[PATCH v5 00/44] dma-mapping: Use unsigned long for dma_attrs
Hi,
This is fifth approach for replacing struct dma_attrs with unsigned
long.
The main patch (1/44) doing the change is split into many subpatches
for easier review (2-42). They should be squashed together when
applying.
Rebased on v4.7-rc5.
For easier testing the patchset is available here:
repo: https://github.com/krzk/linux
branch: for-next/dma-attrs-const-v5
Changes since v4
1. Collect some acks. Still need more.
2. Minor fixes pointed by Robin Murphy.
3. Applied changes from Bart Van Assche's comment.
4. More tests and builds (using https://www.kernel.org/pub/tools/crosstool/).
Changes since v3
1. Collect some acks.
2. Drop wrong patch 1/45 ("powerpc: dma-mapping: Don't hard-code
the value of DMA_ATTR_WEAK_ORDERING").
3. Minor fix pointed out by Michael Ellerman.
Changes since v2
1. Follow Christoph Hellwig's comments (don't use BIT add
documentation, remove dma_get_attr).
Rationale
=
The dma-mapping core and the implementations do not change the
DMA attributes passed by pointer. Thus the pointer can point to const
data. However the attributes do not have to be a bitfield. Instead
unsigned long will do fine:
1. This is just simpler. Both in terms of reading the code and setting
attributes. Instead of initializing local attributes on the stack
and passing pointer to it to dma_set_attr(), just set the bits.
2. It brings safeness and checking for const correctness because the
attributes are passed by value.
Best regards,
Krzysztof
Krzysztof Kozlowski (44):
dma-mapping: Use unsigned long for dma_attrs
alpha: dma-mapping: Use unsigned long for dma_attrs
arc: dma-mapping: Use unsigned long for dma_attrs
ARM: dma-mapping: Use unsigned long for dma_attrs
arm64: dma-mapping: Use unsigned long for dma_attrs
avr32: dma-mapping: Use unsigned long for dma_attrs
blackfin: dma-mapping: Use unsigned long for dma_attrs
c6x: dma-mapping: Use unsigned long for dma_attrs
cris: dma-mapping: Use unsigned long for dma_attrs
frv: dma-mapping: Use unsigned long for dma_attrs
drm/exynos: dma-mapping: Use unsigned long for dma_attrs
drm/mediatek: dma-mapping: Use unsigned long for dma_attrs
drm/msm: dma-mapping: Use unsigned long for dma_attrs
drm/nouveau: dma-mapping: Use unsigned long for dma_attrs
drm/rockship: dma-mapping: Use unsigned long for dma_attrs
infiniband: dma-mapping: Use unsigned long for dma_attrs
iommu: dma-mapping: Use unsigned long for dma_attrs
[media] dma-mapping: Use unsigned long for dma_attrs
xen: dma-mapping: Use unsigned long for dma_attrs
swiotlb: dma-mapping: Use unsigned long for dma_attrs
powerpc: dma-mapping: Use unsigned long for dma_attrs
video: dma-mapping: Use unsigned long for dma_attrs
x86: dma-mapping: Use unsigned long for dma_attrs
iommu: intel: dma-mapping: Use unsigned long for dma_attrs
h8300: dma-mapping: Use unsigned long for dma_attrs
hexagon: dma-mapping: Use unsigned long for dma_attrs
ia64: dma-mapping: Use unsigned long for dma_attrs
m68k: dma-mapping: Use unsigned long for dma_attrs
metag: dma-mapping: Use unsigned long for dma_attrs
microblaze: dma-mapping: Use unsigned long for dma_attrs
mips: dma-mapping: Use unsigned long for dma_attrs
mn10300: dma-mapping: Use unsigned long for dma_attrs
nios2: dma-mapping: Use unsigned long for dma_attrs
openrisc: dma-mapping: Use unsigned long for dma_attrs
parisc: dma-mapping: Use unsigned long for dma_attrs
misc: mic: dma-mapping: Use unsigned long for dma_attrs
s390: dma-mapping: Use unsigned long for dma_attrs
sh: dma-mapping: Use unsigned long for dma_attrs
sparc: dma-mapping: Use unsigned long for dma_attrs
tile: dma-mapping: Use unsigned long for dma_attrs
unicore32: dma-mapping: Use unsigned long for dma_attrs
xtensa: dma-mapping: Use unsigned long for dma_attrs
dma-mapping: Remove dma_get_attr
dma-mapping: Document the DMA attributes next to the declaration
Documentation/DMA-API.txt | 33 +++---
Documentation/DMA-attributes.txt | 2 +-
arch/alpha/include/asm/dma-mapping.h | 2 -
arch/alpha/kernel/pci-noop.c | 2 +-
arch/alpha/kernel/pci_iommu.c | 12 +-
arch/arc/mm/dma.c | 12 +-
arch/arm/common/dmabounce.c| 4 +-
arch/arm/include/asm/dma-mapping.h | 13 +--
arch/arm/include/asm/xen/page-coherent.h | 16 +--
arch/arm/mm/dma-mapping.c | 117 +--
arch/arm/xen/mm.c | 8 +-
arch/arm64/mm/dma-mapping.c| 66 +--
arch/avr32/mm/dma-coherent.c | 12 +-
arch/blackfin/kernel/dma-mapping.c | 8 +-
arch/c6x/include/asm/dma-mapping.h | 4 +-
arch/c6x/kernel/dma.c | 9
[PATCH v5 03/44] arc: dma-mapping: Use unsigned long for dma_attrs
Split out subsystem specific changes for easier reviews. This will be
squashed with main commit.
