__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x). This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.
Other use cases are for storing and retrieving data from the current
processors percpu area. __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.
__get_cpu_var() is defined as :
#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.
this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.
This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset. Thereby address calculations are avoided and less registers
are used when code is generated.
At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.
The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e. using a global
register that may be set to the per cpu base.
Transformations done to __get_cpu_var()
1. Determine the address of the percpu instance of the current processor.
DEFINE_PER_CPU(int, y);
int *x = &__get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(&y);
2. Same as #1 but this time an array structure is involved.
DEFINE_PER_CPU(int, y[20]);
int *x = __get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(y);
3. Retrieve the content of the current processors instance of a per cpu
variable.
DEFINE_PER_CPU(int, y);
int x = __get_cpu_var(y)
Converts to
int x = __this_cpu_read(y);
4. Retrieve the content of a percpu struct
DEFINE_PER_CPU(struct mystruct, y);
struct mystruct x = __get_cpu_var(y);
Converts to
memcpy(&x, this_cpu_ptr(&y), sizeof(x));
5. Assignment to a per cpu variable
DEFINE_PER_CPU(int, y)
__get_cpu_var(y) = x;
Converts to
__this_cpu_write(y, x);
6. Increment/Decrement etc of a per cpu variable
DEFINE_PER_CPU(int, y);
__get_cpu_var(y)++
Converts to
__this_cpu_inc(y)
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
remove obsolete calls to strict_strto* and replace them
with kstrto* calls accordingly.
Signed-off-by: Daniel Walter <dwalter@google.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Use macro flag BOOTMEM_DEFAULT instead of magic number 0 for reserve_bootmem.
Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
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 <cmetcalf@tilera.com>
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 <asm/cmpxchg.h>
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 <asm/system.h> to <asm/switch_to.h> 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 <asm/hw_irq.h>
tile: use asm-generic version of <asm/local64.h>
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
...
Should check the return value of kzalloc first to avoid the null pointer.
Then can dereference the non-null pointer to access the fields of struct
resource.
Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
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 <cmetcalf@tilera.com>
We use virt_to_pte(NULL, va) a lot, which isn't very obvious.
I added virt_to_kpte(va) as a more obvious wrapper function,
that also validates the va as being a kernel adddress.
And, I fixed the semantics of virt_to_pte() so that we handle
the pud and pmd the same way, and we now document the fact that
we handle the final pte level differently.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
The existing code relied on the hardware definition (<arch/chip.h>)
to specify how much VA and PA space was available. It's convenient
to allow customizing this for some configurations, so provide symbols
MAX_PA_WIDTH and MAX_VA_WIDTH in <asm/page.h> that can be modified
if desired.
Additionally, move away from the MEM_XX_INTRPT nomenclature to
define the start of various regions within the VA space. In fact
the cleaner symbol is, for example, MEM_SV_START, to indicate the
start of the area used for supervisor code; the actual address of the
interrupt vectors is not as important, and can be changed if desired.
As part of this change, convert from "intrpt1" nomenclature (which
built in the old privilege-level 1 model) to a simple "intrpt".
Also strip out some tilepro-specific code supporting modifying the
PL the kernel could run at, since we don't actually support using
different PLs in tilepro, only tilegx.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This change adds support for the "memmap" boot parameter similar
to what x86 provides. The tile version supports "memmap=1G$5G",
for example, as a way to reserve a 1 GB range starting at PA 5GB.
The memory is reserved via bootmem during startup, and we create a
suitable "struct resource" marked as "Reserved" so you can see the
range reported by /proc/iomem. Up to 64 such regions can currently
be reserved on the boot command line.
We do not support the x86 options "memmap=nn@ss" (force some memory
to be available at the given address) since it's pointless to try to
have Linux use memory the Tilera hypervisor hasn't given it. We do
not support "memmap=nn#ss" to add an ACPI range for later processing,
since we don't support ACPI. We do not support "memmap=exactmap"
since we don't support reading the e820 information from the BIOS
like x86 does. I did add support for "memmap=nn" (and the synonym
"mem=nn") which cap the highest PA value at "nn"; these are both
just a synonym for the existing tile boot option "maxmem".
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Fix a bug in the tilepro PCI resource allocation code that could make
the bootmem allocator unhappy if 4GB is installed on mshim 0.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.
After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.
Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings. In any case, they are temporary and harmless.
This removes all the arch/tile uses of the __cpuinit macros from
all C files. Currently tile does not have any __CPUINIT used in
assembly files.
