When using the "compat" APIs, architectures will generally want to
be able to make direct syscalls to msgsnd(), shmctl(), etc., and
in the kernel we would want them to be handled directly by
compat_sys_xxx() functions, as is true for other compat syscalls.

However, for historical reasons, several of the existing compat IPC
syscalls do not do this.  semctl() expects a pointer to the fourth
argument, instead of the fourth argument itself.  msgsnd(), msgrcv()
and shmat() expect arguments in different order.

This change adds an ARCH_WANT_OLD_COMPAT_IPC config option that can be
set to preserve this behavior for ports that use it (x86, sparc, powerpc,
s390, and mips).  No actual semantics are changed for those architectures,
and there is only a minimal amount of code refactoring in ipc/compat.c.

Newer architectures like tile (and perhaps future architectures such
as arm64 and unicore64) should not select this option, and thus can
avoid having any IPC-specific code at all in their architecture-specific
compat layer.  In the same vein, if this option is not selected, IPC_64
mode is assumed, since that's what the <asm-generic> headers expect.

The workaround code in "tile" for msgsnd() and msgrcv() is removed
with this change; it also fixes the bug that shmat() and semctl() were
not being properly handled.
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

These changes make the syscall table line up correctly for
tilegx compat mode, and remove the stale sys32_fadvise64() function,
which isn't actually used by any syscall table.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

The existing <asm-generic/unistd.h> mechanism doesn't really provide
enough to create the 64-bit "compat" ABI properly in a generic way,
since the compat ABI is a mix of things were you can re-use the 64-bit
versions of syscalls and things where you need a compat wrapper.

To provide this in the most direct way possible, I added two new macros
to go along with the existing __SYSCALL and __SC_3264 macros: __SC_COMP
and SC_COMP_3264.  These macros take an additional argument, typically a
"compat_sys_xxx" function, which is passed to __SYSCALL if you define
__SYSCALL_COMPAT when including the header, resulting in a pointer to
the compat function being placed in the generated syscall table.

The change also adds some missing definitions to <linux/compat.h> so that
it actually has declarations for all the compat syscalls, since the
"[nr] = ##call" approach requires proper C declarations for all the
functions included in the syscall table.

Finally, compat.c defines compat_sys_sigpending() and
compat_sys_sigprocmask() even if the underlying architecture doesn't
request it, which tries to pull in undefined compat_old_sigset_t defines.
We need to guard those compat syscall definitions with appropriate
__ARCH_WANT_SYS_xxx ifdefs.
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The existing asm-generic/stat.h specifies st_mtime, etc., as a 32-value,
and works well for 32-bit architectures (currently microblaze, score,
and 32-bit tile).  However, for 64-bit architectures it isn't sufficient
to return 32 bits of time_t; this isn't good insurance against the 2037
rollover.  (It also makes glibc support less convenient, since we can't
use glibc's handy STAT_IS_KERNEL_STAT mode.)

This change extends the two "timespec" fields for each of the three atime,
mtime, and ctime fields from "int" to "long".  As a result, on 32-bit
platforms nothing changes, and 64-bit platforms will now work as expected.

The only wrinkle is 32-bit userspace under 64-bit kernels taking advantage
of COMPAT mode.  For these, we leave the "struct stat64" definitions with
the "int" versions of the time_t and nsec fields, so that architectures
can implement compat_sys_stat64() and friends with sys_stat64(), etc.,
and get the expected 32-bit structure layout.  This requires a
field-by-field copy in the kernel, implemented by the code guarded
under __ARCH_WANT_STAT64.

This does mean that the shape of the "struct stat" and "struct stat64"
structures is different on a 64-bit kernel, but only one of the two
structures should ever be used by any given process: "struct stat"
is meant for 64-bit userspace only, and "struct stat64" for 32-bit
userspace only.  (On a 32-bit kernel the two structures continue to have
the same shape, since "long" is 32 bits.)

The alternative is keeping the two structures the same shape on 64-bit
kernels, which means a 64-bit time_t in "struct stat64" for 32-bit
processes.  This is a little unnatural since 32-bit userspace can't
do anything with 64 bits of time_t information, since time_t is just
"long", not "int64_t"; and in any case 32-bit userspace might expect
to be running under a 32-bit kernel, which can't provide the high 32
bits anyway.  In the case of a 32-bit kernel we'd then be extending the
kernel's 32-bit time_t to 64 bits, then truncating it back to 32 bits
again in userspace, for no particular reason.  And, as mentioned above,
if we have 64-bit time_t for 32-bit processes we can't easily use glibc's
STAT_IS_KERNEL_STAT, since glibc's stat structure requires an embedded
"struct timespec", which is a pair of "long" (32-bit) values in a 32-bit
userspace.  "Inventive" solutions are possible, but are pretty hacky.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>

Previously, we tried to pass 64-bit arguments through the
"COMPAT" mode 32-bit syscall API, which turned out not to work
well.  Now we just use straight 32-bit arguments in COMPAT mode,
thus requiring individual registers to be read/written with
two syscalls.  Of course this is uncommon, since usually all
the registers are read or written at once.

The restructuring applies to all the tile platforms, but is
plausibly better than the original code in any case.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

With this change we now include <asm-generic/syscalls.h> into the "tile"
version of the header.  To take full advantage of the prototypes there,
we also change our naming convention for "struct pt_regs *" syscalls so
that, e.g., _sys_execve() is the "true" syscall entry, which sets the
appropriate register to point to the pt_regs before calling sys_execve().

While doing this I realized I no longer needed the fork and vfork
entry point stubs, since those functions aren't in the generic
syscall ABI, so I removed them as well.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This commit is primarily changes caused by reviewing "sparse"
and "checkpatch" output on our sources, so is somewhat noisy, since
things like "printk() -> pr_err()" (or whatever) throughout the
codebase tend to get tedious to read.  Rather than trying to tease
apart precisely which things changed due to which type of code
review, this commit includes various cleanups in the code:

- sparse: Add declarations in headers for globals.
- sparse: Fix __user annotations.
- sparse: Using gfp_t consistently instead of int.
- sparse: removing functions not actually used.
- checkpatch: Clean up printk() warnings by using pr_info(), etc.;
  also avoid partial-line printks except in bootup code.
  - checkpatch: Use exposed structs rather than typedefs.
  - checkpatch: Change some C99 comments to C89 comments.

In addition, a couple of minor other changes are rolled in
to this commit:

- Add support for a "raise" instruction to cause SIGFPE, etc., to be raised.
- Remove some compat code that is unnecessary when we fully eliminate
  some of the deprecated syscalls from the generic syscall ABI.
- Update the tile_defconfig to reflect current config contents.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>

This change is the core kernel support for TILEPro and TILE64 chips.
No driver support (except the console driver) is included yet.

This includes the relevant Linux headers in asm/; the low-level
low-level "Tile architecture" headers in arch/, which are
shared with the hypervisor, etc., and are build-system agnostic;
and the relevant hypervisor headers in hv/.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: NPaul Mundt <lethal@linux-sh.org>