freebsd-nq/sys/dev/altera/avgen/altera_avgen.c
Robert Watson cf8248866d Add altera_avgen(4), a generic device driver to be used by hard and soft
CPU cores on Altera FPGAs.  The device driver allows memory-mapped devices
on Altera's Avalon SoC bus to be exported to userspace via device nodes.
device.hints directories dictate device name, permissible access methods,
physical address and length, and I/O alignment.  Devices can be accessed
using read(2)/write(2), but also memory mapped in userspace using mmap(2).

Devices attach directly to the Nexus, as is common for embedded device
drivers; in the future something more mature might be desirable.  There is
currently no facility to support directing device-originated interrupts to
userspace.

In the future, this device driver may be renamed to socgen(4), as it can
in principle also be used with other system-on-chip (SoC) busses, such as
Axi on ASICs and FPGAs.  However, we have only tested it on Avalon busses
with memory-mapped ROMs, frame buffers, etc.

Sponsored by:	DARPA, AFRL
2012-08-25 11:07:43 +00:00

452 lines
12 KiB
C

/*-
* Copyright (c) 2012 Robert N. M. Watson
* All rights reserved.
*
* This software was developed by SRI International and the University of
* Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
* ("CTSRD"), as part of the DARPA CRASH research programme.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/condvar.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/rman.h>
#include <sys/stat.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <machine/vm.h>
#include <vm/vm.h>
#include <dev/altera/avgen/altera_avgen.h>
/*
* Generic device driver for allowing read(), write(), and mmap() on
* memory-mapped, Avalon-attached devices. There is no actual dependence on
* Avalon, so conceivably this should just be soc_dev or similar, since many
* system-on-chip bus environments would work fine with the same code.
*/
static d_mmap_t altera_avgen_mmap;
static d_read_t altera_avgen_read;
static d_write_t altera_avgen_write;
static struct cdevsw avg_cdevsw = {
.d_version = D_VERSION,
.d_mmap = altera_avgen_mmap,
.d_read = altera_avgen_read,
.d_write = altera_avgen_write,
.d_name = "altera_avgen",
};
static int
altera_avgen_read(struct cdev *dev, struct uio *uio, int flag)
{
struct altera_avgen_softc *sc;
u_long offset, size;
#ifdef NOTYET
uint64_t v8;
#endif
uint32_t v4;
uint16_t v2;
uint8_t v1;
u_int width;
int error;
sc = dev->si_drv1;
if ((sc->avg_flags & ALTERA_AVALON_FLAG_READ) == 0)
return (EACCES);
width = sc->avg_width;
if (uio->uio_offset < 0 || uio->uio_offset % width != 0 ||
uio->uio_resid % width != 0)
return (ENODEV);
size = rman_get_size(sc->avg_res);
if ((uio->uio_offset + uio->uio_resid < 0) ||
(uio->uio_offset + uio->uio_resid > size))
return (ENODEV);
while (uio->uio_resid > 0) {
offset = uio->uio_offset;
if (offset + width > size)
return (ENODEV);
switch (width) {
case 1:
v1 = bus_read_1(sc->avg_res, offset);
error = uiomove(&v1, sizeof(v1), uio);
break;
case 2:
v2 = bus_read_2(sc->avg_res, offset);
error = uiomove(&v2, sizeof(v2), uio);
break;
case 4:
v4 = bus_read_4(sc->avg_res, offset);
error = uiomove(&v4, sizeof(v4), uio);
break;
#ifdef NOTYET
case 8:
v8 = bus_read_8(sc->avg_res, offset);
error = uiomove(&v8, sizeof(v8), uio);
break;
#endif
default:
panic("%s: unexpected widthment %u", __func__, width);
}
if (error)
return (error);
}
return (0);
}
static int
altera_avgen_write(struct cdev *dev, struct uio *uio, int flag)
{
struct altera_avgen_softc *sc;
u_long offset, size;
#ifdef NOTYET