[1] https://lkml.org/lkml/2013/5/20/589
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Normalize global variables exported by vmlinux.lds to conform usage
guidelines from include/asm-generic/sections.h.
1) Use _text to mark the start of the kernel image including the head
text, and _stext to mark the start of the .text section.
2) Export mandatory global variables __init_begin and __init_end.
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current Tilera boot infrastructure now provides the initramfs
to Linux as a Tilera-hypervisor file named "initramfs", rather than
"initramfs.cpio.gz", as before. (This makes it reasonable to use
other compression techniques than gzip on the file without having to
worry about the name causing confusion.) Adapt to use the new name,
but also fall back to checking for the old name.
Cc'ing to stable so that older kernels will remain compatible with
newer Tilera boot infrastructure.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: stable@vger.kernel.org
This change uses the TRIO IOMMU to map the PCI DMA space and physical
memory at different addresses. We also now use the dma_mapping_ops
to provide support for non-PCI DMA, PCIe DMA (64-bit) and legacy PCI
DMA (32-bit). We use the kernel's software I/O TLB framework
(i.e. bounce buffers) for the legacy 32-bit PCI device support since
there are a limited number of TLB entries in the IOMMU and it is
non-trivial to handle indexing, searching, matching, etc. For 32-bit
devices the performance impact of bounce buffers should not be a concern.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This is required for PCI root complex legacy support and USB OHCI root
complex support. With this change tilegx now supports allocating memory
whose PA fits in 32 bits.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This change implements PCIe root complex support for tilegx using
the kernel support layer for accessing the TRIO hardware shim.
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> [changes in 07487f3]
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Some code was moved from init_task.c to setup.c but the appropriate
header needed to be moved as well.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Pull tile updates from Chris Metcalf:
"These changes cover a range of new arch/tile features and
optimizations. They've been through LKML review and on linux-next for
a month or so. There's also one bug-fix that just missed 3.4, which
I've marked for stable."
Fixed up trivial conflict in arch/tile/Kconfig (new added tile Kconfig
entries clashing with the generic timer/clockevents changes).
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
tile: default to tilegx_defconfig for ARCH=tile
tile: fix bug where fls(0) was not returning 0
arch/tile: mark TILEGX as not EXPERIMENTAL
tile/mm/fault.c: Port OOM changes to handle_page_fault
arch/tile: add descriptive text if the kernel reports a bad trap
arch/tile: allow querying cpu module information from the hypervisor
arch/tile: fix hardwall for tilegx and generalize for idn and ipi
arch/tile: support multiple huge page sizes dynamically
mm: add new arch_make_huge_pte() method for tile support
arch/tile: support kexec() for tilegx
arch/tile: support <asm/cachectl.h> header for cacheflush() syscall
arch/tile: Allow tilegx to build with either 16K or 64K page size
arch/tile: optimize get_user/put_user and friends
arch/tile: support building big-endian kernel
arch/tile: allow building Linux with transparent huge pages enabled
arch/tile: use interrupt critical sections less
This change adds support for a new "super" bit in the PTE, using the new
arch_make_huge_pte() method. The Tilera hypervisor sees the bit set at a
given level of the page table and gangs together 4, 16, or 64 consecutive
pages from that level of the hierarchy to create a larger TLB entry.
One extra "super" page size can be specified at each of the three levels
of the page table hierarchy on tilegx, using the "hugepagesz" argument
on the boot command line. A new hypervisor API is added to allow Linux
to tell the hypervisor how many PTEs to gang together at each level of
the page table.
To allow pre-allocating huge pages larger than the buddy allocator can
handle, this change modifies the Tilera bootmem support to put all of
memory on tilegx platforms into bootmem.
As part of this change I eliminate the vestigial CONFIG_HIGHPTE support,
which never worked anyway, and eliminate the hv_page_size() API in favor
of the standard vma_kernel_pagesize() API.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This change introduces new flags for the hv_install_context()
API that passes a page table pointer to the hypervisor. Clients
can explicitly request 4K, 16K, or 64K small pages when they
install a new context. In practice, the page size is fixed at
kernel compile time and the same size is always requested every
time a new page table is installed.
The <hv/hypervisor.h> header changes so that it provides more abstract
macros for managing "page" things like PFNs and page tables. For
example there is now a HV_DEFAULT_PAGE_SIZE_SMALL instead of the old
HV_PAGE_SIZE_SMALL. The various PFN routines have been eliminated and
only PA- or PTFN-based ones remain (since PTFNs are always expressed
in fixed 2KB "page" size). The page-table management macros are
renamed with a leading underscore and take page-size arguments with
the presumption that clients will use those macros in some single
place to provide the "real" macros they will use themselves.
