Commit 60b8f172 authored by Dan Williams's avatar Dan Williams
Browse files

cxl/pmem: Translate NVDIMM label commands to CXL label commands 



The LIBNVDIMM IOCTL UAPI calls back to the nvdimm-bus-provider to
translate the Linux command payload to the device native command format.
The LIBNVDIMM commands get-config-size, get-config-data, and
set-config-data, map to the CXL memory device commands device-identify,
get-lsa, and set-lsa. Recall that the label-storage-area (LSA) on an
NVDIMM device arranges for the provisioning of namespaces. Additionally
for CXL the LSA is used for provisioning regions as well.

The data from device-identify is already cached in the 'struct cxl_mem'
instance associated with @cxl_nvd, so that payload return is simply
crafted and no CXL command is issued. The conversion for get-lsa is
straightforward, but the conversion for set-lsa requires an allocation
to append the set-lsa header in front of the payload.

Reviewed-by: default avatarBen Widawsky <ben.widawsky@intel.com>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/163122524923.2534512.9431316965424264864.stgit@dwillia2-desk3.amr.corp.intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 12f3856a

drivers/cxl/pmem.c

+124 −4
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/* Copyright(c) 2021 Intel Corporation. All rights reserved. */

#include <linux/libnvdimm.h>

#include <asm/unaligned.h>

#include <linux/device.h>

#include <linux/module.h>

#include <linux/ndctl.h>
@@ -47,9 +48,9 @@ static int cxl_nvdimm_probe(struct device *dev) 
{

	struct cxl_nvdimm *cxl_nvd = to_cxl_nvdimm(dev);

	struct cxl_memdev *cxlmd = cxl_nvd->cxlmd;

	unsigned long flags = 0, cmd_mask = 0;

	struct cxl_mem *cxlm = cxlmd->cxlm;

	struct cxl_nvdimm_bridge *cxl_nvb;

	unsigned long flags = 0;

	struct nvdimm *nvdimm;

	int rc;
@@ -69,8 +70,11 @@ static int cxl_nvdimm_probe(struct device *dev) 
		goto out;



	set_bit(NDD_LABELING, &flags);

	nvdimm = nvdimm_create(cxl_nvb->nvdimm_bus, cxl_nvd, NULL, flags, 0, 0,

			       NULL);

	set_bit(ND_CMD_GET_CONFIG_SIZE, &cmd_mask);

	set_bit(ND_CMD_GET_CONFIG_DATA, &cmd_mask);

	set_bit(ND_CMD_SET_CONFIG_DATA, &cmd_mask);

	nvdimm = nvdimm_create(cxl_nvb->nvdimm_bus, cxl_nvd, NULL, flags,

			       cmd_mask, 0, NULL);

	if (!nvdimm) {

		rc = -ENOMEM;

		goto out;
@@ -91,11 +95,127 @@ static struct cxl_driver cxl_nvdimm_driver = { 
	.id = CXL_DEVICE_NVDIMM,

};



static int cxl_pmem_get_config_size(struct cxl_mem *cxlm,

				    struct nd_cmd_get_config_size *cmd,

				    unsigned int buf_len)

{

	if (sizeof(*cmd) > buf_len)

		return -EINVAL;



	*cmd = (struct nd_cmd_get_config_size) {

		 .config_size = cxlm->lsa_size,

		 .max_xfer = cxlm->payload_size,

	};



	return 0;

}



static int cxl_pmem_get_config_data(struct cxl_mem *cxlm,

				    struct nd_cmd_get_config_data_hdr *cmd,

				    unsigned int buf_len)

{

	struct cxl_mbox_get_lsa {

		u32 offset;

		u32 length;

	} get_lsa;

	int rc;



	if (sizeof(*cmd) > buf_len)

		return -EINVAL;

	if (struct_size(cmd, out_buf, cmd->in_length) > buf_len)

		return -EINVAL;



	get_lsa = (struct cxl_mbox_get_lsa) {

		.offset = cmd->in_offset,

		.length = cmd->in_length,

	};



	rc = cxl_mem_mbox_send_cmd(cxlm, CXL_MBOX_OP_GET_LSA, &get_lsa,

				   sizeof(get_lsa), cmd->out_buf,

				   cmd->in_length);

	cmd->status = 0;



	return rc;

}



static int cxl_pmem_set_config_data(struct cxl_mem *cxlm,

				    struct nd_cmd_set_config_hdr *cmd,

				    unsigned int buf_len)

{

	struct cxl_mbox_set_lsa {

		u32 offset;

		u32 reserved;

		u8 data[];

	} *set_lsa;

	int rc;



	if (sizeof(*cmd) > buf_len)

		return -EINVAL;



	/* 4-byte status follows the input data in the payload */

	if (struct_size(cmd, in_buf, cmd->in_length) + 4 > buf_len)

		return -EINVAL;



	set_lsa =

		kvzalloc(struct_size(set_lsa, data, cmd->in_length), GFP_KERNEL);

	if (!set_lsa)

		return -ENOMEM;



	*set_lsa = (struct cxl_mbox_set_lsa) {

		.offset = cmd->in_offset,

	};

	memcpy(set_lsa->data, cmd->in_buf, cmd->in_length);



	rc = cxl_mem_mbox_send_cmd(cxlm, CXL_MBOX_OP_SET_LSA, set_lsa,

				   struct_size(set_lsa, data, cmd->in_length),

				   NULL, 0);



	/*

	 * Set "firmware" status (4-packed bytes at the end of the input

	 * payload.

	 */

	put_unaligned(0, (u32 *) &cmd->in_buf[cmd->in_length]);

	kvfree(set_lsa);



	return rc;

}



static int cxl_pmem_nvdimm_ctl(struct nvdimm *nvdimm, unsigned int cmd,

			       void *buf, unsigned int buf_len)

{

	struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm);

	unsigned long cmd_mask = nvdimm_cmd_mask(nvdimm);

	struct cxl_memdev *cxlmd = cxl_nvd->cxlmd;

	struct cxl_mem *cxlm = cxlmd->cxlm;



	if (!test_bit(cmd, &cmd_mask))

		return -ENOTTY;



	switch (cmd) {

	case ND_CMD_GET_CONFIG_SIZE:

		return cxl_pmem_get_config_size(cxlm, buf, buf_len);

	case ND_CMD_GET_CONFIG_DATA:

		return cxl_pmem_get_config_data(cxlm, buf, buf_len);

	case ND_CMD_SET_CONFIG_DATA:

		return cxl_pmem_set_config_data(cxlm, buf, buf_len);

	default:

		return -ENOTTY;

	}

}



static int cxl_pmem_ctl(struct nvdimm_bus_descriptor *nd_desc,

			struct nvdimm *nvdimm, unsigned int cmd, void *buf,

			unsigned int buf_len, int *cmd_rc)

{

	/*

	 * No firmware response to translate, let the transport error

	 * code take precedence.

	 */

	*cmd_rc = 0;



	if (!nvdimm)

		return -ENOTTY;

	return cxl_pmem_nvdimm_ctl(nvdimm, cmd, buf, buf_len);

}



static bool online_nvdimm_bus(struct cxl_nvdimm_bridge *cxl_nvb)