kernel/linux.git/include/linux/iommu-dma.h, branch v6.18.22

dma-mapping: export new dma_*map_phys() interface

2025-09-11T22:18:21+00:00

Introduce new DMA mapping functions dma_map_phys() and dma_unmap_phys() that operate directly on physical addresses instead of page+offset parameters. This provides a more efficient interface for drivers that already have physical addresses available. The new functions are implemented as the primary mapping layer, with the existing dma_map_page_attrs()/dma_map_resource() and dma_unmap_page_attrs()/dma_unmap_resource() functions converted to simple wrappers around the phys-based implementations. In case dma_map_page_attrs(), the struct page is converted to physical address with help of page_to_phys() function and dma_map_resource() provides physical address as is together with addition of DMA_ATTR_MMIO attribute. The old page-based API is preserved in mapping.c to ensure that existing code won't be affected by changing EXPORT_SYMBOL to EXPORT_SYMBOL_GPL variant for dma_*map_phys(). Reviewed-by: Jason Gunthorpe Reviewed-by: Keith Busch Signed-off-by: Leon Romanovsky Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/54cc52af91777906bbe4a386113437ba0bcfba9c.1757423202.git.leonro@nvidia.com

iommu/dma: rename iommu_dma_map_page to iommu_dma_map_phys

2025-09-11T22:18:20+00:00

Rename the IOMMU DMA mapping functions to better reflect their actual calling convention. The functions iommu_dma_map_page() and iommu_dma_unmap_page() are renamed to iommu_dma_map_phys() and iommu_dma_unmap_phys() respectively, as they already operate on physical addresses rather than page structures. The calling convention changes from accepting (struct page *page, unsigned long offset) to (phys_addr_t phys), which eliminates the need for page-to-physical address conversion within the functions. This renaming prepares for the broader DMA API conversion from page-based to physical address-based mapping throughout the kernel. All callers are updated to pass physical addresses directly, including dma_map_page_attrs(), scatterlist mapping functions, and DMA page allocation helpers. The change simplifies the code by removing the page_to_phys() + offset calculation that was previously done inside the IOMMU functions. Reviewed-by: Jason Gunthorpe Signed-off-by: Leon Romanovsky Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/ed172f95f8f57782beae04f782813366894e98df.1757423202.git.leonro@nvidia.com

iommu/dma: remove most stubs in iommu-dma.h

2024-09-22T16:48:00+00:00

The direct calls from mapping.c all guarded by use_dma_iommu(), so don't bother to provide stubs, but instead just expose the prototypes unconditionally. Signed-off-by: Christoph Hellwig Reviewed-by: Leon Romanovsky

dma-mapping: fix vmap and mmap of noncontiougs allocations

2024-09-22T16:47:51+00:00

Commit b5c58b2fdc42 ("dma-mapping: direct calls for dma-iommu") switched to use direct calls to dma-iommu, but missed the dma_vmap_noncontiguous, dma_vunmap_noncontiguous and dma_mmap_noncontiguous behavior keyed off the presence of the alloc_noncontiguous method. Fix this by removing the now unused alloc_noncontiguous and free_noncontiguous methods and moving the vmapping and mmaping of the noncontiguous allocations into the iommu code, as it is the only provider of actually noncontiguous allocations. Fixes: b5c58b2fdc42 ("dma-mapping: direct calls for dma-iommu") Reported-by: Xi Ruoyao Signed-off-by: Christoph Hellwig Reviewed-by: Leon Romanovsky Tested-by: Xi Ruoyao