I happened to notice the old hv_set_caching() API was totally broken
(it assumed 4KB pages) so I changed it so it would nominally work
correctly with other page sizes.
Tag modules with the page size so you can't load a module built with
a conflicting page size. (And add a test for SMP while we're at it.)
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Same code. Use the generic version. The special Makefile treatment is
pointless anyway as init_task.o contains only data which is handled by
the linker script. So no point on being treated like head text.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Link: http://lkml.kernel.org/r/20120503085035.528129988@linutronix.de
Pull arch/tile bug fixes from Chris Metcalf:
"This includes Paul Gortmaker's change to fix the <asm/system.h>
disintegration issues on tile, a fix to unbreak the tilepro ethernet
driver, and a backlog of bugfix-only changes from internal Tilera
development over the last few months.
They have all been to LKML and on linux-next for the last few days.
The EDAC change to MAINTAINERS is an oddity but discussion on the
linux-edac list suggested I ask you to pull that change through my
tree since they don't have a tree to pull edac changes from at the
moment."
* 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: (39 commits)
drivers/net/ethernet/tile: fix netdev_alloc_skb() bombing
MAINTAINERS: update EDAC information
tilepro ethernet driver: fix a few minor issues
tile-srom.c driver: minor code cleanup
edac: say "TILEGx" not "TILEPro" for the tilegx edac driver
arch/tile: avoid accidentally unmasking NMI-type interrupt accidentally
arch/tile: remove bogus performance optimization
arch/tile: return SIGBUS for addresses that are unaligned AND invalid
arch/tile: fix finv_buffer_remote() for tilegx
arch/tile: use atomic exchange in arch_write_unlock()
arch/tile: stop mentioning the "kvm" subdirectory
arch/tile: export the page_home() function.
arch/tile: fix pointer cast in cacheflush.c
arch/tile: fix single-stepping over swint1 instructions on tilegx
arch/tile: implement panic_smp_self_stop()
arch/tile: add "nop" after "nap" to help GX idle power draw
arch/tile: use proper memparse() for "maxmem" options
arch/tile: fix up locking in pgtable.c slightly
arch/tile: don't leak kernel memory when we unload modules
arch/tile: fix bug in delay_backoff()
...
Not associated with any code changes, so I'm just lumping these
comment changes into a commit by themselves.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This has been obsolescent for a while; time for the final push.
In adjacent context, replaced old cpus_* with cpumask_*.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: David S. Miller <davem@davemloft.net> (arch/sparc)
Acked-by: Chris Metcalf <cmetcalf@tilera.com> (arch/tile)
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: linux-hexagon@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: sparclinux@vger.kernel.org
Several fixes as well where the +1 was missing.
Done via coccinelle scripts like:
@@
struct resource *ptr;
@@
- ptr->end - ptr->start + 1
+ resource_size(ptr)
and some grep and typing.
Mostly uncompiled, no cross-compilers.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The Tilera architecture traditionally supports 64KB page sizes
to improve TLB utilization and improve performance when the
hardware is being used primarily to run a single application.
For more generic server scenarios, it can be beneficial to run
with 4KB page sizes, so this commit allows that to be specified
(by modifying the arch/tile/include/hv/pagesize.h header).
As part of this change, we also re-worked the PTE management
slightly so that PTE writes all go through a __set_pte() function
where we can do some additional validation. The set_pte_order()
function was eliminated since the "order" argument wasn't being used.
One bug uncovered was in the PCI DMA code, which wasn't properly
flushing the specified range. This was benign with 64KB pages,
but with 4KB pages we were getting some larger flushes wrong.
The per-cpu memory reservation code also needed updating to
conform with the newer percpu stuff; before it always chose 64KB,
and that was always correct, but with 4KB granularity we now have
to pay closer attention and reserve the amount of memory that will
be requested when the percpu code starts allocating.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
glibc assumes that it can count /sys/devices/system/cpu/cpu* to get
the number of configured cpus. For this to be valid on tile, we need
to generate a "cpu" entry for all cpus, including the ones that are
not currently allocated for Linux's use.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This completes the tile migration to the new naming scheme for
the architecture-specific irq management code.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
While not a port to KVM (yet), this change modifies the kernel
to be able to build either at PL1 or at PL2 with a suitable
config switch. Pushing up this change avoids handling branch
merge issues going forward with the KVM work.
Signed-off-by: Chris 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: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd 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: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Paul Mundt <lethal@linux-sh.org>
