From 77785117f9c73fd71a440a5ac86dd80752967adc Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Wed, 10 Jan 2024 20:10:10 -0800 Subject: [PATCH] iommu: Add iommu_copy_struct_from_user_array helper Wrap up the data pointer/num sanity and __iommu_copy_struct_from_user() call for iommu drivers to copy driver specific data at a specific location in the struct iommu_user_data_array. And expect it to be used in cache_invalidate_user ops for example. Link: https://lore.kernel.org/r/20240111041015.47920-4-yi.l.liu@intel.com Reviewed-by: Kevin Tian Signed-off-by: Nicolin Chen Co-developed-by: Yi Liu Signed-off-by: Yi Liu Signed-off-by: Jason Gunthorpe --- include/linux/iommu.h | 51 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 93c0d12dd047c..9dbadf74a3a1e 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -341,6 +341,57 @@ static inline int __iommu_copy_struct_from_user( sizeof(*kdst), \ offsetofend(typeof(*kdst), min_last)) +/** + * __iommu_copy_struct_from_user_array - Copy iommu driver specific user space + * data from an iommu_user_data_array + * @dst_data: Pointer to an iommu driver specific user data that is defined in + * include/uapi/linux/iommufd.h + * @src_array: Pointer to a struct iommu_user_data_array for a user space array + * @data_type: The data type of the @dst_data. Must match with @src_array.type + * @index: Index to the location in the array to copy user data from + * @data_len: Length of current user data structure, i.e. sizeof(struct _dst) + * @min_len: Initial length of user data structure for backward compatibility. + * This should be offsetofend using the last member in the user data + * struct that was initially added to include/uapi/linux/iommufd.h + */ +static inline int __iommu_copy_struct_from_user_array( + void *dst_data, const struct iommu_user_data_array *src_array, + unsigned int data_type, unsigned int index, size_t data_len, + size_t min_len) +{ + struct iommu_user_data src_data; + + if (WARN_ON(!src_array || index >= src_array->entry_num)) + return -EINVAL; + if (!src_array->entry_num) + return -EINVAL; + src_data.uptr = src_array->uptr + src_array->entry_len * index; + src_data.len = src_array->entry_len; + src_data.type = src_array->type; + + return __iommu_copy_struct_from_user(dst_data, &src_data, data_type, + data_len, min_len); +} + +/** + * iommu_copy_struct_from_user_array - Copy iommu driver specific user space + * data from an iommu_user_data_array + * @kdst: Pointer to an iommu driver specific user data that is defined in + * include/uapi/linux/iommufd.h + * @user_array: Pointer to a struct iommu_user_data_array for a user space + * array + * @data_type: The data type of the @kdst. Must match with @user_array->type + * @index: Index to the location in the array to copy user data from + * @min_last: The last member of the data structure @kdst points in the + * initial version. + * Return 0 for success, otherwise -error. + */ +#define iommu_copy_struct_from_user_array(kdst, user_array, data_type, index, \ + min_last) \ + __iommu_copy_struct_from_user_array( \ + kdst, user_array, data_type, index, sizeof(*(kdst)), \ + offsetofend(typeof(*(kdst)), min_last)) + /** * struct iommu_ops - iommu ops and capabilities * @capable: check capability -- 2.30.2