diff --git a/Documentation/driver-api/cxl/memory-devices.rst b/Documentation/driver-api/cxl/memory-devices.rst
index 71617e9002f1ada87fd9bcc05b03f0212206058f..43177e700d6223b0e660da290c1f7dd301a22626 100644
--- a/Documentation/driver-api/cxl/memory-devices.rst
+++ b/Documentation/driver-api/cxl/memory-devices.rst
@@ -13,3 +13,17 @@ Address space is handled via HDM (Host Managed Device Memory) decoders
that optionally define a device's contribution to an interleaved address
range across multiple devices underneath a host-bridge or interleaved
across host-bridges.
+
+Driver Infrastructure
+=====================
+
+This section covers the driver infrastructure for a CXL memory device.
+
+CXL Memory Device
+-----------------
+
+.. kernel-doc:: drivers/cxl/mem.c
+ :doc: cxl mem
+
+.. kernel-doc:: drivers/cxl/mem.c
+ :internal:
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
new file mode 100644
index 0000000000000000000000000000000000000000..baac26d9e63b9729685647decdf40d6c14e443ce
--- /dev/null
+++ b/drivers/cxl/cxl.h
@@ -0,0 +1,90 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright(c) 2020 Intel Corporation. */
+
+#ifndef __CXL_H__
+#define __CXL_H__
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+
+/* CXL 2.0 8.2.8.1 Device Capabilities Array Register */
+#define CXLDEV_CAP_ARRAY_OFFSET 0x0
+#define CXLDEV_CAP_ARRAY_CAP_ID 0
+#define CXLDEV_CAP_ARRAY_ID_MASK GENMASK_ULL(15, 0)
+#define CXLDEV_CAP_ARRAY_COUNT_MASK GENMASK_ULL(47, 32)
+/* CXL 2.0 8.2.8.2 CXL Device Capability Header Register */
+#define CXLDEV_CAP_HDR_CAP_ID_MASK GENMASK(15, 0)
+/* CXL 2.0 8.2.8.2.1 CXL Device Capabilities */
+#define CXLDEV_CAP_CAP_ID_DEVICE_STATUS 0x1
+#define CXLDEV_CAP_CAP_ID_PRIMARY_MAILBOX 0x2
+#define CXLDEV_CAP_CAP_ID_SECONDARY_MAILBOX 0x3
+#define CXLDEV_CAP_CAP_ID_MEMDEV 0x4000
+
+/* CXL 2.0 8.2.8.4 Mailbox Registers */
+#define CXLDEV_MBOX_CAPS_OFFSET 0x00
+#define CXLDEV_MBOX_CAP_PAYLOAD_SIZE_MASK GENMASK(4, 0)
+#define CXLDEV_MBOX_CTRL_OFFSET 0x04
+#define CXLDEV_MBOX_CTRL_DOORBELL BIT(0)
+#define CXLDEV_MBOX_CMD_OFFSET 0x08
+#define CXLDEV_MBOX_CMD_COMMAND_OPCODE_MASK GENMASK_ULL(15, 0)
+#define CXLDEV_MBOX_CMD_PAYLOAD_LENGTH_MASK GENMASK_ULL(36, 16)
+#define CXLDEV_MBOX_STATUS_OFFSET 0x10
+#define CXLDEV_MBOX_STATUS_RET_CODE_MASK GENMASK_ULL(47, 32)
+#define CXLDEV_MBOX_BG_CMD_STATUS_OFFSET 0x18
+#define CXLDEV_MBOX_PAYLOAD_OFFSET 0x20
+
+/* CXL 2.0 8.2.8.5.1.1 Memory Device Status Register */
+#define CXLMDEV_STATUS_OFFSET 0x0
+#define CXLMDEV_DEV_FATAL BIT(0)
+#define CXLMDEV_FW_HALT BIT(1)
+#define CXLMDEV_STATUS_MEDIA_STATUS_MASK GENMASK(3, 2)
+#define CXLMDEV_MS_NOT_READY 0
+#define CXLMDEV_MS_READY 1
+#define CXLMDEV_MS_ERROR 2
+#define CXLMDEV_MS_DISABLED 3
+#define CXLMDEV_READY(status) \
+ (FIELD_GET(CXLMDEV_STATUS_MEDIA_STATUS_MASK, status) == \
+ CXLMDEV_MS_READY)
+#define CXLMDEV_MBOX_IF_READY BIT(4)
+#define CXLMDEV_RESET_NEEDED_MASK GENMASK(7, 5)
+#define CXLMDEV_RESET_NEEDED_NOT 0
+#define CXLMDEV_RESET_NEEDED_COLD 1
+#define CXLMDEV_RESET_NEEDED_WARM 2
+#define CXLMDEV_RESET_NEEDED_HOT 3
+#define CXLMDEV_RESET_NEEDED_CXL 4
+#define CXLMDEV_RESET_NEEDED(status) \
+ (FIELD_GET(CXLMDEV_RESET_NEEDED_MASK, status) != \
+ CXLMDEV_RESET_NEEDED_NOT)
+
+/**
+ * struct cxl_mem - A CXL memory device
+ * @pdev: The PCI device associated with this CXL device.
