[PowerPC] De-giant powermac_nvram, update documentation

* Remove the giant lock requirement from powermac_nvram.
* Update manual pages to reflect current state.

Reviewed by:	bcr (manpages), jhibbits
Sponsored by:	Tag1 Consulting, Inc.
Differential Revision:	https://reviews.freebsd.org/D24812
This commit is contained in:
Brandon Bergren 2020-06-19 18:36:10 +00:00
parent 188aee740f
commit 37f530582d
4 changed files with 37 additions and 13 deletions

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@ -25,7 +25,7 @@
.\"
.\" $FreeBSD$
.\"
.Dd September 5, 2010
.Dd June 19, 2020
.Dt POWERMAC_NVRAM 4 powerpc
.Os
.Sh NAME
@ -50,8 +50,10 @@ The
.Nm
driver provides access to the Open Firmware configuration NVRAM
available on the Apple PowerPC-based machines.
.Pp
This driver currently supports "Core99" machines containing a Sharp, Micron,
or AMD NVRAM.
.Sh SEE ALSO
.Xr eeprom 8 ,
.Xr nvram 8
.Sh HISTORY
The

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@ -34,6 +34,8 @@
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/sx.h>
#include <sys/uio.h>
#include <dev/ofw/openfirm.h>
@ -99,7 +101,6 @@ static d_write_t powermac_nvram_write;
static struct cdevsw powermac_nvram_cdevsw = {
.d_version = D_VERSION,
.d_flags = D_NEEDGIANT,
.d_open = powermac_nvram_open,
.d_close = powermac_nvram_close,
.d_read = powermac_nvram_read,
@ -180,6 +181,8 @@ powermac_nvram_attach(device_t dev)
"powermac_nvram");
sc->sc_cdev->si_drv1 = sc;
sx_init(&sc->sc_lock, "powermac_nvram");
return 0;
}
@ -195,6 +198,8 @@ powermac_nvram_detach(device_t dev)
if (sc->sc_cdev != NULL)
destroy_dev(sc->sc_cdev);
sx_destroy(&sc->sc_lock);
return 0;
}
@ -203,11 +208,17 @@ static int
powermac_nvram_open(struct cdev *dev, int flags, int fmt, struct thread *td)
{
struct powermac_nvram_softc *sc = dev->si_drv1;
int err;
err = 0;
sx_xlock(&sc->sc_lock);
if (sc->sc_isopen)
return EBUSY;
sc->sc_isopen = 1;
err = EBUSY;
else
sc->sc_isopen = 1;
sc->sc_rpos = sc->sc_wpos = 0;
sx_xunlock(&sc->sc_lock);
return 0;
}
@ -218,10 +229,12 @@ powermac_nvram_close(struct cdev *dev, int fflag, int devtype, struct thread *td
struct core99_header *header;
vm_offset_t bank;
sx_xlock(&sc->sc_lock);
if (sc->sc_wpos != sizeof(sc->sc_data)) {
/* Short write, restore in-memory copy */
bcopy((void *)sc->sc_bank, (void *)sc->sc_data, NVRAM_SIZE);
sc->sc_isopen = 0;
sx_xunlock(&sc->sc_lock);
return 0;
}
@ -242,10 +255,12 @@ powermac_nvram_close(struct cdev *dev, int fflag, int devtype, struct thread *td
if (erase_bank(sc->sc_dev, (uint8_t *)bank) != 0 ||
write_bank(sc->sc_dev, (uint8_t *)bank, sc->sc_data) != 0) {
sc->sc_isopen = 0;
sx_xunlock(&sc->sc_lock);
return ENOSPC;
}
sc->sc_bank = bank;
sc->sc_isopen = 0;
sx_xunlock(&sc->sc_lock);
return 0;
}
@ -256,6 +271,8 @@ powermac_nvram_read(struct cdev *dev, struct uio *uio, int ioflag)
struct powermac_nvram_softc *sc = dev->si_drv1;
rv = 0;
sx_xlock(&sc->sc_lock);
while (uio->uio_resid > 0) {
data_available = sizeof(sc->sc_data) - sc->sc_rpos;
if (data_available > 0) {
@ -269,6 +286,8 @@ powermac_nvram_read(struct cdev *dev, struct uio *uio, int ioflag)
break;
}
}
sx_xunlock(&sc->sc_lock);
return rv;
}
@ -282,6 +301,8 @@ powermac_nvram_write(struct cdev *dev, struct uio *uio, int ioflag)
return EINVAL;
rv = 0;
sx_xlock(&sc->sc_lock);
while (uio->uio_resid > 0) {
data_available = sizeof(sc->sc_data) - sc->sc_wpos;
if (data_available > 0) {
@ -295,6 +316,8 @@ powermac_nvram_write(struct cdev *dev, struct uio *uio, int ioflag)
break;
}
}
sx_xunlock(&sc->sc_lock);
return rv;
}
@ -500,6 +523,8 @@ erase_bank(device_t dev, uint8_t *bank)
struct powermac_nvram_softc *sc;
sc = device_get_softc(dev);
sx_assert(&sc->sc_lock, SA_XLOCKED);
if (sc->sc_type == FLASH_TYPE_AMD)
return (erase_bank_amd(dev, bank));
else
@ -512,6 +537,8 @@ write_bank(device_t dev, uint8_t *bank, uint8_t *data)
struct powermac_nvram_softc *sc;
sc = device_get_softc(dev);
sx_assert(&sc->sc_lock, SA_XLOCKED);
if (sc->sc_type == FLASH_TYPE_AMD)
return (write_bank_amd(dev, bank, data));
else

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@ -49,6 +49,7 @@
struct powermac_nvram_softc {
device_t sc_dev;
struct sx sc_lock;
phandle_t sc_node;
vm_offset_t sc_bank;
vm_offset_t sc_bank0;

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@ -25,7 +25,7 @@
.\"
.\" $FreeBSD$
.\"
.Dd August 1, 2006
.Dd June 19, 2020
.Dt NVRAM 8 powerpc
.Os
.Sh NAME
@ -98,8 +98,7 @@ to
.Pp
.Dl "nvram -d foo -d bar baz=100"
.Sh SEE ALSO
.Xr powermac_nvram 4 ,
.Xr eeprom 8
.Xr powermac_nvram 4
.Sh HISTORY
The
.Nm
@ -111,8 +110,3 @@ Darwin/Mac OS X
utility.
.Sh AUTHORS
.An Maxim Sobolev Aq Mt sobomax@FreeBSD.org
.Sh BUGS
Currently,
.Nm
only supports systems equipped with AMD flash and is only tested on Apple
G4-based Mac Mini machines.