uint64_t v8;
#endif
uint32_t v4;
uint16_t v2;
uint8_t v1;
u_int width;
int error;
sc = dev->si_drv1;
if ((sc->avg_flags & ALTERA_AVALON_FLAG_WRITE) == 0)
return (EACCES);
width = sc->avg_width;
if (uio->uio_offset < 0 || uio->uio_offset % width != 0 ||
uio->uio_resid % width != 0)
return (ENODEV);
size = rman_get_size(sc->avg_res);
while (uio->uio_resid > 0) {
offset = uio->uio_offset;
if (offset + width > size)
return (ENODEV);
switch (width) {
case 1:
error = uiomove(&v1, sizeof(v1), uio);
if (error)
return (error);
bus_write_1(sc->avg_res, offset, v1);
break;
case 2:
error = uiomove(&v2, sizeof(v2), uio);
if (error)
return (error);
bus_write_2(sc->avg_res, offset, v2);
break;
case 4:
error = uiomove(&v4, sizeof(v4), uio);
if (error)
return (error);
bus_write_4(sc->avg_res, offset, v4);
break;
#ifdef NOTYET
case 8:
error = uiomove(&v8, sizeof(v8), uio);
if (error)
return (error);
bus_write_8(sc->avg_res, offset, v8);
break;
#endif
default:
panic("%s: unexpected width %u", __func__, width);
}
}
return (0);
}
static int
altera_avgen_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
int nprot, vm_memattr_t *memattr)
{
struct altera_avgen_softc *sc;
sc = dev->si_drv1;
if (nprot & VM_PROT_READ) {
if ((sc->avg_flags & ALTERA_AVALON_FLAG_MMAP_READ) == 0)
return (EACCES);
}
if (nprot & VM_PROT_WRITE) {
if ((sc->avg_flags & ALTERA_AVALON_FLAG_MMAP_WRITE) == 0)
return (EACCES);
}
if (nprot & VM_PROT_EXECUTE) {
if ((sc->avg_flags & ALTERA_AVALON_FLAG_MMAP_EXEC) == 0)
return (EACCES);
}
if (trunc_page(offset) == offset &&
rman_get_size(sc->avg_res) >= offset + PAGE_SIZE) {
*paddr = rman_get_start(sc->avg_res) + offset;
*memattr = VM_MEMATTR_UNCACHEABLE;
} else
return (ENODEV);
return (0);
}
static int
altera_avgen_nexus_probe(device_t dev)
{
device_set_desc(dev, "Generic Altera Avalon device attachment");
return (BUS_PROBE_DEFAULT);
}
static int
altera_avgen_process_options(struct altera_avgen_softc *sc,
const char *str_fileio, const char *str_mmapio, const char *str_devname,
int devunit)
{
const char *cp;
device_t dev = sc->avg_dev;
/*
* Check for valid combinations of options.
*/
if (str_fileio == NULL && str_mmapio == NULL) {
device_printf(dev,
"at least one of %s or %s must be specified\n",
ALTERA_AVALON_STR_FILEIO, ALTERA_AVALON_STR_MMAPIO);
return (ENXIO);
}
if (str_devname == NULL && devunit != -1) {
device_printf(dev, "%s requires %s be specified\n",
ALTERA_AVALON_STR_DEVUNIT, ALTERA_AVALON_STR_DEVNAME);
return (ENXIO);
}
/*
* Extract, digest, and save values.
*/
switch (sc->avg_width) {
case 1:
case 2:
case 4:
#ifdef NOTYET
case 8:
#endif
break;
default:
device_printf(dev, "%s unsupported value %u\n",
ALTERA_AVALON_STR_WIDTH, sc->avg_width);
return (ENXIO);
}
sc->avg_flags = 0;
if (str_fileio != NULL) {
for (cp = str_fileio; *cp != '\0'; cp++) {
switch (*cp) {
case ALTERA_AVALON_CHAR_READ:
sc->avg_flags |= ALTERA_AVALON_FLAG_READ;
break;
case ALTERA_AVALON_CHAR_WRITE:
sc->avg_flags |= ALTERA_AVALON_FLAG_WRITE;
break;
default:
device_printf(dev,
"invalid %s character %c\n",
ALTERA_AVALON_STR_FILEIO, *cp);
return (ENXIO);
}
}
}
if (str_mmapio != NULL) {
for (cp = str_mmapio; *cp != '\0'; cp++) {
switch (*cp) {
case ALTERA_AVALON_CHAR_READ:
sc->avg_flags |= ALTERA_AVALON_FLAG_MMAP_READ;
break;
case ALTERA_AVALON_CHAR_WRITE:
sc->avg_flags |=
ALTERA_AVALON_FLAG_MMAP_WRITE;
break;
case ALTERA_AVALON_CHAR_EXEC:
sc->avg_flags |= ALTERA_AVALON_FLAG_MMAP_EXEC;
break;
default:
device_printf(dev,
"invalid %s character %c\n",
ALTERA_AVALON_STR_MMAPIO, *cp);
return (ENXIO);
}
}
}