+ * @regs: IO mappings to the device's MMIO
+ * @status_regs: CXL 2.0 8.2.8.3 Device Status Registers
+ * @mbox_regs: CXL 2.0 8.2.8.4 Mailbox Registers
+ * @memdev_regs: CXL 2.0 8.2.8.5 Memory Device Registers
+ * @payload_size: Size of space for payload
+ * (CXL 2.0 8.2.8.4.3 Mailbox Capabilities Register)
+ * @mbox_mutex: Mutex to synchronize mailbox access.
+ * @firmware_version: Firmware version for the memory device.
+ * @pmem_range: Persistent memory capacity information.
+ * @ram_range: Volatile memory capacity information.
+ */
+struct cxl_mem {
+ struct pci_dev *pdev;
+ void __iomem *regs;
+
+ void __iomem *status_regs;
+ void __iomem *mbox_regs;
+ void __iomem *memdev_regs;
+
+ size_t payload_size;
+ struct mutex mbox_mutex; /* Protects device mailbox and firmware */
+ char firmware_version[0x10];
+
+ struct range pmem_range;
+ struct range ram_range;
+};
+
+#endif /* __CXL_H__ */
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index ce33c5ee77c9c03859fc7d049d91a9db7171d755..04e15759bc9b8a21cb6d7148c1eb4b4de64105a8 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -3,7 +3,491 @@
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/io.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
#include "pci.h"
+#include "cxl.h"
+
+/**
+ * DOC: cxl mem
+ *
+ * This implements a CXL memory device ("type-3") as it is defined by the
+ * Compute Express Link specification.
+ *
+ * The driver has several responsibilities, mainly:
+ * - Create the memX device and register on the CXL bus.
+ * - Enumerate device's register interface and map them.
+ * - Probe the device attributes to establish sysfs interface.
+ * - Provide an IOCTL interface to userspace to communicate with the device for
+ * things like firmware update.
+ * - Support management of interleave sets.
+ * - Handle and manage error conditions.
+ */
+
+#define cxl_doorbell_busy(cxlm) \
+ (readl((cxlm)->mbox_regs + CXLDEV_MBOX_CTRL_OFFSET) & \
+ CXLDEV_MBOX_CTRL_DOORBELL)
+
+/* CXL 2.0 - 8.2.8.4 */
+#define CXL_MAILBOX_TIMEOUT_MS (2 * HZ)
+
+enum opcode {
+ CXL_MBOX_OP_IDENTIFY = 0x4000,
+ CXL_MBOX_OP_MAX = 0x10000
+};
+
+/**
+ * struct mbox_cmd - A command to be submitted to hardware.
+ * @opcode: (input) The command set and command submitted to hardware.
+ * @payload_in: (input) Pointer to the input payload.
+ * @payload_out: (output) Pointer to the output payload. Must be allocated by
+ * the caller.
+ * @size_in: (input) Number of bytes to load from @payload_in.
