While no problems have been observed in practice yet, modern compilers
may reorder memory access operations, and that could lead to problems
with memory-mapped I/O typically done by drivers. This patch prevents
any potentially problematic reordering by the compiler in the AHCI
driver.
This patch adds support for executing multiple concurrent requests on
different devices on the same AHCI controller. The libdriver library
has been extended to include a generic multithreading interface, and
the AHCI driver has been extended to make use of this interface.
The original version of this code has been written by Arne Welzel.
Improves cache locality by grouping together dependency generation
with building for each program instead of doing a whole-tree dep
generation phase followed by a whole-tree build phase
. it's a good extra interface to have but doesn't
meet standardised functionality
. applications (in pkgsrc) find it and expect
full functionality the minix mmap doesn't offter
. on the whole probably better to hide these functions
(mmap and friends) until they are grown up; the base system
can use the new minix_* names
- the pointers must be flagged as volatile because otherwise they
might be "optimized" by a compiler. It is a common good
practice to access the registers this way, the keyword is in C
for a reason.
- for instance, in eeprom_eerd() when polling a register the
compiler, under certain conditions, may decide upon the first
read and if it does not break the loop it assumes that the
value is not going to change and thus stays in an infinite
loop.
3 sets of libraries are built now:
. ack: all libraries that ack can compile (/usr/lib/i386/)
. clang+elf: all libraries with minix headers (/usr/lib/)
. clang+elf: all libraries with netbsd headers (/usr/netbsd/)
Once everything can be compiled with netbsd libraries and headers, the
/usr/netbsd hierarchy will be obsolete and its libraries compiled with
netbsd headers will be installed in /usr/lib, and its headers
in /usr/include. (i.e. minix libc and current minix headers set
will be gone.)
To use the NetBSD libc system (libraries + headers) before
it is the default libc, see:
http://wiki.minix3.org/en/DevelopersGuide/UsingNetBSDCode
This wiki page also documents the maintenance of the patch
files of minix-specific changes to imported NetBSD code.
Changes in this commit:
. libsys: Add NBSD compilation and create a safe NBSD-based libc.
. Port rest of libraries (except libddekit) to new header system.
. Enable compilation of libddekit with new headers.
. Enable kernel compilation with new headers.
. Enable drivers compilation with new headers.
. Port legacy commands to new headers and libc.
. Port servers to new headers.
. Add <sys/sigcontext.h> in compat library.
. Remove dependency file in tree.
. Enable compilation of common/lib/libc/atomic in libsys
. Do not generate RCSID strings in libc.
. Temporarily disable zoneinfo as they are incompatible with NetBSD format
. obj-nbsd for .gitignore
. Procfs: use only integer arithmetic. (Antoine Leca)
. Increase ramdisk size to create NBSD-based images.
. Remove INCSYMLINKS handling hack.
. Add nbsd_include/sys/exec_elf.h
. Enable ELF compilation with NBSD libc.
. Add 'make nbsdsrc' in tools to download reference NetBSD sources.
. Automate minix-port.patch creation.
. Avoid using fstavfs() as it is *extremely* slow and unneeded.
. Set err() as PRIVATE to avoid name clash with libc.
. [NBSD] servers/vm: remove compilation warnings.
. u32 is not a long in NBSD headers.
. UPDATING info on netbsd hierarchy
. commands fixes for netbsd libc
sys_umap now supports only:
- looking up the physical address of a virtual address in the address space
of the caller;
- looking up the physical address of a grant for which the caller is the
grantee.
This is enough for nearly all umap users. The new sys_umap_remote supports
lookups in arbitrary address spaces and grants for arbitrary grantees.
- when ACPI does not find mappings for pci brdiges, do no panic,
only report a warning and continue to a fallback which uses
only the root bus IRQ routing table. Fail only if that is not
present.
Before safecopies, the IO_ENDPT and DL_ENDPT message fields were needed
to know which actual process to copy data from/to, as that process may
not always be the caller. Now that we have full safecopy support, these
fields have become useless for that purpose: the owner of the grant is
*always* the caller. Allowing the caller to supply another endpoint is
in fact dangerous, because the callee may then end up using a grant
from a third party. One could call this a variant of the confused
deputy problem.
From now on, safecopy calls should always use the caller's endpoint as
grant owner. This fully obsoletes the DL_ENDPT field in the
inet/ethernet protocol. IO_ENDPT has other uses besides identifying the
grant owner though. This patch renames IO_ENDPT to USER_ENDPT, not only
because that is a more fitting name (it should never be used for I/O
after all), but also in order to intentionally break any old system
source code outside the base system. If this patch breaks your code,
fixing it is fairly simple:
- DL_ENDPT should be replaced with m_source;
- IO_ENDPT should be replaced with m_source when used for safecopies;
- IO_ENDPT should be replaced with USER_ENDPT for any other use, e.g.
when setting REP_ENDPT, matching requests in CANCEL calls, getting
DEV_SELECT flags, and retrieving of the real user process's endpoint
in DEV_OPEN.
The changes in this patch are binary backward compatible.
M include/Makefile
A include/minix/input.h
M include/minix/com.h
M drivers/tty/keyboard.c
M drivers/tty/tty.c
M drivers/tty/tty.h
M include/minix/syslib.h
M lib/libsys/Makefile
A lib/libsys/input.c
- every pci device which implements _PRT acpi method is considered to
be a pci-to-pci bridge
- acpi driver constructs a hierarchy of pci-to-pci bridges
- when pci driver identifies a pci-to-pci bridge it tells acpi driver
what is the primary and the secondary bus for this device
- when pci requests IRQ routing information from acpi, it passes the
bus number too to be able to identify the device accurately
