Commit Graph

52 Commits

Author SHA1 Message Date
Sumit Bhattacharya ea2e7057c0 ARM: 7172/1: dma: Drop GFP_COMP for DMA memory allocations
dma_alloc_coherent wants to split pages after allocation in order to
reduce the memory footprint. This does not work well with GFP_COMP
pages, so drop this flag before allocation.

This patch is ported from arch/avr32
(commit 3611553ef9).

[swarren: s/HUGETLB_PAGE/HUGETLBFS/ in comment, minor comment cleanup]

Signed-off-by: Sumit Bhattacharya <sumitb@nvidia.com>
Tested-by: Varun Colbert <vcolbert@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-11-26 21:58:53 +00:00
Catalin Marinas 53cbcbcf43 ARM: 7166/1: Use PMD_SHIFT instead of PGDIR_SHIFT in dma-consistent.c
Commit 99d1717d (ARM: Add init_consistent_dma_size()) introduces dynamic
allocation of the consistent_pte array. The number of PTEs should be
calculated based on the number of PMD entries rather than PGD, hence the
PMD_SHIFT.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-11-21 13:12:19 +00:00
Linus Torvalds 1fdb24e969 Merge branch 'devel-stable' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm
* 'devel-stable' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm: (178 commits)
  ARM: 7139/1: fix compilation with CONFIG_ARM_ATAG_DTB_COMPAT and large TEXT_OFFSET
  ARM: gic, local timers: use the request_percpu_irq() interface
  ARM: gic: consolidate PPI handling
  ARM: switch from NO_MACH_MEMORY_H to NEED_MACH_MEMORY_H
  ARM: mach-s5p64x0: remove mach/memory.h
  ARM: mach-s3c64xx: remove mach/memory.h
  ARM: plat-mxc: remove mach/memory.h
  ARM: mach-prima2: remove mach/memory.h
  ARM: mach-zynq: remove mach/memory.h
  ARM: mach-bcmring: remove mach/memory.h
  ARM: mach-davinci: remove mach/memory.h
  ARM: mach-pxa: remove mach/memory.h
  ARM: mach-ixp4xx: remove mach/memory.h
  ARM: mach-h720x: remove mach/memory.h
  ARM: mach-vt8500: remove mach/memory.h
  ARM: mach-s5pc100: remove mach/memory.h
  ARM: mach-tegra: remove mach/memory.h
  ARM: plat-tcc: remove mach/memory.h
  ARM: mach-mmp: remove mach/memory.h
  ARM: mach-cns3xxx: remove mach/memory.h
  ...

Fix up mostly pretty trivial conflicts in:
 - arch/arm/Kconfig
 - arch/arm/include/asm/localtimer.h
 - arch/arm/kernel/Makefile
 - arch/arm/mach-shmobile/board-ap4evb.c
 - arch/arm/mach-u300/core.c
 - arch/arm/mm/dma-mapping.c
 - arch/arm/mm/proc-v7.S
 - arch/arm/plat-omap/Kconfig
largely due to some CONFIG option renaming (ie CONFIG_PM_SLEEP ->
CONFIG_ARM_CPU_SUSPEND for the arm-specific suspend code etc) and
addition of NEED_MACH_MEMORY_H next to HAVE_IDE.
2011-10-28 12:02:27 -07:00
Russell King 06afb1a087 Merge branches 'arnd-randcfg-fixes', 'debug', 'io' (early part), 'l2x0', 'p2v', 'pgt' (early part) and 'smp' into for-linus 2011-10-25 08:19:29 +01:00
Russell King d8e89b47e0 ARM: dma-mapping: free allocated page if unable to map
If the attempt to map a page for DMA fails (eg, because we're out of
mapping space) then we must not hold on to the page we allocated for
DMA - doing so will result in a memory leak.

Cc: <stable@kernel.org>
Reported-by: Bryan Phillippe <bp@darkforest.org>
Tested-by: Bryan Phillippe <bp@darkforest.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-26 09:36:50 +01:00
Catalin Marinas e73fc88e19 ARM: 7059/1: LPAE: Use PMD_(SHIFT|SIZE|MASK) instead of PGDIR_*
PGDIR_SHIFT and PMD_SHIFT for the classic 2-level page table format have
the same value (21). This patch converts the PGDIR_* uses in the kernel
to the PMD_* equivalent so that LPAE builds can reuse the same code.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-08-23 15:30:33 +01:00
Jon Medhurst 97fef8bda9 ARM: Remove support for macro CONSISTENT_DMA_SIZE
There are now no platforms which set this macro.

Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
2011-08-22 12:00:12 +00:00
Jon Medhurst 99d1717dd7 ARM: Add init_consistent_dma_size()
This function can be called during boot to increase the size of the consistent
DMA region above it's default value of 2MB. It must be called before the memory
allocator is initialised, i.e. before any core_initcall.

Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2011-08-22 12:00:10 +00:00
Russell King 022ae537b2 ARM: dma: replace ISA_DMA_THRESHOLD with a variable
ISA_DMA_THRESHOLD has been unused by non-arch code, so lets now get
rid of it from ARM by replacing it with arm_dma_zone_mask.  Move
dma_supported() and dma_set_mask() out of line, and have
dma_supported() check this new variable instead.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-12 11:08:12 +01:00
Russell King 196f020fbb Merge branches 'fixes', 'pgt-next' and 'versatile' into devel 2011-03-20 09:32:12 +00:00
Russell King 516295e5ab ARM: pgtable: add pud-level code
Add pud_offset() et.al. between the pgd and pmd code in preparation of
using pgtable-nopud.h rather than 4level-fixup.h.

This incorporates a fix from Jamie Iles <jamie@jamieiles.com> for
uaccess_with_memcpy.c.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-21 19:24:14 +00:00
Linus Walleij 0adfca6ff2 ARM: 6622/1: fix dma_unmap_sg() documentation
The kerneldoc for this function is at odds with the DMA-API
document, which holds, so fix it.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-01-12 19:42:13 +00:00
Russell King 4073723acb Merge branch 'misc' into devel
Conflicts:
	arch/arm/Kconfig
	arch/arm/common/Makefile
	arch/arm/kernel/Makefile
	arch/arm/kernel/smp.c
2011-01-06 22:32:52 +00:00
Russell King 4ec3eb1363 Merge branch 'smp' into misc
Conflicts:
	arch/arm/kernel/entry-armv.S
	arch/arm/mm/ioremap.c
2011-01-06 22:32:03 +00:00
Russell King 24056f5250 ARM: DMA: add support for DMA debugging
Add ARM support for the DMA debug infrastructure, which allows the
DMA API usage to be debugged.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-01-06 22:31:11 +00:00
Russell King 9eedd96301 ARM: DMA: Replace page_to_dma()/dma_to_page() with pfn_to_dma()/dma_to_pfn()
Replace the page_to_dma() and dma_to_page() macros with their PFN
equivalents.  This allows us to map parts of memory which do not have
a struct page allocated to them to bus addresses.  This will be used
internally by dma_alloc_coherent()/dma_alloc_writecombine().

Build tested on Versatile, OMAP1, IOP13xx and KS8695.

Tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-01-03 11:27:43 +00:00
Nicolas Pitre 39af22a792 ARM: get rid of kmap_high_l1_vipt()
Since commit 3e4d3af501 "mm: stack based kmap_atomic()", it is no longer
necessary to carry an ad hoc version of kmap_atomic() added in commit
7e5a69e83b "ARM: 6007/1: fix highmem with VIPT cache and DMA" to cope
with reentrancy.

In fact, it is now actively wrong to rely on fixed kmap type indices
(namely KM_L1_CACHE) as kmap_atomic() totally ignores them now and a
concurrent instance of it may reuse any slot for any purpose.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2010-12-19 12:56:46 -05:00
Russell King c947f69fff ARM: Fix DMA coherent allocator alignment
An out by one bug meant that the DMA coherent allocator was aligning
to one more bit than it should, causing it to run out of available
memory quicker.  Fix this.

Reported-by: Petr Štetiar <ynezz@true.cz>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-07 16:10:15 +00:00
Catalin Marinas c01778001a ARM: 6379/1: Assume new page cache pages have dirty D-cache
There are places in Linux where writes to newly allocated page cache
pages happen without a subsequent call to flush_dcache_page() (several
PIO drivers including USB HCD). This patch changes the meaning of
PG_arch_1 to be PG_dcache_clean and always flush the D-cache for a newly
mapped page in update_mmu_cache().

The patch also sets the PG_arch_1 bit in the DMA cache maintenance
function to avoid additional cache flushing in update_mmu_cache().