+ * @size_out: (input) Max number of bytes loaded into @payload_out.
+ * (output) Number of bytes generated by the device. For fixed size
+ * outputs commands this is always expected to be deterministic. For
+ * variable sized output commands, it tells the exact number of bytes
+ * written.
+ * @return_code: (output) Error code returned from hardware.
+ *
+ * This is the primary mechanism used to send commands to the hardware.
+ * All the fields except @payload_* correspond exactly to the fields described in
+ * Command Register section of the CXL 2.0 8.2.8.4.5. @payload_in and
+ * @payload_out are written to, and read from the Command Payload Registers
+ * defined in CXL 2.0 8.2.8.4.8.
+ */
+struct mbox_cmd {
+ u16 opcode;
+ void *payload_in;
+ void *payload_out;
+ size_t size_in;
+ size_t size_out;
+ u16 return_code;
+#define CXL_MBOX_SUCCESS 0
+};
+
+static int cxl_mem_wait_for_doorbell(struct cxl_mem *cxlm)
+{
+ const unsigned long start = jiffies;
+ unsigned long end = start;
+
+ while (cxl_doorbell_busy(cxlm)) {
+ end = jiffies;
+
+ if (time_after(end, start + CXL_MAILBOX_TIMEOUT_MS)) {
+ /* Check again in case preempted before timeout test */
+ if (!cxl_doorbell_busy(cxlm))
+ break;
+ return -ETIMEDOUT;
+ }
+ cpu_relax();
+ }
+
+ dev_dbg(&cxlm->pdev->dev, "Doorbell wait took %dms",
+ jiffies_to_msecs(end) - jiffies_to_msecs(start));
+ return 0;
+}
+
+static void cxl_mem_mbox_timeout(struct cxl_mem *cxlm,
+ struct mbox_cmd *mbox_cmd)
+{
+ struct device *dev = &cxlm->pdev->dev;
+
+ dev_dbg(dev, "Mailbox command (opcode: %#x size: %zub) timed out\n",
+ mbox_cmd->opcode, mbox_cmd->size_in);
+}
+
+/**
+ * __cxl_mem_mbox_send_cmd() - Execute a mailbox command
+ * @cxlm: The CXL memory device to communicate with.
+ * @mbox_cmd: Command to send to the memory device.
+ *
+ * Context: Any context. Expects mbox_mutex to be held.
+ * Return: -ETIMEDOUT if timeout occurred waiting for completion. 0 on success.
+ * Caller should check the return code in @mbox_cmd to make sure it
+ * succeeded.
+ *
+ * This is a generic form of the CXL mailbox send command thus only using the
+ * registers defined by the mailbox capability ID - CXL 2.0 8.2.8.4. Memory
+ * devices, and perhaps other types of CXL devices may have further information
+ * available upon error conditions. Driver facilities wishing to send mailbox
+ * commands should use the wrapper command.
+ *
+ * The CXL spec allows for up to two mailboxes. The intention is for the primary
+ * mailbox to be OS controlled and the secondary mailbox to be used by system
+ * firmware. This allows the OS and firmware to communicate with the device and
+ * not need to coordinate with each other. The driver only uses the primary
+ * mailbox.
+ */
+static int __cxl_mem_mbox_send_cmd(struct cxl_mem *cxlm,
+ struct mbox_cmd *mbox_cmd)
+{
+ void __iomem *payload = cxlm->mbox_regs + CXLDEV_MBOX_PAYLOAD_OFFSET;
+ u64 cmd_reg, status_reg;
+ size_t out_len;
+ int rc;
+
+ lockdep_assert_held(&cxlm->mbox_mutex);
+
+ /*
+ * Here are the steps from 8.2.8.4 of the CXL 2.0 spec.
