iommufd: Generalize iopt_pages address

The starting address in iopt_pages is currently a __user *uptr.
Generalize to allow other types of addresses.  Refactor iopt_alloc_pages()
and iopt_map_user_pages() into address-type specific and common functions.

Link: https://patch.msgid.link/r/1729861919-234514-4-git-send-email-steven.sistare@oracle.com
Suggested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c
index 68ad91d42d037ef36f1d8fad71375b858f4b1a09..874ee9ea7efc8cc982631a0331351cf7280ccfad 100644 (file)
--- a/drivers/iommu/iommufd/io_pagetable.c
+++ b/drivers/iommu/iommufd/io_pagetable.c
@@ -384,6 +384,34 @@ out_unlock_domains:
        return rc;
 }
 
+static int iopt_map_common(struct iommufd_ctx *ictx, struct io_pagetable *iopt,
+                          struct iopt_pages *pages, unsigned long *iova,
+                          unsigned long length, unsigned long start_byte,
+                          int iommu_prot, unsigned int flags)
+{
+       struct iopt_pages_list elm = {};
+       LIST_HEAD(pages_list);
+       int rc;
+
+       elm.pages = pages;
+       elm.start_byte = start_byte;
+       if (ictx->account_mode == IOPT_PAGES_ACCOUNT_MM &&
+           elm.pages->account_mode == IOPT_PAGES_ACCOUNT_USER)
+               elm.pages->account_mode = IOPT_PAGES_ACCOUNT_MM;
+       elm.length = length;
+       list_add(&elm.next, &pages_list);
+
+       rc = iopt_map_pages(iopt, &pages_list, length, iova, iommu_prot, flags);
+       if (rc) {
+               if (elm.area)
+                       iopt_abort_area(elm.area);
+               if (elm.pages)
+                       iopt_put_pages(elm.pages);
+               return rc;
+       }
+       return 0;
+}
+
 /**
  * iopt_map_user_pages() - Map a user VA to an iova in the io page table
  * @ictx: iommufd_ctx the iopt is part of
@@ -408,29 +436,14 @@ int iopt_map_user_pages(struct iommufd_ctx *ictx, struct io_pagetable *iopt,
                        unsigned long length, int iommu_prot,
                        unsigned int flags)
 {
-       struct iopt_pages_list elm = {};
-       LIST_HEAD(pages_list);
-       int rc;
+       struct iopt_pages *pages;
 
-       elm.pages = iopt_alloc_pages(uptr, length, iommu_prot & IOMMU_WRITE);
-       if (IS_ERR(elm.pages))
-               return PTR_ERR(elm.pages);
-       if (ictx->account_mode == IOPT_PAGES_ACCOUNT_MM &&
-           elm.pages->account_mode == IOPT_PAGES_ACCOUNT_USER)
-               elm.pages->account_mode = IOPT_PAGES_ACCOUNT_MM;
-       elm.start_byte = uptr - elm.pages->uptr;
-       elm.length = length;
-       list_add(&elm.next, &pages_list);
+       pages = iopt_alloc_user_pages(uptr, length, iommu_prot & IOMMU_WRITE);
+       if (IS_ERR(pages))
+               return PTR_ERR(pages);
 
-       rc = iopt_map_pages(iopt, &pages_list, length, iova, iommu_prot, flags);
-       if (rc) {
-               if (elm.area)
-                       iopt_abort_area(elm.area);
-               if (elm.pages)
-                       iopt_put_pages(elm.pages);
-               return rc;
-       }
-       return 0;
+       return iopt_map_common(ictx, iopt, pages, iova, length,
+                              uptr - pages->uptr, iommu_prot, flags);
 }
 
 struct iova_bitmap_fn_arg {

diff --git a/drivers/iommu/iommufd/io_pagetable.h b/drivers/iommu/iommufd/io_pagetable.h
index c61d74471684eefd0bb11052d99b68e688249449..8e482663c91aebc3712ded819bcbefc035f7a2f6 100644 (file)
--- a/drivers/iommu/iommufd/io_pagetable.h
+++ b/drivers/iommu/iommufd/io_pagetable.h
@@ -175,6 +175,10 @@ enum {
        IOPT_PAGES_ACCOUNT_MM = 2,
 };
 
