All efivars operations are protected by a spinlock which prevents
interruptions and preemption. This is too restricted, we just need a
lock preventing concurrency.
The idea is to use a semaphore of count 1 and to have two ways of
locking, depending on the context:
- In interrupt context, we call down_trylock(), if it fails we return
an error
- In normal context, we call down_interruptible()
We don't use a mutex here because the mutex_trylock() function must not
be called from interrupt context, whereas the down_trylock() can.
Signed-off-by: Sylvain Chouleur <sylvain.chouleur@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sylvain Chouleur <sylvain.chouleur@gmail.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
This patch replaces the spinlock in the efivars struct with a single lock
for the whole vars.c file. The goal of this lock is to protect concurrent
calls to efi variable services, registering and unregistering. This allows
us to register new efivars operations without having in-progress call.
Signed-off-by: Sylvain Chouleur <sylvain.chouleur@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sylvain Chouleur <sylvain.chouleur@gmail.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Now that efi.memmap is available all of the time there's no need to
allocate and build a separate copy of the EFI memory map.
Furthermore, efi.memmap contains boot services regions but only those
regions that have been reserved via efi_mem_reserve(). Using
efi.memmap allows us to pass boot services across kexec reboot so that
the ESRT and BGRT drivers will now work.
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Today, it is not possible for drivers to reserve EFI boot services for
access after efi_free_boot_services() has been called on x86. For
ARM/arm64 it can be done simply by calling memblock_reserve().
Having this ability for all three architectures is desirable for a
couple of reasons,
1) It saves drivers copying data out of those regions
2) kexec reboot can now make use of things like ESRT
Instead of using the standard memblock_reserve() which is insufficient
to reserve the region on x86 (see efi_reserve_boot_services()), a new
API is introduced in this patch; efi_mem_reserve().
efi.memmap now always represents which EFI memory regions are
available. On x86 the EFI boot services regions that have not been
reserved via efi_mem_reserve() will be removed from efi.memmap during
efi_free_boot_services().
This has implications for kexec, since it is not possible for a newly
kexec'd kernel to access the same boot services regions that the
initial boot kernel had access to unless they are reserved by every
kexec kernel in the chain.
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
While efi_memmap_init_{early,late}() exist for architecture code to
install memory maps from firmware data and for the virtual memory
regions respectively, drivers don't care which stage of the boot we're
at and just want to swap the existing memmap for a modified one.
efi_memmap_install() abstracts the details of how the new memory map
should be mapped and the existing one unmapped.
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Drivers need a way to access the EFI memory map at runtime. ARM and
arm64 currently provide this by remapping the EFI memory map into the
vmalloc space before setting up the EFI virtual mappings.
x86 does not provide this functionality which has resulted in the code
in efi_mem_desc_lookup() where it will manually map individual EFI
memmap entries if the memmap has already been torn down on x86,
/*
* If a driver calls this after efi_free_boot_services,
* ->map will be NULL, and the target may also not be mapped.
* So just always get our own virtual map on the CPU.
*
*/
md = early_memremap(p, sizeof (*md));
There isn't a good reason for not providing a permanent EFI memory map
for runtime queries, especially since the EFI regions are not mapped
into the standard kernel page tables.
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Every EFI architecture apart from ia64 needs to setup the EFI memory
map at efi.memmap, and the code for doing that is essentially the same
across all implementations. Therefore, it makes sense to factor this
out into the common code under drivers/firmware/efi/.
The only slight variation is the data structure out of which we pull
the initial memory map information, such as physical address, memory
descriptor size and version, etc. We can address this by passing a
generic data structure (struct efi_memory_map_data) as the argument to
efi_memmap_init_early() which contains the minimum info required for
initialising the memory map.