Tested-by: Rabin Vincent <rabin.vincent@stericsson.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-09-19 12:17:43 +01:00
Russell King 2be23c475a ARM: Ensure PTE modifications via dma_alloc_coherent are visible
Dave Hylands reports:
| We've observed a problem with dma_alloc_writecombine when the system
| is under heavy load (heavy bus traffic).  We've managed to reduce the
| problem to the following snippet, which is run from a kthread in a
| continuous loop:
|
|   void *virtAddr;
|   dma_addr_t physAddr;
|   unsigned int numBytes = 256;
|
|   for (;;) {
|       virtAddr = dma_alloc_writecombine(NULL,
|             numBytes, &physAddr, GFP_KERNEL);
|       if (virtAddr == NULL) {
|          printk(KERN_ERR "Running out of memory\n");
|          break;
|       }
|
|       /* access DMA memory allocated */
|       tmp = virtAddr;
|       *tmp = 0x77;
|
|       /* free DMA memory */
|       dma_free_writecombine(NULL,
|             numBytes, virtAddr, physAddr);
|
|         ...sleep here...
|     }
|
| By itself, the code will run forever with no issues. However, as we
| increase our bus traffic (typically using DMA) then the *tmp = 0x77
| line will eventually cause a page fault. If we add a small delay (a
| few microseconds) before the *tmp = 0x77, then we don't see a page
| fault, even under heavy load.

A dsb() is required after modifying the PTE entries to ensure that they
will always be visible.  Add this dsb().

Reported-by: Dave Hylands <dhylands@gmail.com>
Tested-by: Dave Hylands <dhylands@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-09-08 16:27:56 +01:00
Russell King 5bc23d32d8 ARM: DMA coherent allocator: align remapped addresses
The DMA coherent remap area is used to provide an uncached mapping
of memory for coherency with DMA engines.  Currently, we look for
any free hole which our allocation will fit in with page alignment.

However, this can lead to fragmentation of the area, and allows small
allocations to cross L1 entry boundaries.  This is undesirable as we
want to move towards allocating sections of memory.

Align allocations according to the size, limiting the alignment between
the page and section sizes.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-27 10:43:48 +01:00
Catalin Marinas a5e9d38b22 ARM: 6186/1: Avoid the CONSISTENT_DMA_SIZE warning on noMMU builds
This macro is not defined when !CONFIG_MMU so this patch moves the
CONSISTENT_* definitions to the CONFIG_MMU section.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-01 10:12:07 +01:00
Nicolas Pitre 7e5a69e83b ARM: 6007/1: fix highmem with VIPT cache and DMA
The VIVT cache of a highmem page is always flushed before the page
is unmapped.  This cache flush is explicit through flush_cache_kmaps()
in flush_all_zero_pkmaps(), or through __cpuc_flush_dcache_area() in
kunmap_atomic().  There is also an implicit flush of those highmem pages
that were part of a process that just terminated making those pages free
as the whole VIVT cache has to be flushed on every task switch. Hence
unmapped highmem pages need no cache maintenance in that case.

However unmapped pages may still be cached with a VIPT cache because the
cache is tagged with physical addresses.  There is no need for a whole
cache flush during task switching for that reason, and despite the
explicit cache flushes in flush_all_zero_pkmaps() and kunmap_atomic(),
some highmem pages that were mapped in user space end up still cached
even when they become unmapped.

So, we do have to perform cache maintenance on those unmapped highmem
pages in the context of DMA when using a VIPT cache.  Unfortunately,
it is not possible to perform that cache maintenance using physical
addresses as all the L1 cache maintenance coprocessor functions accept
virtual addresses only.  Therefore we have no choice but to set up a
temporary virtual mapping for that purpose.

And of course the explicit cache flushing when unmapping a highmem page
on a system with a VIPT cache now can go, which should increase
performance.

While at it, because the code in __flush_dcache_page() has to be modified
anyway, let's also make sure the mapped highmem pages are pinned with
kmap_high_get() for the duration of the cache maintenance operation.
Because kunmap() does unmap highmem pages lazily, it was reported by
Gary King <GKing@nvidia.com> that those pages ended up being unmapped
during cache maintenance on SMP causing segmentation faults.

Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-04-14 11:11:27 +01:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Russell King 2741ecb4ce Merge branch 'misc2' into devel 2010-02-25 22:09:41 +00:00
Fenkart/Bostandzhyan a7bd08c82e ARM: 5927/1: Make delimiters of DMA area globally visibly.
Adds DMA area to 'virtual memory map' startup message

Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andreas Fenkart <andreas.fenkart@streamunlimited.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-15 21:40:32 +00:00
Russell King 2ffe2da3e7 ARM: dma-mapping: fix for speculative prefetching
ARMv6 and ARMv7 CPUs can perform speculative prefetching, which makes
DMA cache coherency handling slightly more interesting.  Rather than
being able to rely upon the CPU not accessing the DMA buffer until DMA
has completed, we now must expect that the cache could be loaded with
possibly stale data from the DMA buffer.

Where DMA involves data being transferred to the device, we clean the
cache before handing it over for DMA, otherwise we invalidate the buffer
to get rid of potential writebacks.  On DMA Completion, if data was
transferred from the device, we invalidate the buffer to get rid of
any stale speculative prefetches.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
2010-02-15 15:22:25 +00:00
Russell King a9c9147eb9 ARM: dma-mapping: provide per-cpu type map/unmap functions
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
2010-02-15 15:22:20 +00:00
Russell King 93f1d629e2 ARM: dma-mapping: simplify dma_cache_maint_page
dma_cache_maint_contiguous is now simple enough to live inside
dma_cache_maint_page, so move it there.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
2010-02-15 15:22:16 +00:00
Russell King 65af191a04 ARM: dma-mapping: move selection of page ops out of dma_cache_maint_contiguous
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
2010-02-15 15:22:14 +00:00
Russell King 4ea0d7371e ARM: dma-mapping: push buffer ownership down into dma-mapping.c
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
2010-02-15 15:22:11 +00:00
Russell King 18eabe2347 ARM: dma-mapping: introduce the idea of buffer ownership
The DMA API has the notion of buffer ownership; make it explicit in the
ARM implementation of this API.  This gives us a set of hooks to allow
us to deal with CPU cache issues arising from non-cache coherent DMA.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-By: Jamie Iles <jamie@jamieiles.com>
2010-02-15 15:21:43 +00:00
Russell King 26a26d3296 ARM: dma-mapping: switch ARMv7 DMA mappings to retain 'memory' attribute
On ARMv7, it is invalid to map the same physical address multiple times
with different memory types.  Since system RAM is already mapped as
'memory', subsequent remapping of it must retain this attribute.

However, DMA memory maps it as "strongly ordered".  Fix this by introducing
'pgprot_dmacoherent()' which provides the necessary page table bits for
DMA mappings.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
2009-11-24 17:41:36 +00:00
Russell King acaac256b3 ARM: dma-mapping: get rid of setting/clearing the reserved page bit
It's unnecessary; x86 doesn't do it, and ALSA doesn't require it
anymore.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Ungerer <gerg@uclinux.org>
2009-11-24 17:41:36 +00:00
Russell King 31ebf94435 ARM: dma-mapping: Factor out noMMU dma buffer allocation code
This entirely separates the DMA coherent buffer remapping code from
the allocation code, and gets rid of the duplicate copy in the !MMU
section.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Ungerer <gerg@uclinux.org>
2009-11-24 17:41:35 +00:00
Russell King ebd7a845fa ARM: dma-mapping: clean up coherent arch dma allocation
IXP23xx added support for dma_alloc_coherent() for DMA arches with an
exception in dma_alloc_coherent().  This is a subset of what goes on
in __dma_alloc(), and there is no reason why dma_alloc_writecombine()
should not be given the same treatment (except, maybe, that IXP23xx
doesn't use it.)

We can better deal with this by moving the arch_is_coherent() test
inside __dma_alloc() and killing the code duplication.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Ungerer <gerg@uclinux.org>
2009-11-24 17:41:35 +00:00
Russell King 88c58f3b92 ARM: dma-mapping: move consistent_init into CONFIG_MMU section
No point wrapping the contents of this function with #ifdef CONFIG_MMU
when we can place it and the core_initcall() entirely within the
existing conditional block.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Ungerer <gerg@uclinux.org>
2009-11-24 17:41:35 +00:00
Russell King 695ae0af5a ARM: dma-mapping: factor dma_free_coherent() common code
We effectively have three implementations of dma_free_coherent() mixed up
in the code; the incoherent MMU, coherent MMU and noMMU versions.

The coherent MMU and noMMU versions are actually functionally identical.
The incoherent MMU version is almost the same, but with the additional
step of unmapping the secondary mapping.

