diff options
| author | Moti Haimovski <moti.haimovski@intel.com> | 2024-09-08 15:01:26 +0300 |
|---|---|---|
| committer | Koby Elbaz <koby.elbaz@intel.com> | 2025-09-25 09:09:30 +0300 |
| commit | 513024d5a0e34fd34247043f1876b6138ca52847 (patch) | |
| tree | 836ffcc97ea983df3a7a2d8656e28b613ad455ef | |
| parent | 0668db41b5d8a834a04be3b281fa9452dcf3dc18 (diff) | |
accel/habanalabs: support mapping cb with vmalloc-backed coherent memory
When IOMMU is enabled, dma_alloc_coherent() with GFP_USER may return
addresses from the vmalloc range. If such an address is mapped without
VM_MIXEDMAP, vm_insert_page() will trigger a BUG_ON due to the
VM_PFNMAP restriction.
Fix this by checking for vmalloc addresses and setting VM_MIXEDMAP
in the VMA before mapping. This ensures safe mapping and avoids kernel
crashes. The memory is still driver-allocated and cannot be accessed
directly by userspace.
Signed-off-by: Moti Haimovski <moti.haimovski@intel.com>
Reviewed-by: Koby Elbaz <koby.elbaz@intel.com>
Signed-off-by: Koby Elbaz <koby.elbaz@intel.com>
| -rw-r--r-- | drivers/accel/habanalabs/gaudi/gaudi.c | 19 | ||||
| -rw-r--r-- | drivers/accel/habanalabs/gaudi2/gaudi2.c | 7 |
2 files changed, 26 insertions, 0 deletions
diff --git a/drivers/accel/habanalabs/gaudi/gaudi.c b/drivers/accel/habanalabs/gaudi/gaudi.c index fa893a9b826e..34771d75da9d 100644 --- a/drivers/accel/habanalabs/gaudi/gaudi.c +++ b/drivers/accel/habanalabs/gaudi/gaudi.c @@ -4168,10 +4168,29 @@ static int gaudi_mmap(struct hl_device *hdev, struct vm_area_struct *vma, vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP | VM_DONTCOPY | VM_NORESERVE); +#ifdef _HAS_DMA_MMAP_COHERENT + /* + * If dma_alloc_coherent() returns a vmalloc address, set VM_MIXEDMAP + * so vm_insert_page() can handle it safely. Without this, the kernel + * may BUG_ON due to VM_PFNMAP. + */ + if (is_vmalloc_addr(cpu_addr)) + vm_flags_set(vma, VM_MIXEDMAP); + rc = dma_mmap_coherent(hdev->dev, vma, cpu_addr, (dma_addr - HOST_PHYS_BASE), size); if (rc) dev_err(hdev->dev, "dma_mmap_coherent error %d", rc); +#else + + rc = remap_pfn_range(vma, vma->vm_start, + virt_to_phys(cpu_addr) >> PAGE_SHIFT, + size, vma->vm_page_prot); + if (rc) + dev_err(hdev->dev, "remap_pfn_range error %d", rc); + + #endif + return rc; } diff --git a/drivers/accel/habanalabs/gaudi2/gaudi2.c b/drivers/accel/habanalabs/gaudi2/gaudi2.c index 72bfc5e639e4..03dde63ed875 100644 --- a/drivers/accel/habanalabs/gaudi2/gaudi2.c +++ b/drivers/accel/habanalabs/gaudi2/gaudi2.c @@ -6832,6 +6832,13 @@ static int gaudi2_mmap(struct hl_device *hdev, struct vm_area_struct *vma, VM_DONTCOPY | VM_NORESERVE); #ifdef _HAS_DMA_MMAP_COHERENT + /* + * If dma_alloc_coherent() returns a vmalloc address, set VM_MIXEDMAP + * so vm_insert_page() can handle it safely. Without this, the kernel + * may BUG_ON due to VM_PFNMAP. + */ + if (is_vmalloc_addr(cpu_addr)) + vm_flags_set(vma, VM_MIXEDMAP); rc = dma_mmap_coherent(hdev->dev, vma, cpu_addr, dma_addr, size); if (rc) |