In the process, this patch also fixes a few undesirable implementation
differences:
- ARM and arm64 were failing to clear the EFI_MEMMAP bit when
unmapping the early EFI memory map. EFI_MEMMAP indicates whether
the EFI memory map is mapped (not the regions contained within) and
can be traversed. It's more correct to set the bit as soon as we
memremap() the passed in EFI memmap.
- Rename efi_unmmap_memmap() to efi_memmap_unmap() to adhere to the
regular naming scheme.
This patch also uses a read-write mapping for the memory map instead
of the read-only mapping currently used on ARM and arm64. x86 needs
the ability to update the memory map in-place when assigning virtual
addresses to regions (efi_map_region()) and tagging regions when
reserving boot services (efi_reserve_boot_services()).
There's no way for the generic fake_mem code to know which mapping to
use without introducing some arch-specific constant/hook, so just use
read-write since read-only is of dubious value for the EFI memory map.
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
The rcar_fcp_enable() function immediately returns successfully when the
FCP device pointer is NULL to avoid forcing the users to check the FCP
device manually before every call. However, the stub version of the
function used when the FCP driver is disabled returns -ENOSYS
unconditionally, resulting in a different API contract for the two
versions of the function.
As a user that requires FCP support will fail at probe time when calling
rcar_fcp_get() if the FCP driver is disabled, the stub version of the
rcar_fcp_enable() function will only be called with a NULL FCP device.
We can thus return 0 unconditionally to align the behaviour with the
normal version of the function.
Reported-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
After commit adf0516845 ("netfilter: remove ip_conntrack* sysctl
compat code"), ctl_table_path member in struct nf_conntrack_l3proto{}
is not used anymore, remove it.
Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The codes will be called:
MEDIA_BUS_FMT_SBGGR16_1X16
MEDIA_BUS_FMT_SGBRG16_1X16
MEDIA_BUS_FMT_SGRBG16_1X16
MEDIA_BUS_FMT_SRGGB16_1X16
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This patch removes the soc_camera API dependency from pxa_camera.
In the current status :
- all previously captures are working the same on pxa270
- the s_crop() call was removed, judged not working
(see what happens soc_camera_s_crop() when get_crop() == NULL)
- if the pixel clock is provided by then sensor, ie. not MCLK, the dual
stage change is not handled yet.
=> there is no in-tree user of this, so I'll let it that way
- the MCLK is not yet finished, it's as in the legacy way,
ie. activated at video device opening and closed at video device
closing.
In a subsequence patch pxa_camera_mclk_ops should be used, and
platform data MCLK ignored. It will be the sensor's duty to request
the clock and enable it, which will end in pxa_camera_mclk_ops.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
In systems with heterogeneous CPUs, there are multiple logical CPU PMUs,
each of which covers a subset of CPUs in the system. In some cases
userspace needs to know which CPUs a given logical PMU covers, so we'd
like to expose a cpumask under sysfs, similar to what is done for uncore
PMUs.
Unfortunately, prior to commit 00e727bb38 ("perf stat: Balance
opening and reading events"), perf stat only correctly handled a cpumask
holding a single CPU, and only when profiling in system-wide mode. In
other cases, the presence of a cpumask file could cause perf stat to
behave erratically.
Thus, exposing a cpumask file would break older perf binaries in cases
where they would otherwise work.
To avoid this issue while still providing userspace with the information
it needs, this patch exposes a differently-named file (cpus) under
sysfs. New tools can look for this and operate correctly, while older
tools will not be adversely affected by its presence.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
In preparation for adding common attribute groups, add an array of
attribute group pointers to arm_pmu, which will be used if the
backend hasn't already set pmu::attr_groups.
Subsequent patches will move backends over to using these, before adding
common fields.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
There is a warning there, because it was pointing to a different
name. Fix it.
