INTEL_IOMMU_FLOPPY_WA workaround was introduced to create direct mappings
for first 16MB for floppy devices as the floppy drivers were not using
dma apis. We need not do this direct map if floppy driver is not
enabled.

INTEL_IOMMU_FLOPPY_WA is generally not a good idea. Iommu will be
mapping pages in this address range while kernel would also be
allocating from this range(mostly on memory stress). A misbehaving
device using this domain will have access to the pages that the
kernel might be actively using. We noticed this while running a test
that was trying to figure out if any pages used by kernel is in iommu
page tables.

This patch reduces the scope of the above issue by disabling the
workaround when floppy driver is not enabled. But we would still need to
fix the floppy driver to use dma apis so that we need not do direct map
without reserving the pages. Or the other option is to reserve this
memory range in firmware so that kernel will not use the pages.

Fixes: d850c2ee5fe2 ("iommu/vt-d: Expose ISA direct mapping region via iommu_get_resv_regions")
Fixes: 49a0429e53f2 ("Intel IOMMU: Iommu floppy workaround")
Signed-off-by: Vineeth Pillai (Google) <vineeth@bitbyteword.org>
Link: https://lore.kernel.org/r/20251002161625.1155133-1-vineeth@bitbyteword.org
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

Replace the VT-d iommu_domain implementation of the VT-d second stage and
first stage page tables with the iommupt VTDSS and x86_64
pagetables. x86_64 is shared with the AMD driver.

There are a couple notable things in VT-d:
- Like AMD the second stage format is not sign extended, unlike AMD it
  cannot decode a full 64 bits. The first stage format is a normal sign
  extended x86 page table
- The HW caps can indicate how many levels, how many address bits and what
  leaf page sizes are supported in HW. As before the highest number of
  levels that can translate the entire supported address width is used.
  The supported page sizes are adjusted directly from the dedicated
  first/second stage cap bits.
- VTD requires flushing 'write buffers'. This logic is left unchanged,
  the write buffer flushes on any gather flush or through iotlb_sync_map.
- Like ARM, VTD has an optional non-coherent page table walker that
  requires cache flushing. This is supported through PT_FEAT_DMA_INCOHERENT
  the same as ARM, however x86 can't use the DMA API for flush, it must
  call the arch function clflush_cache_range()
- The PT_FEAT_DYNAMIC_TOP can probably be supported on VT-d someday for the
  second stage when it uses 128 bit atomic stores for the HW context
  structures.
- PT_FEAT_VTDSS_FORCE_WRITEABLE is used to work around ERRATA_772415_SPR17
- A kernel command line parameter "sp_off" disables all page sizes except
  4k

Remove all the unused iommu_domain page table code. The debugfs paths have
their own independent page table walker that is left alone for now.

This corrects a race with the non-coherent walker that the ARM
implementations have fixed:

     CPU 0                               CPU 1
  pfn_to_dma_pte()                    pfn_to_dma_pte()
   pte = &parent[offset];
   if (!dma_pte_present(pte)) {
     try_cmpxchg64(&pte->val)
					pte = &parent[offset];
					.. dma_pte_present(pte) ..
				        [...]
					// iommu_map() completes
					// Device does DMA
     domain_flush_cache(pte)

The CPU 1 mapping operation shares a page table level with the CPU 0
mapping operation. CPU 0 installed a new page table level but has not
flushed it yet. CPU1 returns from iommu_map() and the device does DMA. The
non coherent walker fails to see the new table level installed by CPU 0
and fails the DMA with non-present.

The iommupt PT_FEAT_DMA_INCOHERENT implementation uses the ARM design of
storing a flag when CPU 0 completes the flush. If the flag is not set CPU
1 will also flush to ensure the HW can fully walk to the PTE being
installed.

Cc: Tina Zhang <tina.zhang@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

Move IOMMU_IOPF from under INTEL_IOMMU_SVM into INTEL_IOMMU. This
certifies that the core intel iommu utilizes the IOPF library
functions, independent of the INTEL_IOMMU_SVM config.

