linux/arch/tile/include/asm, branch v3.12

tile: use a more conservative __my_cpu_offset in CONFIG_PREEMPT

2013-09-30T14:34:41Z

It turns out the kernel relies on barrier() to force a reload of the percpu offset value. Since we can't easily modify the definition of barrier() to include "tp" as an output register, we instead provide a definition of __my_cpu_offset as extended assembly that includes a fake stack read to hazard against barrier(), forcing gcc to know that it must reread "tp" and recompute anything based on "tp" after a barrier. This fixes observed hangs in the slub allocator when we are looping on a percpu cmpxchg_double. A similar fix for ARMv7 was made in June in change 509eb76ebf97. Cc: stable@vger.kernel.org Signed-off-by: Chris Metcalf

tile: include: asm: use 'long long' instead of 'u64' for atomic64_t and its related functions

2013-09-27T20:08:56Z

atomic* value is signed value, and atomic* functions need also process signed value (parameter value, and return value), so use 'long long' instead of 'u64'. After replacement, it will also fix a bug for atomic64_add_negative(): "u64 is never less than 0". The modifications are: in vim, use "1,% s/\/long long/g" command. remove redundant '__aligned(8)'. be sure of 80 (and macro '\') columns limitation after replacement. Signed-off-by: Chen Gang Signed-off-by: Chris Metcalf [re-instated const cast]

tile: remove HUGE_VMAP dead code

2013-09-13T15:15:24Z

A config option to allow a variant vmap() using huge pages that was never upstreamed had some bits of code related to it scattered around the tile architecture; the config option was removed downstream and this commit cleans up the scattered evidence of it from the upstream as well. Signed-off-by: Chris Metcalf

Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile

2013-09-06T18:14:33Z

Pull Tile arch updates from Chris Metcalf: "These changes bring in a bunch of new functionality that has been maintained internally at Tilera over the last year, plus other stray bits of work that I've taken into the tile tree from other folks. The changes include some PCI root complex work, interrupt-driven console support, support for performing fast-path unaligned data fixups by kernel-based JIT code generation, CONFIG_PREEMPT support, vDSO support for gettimeofday(), a serial driver for the tilegx on-chip UART, KGDB support, more optimized string routines, support for ftrace and kprobes, improved ASLR, and many bug fixes. We also remove support for the old TILE64 chip, which is no longer buildable" * git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: (85 commits) tile: refresh tile defconfig files tile: rework tile PCI RC: make default consistent DMA mask 32-bit tile: add null check for kzalloc in tile/kernel/setup.c tile: make __write_once a synonym for __read_mostly tile: remove support for TILE64 tile: use asm-generic/bitops/builtin-*.h tile: eliminate no-op "noatomichash" boot argument tile: use standard tile_bundle_bits type in traps.c tile: simplify code referencing hypervisor API addresses tile: change to in comments tile: mark pcibios_init() as __init tile: check for correct compiler earlier in asm-offsets.c tile: use standard 'generic-y' model for tile: use asm-generic version of tile PCI RC: add comment about "PCI hole" problem tile: remove DEBUG_EXTRA_FLAGS kernel config option tile: add virt_to_kpte() API and clean up and document behavior tile: support FRAME_POINTER tile: support reporting Tilera hypervisor statistics ...

tile: rework

2013-09-06T17:06:25Z

The macrology in cmpxchg.h was designed to allow arbitrary pointer and integer values to be passed through the routines. To support cmpxchg() on 64-bit values on the 32-bit tilepro architecture, we used the idiom "(typeof(val))(typeof(val-val))". This way, in the "size 8" branch of the switch, when the underlying cmpxchg routine returns a 64-bit quantity, we cast it first to a typeof(val-val) quantity (i.e. size_t if "val" is a pointer) with no warnings about casting between pointers and integers of different sizes, then cast onwards to typeof(val), again with no warnings. If val is not a pointer type, the additional cast is a no-op. We can't replace the typeof(val-val) cast with (for example) unsigned long, since then if "val" is really a 64-bit type, we cast away the high bits. HOWEVER, this fails with current gcc (through 4.7 at least) if "val" is a pointer to an incomplete type. Unfortunately gcc isn't smart enough to realize that "val - val" will always be a size_t type even if it's an incomplete type pointer. Accordingly, I've reworked the way we handle the casting. We have given up the ability to use cmpxchg() on 64-bit values on tilepro, which is OK in the kernel since we should use cmpxchg64() explicitly on such values anyway. As a result, I can just use simple "unsigned long" casts internally. As I reworked it, I realized it would be cleaner to move the architecture-specific conditionals for cmpxchg and xchg out of the atomic.h headers and into cmpxchg, and then use the cmpxchg() and xchg() primitives directly in atomic.h and elsewhere. This allowed the cmpxchg.h header to stand on its own without relying on the implicit include of it that is performed by . It also allowed collapsing the atomic_xchg/atomic_cmpxchg routines from atomic_{32,64}.h into atomic.h. I improved the tests that guard the allowed size of the arguments to the routines to use a __compiletime_error() test. (By avoiding the use of BUILD_BUG, I could include cmpxchg.h into bitops.h as well and use the macros there, which is otherwise impossible due to include order dependency issues.) The tilepro _atomic_xxx internal methods were previously set up to take atomic_t and atomic64_t arguments, which isn't as convenient with the new model, so I modified them to take int or u64 arguments, which is consistent with how they used the arguments internally anyway, so provided some nice simplification there too. Signed-off-by: Chris Metcalf

tile PCI RC: make default consistent DMA mask 32-bit

2013-09-03T18:53:37Z

This change sets the PCI devices' initial DMA capabilities conservatively and promotes them at the request of the driver, as opposed to assuming advanced DMA capabilities. The old design runs the risk of breaking drivers that assume default capabilities. Signed-off-by: Chris Metcalf

tile: make __write_once a synonym for __read_mostly

2013-09-03T18:53:32Z

This was really only useful for TILE64 when we mapped the kernel data with small pages. Now we use a huge page and we really don't want to map different parts of the kernel data in different ways. We retain the __write_once name in case we want to bring it back to life at some point in the future. Note that this change uncovered a latent bug where the "smp_topology" variable happened to always be aligned mod 8 so we could store two "int" values at once, but when we eliminated __write_once it ended up only aligned mod 4. Fix with an explicit annotation. Signed-off-by: Chris Metcalf

tile: remove support for TILE64

2013-09-03T18:53:29Z

This chip is no longer being actively developed for (it was superceded by the TILEPro64 in 2008), and in any case the existing compiler and toolchain in the community do not support it. It's unlikely that the kernel works with TILE64 at this point as the configuration has not been tested in years. The support is also awkward as it requires maintaining a significant number of ifdefs. So, just remove it altogether. Signed-off-by: Chris Metcalf

tile: use asm-generic/bitops/builtin-*.h

2013-09-03T18:53:27Z

The definisions of __ffs(), __fls(), and ffs() for tile are almost same as asm-generic/bitops-*.h. The only difference is that it is defined as __always_inline or inline. So this switches to use those headers. Signed-off-by: Akinobu Mita Signed-off-by: Chris Metcalf [moved #includes to end]

tile: use standard 'generic-y' model for

2013-09-03T18:52:25Z

Signed-off-by: Chris Metcalf