Commit cbbca60a authored by Dave Jiang's avatar Dave Jiang
Browse files

cxl: Enumerate feature commands 



Add feature commands enumeration code in order to detect and enumerate
the 3 feature related commands "get supported features", "get feature",
and "set feature". The enumeration will help determine whether the driver
can issue any of the 3 commands to the device.

Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
Reviewed-by: default avatarLi Ming <ming.li@zohomail.com>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: default avatarDavidlohr Bueso <dave@stgolabs.net>
Tested-by: default avatarShiju Jose <shiju.jose@huawei.com>
Link: https://patch.msgid.link/20250220194438.2281088-2-dave.jiang@intel.com


Signed-off-by: default avatarDave Jiang <dave.jiang@intel.com>
parent 5666a7e7

drivers/cxl/core/mbox.c

+35 −1
Original line number Diff line number Diff line
@@ -706,6 +706,35 @@ static int cxl_xfer_log(struct cxl_memdev_state *mds, uuid_t *uuid, 
	return 0;

}



static int check_features_opcodes(u16 opcode, int *ro_cmds, int *wr_cmds)

{

	switch (opcode) {

	case CXL_MBOX_OP_GET_SUPPORTED_FEATURES:

	case CXL_MBOX_OP_GET_FEATURE:

		(*ro_cmds)++;

		return 1;

	case CXL_MBOX_OP_SET_FEATURE:

		(*wr_cmds)++;

		return 1;

	default:

		return 0;

	}

}



/* 'Get Supported Features' and 'Get Feature' */

#define MAX_FEATURES_READ_CMDS	2

static void set_features_cap(struct cxl_mailbox *cxl_mbox,

			     int ro_cmds, int wr_cmds)

{

	/* Setting up Features capability while walking the CEL */

	if (ro_cmds == MAX_FEATURES_READ_CMDS) {

		if (wr_cmds)

			cxl_mbox->feat_cap = CXL_FEATURES_RW;

		else

			cxl_mbox->feat_cap = CXL_FEATURES_RO;

	}

}



/**

 * cxl_walk_cel() - Walk through the Command Effects Log.

 * @mds: The driver data for the operation
@@ -721,7 +750,7 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel) 
	struct cxl_cel_entry *cel_entry;

	const int cel_entries = size / sizeof(*cel_entry);

	struct device *dev = mds->cxlds.dev;

	int i;

	int i, ro_cmds = 0, wr_cmds = 0;



	cel_entry = (struct cxl_cel_entry *) cel;
@@ -735,6 +764,9 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel) 
			enabled++;

		}



		enabled += check_features_opcodes(opcode, &ro_cmds,

						  &wr_cmds);



		if (cxl_is_poison_command(opcode)) {

			cxl_set_poison_cmd_enabled(&mds->poison, opcode);

			enabled++;
@@ -748,6 +780,8 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel) 
		dev_dbg(dev, "Opcode 0x%04x %s\n", opcode,

			enabled ? "enabled" : "unsupported by driver");

	}



	set_features_cap(cxl_mbox, ro_cmds, wr_cmds);

}



static struct cxl_mbox_get_supported_logs *cxl_get_gsl(struct cxl_memdev_state *mds)

drivers/cxl/cxlmem.h

+3 −0
Original line number Diff line number Diff line
@@ -490,6 +490,9 @@ enum cxl_opcode { 
	CXL_MBOX_OP_GET_LOG_CAPS	= 0x0402,

	CXL_MBOX_OP_CLEAR_LOG           = 0x0403,

	CXL_MBOX_OP_GET_SUP_LOG_SUBLIST = 0x0405,

	CXL_MBOX_OP_GET_SUPPORTED_FEATURES	= 0x0500,

	CXL_MBOX_OP_GET_FEATURE		= 0x0501,

	CXL_MBOX_OP_SET_FEATURE		= 0x0502,

	CXL_MBOX_OP_IDENTIFY		= 0x4000,

	CXL_MBOX_OP_GET_PARTITION_INFO	= 0x4100,

	CXL_MBOX_OP_SET_PARTITION_INFO	= 0x4101,

include/cxl/features.h

0 → 100644
+13 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only */

/* Copyright(c) 2024-2025 Intel Corporation. */

#ifndef __CXL_FEATURES_H__

#define __CXL_FEATURES_H__



/* Feature commands capability supported by a device */

enum cxl_features_capability {

	CXL_FEATURES_NONE = 0,

	CXL_FEATURES_RO,

	CXL_FEATURES_RW,

};



#endif

include/cxl/mailbox.h

+3 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
#ifndef __CXL_MBOX_H__

#define __CXL_MBOX_H__

#include <linux/rcuwait.h>

#include <cxl/features.h>

#include <uapi/linux/cxl_mem.h>



/**
@@ -51,6 +52,7 @@ struct cxl_mbox_cmd { 
 * @mbox_mutex: mutex protects device mailbox and firmware

 * @mbox_wait: rcuwait for mailbox

 * @mbox_send: @dev specific transport for transmitting mailbox commands

 * @feat_cap: Features capability

 */

struct cxl_mailbox {

	struct device *host;
@@ -60,6 +62,7 @@ struct cxl_mailbox { 
	struct mutex mbox_mutex; /* lock to protect mailbox context */

	struct rcuwait mbox_wait;

	int (*mbox_send)(struct cxl_mailbox *cxl_mbox, struct cxl_mbox_cmd *cmd);

	enum cxl_features_capability feat_cap;

};



int cxl_mailbox_init(struct cxl_mailbox *cxl_mbox, struct device *host);