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[PATCH v4 0/7] iommu: split mapping to page sizes as supported by the hardware

October 17th, 2011 - 07:30 am ET by Ohad Ben-Cohen | Report spam
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v3->v4:
- simplify splitter logic (Joerg)
- declare supported page-sizes in the iommu_ops, without extending iommu_register (Joerg)
- iommu_unmap should now return bytes too (Joerg)
- don't cache min_pgsize anymore (Joerg)
- handle cases when ->unmap() actually unmaps more than requested (Joerg)
- unroll iommu_unmap completely in case it fails (KyongHo)
- use size_t for size parameters (KyongHo)
- add a patch to remove the bytes->order->bytes conversion we had
- rabase to master branch of the iommu tree (Joerg)

v2->v3:
- s/KB/KiB/ (David W)

v1->v2:
- split to patches (by keeping the old code around until all drivers are converted) (Joerg)

Tested with OMAP3 (omap3isp) and OMAP4 (rpmsg/remoteproc).
Compile tested with X86_64.

Ohad Ben-Cohen (7):
iommu/core: stop converting bytes to page order back and forth
iommu/core: split mapping to page sizes as supported by the hardware
iommu/omap: announce supported page sizes
iommu/msm: announce supported page sizes
iommu/amd: announce supported page sizes
iommu/intel: announce supported page sizes
iommu/core: remove the temporary pgsize settings

drivers/iommu/amd_iommu.c | 32 +++++++++
drivers/iommu/intel-iommu.c | 30 ++++++++
drivers/iommu/iommu.c | 119 ++++++++++++++++++++++++++++++++++++++-
drivers/iommu/msm_iommu.c | 25 ++++--
drivers/iommu/omap-iommu.c | 18 +++
drivers/iommu/omap-iovmm.c | 17 ++-
include/linux/iommu.h | 26 +++++++--
virt/kvm/iommu.c | 8 ++--
8 files changed, 205 insertions(+), 70 deletions(-)

1.7.4.1

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#1 Ohad Ben-Cohen
October 17th, 2011 - 07:30 am ET | Report spam
Let the IOMMU core know we support arbitrary page sizes (as long as
they're an order of 4KiB).

This way the IOMMU core will retain the existing behavior we're used to;
it will let us map regions that:
- their size is an order of 4KiB
- they are naturally aligned

Signed-off-by: Ohad Ben-Cohen
Cc: Joerg Roedel

drivers/iommu/amd_iommu.c | 19 +++++++++++++++++++
1 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 32d502e..d654b59 100644
a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -41,6 +41,24 @@

#define LOOP_TIMEOUT 100000

+/*
+ * This bitmap is used to advertise the page sizes our hardware support
+ * to the IOMMU core, which will then use this information to split
+ * physically contiguous memory regions it is mapping into page sizes
+ * that we support.
+ *
+ * Traditionally the IOMMU core just handed us the mappings directly,
+ * after making sure the size is an order of a 4KiB page and that the
+ * mapping has natural alignment.
+ *
+ * To retain this behavior, we currently advertise that we support
+ * all page sizes that are an order of 4KiB.
+ *
+ * If at some point we'd like to utilize the IOMMU core's new behavior,
+ * we could change this to advertise the real page sizes we support.
+ */
+#define AMD_IOMMU_PGSIZES (~0xFFFUL)
+
static DEFINE_RWLOCK(amd_iommu_devtable_lock);

/* A list of preallocated protection domains */
@@ -2779,6 +2797,7 @@ static struct iommu_ops amd_iommu_ops = {
.unmap = amd_iommu_unmap,
.iova_to_phys = amd_iommu_iova_to_phys,
.domain_has_cap = amd_iommu_domain_has_cap,
+ .pgsize_bitmap = AMD_IOMMU_PGSIZES,
};

/*****************************************************************************
1.7.4.1

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