+ * 1. Caller reads MB Control Register to verify doorbell is clear
+ * 2. Caller writes Command Register
+ * 3. Caller writes Command Payload Registers if input payload is non-empty
+ * 4. Caller writes MB Control Register to set doorbell
+ * 5. Caller either polls for doorbell to be clear or waits for interrupt if configured
+ * 6. Caller reads MB Status Register to fetch Return code
+ * 7. If command successful, Caller reads Command Register to get Payload Length
+ * 8. If output payload is non-empty, host reads Command Payload Registers
+ *
+ * Hardware is free to do whatever it wants before the doorbell is rung,
+ * and isn't allowed to change anything after it clears the doorbell. As
+ * such, steps 2 and 3 can happen in any order, and steps 6, 7, 8 can
+ * also happen in any order (though some orders might not make sense).
+ */
+
+ /* #1 */
+ if (cxl_doorbell_busy(cxlm)) {
+ dev_err_ratelimited(&cxlm->pdev->dev,
+ "Mailbox re-busy after acquiring\n");
+ return -EBUSY;
+ }
+
+ cmd_reg = FIELD_PREP(CXLDEV_MBOX_CMD_COMMAND_OPCODE_MASK,
+ mbox_cmd->opcode);
+ if (mbox_cmd->size_in) {
+ if (WARN_ON(!mbox_cmd->payload_in))
+ return -EINVAL;
+
+ cmd_reg |= FIELD_PREP(CXLDEV_MBOX_CMD_PAYLOAD_LENGTH_MASK,
+ mbox_cmd->size_in);
+ memcpy_toio(payload, mbox_cmd->payload_in, mbox_cmd->size_in);
+ }
+
+ /* #2, #3 */
+ writeq(cmd_reg, cxlm->mbox_regs + CXLDEV_MBOX_CMD_OFFSET);
+
+ /* #4 */
+ dev_dbg(&cxlm->pdev->dev, "Sending command\n");
+ writel(CXLDEV_MBOX_CTRL_DOORBELL,
+ cxlm->mbox_regs + CXLDEV_MBOX_CTRL_OFFSET);
+
+ /* #5 */
+ rc = cxl_mem_wait_for_doorbell(cxlm);
+ if (rc == -ETIMEDOUT) {
+ cxl_mem_mbox_timeout(cxlm, mbox_cmd);
+ return rc;
+ }
+
+ /* #6 */
+ status_reg = readq(cxlm->mbox_regs + CXLDEV_MBOX_STATUS_OFFSET);
+ mbox_cmd->return_code =
+ FIELD_GET(CXLDEV_MBOX_STATUS_RET_CODE_MASK, status_reg);
+
+ if (mbox_cmd->return_code != 0) {
+ dev_dbg(&cxlm->pdev->dev, "Mailbox operation had an error\n");
+ return 0;
+ }
+
+ /* #7 */
+ cmd_reg = readq(cxlm->mbox_regs + CXLDEV_MBOX_CMD_OFFSET);
+ out_len = FIELD_GET(CXLDEV_MBOX_CMD_PAYLOAD_LENGTH_MASK, cmd_reg);
+
+ /* #8 */
+ if (out_len && mbox_cmd->payload_out) {
+ /*
+ * Sanitize the copy. If hardware misbehaves, out_len per the
+ * spec can actually be greater than the max allowed size (21
+ * bits available but spec defined 1M max). The caller also may
+ * have requested less data than the hardware supplied even
+ * within spec.
+ */
+ size_t n = min3(mbox_cmd->size_out, cxlm->payload_size, out_len);
+
+ memcpy_fromio(mbox_cmd->payload_out, payload, n);
+ mbox_cmd->size_out = n;
+ } else {
+ mbox_cmd->size_out = 0;
+ }
+
+ return 0;
+}
+
+/**
+ * cxl_mem_mbox_get() - Acquire exclusive access to the mailbox.
+ * @cxlm: The memory device to gain access to.
+ *
+ * Context: Any context. Takes the mbox_mutex.
+ * Return: 0 if exclusive access was acquired.
