Messages in this thread | | | Date | Wed, 2 Apr 2008 14:19:23 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH -mm] SWIOTLB: use iommu_is_span_boundary helper function |
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On Thu, 3 Apr 2008 06:02:35 +0900 FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> wrote:
> iommu_is_span_boundary in lib/iommu-helper.c was exported for PARISC > IOMMUs (commit 3715863aa142c4f4c5208f5f3e5e9bac06006d2f). SWIOTLB can > use it instead of the homegrown function. > > Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: H. Peter Anvin <hpa@zytor.com> > Cc: Tony Luck <tony.luck@intel.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > --- > arch/ia64/Kconfig | 5 ++++- > arch/x86/Kconfig | 5 ++--- > lib/swiotlb.c | 14 +++----------- > 3 files changed, 9 insertions(+), 15 deletions(-) > > diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig > index 53b8410..6840a13 100644 > --- a/arch/ia64/Kconfig > +++ b/arch/ia64/Kconfig > @@ -47,6 +47,9 @@ config MMU > config SWIOTLB > bool > > +config IOMMU_HELPER > + bool > + > config GENERIC_LOCKBREAK > bool > default y > @@ -624,7 +627,7 @@ config IRQ_PER_CPU > default y > > config IOMMU_HELPER > - def_bool (IA64_HP_ZX1 || IA64_HP_ZX1_SWIOTLB || IA64_GENERIC) > + def_bool (IA64_HP_ZX1 || IA64_HP_ZX1_SWIOTLB || IA64_GENERIC || SWIOTLB) > > source "arch/ia64/hp/sim/Kconfig" > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 1f44517..e6c01c2 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -502,9 +502,6 @@ config CALGARY_IOMMU_ENABLED_BY_DEFAULT > Calgary anyway, pass 'iommu=calgary' on the kernel command line. > If unsure, say Y. > > -config IOMMU_HELPER > - def_bool (CALGARY_IOMMU || GART_IOMMU) > - > # need this always selected by IOMMU for the VIA workaround > config SWIOTLB > bool > @@ -515,6 +512,8 @@ config SWIOTLB > access 32-bits of memory can be used on systems with more than > 3 GB of memory. If unsure, say Y. > > +config IOMMU_HELPER > + def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB) > > config NR_CPUS > int "Maximum number of CPUs (2-255)" > diff --git a/lib/swiotlb.c b/lib/swiotlb.c > index 62c9a18..b50c7e0 100644 > --- a/lib/swiotlb.c > +++ b/lib/swiotlb.c > @@ -31,6 +31,7 @@ > > #include <linux/init.h> > #include <linux/bootmem.h> > +#include <linux/iommu-helper.h> > > #define OFFSET(val,align) ((unsigned long) \ > ( (val) & ( (align) - 1))) > @@ -282,15 +283,6 @@ address_needs_mapping(struct device *hwdev, dma_addr_t addr) > return (addr & ~mask) != 0; > } > > -static inline unsigned int is_span_boundary(unsigned int index, > - unsigned int nslots, > - unsigned long offset_slots, > - unsigned long max_slots) > -{ > - unsigned long offset = (offset_slots + index) & (max_slots - 1); > - return offset + nslots > max_slots; > -} > - > /* > * Allocates bounce buffer and returns its kernel virtual address. > */ > @@ -338,8 +330,8 @@ map_single(struct device *hwdev, char *buffer, size_t size, int dir) > wrap = index; > > do { > - while (is_span_boundary(index, nslots, offset_slots, > - max_slots)) { > + while (iommu_is_span_boundary(index, nslots, offset_slots, > + max_slots)) { > index += stride; > if (index >= io_tlb_nslabs) > index = 0;
Fair enough.
It's confusing that iommu_is_span_boundary() uses index, nr, shift and boundary_size whereas is_span_boundary() used index, nslots, offset_slots, and max_slots. Which one was most accurate, clearer, etc?
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