While here, use struct &foo, instead of &struct foo.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Document vb2_ops_wait_prepare() and vb2_ops_wait_finish(),
in order to fix those two warnings:
Documentation/media/kapi/v4l2-dev.rst:166: WARNING: c:func reference target not found: vb2_ops_wait_prepare
Documentation/media/kapi/v4l2-dev.rst:166: WARNING: c:func reference target not found: vb2_ops_wait_finish
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
There are a few issues at the documentation: fields not documented,
bad cross refrences, etc.
Fix them.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
There are several functions documented at the C file. Move
them to the header, as this is the one used to build the
media books.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
There are several small issues with the documentation. Fix them,
in order to avoid producing warnings.
While here, also make checkpatch.pl happy.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
There are several functions that were documented at the .c
file. As we only include the headers, we need to move them to
there, in order to have documentation.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
The kernel-doc C parser doesn't like opaque structures. So,
document it on another way.
This should get rid of this warning:
./include/media/v4l2-mem2mem.h:62: error: Cannot parse struct or union!
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Several routines are somewhat documented at v4l2-mem2mem.c
file. Move what's there to the header file.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Fix this warning:
Documentation/media/kapi/mc-core.rst:97: WARNING: c:func reference target not found: media_devnode_release
The media_device_release() is a function internal to media-devnode.c,
and not exported elsewhere. So, we can't cross-reference it here.
Make it explicit at the documentation.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Trivially fix those broken references, by copying the structs
fron the header, just like other API documentation at the
DVB side.
This doesn't have the level of quality used at the V4L2 side
of the API, but, as this documents a deprecated API, used
only by av7110 driver, it doesn't make much sense to invest
time making it better.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Now that scripts/kernel-doc was fixed to parse the typedef
argument used here, let it produce documentation.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Fix some minor issues at the documentation tags on this file,
adding cross-references where needed, and fixing some broken
ones.
While here, fix a few spaces before tabs to make Checkpatch happier.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
There are several undocumented functions here; document them.
While here, make checkpatch.pl happy.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Change the parse-headers.pl and the corresponding files to use
the C domain for enum references.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
The prepare_ext_ctrls() function is actually internal to the
v4l2-ctrls.c implementation, so it doesn't have a declaration
for the kAPI header to reference it.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
The typedefs and a macro are not defined. While here, improve a
few bits on the documentation.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
There are some structs/enums that aren't documented via
kernel-doc markup. Add documentation for them.
Fix those warnings:
./include/media/rc-map.h:103: WARNING: c:type reference target not found: rc_map_list
./include/media/rc-map.h:110: WARNING: c:type reference target not found: rc_map_list
./include/media/rc-map.h:117: WARNING: c:type reference target not found: rc_map
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
There are several issues on the documentation:
- the media.h header were not properly referenced;
- verbatim expressions were not properly marked as such;
- struct member references were wrong;
- some notes were not using the right markup;
- a comment that were moved to the kernel-doc markup were
duplicated as a comment inside the struct media_entity;
- some args were not pointing to the struct they're using;
- macros weren't documented.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
PKRU is the register that lets you disallow writes or all access to a given
protection key.
The XSAVE hardware defines an "init state" of 0 for PKRU: its most
permissive state, allowing access/writes to everything. Since we start off
all new processes with the init state, we start all processes off with the
most permissive possible PKRU.
This is unfortunate. If a thread is clone()'d [1] before a program has
time to set PKRU to a restrictive value, that thread will be able to write
to all data, no matter what pkey is set on it. This weakens any integrity
guarantees that we want pkeys to provide.
To fix this, we define a very restrictive PKRU to override the
XSAVE-provided value when we create a new FPU context. We choose a value
that only allows access to pkey 0, which is as restrictive as we can
practically make it.
This does not cause any practical problems with applications using
protection keys because we require them to specify initial permissions for
each key when it is allocated, which override the restrictive default.
In the end, this ensures that threads which do not know how to manage their
own pkey rights can not do damage to data which is pkey-protected.