+ */
+static int cxl_mem_mbox_get(struct cxl_mem *cxlm)
+{
+ struct device *dev = &cxlm->pdev->dev;
+ u64 md_status;
+ int rc;
+
+ mutex_lock_io(&cxlm->mbox_mutex);
+
+ /*
+ * XXX: There is some amount of ambiguity in the 2.0 version of the spec
+ * around the mailbox interface ready (8.2.8.5.1.1). The purpose of the
+ * bit is to allow firmware running on the device to notify the driver
+ * that it's ready to receive commands. It is unclear if the bit needs
+ * to be read for each transaction mailbox, ie. the firmware can switch
+ * it on and off as needed. Second, there is no defined timeout for
+ * mailbox ready, like there is for the doorbell interface.
+ *
+ * Assumptions:
+ * 1. The firmware might toggle the Mailbox Interface Ready bit, check
+ * it for every command.
+ *
+ * 2. If the doorbell is clear, the firmware should have first set the
+ * Mailbox Interface Ready bit. Therefore, waiting for the doorbell
+ * to be ready is sufficient.
+ */
+ rc = cxl_mem_wait_for_doorbell(cxlm);
+ if (rc) {
+ dev_warn(dev, "Mailbox interface not ready\n");
+ goto out;
+ }
+
+ md_status = readq(cxlm->memdev_regs + CXLMDEV_STATUS_OFFSET);
+ if (!(md_status & CXLMDEV_MBOX_IF_READY && CXLMDEV_READY(md_status))) {
+ dev_err(dev, "mbox: reported doorbell ready, but not mbox ready\n");
+ rc = -EBUSY;
+ goto out;
+ }
+
+ /*
+ * Hardware shouldn't allow a ready status but also have failure bits
+ * set. Spit out an error, this should be a bug report
+ */
+ rc = -EFAULT;
+ if (md_status & CXLMDEV_DEV_FATAL) {
+ dev_err(dev, "mbox: reported ready, but fatal\n");
+ goto out;
+ }
+ if (md_status & CXLMDEV_FW_HALT) {
+ dev_err(dev, "mbox: reported ready, but halted\n");
+ goto out;
+ }
+ if (CXLMDEV_RESET_NEEDED(md_status)) {
+ dev_err(dev, "mbox: reported ready, but reset needed\n");
+ goto out;
+ }
+
+ /* with lock held */
+ return 0;
+
+out:
+ mutex_unlock(&cxlm->mbox_mutex);
+ return rc;
+}
+
+/**
+ * cxl_mem_mbox_put() - Release exclusive access to the mailbox.
+ * @cxlm: The CXL memory device to communicate with.
+ *
+ * Context: Any context. Expects mbox_mutex to be held.
+ */
+static void cxl_mem_mbox_put(struct cxl_mem *cxlm)
+{
+ mutex_unlock(&cxlm->mbox_mutex);
+}
+
+/**
+ * cxl_mem_mbox_send_cmd() - Send a mailbox command to a memory device.
+ * @cxlm: The CXL memory device to communicate with.
+ * @opcode: Opcode for the mailbox command.
+ * @in: The input payload for the mailbox command.
+ * @in_size: The length of the input payload
+ * @out: Caller allocated buffer for the output.
+ * @out_size: Expected size of output.
+ *
+ * Context: Any context. Will acquire and release mbox_mutex.
+ * Return:
+ * * %>=0 - Number of bytes returned in @out.
+ * * %-E2BIG - Payload is too large for hardware.
+ * * %-EBUSY - Couldn't acquire exclusive mailbox access.
+ * * %-EFAULT - Hardware error occurred.
+ * * %-ENXIO - Command completed, but device reported an error.
+ * * %-EIO - Unexpected output size.
+ *
+ * Mailbox commands may execute successfully yet the device itself reported an
+ * error. While this distinction can be useful for commands from userspace, the
+ * kernel will only be able to use results when both are successful. It's
+ * expected that all callers of this function know exactly the size of the data
+ * they will consume from the hardware.
