diff options
author | Ben Widawsky <ben.widawsky@intel.com> | 2021-02-17 07:09:51 +0300 |
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committer | Dan Williams <dan.j.williams@intel.com> | 2021-02-17 07:36:38 +0300 |
commit | 8adaf747c9f0b470aea1b0c88583aa0a344e1540 (patch) | |
tree | bfcca72b9429c977778ad98b2d97cb6184f97b9d /drivers/cxl/cxl.h | |
parent | 4cdadfd5e0a70017fec735b7b6d7f2f731842dc6 (diff) | |
download | linux-8adaf747c9f0b470aea1b0c88583aa0a344e1540.tar.xz |
cxl/mem: Find device capabilities
Provide enough functionality to utilize the mailbox of a memory device.
The mailbox is used to interact with the firmware running on the memory
device. The flow is proven with one implemented command, "identify".
Because the class code has already told the driver this is a memory
device and the identify command is mandatory.
CXL devices contain an array of capabilities that describe the
interactions software can have with the device or firmware running on
the device. A CXL compliant device must implement the device status and
the mailbox capability. Additionally, a CXL compliant memory device must
implement the memory device capability. Each of the capabilities can
[will] provide an offset within the MMIO region for interacting with the
CXL device.
The capabilities tell the driver how to find and map the register space
for CXL Memory Devices. The registers are required to utilize the CXL
spec defined mailbox interface. The spec outlines two mailboxes, primary
and secondary. The secondary mailbox is earmarked for system firmware,
and not handled in this driver.
Primary mailboxes are capable of generating an interrupt when submitting
a background command. That implementation is saved for a later time.
Reported-by: Colin Ian King <colin.king@canonical.com> (coverity)
Reported-by: Dan Carpenter <dan.carpenter@oracle.com> (smatch)
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com> (v2)
Link: https://www.computeexpresslink.org/download-the-specification
Link: https://lore.kernel.org/r/20210217040958.1354670-3-ben.widawsky@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl/cxl.h')
-rw-r--r-- | drivers/cxl/cxl.h | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h new file mode 100644 index 000000000000..baac26d9e63b --- /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__ */ |