I would have thought this was a pretty contrived scenario, except that I
heard a bug report from an MPX user who was creating threads in some very
early code before main(). It may be crazy, but folks evidently _do_ it.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-arch@vger.kernel.org
Cc: Dave Hansen <dave@sr71.net>
Cc: mgorman@techsingularity.net
Cc: arnd@arndb.de
Cc: linux-api@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: luto@kernel.org
Cc: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/20160729163021.F3C25D4A@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch adds two new system calls:
int pkey_alloc(unsigned long flags, unsigned long init_access_rights)
int pkey_free(int pkey);
These implement an "allocator" for the protection keys
themselves, which can be thought of as analogous to the allocator
that the kernel has for file descriptors. The kernel tracks
which numbers are in use, and only allows operations on keys that
are valid. A key which was not obtained by pkey_alloc() may not,
for instance, be passed to pkey_mprotect().
These system calls are also very important given the kernel's use
of pkeys to implement execute-only support. These help ensure
that userspace can never assume that it has control of a key
unless it first asks the kernel. The kernel does not promise to
preserve PKRU (right register) contents except for allocated
pkeys.
The 'init_access_rights' argument to pkey_alloc() specifies the
rights that will be established for the returned pkey. For
instance:
pkey = pkey_alloc(flags, PKEY_DENY_WRITE);
will allocate 'pkey', but also sets the bits in PKRU[1] such that
writing to 'pkey' is already denied.
The kernel does not prevent pkey_free() from successfully freeing
in-use pkeys (those still assigned to a memory range by
pkey_mprotect()). It would be expensive to implement the checks
for this, so we instead say, "Just don't do it" since sane
software will never do it anyway.
Any piece of userspace calling pkey_alloc() needs to be prepared
for it to fail. Why? pkey_alloc() returns the same error code
(ENOSPC) when there are no pkeys and when pkeys are unsupported.
They can be unsupported for a whole host of reasons, so apps must
be prepared for this. Also, libraries or LD_PRELOADs might steal
keys before an application gets access to them.
This allocation mechanism could be implemented in userspace.
Even if we did it in userspace, we would still need additional
user/kernel interfaces to tell userspace which keys are being
used by the kernel internally (such as for execute-only
mappings). Having the kernel provide this facility completely
removes the need for these additional interfaces, or having an
implementation of this in userspace at all.
Note that we have to make changes to all of the architectures
that do not use mman-common.h because we use the new
PKEY_DENY_ACCESS/WRITE macros in arch-independent code.
1. PKRU is the Protection Key Rights User register. It is a
usermode-accessible register that controls whether writes
and/or access to each individual pkey is allowed or denied.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: linux-arch@vger.kernel.org
Cc: Dave Hansen <dave@sr71.net>
Cc: arnd@arndb.de
Cc: linux-api@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: luto@kernel.org
Cc: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/20160729163015.444FE75F@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Today, mprotect() takes 4 bits of data: PROT_READ/WRITE/EXEC/NONE.
Three of those bits: READ/WRITE/EXEC get translated directly in to
vma->vm_flags by calc_vm_prot_bits(). If a bit is unset in
mprotect()'s 'prot' argument then it must be cleared in vma->vm_flags
during the mprotect() call.
We do this clearing today by first calculating the VMA flags we
want set, then clearing the ones we do not want to inherit from
the original VMA:
vm_flags = calc_vm_prot_bits(prot, key);
...
newflags = vm_flags;
newflags |= (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC));
However, we *also* want to mask off the original VMA's vm_flags in
which we store the protection key.
To do that, this patch adds a new macro:
ARCH_VM_PKEY_FLAGS
which allows the architecture to specify additional bits that it would
like cleared. We use that to ensure that the VM_PKEY_BIT* bits get
cleared.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Dave Hansen <dave@sr71.net>
Cc: arnd@arndb.de
Cc: linux-api@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: luto@kernel.org
Cc: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/20160729163013.E48D6981@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
pkey_mprotect() is just like mprotect, except it also takes a
protection key as an argument. On systems that do not support
protection keys, it still works, but requires that key=0.
