Investigation of network performance on Sparc shows a high
degree of locking contention in the IOMMU allocator, and it
was noticed that the PowerPC code has a better locking model.
This patch series tries to extract the generic parts of the
PowerPC code so that it can be shared across multiple PCI
devices and architectures.
v10: resend patchv9 without RFC tag, and a new mail Message-Id,
(previous non-RFC attempt did not show up on the patchwork queue?)
Full revision history below:
v2 changes:
- incorporate David Miller editorial comments: sparc specific
fields moved from iommu-common into sparc's iommu_64.h
- make the npools value an input parameter, for the case when
the iommu map size is not very large
- cookie_to_index mapping, and optimizations for span-boundary
check, for use case such as LDC.
v3: eliminate iommu_sparc, rearrange the ->demap indirection to
be invoked under the pool lock.
v4: David Miller review changes:
- s/IOMMU_ERROR_CODE/DMA_ERROR_CODE
- page_table_map_base and page_table_shift are unsigned long, not u32.
v5: removed ->cookie_to_index and ->demap indirection from the
iommu_tbl_ops The caller needs to call these functions as needed,
before invoking the generic arena allocator functions.
Added the "skip_span_boundary" argument to iommu_tbl_pool_init() for
those callers like LDC which do no care about span boundary checks.
v6: removed iommu_tbl_ops, and instead pass the ->flush_all as
an indirection to iommu_tbl_pool_init(); only invoke ->flush_all
when there is no large_pool, based on the assumption that large-pool
usage is infrequently encountered
v7: moved pool_hash initialization to lib/iommu-common.c and cleaned up
code duplication from sun4v/sun4u/ldc.
v8: Addresses BenH comments with one exception: I've left the
IOMMU_POOL_HASH as is, so that powerpc can tailor it to their
convenience. Discard trylock for simple spin_lock to acquire pool
v9: Addresses latest BenH comments: need_flush checks, add support
for dma mask and align_order.
v10: resend without RFC tag, and new mail Message-Id.
Sowmini Varadhan (3):
Break up monolithic iommu table/lock into finer graularity pools and
lock
Make sparc64 use scalable lib/iommu-common.c functions
Make LDC use common iommu poll management functions
arch/sparc/include/asm/iommu_64.h | 7 +-
arch/sparc/kernel/iommu.c | 172 ++++++------------------
arch/sparc/kernel/iommu_common.h | 8 -
arch/sparc/kernel/ldc.c | 153 +++++++++------------
arch/sparc/kernel/pci_sun4v.c | 183 ++++++++++++--------------
include/linux/iommu-common.h | 51 +++++++
lib/Makefile | 2 +-
lib/iommu-common.c | 266 +++++++++++++++++++++++++++++++++++++
8 files changed, 511 insertions(+), 331 deletions(-)
create mode 100644 include/linux/iommu-common.h
create mode 100644 lib/iommu-common.c
--
To unsubscribe from this list: send the line "unsubscribe sparclinux" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