+ *
+ * See __cxl_mem_mbox_send_cmd()
+ */
+static int cxl_mem_mbox_send_cmd(struct cxl_mem *cxlm, u16 opcode,
+ void *in, size_t in_size,
+ void *out, size_t out_size)
+{
+ struct mbox_cmd mbox_cmd = {
+ .opcode = opcode,
+ .payload_in = in,
+ .size_in = in_size,
+ .size_out = out_size,
+ .payload_out = out,
+ };
+ int rc;
+
+ if (out_size > cxlm->payload_size)
+ return -E2BIG;
+
+ rc = cxl_mem_mbox_get(cxlm);
+ if (rc)
+ return rc;
+
+ rc = __cxl_mem_mbox_send_cmd(cxlm, &mbox_cmd);
+ cxl_mem_mbox_put(cxlm);
+ if (rc)
+ return rc;
+
+ /* TODO: Map return code to proper kernel style errno */
+ if (mbox_cmd.return_code != CXL_MBOX_SUCCESS)
+ return -ENXIO;
+
+ if (mbox_cmd.size_out != out_size)
+ return -EIO;
+
+ return 0;
+}
+
+/**
+ * cxl_mem_setup_regs() - Setup necessary MMIO.
+ * @cxlm: The CXL memory device to communicate with.
+ *
+ * Return: 0 if all necessary registers mapped.
+ *
+ * A memory device is required by spec to implement a certain set of MMIO
+ * regions. The purpose of this function is to enumerate and map those
+ * registers.
+ */
+static int cxl_mem_setup_regs(struct cxl_mem *cxlm)
+{
+ struct device *dev = &cxlm->pdev->dev;
+ int cap, cap_count;
+ u64 cap_array;
+
+ cap_array = readq(cxlm->regs + CXLDEV_CAP_ARRAY_OFFSET);
+ if (FIELD_GET(CXLDEV_CAP_ARRAY_ID_MASK, cap_array) !=
+ CXLDEV_CAP_ARRAY_CAP_ID)
+ return -ENODEV;
+
+ cap_count = FIELD_GET(CXLDEV_CAP_ARRAY_COUNT_MASK, cap_array);
+
+ for (cap = 1; cap <= cap_count; cap++) {
+ void __iomem *register_block;
+ u32 offset;
+ u16 cap_id;
+
+ cap_id = FIELD_GET(CXLDEV_CAP_HDR_CAP_ID_MASK,
+ readl(cxlm->regs + cap * 0x10));
+ offset = readl(cxlm->regs + cap * 0x10 + 0x4);
+ register_block = cxlm->regs + offset;
+
+ switch (cap_id) {
+ case CXLDEV_CAP_CAP_ID_DEVICE_STATUS:
+ dev_dbg(dev, "found Status capability (0x%x)\n", offset);
+ cxlm->status_regs = register_block;
+ break;
+ case CXLDEV_CAP_CAP_ID_PRIMARY_MAILBOX:
+ dev_dbg(dev, "found Mailbox capability (0x%x)\n", offset);
+ cxlm->mbox_regs = register_block;
+ break;
+ case CXLDEV_CAP_CAP_ID_SECONDARY_MAILBOX:
+ dev_dbg(dev, "found Secondary Mailbox capability (0x%x)\n", offset);
+ break;
+ case CXLDEV_CAP_CAP_ID_MEMDEV:
+ dev_dbg(dev, "found Memory Device capability (0x%x)\n", offset);
+ cxlm->memdev_regs = register_block;
+ break;
+ default:
+ dev_dbg(dev, "Unknown cap ID: %d (0x%x)\n", cap_id, offset);
+ break;
+ }
+ }
+
+ if (!cxlm->status_regs || !cxlm->mbox_regs || !cxlm->memdev_regs) {
+ dev_err(dev, "registers not found: %s%s%s\n",
+ !cxlm->status_regs ? "status " : "",
+ !cxlm->mbox_regs ? "mbox " : "",
+ !cxlm->memdev_regs ? "memdev" : "");
+ return -ENXIO;
+ }
+
+ return 0;
+}
+
+static int cxl_mem_setup_mailbox(struct cxl_mem *cxlm)
+{
+ const int cap = readl(cxlm->mbox_regs + CXLDEV_MBOX_CAPS_OFFSET);
+
+ cxlm->payload_size =
+ 1 << FIELD_GET(CXLDEV_MBOX_CAP_PAYLOAD_SIZE_MASK, cap);
+
+ /*
+ * CXL 2.0 8.2.8.4.3 Mailbox Capabilities Register
+ *
+ * If the size is too small, mandatory commands will not work and so
+ * there's no point in going forward. If the size is too large, there's
+ * no harm is soft limiting it.
