prp_small_pool =
+		dmam_pool_create("prp list 256", anv->dev, 256, 256, 0);
+	if (!anv->prp_small_pool) {
+		ret = -ENOMEM;
+		goto put_dev;
+	}
+
+	WARN_ON_ONCE(apple_nvme_iod_alloc_size() > PAGE_SIZE);
+	anv->iod_mempool =
+		mempool_create_kmalloc_pool(1, apple_nvme_iod_alloc_size());
+	if (!anv->iod_mempool) {
+		ret = -ENOMEM;
+		goto put_dev;
+	}
+	ret = devm_add_action_or_reset(
+		anv->dev, (void (*)(void *))mempool_destroy, anv->iod_mempool);
+	if (ret)
+		goto put_dev;
+
+	ret = apple_nvme_alloc_tagsets(anv);
+	if (ret)
+		goto put_dev;
+
+	ret = devm_request_irq(anv->dev, anv->irq, apple_nvme_irq, 0,
+			       "nvme-apple", anv);
+	if (ret) {
+		dev_err_probe(dev, ret, "Failed to request IRQ");
+		goto put_dev;
+	}
+
+	anv->rtk =
+		devm_apple_rtkit_init(dev, anv, NULL, 0, &apple_nvme_rtkit_ops);
+	if (IS_ERR(anv->rtk)) {
+		ret = dev_err_probe(dev, PTR_ERR(anv->rtk),
+				    "Failed to initialize RTKit");
+		goto put_dev;
+	}
+
+	ret = nvme_init_ctrl(&anv->ctrl, anv->dev, &nvme_ctrl_ops,
+			     NVME_QUIRK_SKIP_CID_GEN);
+	if (ret) {
+		dev_err_probe(dev, ret, "Failed to initialize nvme_ctrl");
+		goto put_dev;
+	}
+
+	anv->ctrl.admin_q = blk_mq_init_queue(&anv->admin_tagset);
+	if (IS_ERR(anv->ctrl.admin_q)) {
+		ret = -ENOMEM;
+		goto put_dev;
+	}
+
+	if (!blk_get_queue(anv->ctrl.admin_q)) {
+		nvme_start_admin_queue(&anv->ctrl);
+		blk_cleanup_queue(anv->ctrl.admin_q);
+		anv->ctrl.admin_q = NULL;
+		ret = -ENODEV;
+		goto put_dev;
+	}
+
+	nvme_reset_ctrl(&anv->ctrl);
+	async_schedule(apple_nvme_async_probe, anv);
+
+	return 0;
+
+put_dev:
+	put_device(anv->dev);
+	return ret;
+}
+
+static int apple_nvme_remove(struct platform_device *pdev)
+{
+	struct apple_nvme *anv = platform_get_drvdata(pdev);
+
+	nvme_change_ctrl_state(&anv->ctrl, NVME_CTRL_DELETING);
+	flush_work(&anv->ctrl.reset_work);
+	nvme_stop_ctrl(&anv->ctrl);
+	nvme_remove_namespaces(&anv->ctrl);
+	apple_nvme_disable(anv, true);
+	nvme_uninit_ctrl(&anv->ctrl);
+
+	if (apple_rtkit_is_running(anv->rtk))
+		apple_rtkit_shutdown(anv->rtk);
+
+	apple_nvme_detach_genpd(anv);
+
+	return 0;
+}
+
+static void apple_nvme_shutdown(struct platform_device *pdev)
+{
+	struct apple_nvme *anv = platform_get_drvdata(pdev);
+
+	apple_nvme_disable(anv, true);
+	if (apple_rtkit_is_running(anv->rtk))
+		apple_rtkit_shutdown(anv->rtk);
+}
+
+static int apple_nvme_resume(struct device *dev)
+{
+	struct apple_nvme *anv = dev_get_drvdata(dev);
+
+	return nvme_reset_ctrl(&anv->ctrl);
+}
+
+static int apple_nvme_suspend(struct device *dev)
+{
+	struct apple_nvme *anv = dev_get_drvdata(dev);
+	int ret = 0;
+
+	apple_nvme_disable(anv, true);
+
+	if (apple_rtkit_is_running(anv->rtk))
+		ret = apple_rtkit_shutdown(anv->rtk);
+
+	writel(0, anv->mmio_coproc + APPLE_ANS_COPROC_CPU_CONTROL);
+
+	return ret;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(apple_nvme_pm_ops, apple_nvme_suspend,
+				apple_nvme_resume);
+
+static const struct of_device_id apple_nvme_of_match[] = {
+	{ .compatible = "apple,nvme-ans2" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, apple_nvme_of_match);
+
+static struct platform_driver apple_nvme_driver = {
+	.driver = {
+		.name = "nvme-apple",
+		.of_match_table = apple_nvme_of_match,
+		.pm = pm_sleep_ptr(&apple_nvme_pm_ops),
+	},
+	.probe = apple_nvme_probe,
+	.remove = apple_nvme_remove,
+	.shutdown = apple_nvme_shutdown,
+};
+module_platform_driver(apple_nvme_driver);
+
+MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
+MODULE_LICENSE("GPL");