return (0);
}
static int
altera_avgen_nexus_attach(device_t dev)
{
struct altera_avgen_softc *sc;
const char *str_fileio, *str_mmapio;
const char *str_devname;
char devname[SPECNAMELEN + 1];
int devunit, error;
sc = device_get_softc(dev);
sc->avg_dev = dev;
sc->avg_unit = device_get_unit(dev);
/*
* Query non-standard hints to find out what operations are permitted
* on the device, and whether it is cached.
*/
str_fileio = NULL;
str_mmapio = NULL;
str_devname = NULL;
devunit = -1;
sc->avg_width = 1;
error = resource_int_value(device_get_name(dev), device_get_unit(dev),
ALTERA_AVALON_STR_WIDTH, &sc->avg_width);
if (error != 0 && error != ENOENT) {
device_printf(dev, "invalid %s\n", ALTERA_AVALON_STR_WIDTH);
return (error);
}
(void)resource_string_value(device_get_name(dev),
device_get_unit(dev), ALTERA_AVALON_STR_FILEIO, &str_fileio);
(void)resource_string_value(device_get_name(dev),
device_get_unit(dev), ALTERA_AVALON_STR_MMAPIO, &str_mmapio);
(void)resource_string_value(device_get_name(dev),
device_get_unit(dev), ALTERA_AVALON_STR_DEVNAME, &str_devname);
(void)resource_int_value(device_get_name(dev), device_get_unit(dev),
ALTERA_AVALON_STR_DEVUNIT, &devunit);
error = altera_avgen_process_options(sc, str_fileio, str_mmapio,
str_devname, devunit);
if (error)
return (error);
/* Select a device name. */
if (str_devname != NULL) {
if (devunit != -1)
(void)snprintf(devname, sizeof(devname), "%s%d",
str_devname, devunit);
else
(void)snprintf(devname, sizeof(devname), "%s",
str_devname);
} else
snprintf(devname, sizeof(devname), "%s%d", "avgen",
sc->avg_unit);
/* Memory allocation and checking. */
sc->avg_rid = 0;
sc->avg_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
&sc->avg_rid, RF_ACTIVE);
if (sc->avg_res == NULL) {
device_printf(dev, "couldn't map memory\n");
return (ENXIO);
}
if (rman_get_size(sc->avg_res) >= PAGE_SIZE || str_mmapio != NULL) {
if (rman_get_size(sc->avg_res) % PAGE_SIZE != 0) {
device_printf(dev,
"memory region not even multiple of page size\n");
error = ENXIO;
goto error;
}
if (rman_get_start(sc->avg_res) % PAGE_SIZE != 0) {
device_printf(dev, "memory region not page-aligned\n");
error = ENXIO;
goto error;
}
}
/* Device node allocation. */
if (str_devname == NULL) {
str_devname = "altera_avgen%d";
devunit = sc->avg_unit;
}
if (devunit != -1)
sc->avg_cdev = make_dev(&avg_cdevsw, sc->avg_unit, UID_ROOT,
GID_WHEEL, S_IRUSR | S_IWUSR, str_devname, devunit);
else
sc->avg_cdev = make_dev(&avg_cdevsw, sc->avg_unit, UID_ROOT,
GID_WHEEL, S_IRUSR | S_IWUSR, str_devname);
if (sc->avg_cdev == NULL) {
device_printf(sc->avg_dev, "%s: make_dev failed\n", __func__);
error = ENXIO;
goto error;
}
/* XXXRW: Slight race between make_dev(9) and here. */
sc->avg_cdev->si_drv1 = sc;
return (0);
error:
bus_release_resource(dev, SYS_RES_MEMORY, sc->avg_rid, sc->avg_res);
return (error);
}
static int
altera_avgen_nexus_detach(device_t dev)
{
struct altera_avgen_softc *sc;
sc = device_get_softc(dev);
destroy_dev(sc->avg_cdev);
bus_release_resource(dev, SYS_RES_MEMORY, sc->avg_rid, sc->avg_res);
return (0);
}
static device_method_t altera_avgen_nexus_methods[] = {
DEVMETHOD(device_probe, altera_avgen_nexus_probe),
DEVMETHOD(device_attach, altera_avgen_nexus_attach),
DEVMETHOD(device_detach, altera_avgen_nexus_detach),
{ 0, 0 }
};
static driver_t altera_avgen_nexus_driver = {
"altera_avgen",
altera_avgen_nexus_methods,
sizeof(struct altera_avgen_softc),
};
static devclass_t altera_avgen_devclass;
DRIVER_MODULE(avgen, nexus, altera_avgen_nexus_driver, altera_avgen_devclass,
0, 0);