Separate out this additional step into __dma_free_remap() and simplify
the resulting dma_free_coherent() code.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Ungerer <gerg@uclinux.org>
2009-11-24 17:41:35 +00:00
Russell King 04da56943b ARM: dma-mapping: fix nommu dma_alloc_coherent()
The nommu version of dma_alloc_coherent was using kmalloc/kfree to manage
the memory.  dma_alloc_coherent() is expected to work with a granularity
of a page, so this is wrong.  Fix it by using the helper functions now
provided.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Ungerer <gerg@uclinux.org>
2009-11-24 17:41:34 +00:00
Russell King 3e82d012e9 ARM: dma-mapping: fix coherent arch dma_alloc_coherent()
The coherent architecture dma_alloc_coherent was using kmalloc/kfree to
manage the memory.  dma_alloc_coherent() is expected to work with a
granularity of a page, so this is wrong.  Fix it by using the helper
functions now provided.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Ungerer <gerg@uclinux.org>
2009-11-24 17:41:34 +00:00
Russell King 7a9a32a953 ARM: dma-mapping: functions to allocate/free a coherent buffer
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Ungerer <gerg@uclinux.org>
2009-11-24 17:41:34 +00:00
Russell King 13ccf3ad99 ARM: dma-mapping: split out vmregion code from dma coherent mapping code
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Ungerer <gerg@uclinux.org>
2009-11-24 17:41:34 +00:00
Russell King c06e004c72 ARM: Use GFP_DMA only for masks _less_ than 32-bit
We were using GFP_DMA for masks other than 0xffffffff, which is
wrong when some masks are initialized to 0xffffffffffffffff.
This caused such masks to obtain memory from the precious DMA
pool.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-10-25 22:44:30 +00:00
Catalin Marinas ab6494f0c9 nommu: Add noMMU support to the DMA API
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-07-24 12:35:02 +01:00
Nicolas Pitre 43377453af [ARM] introduce dma_cache_maint_page()
This is a helper to be used by the DMA mapping API to handle cache
maintenance for memory identified by a page structure instead of a
virtual address.  Those pages may or may not be highmem pages, and
when they're highmem pages, they may or may not be virtually mapped.
When they're not mapped then there is no L1 cache to worry about. But
even in that case the L2 cache must be processed since unmapped highmem
pages can still be L2 cached.

Signed-off-by: Nicolas Pitre <nico@marvell.com>
2009-03-15 21:01:21 -04:00
Russell King 1522ac3ec9 [ARM] Fix virtual to physical translation macro corner cases
The current use of these macros works well when the conversion is
entirely linear.  In this case, we can be assured that the following
holds true:

	__va(p + s) - s = __va(p)

However, this is not always the case, especially when there is a
non-linear conversion (eg, when there is a 3.5GB hole in memory.)
In this case, if 's' is the size of the region (eg, PAGE_SIZE) and
'p' is the final page, the above is most definitely not true.

So, we must ensure that __va() and __pa() are only used with valid
kernel direct mapped RAM addresses.  This patch tweaks the code
to achieve this.

Tested-by: Charles Moschel <fred99@carolina.rr.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-03-12 23:09:09 +00:00
David Howells 9c93af1ede NOMMU: Rename ARM's struct vm_region
Rename ARM's struct vm_region so that I can introduce my own global version
for NOMMU.  It's feasible that the ARM version may wish to use my global one
instead.

The NOMMU vm_region struct defines areas of the physical memory map that are
under mmap.  This may include chunks of RAM or regions of memory mapped
devices, such as flash.  It is also used to retain copies of file content so
that shareable private memory mappings of files can be made.  As such, it may
be compatible with what is described in the banner comment for ARM's vm_region
struct.

Signed-off-by: David Howells <dhowells@redhat.com>
2009-01-08 12:04:47 +00:00
Russell King 309dbbabee [ARM] dma: don't touch cache on dma_*_for_cpu()
As per the dma_unmap_* calls, we don't touch the cache when a DMA
buffer transitions from device to CPU ownership.  Presently, no
problems have been identified with speculative cache prefetching
which in itself is a new feature in later architectures.  We may
have to revisit the DMA API later for these architectures anyway.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-30 11:01:36 +01:00
Russell King 2638b4dbe7 [ARM] dma: Reduce to one dma_sync_sg_* implementation
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-29 10:40:16 +01:00
Russell King 01135d92c1 [ARM] dma: Reduce to one dma_map_sg()/dma_unmap_sg() implementation
No point having two of these; dma_map_page() can do all the work
for us.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-25 23:39:24 +01:00