/*
* Copyright 2014 IBM Corp.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/sched/clock.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/mm.h>
#include <linux/uaccess.h>
#include <linux/delay.h>
#include <asm/synch.h>
#include <misc/cxl-base.h>
#include "cxl.h"
#include "trace.h"
static int afu_control(struct cxl_afu *afu, u64 command, u64 clear,
u64 result, u64 mask, bool enabled)
{
u64 AFU_Cntl;
unsigned long timeout = jiffies + (HZ * CXL_TIMEOUT);
int rc = 0;
spin_lock(&afu->afu_cntl_lock);
pr_devel("AFU command starting: %llx\n", command);
trace_cxl_afu_ctrl(afu, command);
AFU_Cntl = cxl_p2n_read(afu, CXL_AFU_Cntl_An);
cxl_p2n_write(afu, CXL_AFU_Cntl_An, (AFU_Cntl & ~clear) | command);
AFU_Cntl = cxl_p2n_read(afu, CXL_AFU_Cntl_An);
while ((AFU_Cntl & mask) != result) {
if (time_after_eq(jiffies, timeout)) {
dev_warn(&afu->dev, "WARNING: AFU control timed out!\n");
rc = -EBUSY;
goto out;
}
if (!cxl_ops->link_ok(afu->adapter, afu)) {
afu->enabled = enabled;
rc = -EIO;
goto out;
}
pr_devel_ratelimited("AFU control... (0x%016llx)\n",
AFU_Cntl | command);
cpu_relax();
AFU_Cntl = cxl_p2n_read(afu, CXL_AFU_Cntl_An);
}
if (AFU_Cntl & CXL_AFU_Cntl_An_RA) {
/*
* Workaround for a bug in the XSL used in the Mellanox CX4
* that fails to clear the RA bit after an AFU reset,
* preventing subsequent AFU resets from working.
*/
cxl_p2n_write(afu, CXL_AFU_Cntl_An, AFU_Cntl & ~CXL_AFU_Cntl_An_RA);
}
pr_devel("AFU command complete: %llx\n", command);
afu->enabled = enabled;
out:
trace_cxl_afu_ctrl_done(afu, command, rc);
spin_unlock(&afu->afu_cntl_lock);
return rc;
}
static int afu_enable(struct cxl_afu *afu)
{
pr_devel("AFU enable request\n");
return afu_control(afu, CXL_AFU_Cntl_An_E, 0,
CXL_AFU_Cntl_An_ES_Enabled,
CXL_AFU_Cntl_An_ES_MASK, true);
}
int cxl_afu_disable(struct cxl_afu *afu)
{
pr_devel("AFU disable request\n");
return afu_control(afu, 0, CXL_AFU_Cntl_An_E,
CXL_AFU_Cntl_An_ES_Disabled,
CXL_AFU_Cntl_An_ES_MASK, false);
}
/* This will disable as well as reset */
