copyin() or copyout().
uvm_useracc() tells us whether the mapping permissions allow access to
the desired part of an address space, and many callers assume that
this is the same as knowing whether an attempt to access that part of
the address space will succeed. however, access to user space can
fail for reasons other than insufficient permission, most notably that
paging in any non-resident data can fail due to i/o errors. most of
the callers of uvm_useracc() make the above incorrect assumption. the
rest are all misguided optimizations, which optimize for the case
where an operation will fail. we'd rather optimize for operations
succeeding, in which case we should just attempt the access and handle
failures due to insufficient permissions the same way we handle i/o
errors. since there appear to be no good uses of uvm_useracc(), we'll
just remove it.
indicating an unhandled "command". ERESTART is -1, which can lead to
confusion. ERESTART has been moved to -3 and EPASSTHROUGH has been
placed at -4. No ioctl code should now return -1 anywhere. The
ioctl() system call is now properly restartable.
"off_t" and the return value is a "paddr_t" to allow mappings
at offsets past 2^31 bytes. Somewhat inspired by FreeBSD, which
only changed the offset to a "vm_offset_t".
Includes updates for the i386, pc532 and sh3 mmmmap from Jason Thorpe.
element access instead of C bitfield (hello, BCPL).
- XXX Some TURBOchannel framebuffers might need shutdownhooks(). It
seems not necessarily hardware sprite cursor images are re-initialized
by DECstation PROMs upon exits from kernel.
- XXX It'd be an arguable point to allow user programs to change the
shade of gray freely for pixel value 0 and 1.
- returned EOPNOTSUPP rather than -1.
- no check for negative offset.
many of these fix potential security problems in these drivers.
XXX XXX XXX
the d_mmap cdev routine should be changed to have a prototype like:
paddr_t (*d_mmap) __P((dev_t, off_t, int));
by someone!
bit/pixel format, not planer format. Assign MSB for cursor mask and
LSB for cursor image, where 10 means mask color and 11 for image color.
Image bit order of Bt431 and Bt459 are opposite to MIPS/Alpha processors
while IMS G332 and DC503 (PCC) are indentical.
- Assume that cursor images are 32 pixel padded as ULTRIX/DU ws interface
do. It's natural to X server.
- XXX Vast majority of codes are duplicated between mfb<->tfb and cfb<->sfb.
Code sharing might be achieved in the context of TGA/SFB+ merge.
N.B., Digital UNIX never supports neither PMAG-AA (mfb) nor PMAG-BA (cfb)
for TC Alphas. PMAG-DV (xcfb) is Personal DECstation built in. All should
be good for console, but need much works for cursor/colormap completeness.
mhitch