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linux-next/drivers/misc/ocxl/pasid.c
Frederic Barrat 5ef3166e8a ocxl: Driver code for 'generic' opencapi devices
Add an ocxl driver to handle generic opencapi devices. Of course, it's
not meant to be the only opencapi driver, any device is free to
implement its own. But if a host application only needs basic services
like attaching to an opencapi adapter, have translation faults handled
or allocate AFU interrupts, it should suffice.

The AFU config space must follow the opencapi specification and use
the expected vendor/device ID to be seen by the generic driver.

The driver exposes the device AFUs as a char device in /dev/ocxl/

Note that the driver currently doesn't handle memory attached to the
opencapi device.

Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-24 11:42:58 +11:00

108 lines
2.1 KiB
C

// SPDX-License-Identifier: GPL-2.0+
// Copyright 2017 IBM Corp.
#include "ocxl_internal.h"
struct id_range {
struct list_head list;
u32 start;
u32 end;
};
#ifdef DEBUG
static void dump_list(struct list_head *head, char *type_str)
{
struct id_range *cur;
pr_debug("%s ranges allocated:\n", type_str);
list_for_each_entry(cur, head, list) {
pr_debug("Range %d->%d\n", cur->start, cur->end);
}
}
#endif
static int range_alloc(struct list_head *head, u32 size, int max_id,
char *type_str)
{
struct list_head *pos;
struct id_range *cur, *new;
int rc, last_end;
new = kmalloc(sizeof(struct id_range), GFP_KERNEL);
if (!new)
return -ENOMEM;
pos = head;
last_end = -1;
list_for_each_entry(cur, head, list) {
if ((cur->start - last_end) > size)
break;
last_end = cur->end;
pos = &cur->list;
}
new->start = last_end + 1;
new->end = new->start + size - 1;
if (new->end > max_id) {
kfree(new);
rc = -ENOSPC;
} else {
list_add(&new->list, pos);
rc = new->start;
}
#ifdef DEBUG
dump_list(head, type_str);
#endif
return rc;
}
static void range_free(struct list_head *head, u32 start, u32 size,
char *type_str)
{
bool found = false;
struct id_range *cur, *tmp;
list_for_each_entry_safe(cur, tmp, head, list) {
if (cur->start == start && cur->end == (start + size - 1)) {
found = true;
list_del(&cur->list);
kfree(cur);
break;
}
}
WARN_ON(!found);
#ifdef DEBUG
dump_list(head, type_str);
#endif
}
int ocxl_pasid_afu_alloc(struct ocxl_fn *fn, u32 size)
{
int max_pasid;
if (fn->config.max_pasid_log < 0)
return -ENOSPC;
max_pasid = 1 << fn->config.max_pasid_log;
return range_alloc(&fn->pasid_list, size, max_pasid, "afu pasid");
}
void ocxl_pasid_afu_free(struct ocxl_fn *fn, u32 start, u32 size)
{
return range_free(&fn->pasid_list, start, size, "afu pasid");
}
int ocxl_actag_afu_alloc(struct ocxl_fn *fn, u32 size)
{
int max_actag;
max_actag = fn->actag_enabled;
return range_alloc(&fn->actag_list, size, max_actag, "afu actag");
}
void ocxl_actag_afu_free(struct ocxl_fn *fn, u32 start, u32 size)
{
return range_free(&fn->actag_list, start, size, "afu actag");
}