Signed-off-by: Joel Granados <joel.granados@kernel.org>
Link: https://lore.kernel.org/r/20241015-jag-iopfv8-v4-3-b696ca89ba29@kernel.org
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Directly call into dma-iommu just like we have been doing for dma-direct
for a while.  This avoids the indirect call overhead for IOMMU ops and
removes the need to have DMA ops entirely for many common configurations.

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Pull Kbuild updates from Masahiro Yamada:

 - Generate a list of built DTB files (arch/*/boot/dts/dtbs-list)

 - Use more threads when building Debian packages in parallel

 - Fix warnings shown during the RPM kernel package uninstallation

 - Change OBJECT_FILES_NON_STANDARD_*.o etc. to take a relative path to
   Makefile

 - Support GCC's -fmin-function-alignment flag

 - Fix a null pointer dereference bug in modpost

 - Add the DTB support to the RPM package

 - Various fixes and cleanups in Kconfig

* tag 'kbuild-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (67 commits)
  kconfig: tests: test dependency after shuffling choices
  kconfig: tests: add a test for randconfig with dependent choices
  kconfig: tests: support KCONFIG_SEED for the randconfig runner
  kbuild: rpm-pkg: add dtb files in kernel rpm
  kconfig: remove unneeded menu_is_visible() call in conf_write_defconfig()
  kconfig: check prompt for choice while parsing
  kconfig: lxdialog: remove unused dialog colors
  kconfig: lxdialog: fix button color for blackbg theme
  modpost: fix null pointer dereference
  kbuild: remove GCC's default -Wpacked-bitfield-compat flag
  kbuild: unexport abs_srctree and abs_objtree
  kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1
  kconfig: remove named choice support
  kconfig: use linked list in get_symbol_str() to iterate over menus
  kconfig: link menus to a symbol
  kbuild: fix inconsistent indentation in top Makefile
  kbuild: Use -fmin-function-alignment when available
  alpha: merge two entries for CONFIG_ALPHA_GAMMA
  alpha: merge two entries for CONFIG_ALPHA_EV4
  kbuild: change DTC_FLAGS_<basetarget>.o to take the path relative to $(obj)
  ...

Commit 62edf5dc4a524 ("intel-iommu: Restore DMAR_BROKEN_GFX_WA option for
broken graphics drivers") was introduced 24 years ago as a temporary
workaround for graphics drivers that used physical addresses for DMA and
avoided DMA APIs. This workaround was disabled by default.

As 24 years have passed, it is expected that graphics driver developers
have migrated their drivers to use kernel DMA APIs. Therefore, this
workaround is no longer required and could been removed.

The Intel iommu driver also provides a "igfx_off" option to turn off
the DMA translation for the graphic dedicated IOMMU. Hence, there is
really no good reason to keep this config option.

Suggested-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20240130060823.57990-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

'def_bool X' is a shorthand for 'bool' plus 'default X'.

'def_bool' is redundant where 'bool' is already present, so 'def_bool X'
can be replaced with 'default X', or removed if X is 'n'.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Add CONFIG_IOMMU_IOPF for page fault handling framework and select it
from its real consumer. Move iopf function declaration from iommu-sva.h
to iommu.h and remove iommu-sva.h as it's empty now.

Consolidate all SVA related code into iommu-sva.c:
- Move iommu_sva_domain_alloc() from iommu.c to iommu-sva.c.
- Move sva iopf handling code from io-pgfault.c to iommu-sva.c.

Consolidate iommu_report_device_fault() and iommu_page_response() into
io-pgfault.c.

Export iopf_free_group() and iopf_group_response() for iopf handlers
implemented in modules. Some functions are renamed with more meaningful
names. No other intentional functionality changes.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Longfang Liu <liulongfang@huawei.com>
Link: https://lore.kernel.org/r/20240212012227.119381-11-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>