Otherwise it does exactly what mprotect does.
I expect it to get used like this, if you want to guarantee that
any mapping you create can *never* be accessed without the right
protection keys set up.
int real_prot = PROT_READ|PROT_WRITE;
pkey = pkey_alloc(0, PKEY_DENY_ACCESS);
ptr = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
ret = pkey_mprotect(ptr, PAGE_SIZE, real_prot, pkey);
This way, there is *no* window where the mapping is accessible
since it was always either PROT_NONE or had a protection key set
that denied all access.
We settled on 'unsigned long' for the type of the key here. We
only need 4 bits on x86 today, but I figured that other
architectures might need some more space.
Semantically, we have a bit of a problem if we combine this
syscall with our previously-introduced execute-only support:
What do we do when we mix execute-only pkey use with
pkey_mprotect() use? For instance:
pkey_mprotect(ptr, PAGE_SIZE, PROT_WRITE, 6); // set pkey=6
mprotect(ptr, PAGE_SIZE, PROT_EXEC); // set pkey=X_ONLY_PKEY?
mprotect(ptr, PAGE_SIZE, PROT_WRITE); // is pkey=6 again?
To solve that, we make the plain-mprotect()-initiated execute-only
support only apply to VMAs that have the default protection key (0)
set on them.
Proposed semantics:
1. protection key 0 is special and represents the default,
"unassigned" protection key. It is always allocated.
2. mprotect() never affects a mapping's pkey_mprotect()-assigned
protection key. A protection key of 0 (even if set explicitly)
represents an unassigned protection key.
2a. mprotect(PROT_EXEC) on a mapping with an assigned protection
key may or may not result in a mapping with execute-only
properties. pkey_mprotect() plus pkey_set() on all threads
should be used to _guarantee_ execute-only semantics if this
is not a strong enough semantic.
3. mprotect(PROT_EXEC) may result in an "execute-only" mapping. The
kernel will internally attempt to allocate and dedicate a
protection key for the purpose of execute-only mappings. This
may not be possible in cases where there are no free protection
keys available. It can also happen, of course, in situations
where there is no hardware support for protection keys.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: linux-arch@vger.kernel.org
Cc: Dave Hansen <dave@sr71.net>
Cc: arnd@arndb.de
Cc: linux-api@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: luto@kernel.org
Cc: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/20160729163012.3DDD36C4@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The driver already supports the bcm4339 chipset but only for the variant
that shares the same modalias as the bcm4335, ie. sdio:c00v02D0d4335.
It turns out that there are also bcm4339 devices out there that have a
more distiguishable modalias sdio:c00v02D0d4339.
Reported-by: Steve deRosier <derosier@gmail.com>
Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Common approach to accessing register fields is to define
structures or sets of macros containing mask and shift pair.
Operations on the register are then performed as follows:
field = (reg >> shift) & mask;
reg &= ~(mask << shift);
reg |= (field & mask) << shift;
Defining shift and mask separately is tedious. Ivo van Doorn
came up with an idea of computing them at compilation time
based on a single shifted mask (later refined by Felix) which
can be used like this:
#define REG_FIELD 0x000ff000
field = FIELD_GET(REG_FIELD, reg);
reg &= ~REG_FIELD;
reg |= FIELD_PREP(REG_FIELD, field);
FIELD_{GET,PREP} macros take care of finding out what the
appropriate shift is based on compilation time ffs operation.
GENMASK can be used to define registers (which is usually
less error-prone and easier to match with datasheets).
This approach is the most convenient I've seen so to limit code
multiplication let's move the macros to a global header file.
Attempts to use static inlines instead of macros failed due
to false positive triggering of BUILD_BUG_ON()s, especially with
GCC < 6.0.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dinan Gunawardena <dinan.gunawardena@netronome.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