+enum iopt_address_type {
+       IOPT_ADDRESS_USER = 0,
+};
+
 /*
  * This holds a pinned page list for multiple areas of IO address space. The
  * pages always originate from a linear chunk of userspace VA. Multiple
@@ -195,7 +199,10 @@ struct iopt_pages {
        struct task_struct *source_task;
        struct mm_struct *source_mm;
        struct user_struct *source_user;
-       void __user *uptr;
+       enum iopt_address_type type;
+       union {
+               void __user *uptr;              /* IOPT_ADDRESS_USER */
+       };
        bool writable:1;
        u8 account_mode;
 
@@ -206,8 +213,8 @@ struct iopt_pages {
        struct rb_root_cached domains_itree;
 };
 
-struct iopt_pages *iopt_alloc_pages(void __user *uptr, unsigned long length,
-                                   bool writable);
+struct iopt_pages *iopt_alloc_user_pages(void __user *uptr,
+                                        unsigned long length, bool writable);
 void iopt_release_pages(struct kref *kref);
 static inline void iopt_put_pages(struct iopt_pages *pages)
 {

diff --git a/drivers/iommu/iommufd/pages.c b/drivers/iommu/iommufd/pages.c
index 93d806c9c073180edcdadf8fd7569d234feedf7a..4206e90cc45196ff32c93bc316537ccbc2c4dc20 100644 (file)
--- a/drivers/iommu/iommufd/pages.c
+++ b/drivers/iommu/iommufd/pages.c
@@ -1139,11 +1139,11 @@ static int pfn_reader_first(struct pfn_reader *pfns, struct iopt_pages *pages,
        return 0;
 }
 
-struct iopt_pages *iopt_alloc_pages(void __user *uptr, unsigned long length,
-                                   bool writable)
+static struct iopt_pages *iopt_alloc_pages(unsigned long start_byte,
+                                          unsigned long length,
+                                          bool writable)
 {
        struct iopt_pages *pages;
-       unsigned long end;
 
        /*
         * The iommu API uses size_t as the length, and protect the DIV_ROUND_UP
@@ -1152,9 +1152,6 @@ struct iopt_pages *iopt_alloc_pages(void __user *uptr, unsigned long length,
        if (length > SIZE_MAX - PAGE_SIZE || length == 0)
                return ERR_PTR(-EINVAL);
 
-       if (check_add_overflow((unsigned long)uptr, length, &end))
-               return ERR_PTR(-EOVERFLOW);
-
        pages = kzalloc(sizeof(*pages), GFP_KERNEL_ACCOUNT);
        if (!pages)
                return ERR_PTR(-ENOMEM);
@@ -1164,8 +1161,7 @@ struct iopt_pages *iopt_alloc_pages(void __user *uptr, unsigned long length,
        mutex_init(&pages->mutex);
        pages->source_mm = current->mm;
        mmgrab(pages->source_mm);
-       pages->uptr = (void __user *)ALIGN_DOWN((uintptr_t)uptr, PAGE_SIZE);
-       pages->npages = DIV_ROUND_UP(length + (uptr - pages->uptr), PAGE_SIZE);
+       pages->npages = DIV_ROUND_UP(length + start_byte, PAGE_SIZE);
        pages->access_itree = RB_ROOT_CACHED;
        pages->domains_itree = RB_ROOT_CACHED;
        pages->writable = writable;
@@ -1179,6 +1175,25 @@ struct iopt_pages *iopt_alloc_pages(void __user *uptr, unsigned long length,
        return pages;
 }
 
+struct iopt_pages *iopt_alloc_user_pages(void __user *uptr,
+                                        unsigned long length, bool writable)
+{
+       struct iopt_pages *pages;
+       unsigned long end;
+       void __user *uptr_down =
+               (void __user *) ALIGN_DOWN((uintptr_t)uptr, PAGE_SIZE);
+
+       if (check_add_overflow((unsigned long)uptr, length, &end))
+               return ERR_PTR(-EOVERFLOW);
+
+       pages = iopt_alloc_pages(uptr - uptr_down, length, writable);
+       if (IS_ERR(pages))
+               return pages;
+       pages->uptr = uptr_down;
+       pages->type = IOPT_ADDRESS_USER;
+       return pages;
+}
+
 void iopt_release_pages(struct kref *kref)
 {
        struct iopt_pages *pages = container_of(kref, struct iopt_pages, kref);