dma-mapping: use IOMMU DMA calls for common alloc/free page calls

2024-09-05T11:29:42+00:00

Common alloca and free pages routines are called when IOMMU DMA is used, and internally it calls to DMA ops structure which is not available for default IOMMU. This patch adds necessary if checks to call IOMMU DMA. It fixes the following crash: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000040 Mem abort info: ESR = 0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort info: ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=00000000d20bb000 [0000000000000040] pgd=08000000d20c1003 , p4d=08000000d20c1003 , pud=08000000d20c2003, pmd=0000000000000000 Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP Modules linked in: ipv6 hci_uart venus_core btqca v4l2_mem2mem btrtl qcom_spmi_adc5 sbs_battery btbcm qcom_vadc_common cros_ec_typec videobuf2_v4l2 leds_cros_ec cros_kbd_led_backlight cros_ec_chardev videodev elan_i2c videobuf2_common qcom_stats mc bluetooth coresight_stm stm_core ecdh_generic ecc pwrseq_core panel_edp icc_bwmon ath10k_snoc ath10k_core ath mac80211 phy_qcom_qmp_combo aux_bridge libarc4 coresight_replicator coresight_etm4x coresight_tmc coresight_funnel cfg80211 rfkill coresight qcom_wdt cbmem ramoops reed_solomon pwm_bl coreboot_table backlight crct10dif_ce CPU: 7 UID: 0 PID: 70 Comm: kworker/u32:4 Not tainted 6.11.0-rc6-next-20240903-00003-gdfc6015d0711 #660 Hardware name: Google Lazor Limozeen without Touchscreen (rev5 - rev8) (DT) Workqueue: events_unbound deferred_probe_work_func hub 2-1:1.0: 4 ports detected pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : dma_common_alloc_pages+0x54/0x1b4 lr : dma_common_alloc_pages+0x4c/0x1b4 sp : ffff8000807d3730 x29: ffff8000807d3730 x28: ffff02a7d312f880 x27: 0000000000000001 x26: 000000000000c000 x25: 0000000000000000 x24: 0000000000000001 x23: ffff02a7d23b6898 x22: 0000000000006cc0 x21: 000000000000c000 x20: ffff02a7858bf410 x19: fffffe0a60006000 x18: 0000000000000001 x17: 00000000000000d5 x16: 1fffe054f0bcc261 x15: 0000000000000001 x14: ffff02a7844dc680 x13: 0000000000100180 x12: dead000000000100 x11: dead000000000122 x10: 00000000001001ff x9 : ffff02a87f7b7b00 x8 : ffff02a87f7b7b00 x7 : ffff405977d6b000 x6 : ffff8000807d3310 x5 : ffff02a87f6b6398 x4 : 0000000000000001 x3 : ffff405977d6b000 x2 : ffff02a7844dc600 x1 : 0000000100000000 x0 : fffffe0a60006000 Call trace: dma_common_alloc_pages+0x54/0x1b4 __dma_alloc_pages+0x68/0x90 dma_alloc_pages+0x10/0x1c snd_dma_noncoherent_alloc+0x28/0x8c __snd_dma_alloc_pages+0x30/0x50 snd_dma_alloc_dir_pages+0x40/0x80 do_alloc_pages+0xb8/0x13c preallocate_pcm_pages+0x6c/0xf8 preallocate_pages+0x160/0x1a4 snd_pcm_set_managed_buffer_all+0x64/0xb0 lpass_platform_pcm_new+0xc0/0xe8 snd_soc_pcm_component_new+0x3c/0xc8 soc_new_pcm+0x4fc/0x668 snd_soc_bind_card+0xabc/0xbac snd_soc_register_card+0xf0/0x108 devm_snd_soc_register_card+0x4c/0xa4 sc7180_snd_platform_probe+0x180/0x224 platform_probe+0x68/0xc0 really_probe+0xbc/0x298 __driver_probe_device+0x78/0x12c driver_probe_device+0x3c/0x15c __device_attach_driver+0xb8/0x134 bus_for_each_drv+0x84/0xe0 __device_attach+0x9c/0x188 device_initial_probe+0x14/0x20 bus_probe_device+0xac/0xb0 deferred_probe_work_func+0x88/0xc0 process_one_work+0x14c/0x28c worker_thread+0x2cc/0x3d4 kthread+0x114/0x118 ret_from_fork+0x10/0x20 Code: f9411c19 940000c9 aa0003f3 b4000460 (f9402326) ---[ end trace 0000000000000000 ]--- Fixes: b5c58b2fdc42 ("dma-mapping: direct calls for dma-iommu") Closes: https://lore.kernel.org/all/10431dfd-ce04-4e0f-973b-c78477303c18@notapiano Reported-by: Nícolas F. R. A. Prado #KernelCI Signed-off-by: Leon Romanovsky Tested-by: Nícolas F. R. A. Prado Signed-off-by: Christoph Hellwig

dma-mapping: direct calls for dma-iommu

2024-08-22T04:18:11+00:00

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 Signed-off-by: Leon Romanovsky Acked-by: Greg Kroah-Hartman Acked-by: Robin Murphy Signed-off-by: Christoph Hellwig