habanalabs: restructure hl_mmap

Arrange the hl_mmap code to be more structured and expandable for the
future. Add better defines that describe our usage of the vm_pgoff.

Note that I shamelessly took the code and defines from the amdkfd driver
(my previous driver).

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

diff --git a/drivers/misc/habanalabs/common/command_buffer.c b/drivers/misc/habanalabs/common/command_buffer.c
index e4bbe6a8e00f80a419d959df5148a2bf936bc794..68dfbafe3354954ebd798abbeecfcc413d4bbf4a 100644 (file)
--- a/drivers/misc/habanalabs/common/command_buffer.c
+++ b/drivers/misc/habanalabs/common/command_buffer.c
@@ -183,7 +183,7 @@ int hl_cb_create(struct hl_device *hdev, struct hl_cb_mgr *mgr,
         * idr is 32-bit so we can safely OR it with a mask that is above
         * 32 bit
         */
-       *handle = cb->id | HL_MMAP_CB_MASK;
+       *handle = cb->id | HL_MMAP_TYPE_CB;
        *handle <<= PAGE_SHIFT;
 
        hl_debugfs_add_cb(cb);

diff --git a/drivers/misc/habanalabs/common/device.c b/drivers/misc/habanalabs/common/device.c
index 6e916cc22a4c24b0dac70bac7c52dca7d800c60a..aa7fa9e94651d7cfce96d73ba6a42af51235097b 100644 (file)
--- a/drivers/misc/habanalabs/common/device.c
+++ b/drivers/misc/habanalabs/common/device.c
@@ -123,9 +123,13 @@ static int hl_device_release_ctrl(struct inode *inode, struct file *filp)
 static int hl_mmap(struct file *filp, struct vm_area_struct *vma)
 {
        struct hl_fpriv *hpriv = filp->private_data;
+       unsigned long vm_pgoff;
 
-       if ((vma->vm_pgoff & HL_MMAP_CB_MASK) == HL_MMAP_CB_MASK) {
-               vma->vm_pgoff ^= HL_MMAP_CB_MASK;
+       vm_pgoff = vma->vm_pgoff;
+       vma->vm_pgoff = HL_MMAP_OFFSET_VALUE_GET(vm_pgoff);
+
+       switch (vm_pgoff & HL_MMAP_TYPE_MASK) {
+       case HL_MMAP_TYPE_CB:
                return hl_cb_mmap(hpriv, vma);
        }
 

diff --git a/drivers/misc/habanalabs/common/habanalabs.h b/drivers/misc/habanalabs/common/habanalabs.h
index 6912f88a4b017da7a00c9854f6b7a2636494bea8..cdb7a672ed30aaae4f0359481e66a93db7780215 100644 (file)
--- a/drivers/misc/habanalabs/common/habanalabs.h
+++ b/drivers/misc/habanalabs/common/habanalabs.h
@@ -22,7 +22,19 @@
 
 #define HL_NAME                                "habanalabs"
 
-#define HL_MMAP_CB_MASK                        (0x8000000000000000ull >> PAGE_SHIFT)
+/* Use upper bits of mmap offset to store habana driver specific information.
+ * bits[63:62] - Encode mmap type
+ * bits[45:0]  - mmap offset value
+ *
+ * NOTE: struct vm_area_struct.vm_pgoff uses offset in pages. Hence, these
+ *  defines are w.r.t to PAGE_SIZE
+ */
+#define HL_MMAP_TYPE_SHIFT             (62 - PAGE_SHIFT)
+#define HL_MMAP_TYPE_MASK              (0x3ull << HL_MMAP_TYPE_SHIFT)
+#define HL_MMAP_TYPE_CB                        (0x2ull << HL_MMAP_TYPE_SHIFT)
+
+#define HL_MMAP_OFFSET_VALUE_MASK      (0x3FFFFFFFFFFFull >> PAGE_SHIFT)
+#define HL_MMAP_OFFSET_VALUE_GET(off)  (off & HL_MMAP_OFFSET_VALUE_MASK)
 
 #define HL_PENDING_RESET_PER_SEC       30