+ */
+ cxlm->payload_size = min_t(size_t, cxlm->payload_size, SZ_1M);
+ if (cxlm->payload_size < 256) {
+ dev_err(&cxlm->pdev->dev, "Mailbox is too small (%zub)",
+ cxlm->payload_size);
+ return -ENXIO;
+ }
+
+ dev_dbg(&cxlm->pdev->dev, "Mailbox payload sized %zu",
+ cxlm->payload_size);
+
+ return 0;
+}
+
+static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo,
+ u32 reg_hi)
+{
+ struct device *dev = &pdev->dev;
+ struct cxl_mem *cxlm;
+ void __iomem *regs;
+ u64 offset;
+ u8 bar;
+ int rc;
+
+ cxlm = devm_kzalloc(&pdev->dev, sizeof(*cxlm), GFP_KERNEL);
+ if (!cxlm) {
+ dev_err(dev, "No memory available\n");
+ return NULL;
+ }
+
+ offset = ((u64)reg_hi << 32) | FIELD_GET(CXL_REGLOC_ADDR_MASK, reg_lo);
+ bar = FIELD_GET(CXL_REGLOC_BIR_MASK, reg_lo);
+
+ /* Basic sanity check that BAR is big enough */
+ if (pci_resource_len(pdev, bar) < offset) {
+ dev_err(dev, "BAR%d: %pr: too small (offset: %#llx)\n", bar,
+ &pdev->resource[bar], (unsigned long long)offset);
+ return NULL;
+ }
+
+ rc = pcim_iomap_regions(pdev, BIT(bar), pci_name(pdev));
+ if (rc) {
+ dev_err(dev, "failed to map registers\n");
+ return NULL;
+ }
+ regs = pcim_iomap_table(pdev)[bar];
+
+ mutex_init(&cxlm->mbox_mutex);
+ cxlm->pdev = pdev;
+ cxlm->regs = regs + offset;
+
+ dev_dbg(dev, "Mapped CXL Memory Device resource\n");
+ return cxlm;
+}
static int cxl_mem_dvsec(struct pci_dev *pdev, int dvsec)
{
@@ -28,10 +512,65 @@ static int cxl_mem_dvsec(struct pci_dev *pdev, int dvsec)
return 0;
}
+/**
+ * cxl_mem_identify() - Send the IDENTIFY command to the device.
+ * @cxlm: The device to identify.
+ *
+ * Return: 0 if identify was executed successfully.
+ *
+ * This will dispatch the identify command to the device and on success populate
+ * structures to be exported to sysfs.
+ */
+static int cxl_mem_identify(struct cxl_mem *cxlm)
+{
+ struct cxl_mbox_identify {
+ char fw_revision[0x10];
+ __le64 total_capacity;
+ __le64 volatile_capacity;
+ __le64 persistent_capacity;
+ __le64 partition_align;
+ __le16 info_event_log_size;
+ __le16 warning_event_log_size;
+ __le16 failure_event_log_size;
+ __le16 fatal_event_log_size;
+ __le32 lsa_size;
+ u8 poison_list_max_mer[3];
+ __le16 inject_poison_limit;
+ u8 poison_caps;
+ u8 qos_telemetry_caps;
+ } __packed id;
+ int rc;
+
+ rc = cxl_mem_mbox_send_cmd(cxlm, CXL_MBOX_OP_IDENTIFY, NULL, 0, &id,
+ sizeof(id));
+ if (rc < 0)
+ return rc;
+
+ /*
+ * TODO: enumerate DPA map, as 'ram' and 'pmem' do not alias.