Signed-off-by: Krzysztof Kozlowski
[for arc]
Acked-by: Vineet Gupta
---
arch/arc/mm/dma.c | 8
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index 73d7e4c75b7d..3d1f467d1792 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -22,7 +22,7 @@
static void *arc_dma_alloc(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t gfp, struct dma_attrs *attrs)
+ dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
unsigned long order = get_order(size);
struct page *page;
@@ -90,7 +90,7 @@ static void *arc_dma_alloc(struct device *dev, size_t size,
}
static void arc_dma_free(struct device *dev, size_t size, void *vaddr,
- dma_addr_t dma_handle, struct dma_attrs *attrs)
+ dma_addr_t dma_handle, unsigned long attrs)
{
struct page *page = virt_to_page(dma_handle);
int is_non_coh = 1;
@@ -129,7 +129,7 @@ static void _dma_cache_sync(phys_addr_t paddr, size_t size,
static dma_addr_t arc_dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir,
- struct dma_attrs *attrs)
+ unsigned long attrs)
{
phys_addr_t paddr = page_to_phys(page) + offset;
_dma_cache_sync(paddr, size, dir);
@@ -137,7 +137,7 @@ static dma_addr_t arc_dma_map_page(struct device *dev,
struct page *page,
}
static int arc_dma_map_sg(struct device *dev, struct scatterlist *sg,
- int nents, enum dma_data_direction dir, struct dma_attrs *attrs)
+ int nents, enum dma_data_direction dir, unsigned long attrs)
{
struct scatterlist *s;
int i;
--
1.9.1
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[PATCH v5 43/44] dma-mapping: Remove dma_get_attr
After switching DMA attributes to unsigned long it is easier to just
compare the bits.
Signed-off-by: Krzysztof Kozlowski
[for avr32]
Acked-by: Hans-Christian Noren Egtvedt
[for arc]
Acked-by: Vineet Gupta
[for arm64 and dma-iommu]
Acked-by: Robin Murphy
---
Documentation/DMA-API.txt | 4 +--
arch/arc/mm/dma.c | 4 +--
arch/arm/mm/dma-mapping.c | 36 --
arch/arm/xen/mm.c | 4 +--
arch/arm64/mm/dma-mapping.c| 10 +++
arch/avr32/mm/dma-coherent.c | 4 +--
arch/ia64/sn/pci/pci_dma.c | 10 ++-
arch/metag/kernel/dma.c| 2 +-
arch/mips/mm/dma-default.c | 6 ++---
arch/openrisc/kernel/dma.c | 4 +--
arch/parisc/kernel/pci-dma.c | 2 +-
arch/powerpc/platforms/cell/iommu.c| 12 -
drivers/gpu/drm/rockchip/rockchip_drm_gem.c| 2 +-
drivers/iommu/dma-iommu.c | 2 +-
drivers/media/v4l2-core/videobuf2-dma-contig.c | 2 +-
include/linux/dma-mapping.h| 10 ---
16 files changed, 47 insertions(+), 67 deletions(-)
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index 24f9688bb98a..1d26eeb6b5f6 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -422,9 +422,7 @@ void whizco_dma_map_sg_attrs(struct device *dev, dma_addr_t
dma_addr,
unsigned long attrs)
{
- int foo = dma_get_attr(DMA_ATTR_FOO, attrs);
-
- if (foo)
+ if (attrs & DMA_ATTR_FOO)
/* twizzle the frobnozzle */
diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index 3d1f467d1792..74bbe68dce9d 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -46,7 +46,7 @@ static void *arc_dma_alloc(struct device *dev, size_t size,
* (vs. always going to memory - thus are faster)
*/
if ((is_isa_arcv2() && ioc_exists) ||
- dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs))
+ (attrs & DMA_ATTR_NON_CONSISTENT))
need_coh = 0;
/*
@@ -95,7 +95,7 @@ static void arc_dma_free(struct device *dev, size_t size,
void *vaddr,
struct page *page = virt_to_page(dma_handle);
int is_non_coh = 1;
- is_non_coh = dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs) ||
+ is_non_coh = (attrs & DMA_ATTR_NON_CONSISTENT) ||
(is_isa_arcv2() && ioc_exists);
if (PageHighMem(page) || !is_non_coh)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index ebb3fde99043..43e03b5293d0 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -126,7 +126,7 @@ static dma_addr_t arm_dma_map_page(struct device *dev,
struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
- if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
+ if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
__dma_page_cpu_to_dev(page, offset, size, dir);
return pfn_to_dma(dev, page_to_pfn(page)) + offset;
}
@@ -155,7 +155,7 @@ static dma_addr_t arm_coherent_dma_map_page(struct device
*dev, struct page *pag
static void arm_dma_unmap_page(struct device *dev, dma_addr_t handle,
size_t size, enum dma_data_direction dir, unsigned long attrs)
{
- if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
+ if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
__dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
handle & ~PAGE_MASK, size, dir);
}
@@ -622,9 +622,9 @@ static void __free_from_contiguous(struct device *dev,
struct page *page,
static inline pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot)
{
- prot = dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs) ?
