[patch 06/20] spufs: restore mapping of mssync register

From: arnd
Date: Mon Jun 19 2006 - 14:52:03 EST


A recent change to the way that the mfc file gets mapped made it
impossible to map the SPE Multi-Source Synchronization register
into user space, but that may be needed by some applications.

This restores the missing functionality.

Signed-off-by: Arnd Bergmann <arnd.bergmann@xxxxxxxxxx>

---

Index: powerpc.git/arch/powerpc/platforms/cell/spufs/file.c
===================================================================
--- powerpc.git.orig/arch/powerpc/platforms/cell/spufs/file.c
+++ powerpc.git/arch/powerpc/platforms/cell/spufs/file.c
@@ -825,6 +825,55 @@ DEFINE_SIMPLE_ATTRIBUTE(spufs_signal2_ty
spufs_signal2_type_set, "%llu");

#ifdef CONFIG_SPUFS_MMAP
+static struct page *spufs_mss_mmap_nopage(struct vm_area_struct *vma,
+ unsigned long address, int *type)
+{
+ return spufs_ps_nopage(vma, address, type, 0x0000);
+}
+
+static struct vm_operations_struct spufs_mss_mmap_vmops = {
+ .nopage = spufs_mss_mmap_nopage,
+};
+
+/*
+ * mmap support for problem state MFC DMA area [0x0000 - 0x0fff].
+ * Mapping this area requires that the application have CAP_SYS_RAWIO,
+ * as these registers require special care when read/writing.
+ */
+static int spufs_mss_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ if (!(vma->vm_flags & VM_SHARED))
+ return -EINVAL;
+
+ if (!capable(CAP_SYS_RAWIO))
+ return -EPERM;
+
+ vma->vm_flags |= VM_RESERVED;
+ vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
+ | _PAGE_NO_CACHE);
+
+ vma->vm_ops = &spufs_mss_mmap_vmops;
+ return 0;
+}
+#endif
+
+static int spufs_mss_open(struct inode *inode, struct file *file)
+{
+ struct spufs_inode_info *i = SPUFS_I(inode);
+
+ file->private_data = i->i_ctx;
+ return nonseekable_open(inode, file);
+}
+
+static struct file_operations spufs_mss_fops = {
+ .open = spufs_mss_open,
+#ifdef CONFIG_SPUFS_MMAP
+ .mmap = spufs_mss_mmap,
+#endif
+};
+
+
+#ifdef CONFIG_SPUFS_MMAP
static struct page *spufs_mfc_mmap_nopage(struct vm_area_struct *vma,
unsigned long address, int *type)
{
@@ -1292,6 +1341,7 @@ struct tree_descr spufs_dir_contents[] =
{ "signal2", &spufs_signal2_fops, 0666, },
{ "signal1_type", &spufs_signal1_type, 0666, },
{ "signal2_type", &spufs_signal2_type, 0666, },
+ { "mss", &spufs_mss_fops, 0666, },
{ "mfc", &spufs_mfc_fops, 0666, },
{ "cntl", &spufs_cntl_fops, 0666, },
{ "npc", &spufs_npc_ops, 0666, },

--

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/