+ * For now, only the capacity is exported in sysfs
+ */
+ cxlm->ram_range.start = 0;
+ cxlm->ram_range.end = le64_to_cpu(id.volatile_capacity) - 1;
+
+ cxlm->pmem_range.start = 0;
+ cxlm->pmem_range.end = le64_to_cpu(id.persistent_capacity) - 1;
+
+ memcpy(cxlm->firmware_version, id.fw_revision, sizeof(id.fw_revision));
+
+ return 0;
+}
+
static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
struct device *dev = &pdev->dev;
- int regloc;
+ struct cxl_mem *cxlm = NULL;
+ u32 regloc_size, regblocks;
+ int rc, regloc, i;
+
+ rc = pcim_enable_device(pdev);
+ if (rc)
+ return rc;
regloc = cxl_mem_dvsec(pdev, PCI_DVSEC_ID_CXL_REGLOC_OFFSET);
if (!regloc) {
@@ -39,7 +578,41 @@ static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id)
return -ENXIO;
}
- return 0;
+ /* Get the size of the Register Locator DVSEC */
+ pci_read_config_dword(pdev, regloc + PCI_DVSEC_HEADER1, ®loc_size);
+ regloc_size = FIELD_GET(PCI_DVSEC_HEADER1_LENGTH_MASK, regloc_size);
+
+ regloc += PCI_DVSEC_ID_CXL_REGLOC_BLOCK1_OFFSET;
+ regblocks = (regloc_size - PCI_DVSEC_ID_CXL_REGLOC_BLOCK1_OFFSET) / 8;
+
+ for (i = 0; i < regblocks; i++, regloc += 8) {
+ u32 reg_lo, reg_hi;
+ u8 reg_type;
+
+ /* "register low and high" contain other bits */
+ pci_read_config_dword(pdev, regloc, ®_lo);
+ pci_read_config_dword(pdev, regloc + 4, ®_hi);
+
+ reg_type = FIELD_GET(CXL_REGLOC_RBI_MASK, reg_lo);
+
+ if (reg_type == CXL_REGLOC_RBI_MEMDEV) {
+ cxlm = cxl_mem_create(pdev, reg_lo, reg_hi);
+ break;
+ }
+ }
+
+ if (!cxlm)
+ return -ENODEV;
+
+ rc = cxl_mem_setup_regs(cxlm);
+ if (rc)
+ return rc;
+
+ rc = cxl_mem_setup_mailbox(cxlm);
+ if (rc)
+ return rc;
+
+ return cxl_mem_identify(cxlm);
}
static const struct pci_device_id cxl_mem_pci_tbl[] = {
diff --git a/drivers/cxl/pci.h b/drivers/cxl/pci.h
index e464bea3f4d3f6b98471221d92c4d7bf818e2a3b..af3ec078cf6cbe7cf43173178abe84f826e1b095 100644
--- a/drivers/cxl/pci.h
+++ b/drivers/cxl/pci.h
@@ -9,9 +9,23 @@
* See section 8.1 Configuration Space Registers in the CXL 2.0
* Specification
*/
+#define PCI_DVSEC_HEADER1_LENGTH_MASK GENMASK(31, 20)
#define PCI_DVSEC_VENDOR_ID_CXL 0x1E98
#define PCI_DVSEC_ID_CXL 0x0
#define PCI_DVSEC_ID_CXL_REGLOC_OFFSET 0x8
+#define PCI_DVSEC_ID_CXL_REGLOC_BLOCK1_OFFSET 0xC
+
+/* BAR Indicator Register (BIR) */
+#define CXL_REGLOC_BIR_MASK GENMASK(2, 0)
+
+/* Register Block Identifier (RBI) */
+#define CXL_REGLOC_RBI_MASK GENMASK(15, 8)
+#define CXL_REGLOC_RBI_EMPTY 0
+#define CXL_REGLOC_RBI_COMPONENT 1
+#define CXL_REGLOC_RBI_VIRT 2
+#define CXL_REGLOC_RBI_MEMDEV 3
+
+#define CXL_REGLOC_ADDR_MASK GENMASK(31, 16)
#endif /* __CXL_PCI_H__ */