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| author | Alexey Kardashevskiy <aik@ozlabs.ru> | 2023-03-06 11:30:20 -0600 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-03-14 23:36:27 +1100 |
| commit | 9d67c94335096311c0bc7556ad1022de7385790b (patch) | |
| tree | 818fb720dc6b4700345e0096fc09c85e8bc5d9fe /arch/powerpc/include/asm | |
| parent | eeac8ede17557680855031c6f305ece2378af326 (diff) | |
| download | linux-next-9d67c94335096311c0bc7556ad1022de7385790b.tar.gz | |
powerpc/iommu: Add "borrowing" iommu_table_group_ops
PPC64 IOMMU API defines iommu_table_group_ops which handles DMA windows
for PEs: control the ownership, create/set/unset a table the hardware
for dynamic DMA windows (DDW). VFIO uses the API to implement support on
POWER.
So far only PowerNV IODA2 (POWER8 and newer machines) implemented this
and other cases (POWER7 or nested KVM) did not and instead reused
existing iommu_table structs. This means 1) no DDW 2) ownership transfer
is done directly in the VFIO SPAPR TCE driver.
Soon POWER is going to get its own iommu_ops and ownership control is
going to move there. This implements spapr_tce_table_group_ops which
borrows iommu_table tables. The upside is that VFIO needs to know less
about POWER.
The new ops returns the existing table from create_table() and only
checks if the same window is already set. This is only going to work if
the default DMA window starts table_group.tce32_start and as big as
pe->table_group.tce32_size (not the case for IODA2+ PowerNV).
This changes iommu_table_group_ops::take_ownership() to return an error
if borrowing a table failed.
This should not cause any visible change in behavior for PowerNV.
pSeries was not that well tested/supported anyway.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Timothy Pearson <tpearson@raptorengineering.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
[mpe: Fix CONFIG_IOMMU_API=n build (skiroot_defconfig), & formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/525438831.16998517.1678123820075.JavaMail.zimbra@raptorengineeringinc.com
Diffstat (limited to 'arch/powerpc/include/asm')
| -rw-r--r-- | arch/powerpc/include/asm/iommu.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h index 7e29c73e3dd4..678b5bdc79b1 100644 --- a/arch/powerpc/include/asm/iommu.h +++ b/arch/powerpc/include/asm/iommu.h @@ -175,7 +175,7 @@ struct iommu_table_group_ops { long (*unset_window)(struct iommu_table_group *table_group, int num); /* Switch ownership from platform code to external user (e.g. VFIO) */ - void (*take_ownership)(struct iommu_table_group *table_group); + long (*take_ownership)(struct iommu_table_group *table_group); /* Switch ownership from external user (e.g. VFIO) back to core */ void (*release_ownership)(struct iommu_table_group *table_group); }; @@ -215,6 +215,8 @@ extern long iommu_tce_xchg_no_kill(struct mm_struct *mm, enum dma_data_direction *direction); extern void iommu_tce_kill(struct iommu_table *tbl, unsigned long entry, unsigned long pages); + +extern struct iommu_table_group_ops spapr_tce_table_group_ops; #else static inline void iommu_register_group(struct iommu_table_group *table_group, int pci_domain_number, @@ -303,8 +305,6 @@ extern int iommu_tce_check_gpa(unsigned long page_shift, iommu_tce_check_gpa((tbl)->it_page_shift, (gpa))) extern void iommu_flush_tce(struct iommu_table *tbl); -extern int iommu_take_ownership(struct iommu_table *tbl); -extern void iommu_release_ownership(struct iommu_table *tbl); extern enum dma_data_direction iommu_tce_direction(unsigned long tce); extern unsigned long iommu_direction_to_tce_perm(enum dma_data_direction dir); |