Commit Graph

7 Commits

Author SHA1 Message Date
Jason Gunthorpe
5e2ff240b3 iommu: Clear the freelist after iommu_put_pages_list()
The commit below reworked how iommu_put_pages_list() worked to not do
list_del() on every entry. This was done expecting all the callers to
already re-init the list so doing a per-item deletion is not
efficient.

It was missed that fq_ring_free_locked() re-uses its list after calling
iommu_put_pages_list() and so the leftover list reaches free'd struct
pages and will crash or WARN/BUG/etc.

Reinit the list to empty in fq_ring_free_locked() after calling
iommu_put_pages_list().

Audit to see if any other callers of iommu_put_pages_list() need the list
to be empty:

 - iommu_dma_free_fq_single() and iommu_dma_free_fq_percpu() immediately
   frees the memory

 - iommu_v1_map_pages(), v1_free_pgtable(), domain_exit(),
   riscv_iommu_map_pages() uses a stack variable which goes out of scope

 - intel_iommu_tlb_sync() uses a gather in a iotlb_sync() callback, the
   caller re-inits the gather

Fixes: 13f43d7cf3 ("iommu/pages: Formalize the freelist API")
Reported-by: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
Closes: https://lore.kernel.org/r/SJ1PR11MB61292CE72D7BE06B8810021CB997A@SJ1PR11MB6129.namprd11.prod.outlook.com
Tested-by: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/0-v1-7d4dfa6140f7+11f04-iommu_freelist_init_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-05-16 14:29:16 +02:00
Jason Gunthorpe
b3efacc451 iommu/pages: Allow sub page sizes to be passed into the allocator
Generally drivers have a specific idea what their HW structure size should
be. In a lot of cases this is related to PAGE_SIZE, but not always. ARM64,
for example, allows a 4K IO page table size on a 64K CPU page table
system.

Currently we don't have any good support for sub page allocations, but
make the API accommodate this by accepting a sub page size from the caller
and rounding up internally.

This is done by moving away from order as the size input and using size:
  size == 1 << (order + PAGE_SHIFT)

Following patches convert drivers away from using order and try to specify
allocation sizes independent of PAGE_SIZE.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/15-v4-c8663abbb606+3f7-iommu_pages_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-17 16:22:46 +02:00
Jason Gunthorpe
580ccca4ee iommu/pages: Move the __GFP_HIGHMEM checks into the common code
The entire allocator API is built around using the kernel virtual address,
it is illegal to pass GFP_HIGHMEM in as a GFP flag. Block it in the common
code. Remove the duplicated checks from drivers.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Mostafa Saleh <smostafa@google.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/14-v4-c8663abbb606+3f7-iommu_pages_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-17 16:22:45 +02:00
Jason Gunthorpe
212fcf36c6 iommu/pages: Move from struct page to struct ioptdesc and folio
This brings the iommu page table allocator into the modern world of having
its own private page descriptor and not re-using fields from struct page
for its own purpose. It follows the basic pattern of struct ptdesc which
did this transformation for the CPU page table allocator.

Currently iommu-pages is pretty basic so this isn't a huge benefit,
however I see a coming need for features that CPU allocator has, like sub
PAGE_SIZE allocations, and RCU freeing. This provides the base
infrastructure to implement those cleanly.

Remove numa_node_id() calls from the inlines and instead use NUMA_NO_NODE
which will get switched to numa_mem_id(), which seems to be the right ID
to use for memory allocations.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/13-v4-c8663abbb606+3f7-iommu_pages_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-17 16:22:44 +02:00
Jason Gunthorpe
27bc9f717f iommu/pages: Remove iommu_put_pages_list_old and the _Generic
Nothing uses the old list_head path now, remove it.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/12-v4-c8663abbb606+3f7-iommu_pages_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-17 16:22:43 +02:00
Jason Gunthorpe
13f43d7cf3 iommu/pages: Formalize the freelist API
We want to get rid of struct page references outside the internal
allocator implementation. The free list has the driver open code something
like:

   list_add_tail(&virt_to_page(ptr)->lru, freelist);

Move the above into a small inline and make the freelist into a wrapper
type 'struct iommu_pages_list' so that the compiler can help check all the
conversion.

This struct has also proven helpful in some future ideas to convert to a
singly linked list to get an extra pointer in the struct page, and to
signal that the pages should be freed with RCU.

Use a temporary _Generic so we don't need to rename the free function as
the patches progress.

Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/8-v4-c8663abbb606+3f7-iommu_pages_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-17 16:22:40 +02:00
Jason Gunthorpe
f5af4a4f7c iommu/pages: De-inline the substantial functions
These are called in a lot of places and are not trivial. Move them to the
core module.

Tidy some of the comments and function arguments, fold
__iommu_alloc_account() into its only caller, change
__iommu_free_account() into __iommu_free_page() to remove some
duplication.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Mostafa Saleh <smostafa@google.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/7-v4-c8663abbb606+3f7-iommu_pages_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-17 16:22:39 +02:00