Added BUSC_PCI_DEV_NAME_S and BUSC_PCI_SLOT_NAME_S to support safecopies in PCI.
Added DL_WRITEV_S, DL_READV_S, DL_GETSTAT_S, DL_GRANT, and iovec_s_t to support
safecopies in ethernet drviers. Renamed DL_INIT to DL_CONF, and DL_INIT_REPLY
to DL_CONF_REPLY.
Added SYS_READBIOS and sys_readbios to read from BIOS data areas.
Added GET_KMESS_S for safecopy support in LOG.
Added sys_safe_insb and sys_safe_outsb.
. don't loop doing a receive() after sendrec() - chance of recovering is not
high, and can lead to receive()ing a notify() (which can't happen in sendrec()),
which is terrible
. return status from device when DEV_CANCEL is done on a signal; hardcode EAGAIN to
become EINTR though
For character device i/o, FS does a so-called 'magic' grant to let the
driver copy from or to user space. As this is done in FS address space,
the driver is told to do this in FS address space. The redirection to
the right user process then happens at copy-time in the kernel, using the
FS grant table. This also happens for DEV_READ and DEV_WRITE on block
devices.
For other block device i/o, which happens from/to FS buffers, FS does
a 'direct' grant to its own address space for the driver.
After the i/o returns, this access has to be K-I-L-L-E-D, revoked.
Sometimes this is after a SUSPEND and DEV_REVIVE, in which case the
revoking happens in pipe.c.
This conversion happens in safe_io_conversion() in device.c, called
by dev_io and dev_bio.
FS has to pre-allocate its own space for these grant tables. This happens
in main.c.
from DIO_REQUEST. Also do_vdevio. Also do_sdevio, but this
function also supports grant id's and offsets.
do_segctl: rename protected to prot.
do_umap: support for GRANT_SEG umap.
do_privctl: support SYS_PRIV_SET_GRANTS, which sets location and size
of in-own-address-space grant table.
do_safecopy: functions to verify and perform 'safe' (grant-based) copies.