- pgprot_writecombine(prot) :
- pgprot_dmacoherent(prot);
+ prot = (attrs & DMA_ATTR_WRITE_COMBINE) ?
+ pgprot_writecombine(prot) :
+ pgprot_dmacoherent(prot);
return prot;
}
@@ -744,7 +744,7 @@ static void *__dma_alloc(struct device *dev, size_t size,
dma_addr_t *handle,
.gfp = gfp,
.prot = prot,
.caller = caller,
- .want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs),
+ .want_vaddr = ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0),
};
#ifdef CONFIG_DMA_API_DEBUG
@@ -887,7 +887,7 @@ static void __arm_dma_free(struct device *dev, size_t size,
void *cpu_addr,
.size = PAGE_ALIGN(size),
.cpu_addr = cpu_addr,
.page = page,
- .want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs),
+
[GIT PULL] ARC fixes for 4.7-rc6
Hi Linus, A couple of fixes for ARC. Please pull ! Thx, -Vineet > The following changes since commit 5edb56491d4812c42175980759da53388e5d86f5: Linux 4.7-rc3 (2016-06-12 07:20:35 -0700) are available in the git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc.git/ tags/arc-4.7-rc6-fixes for you to fetch changes up to 9bd54517ee86cb164c734f72ea95aeba4804f10b: arc: unwind: warn only once if DW2_UNWIND is disabled (2016-06-28 11:11:44 +0530) ARC Fix for 4.7-rc6 - Reinstate dwarf unwinder/loadable-modules with new gnu tools Alexey Brodkin (1): arc: unwind: warn only once if DW2_UNWIND is disabled Vineet Gupta (1): ARC: unwind: ensure that .debug_frame is generated (vs. .eh_frame) arch/arc/Makefile| 2 -- arch/arc/kernel/stacktrace.c | 2 +- 2 files changed, 1 insertion(+), 3 deletions(-) ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: Handling Machine check
On Friday 01 July 2016 09:29 AM, Noam Camus wrote: > > Hi Vineet, > > > I wish to ask about how kernel should handle machine check. > > Why it is a dead end unlike other exceptions e.g. " mem error", "inst err"? > > > What will happen if I do call ret_from_exception? > > Where I going to find my self after the rtie? > > should all relevant auxiliary registers needed for proper return from rtie are > expected to be valid? > > > Is there any difference if such exception caused during user or kernel mode? > > > All above comes from special case we have: > > Our chip creates machine check when user code goes beyound memory space > boundary, Inside EV handler I called to FAKE, do_memory_error and > ret_from_exception and I got SIGBUS as expected and I didn't noticed any thing > strange, so I am not sure why we treat this as DEAD END? > > > Note: it is not double fault but rather first exception. > > With standard ARCompact ISA / ARC cores, machine check is typically for fatal errors in *kernel* mode and this by definition is non-recoverable. e.g. if Bus returned error in kernel mode- how do u handle it - i mean u can't RTIE to same instruction and it is not correct to assume to return to next one either. Moreover machine check is taken for nested exceptions - where system is really hosed as ERET/ERSTATUS of orig exception are already clobbered/lost. So the umbrella handling for machine check is halt - otherwise at time of crash - code just keeps spinning/running. If there are new cases where it can be gracefully handled - I'm open to patches to same effect ! -Vineet ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
