[linux] Add uaccess

Add user access API for linux.

On linux userspace virtual == user == phys addresses.  Physical
addresses also being the same is wrong, but there is no general way of
converting userspace addresses to physical as what appears to be
contiguous in userspace is physically fragmented.  Currently only the
DMA memory is special-cased, but its conversion to bus addresses is
done in phys_to_bus.  This is known to break virtio as it is passing
phys addresses to the virtual device.

Signed-off-by: Piotr Jaroszyński <p.jaroszynski@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/config/defaults/linux.h

@@ -9,6 +9,7 @@
 
 #define CONSOLE_LINUX
 #define TIMER_LINUX
+#define UACCESS_LINUX
 
 #define IMAGE_SCRIPT
 

src/include/ipxe/linux/linux_uaccess.h

@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2010 Piotr Jaroszyński <p.jaroszynski@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef _IPXE_LINUX_UACCESS_H
+#define _IPXE_LINUX_UACCESS_H
+
+FILE_LICENCE(GPL2_OR_LATER);
+
+/** @file
+ *
+ * iPXE user access API for linux
+ *
+ * In linux userspace virtual == user == phys addresses.
+ * Physical addresses also being the same is wrong, but there is no general way
+ * of converting userspace addresses to physical as what appears to be
+ * contiguous in userspace is physically fragmented.
+ * Currently only the DMA memory is special-cased, but its conversion to bus
+ * addresses is done in phys_to_bus.
+ * This is known to break virtio as it is passing phys addresses to the virtual
+ * device.
+ */
+
+#ifdef UACCESS_LINUX
+#define UACCESS_PREFIX_linux
+#else
+#define UACCESS_PREFIX_linux __linux_
+#endif
+
+static inline __always_inline userptr_t
+UACCESS_INLINE(linux, phys_to_user)(unsigned long phys_addr)
+{
+	return phys_addr;
+}
+
+static inline __always_inline unsigned long
+UACCESS_INLINE(linux, user_to_phys)(userptr_t userptr, off_t offset)
+{
+	return userptr + offset;
+}
+
+static inline __always_inline userptr_t
+UACCESS_INLINE(linux, virt_to_user)(volatile const void *addr)
+{
+	return trivial_virt_to_user(addr);
+}
+
+static inline __always_inline void *
+UACCESS_INLINE(linux, user_to_virt)(userptr_t userptr, off_t offset)
+{
+	return trivial_user_to_virt(userptr, offset);
+}
+
+static inline __always_inline userptr_t
+UACCESS_INLINE(linux, userptr_add)(userptr_t userptr, off_t offset)
+{
+	return trivial_userptr_add(userptr, offset);
+}
+
+static inline __always_inline void
+UACCESS_INLINE(linux, memcpy_user)(userptr_t dest, off_t dest_off, userptr_t src, off_t src_off, size_t len)
+{
+	trivial_memcpy_user(dest, dest_off, src, src_off, len);
+}
+
+static inline __always_inline void
+UACCESS_INLINE(linux, memmove_user)(userptr_t dest, off_t dest_off, userptr_t src, off_t src_off, size_t len)
+{
+	trivial_memmove_user(dest, dest_off, src, src_off, len);
+}
+
+static inline __always_inline void
+UACCESS_INLINE(linux, memset_user)(userptr_t buffer, off_t offset, int c, size_t len)
+{
+	trivial_memset_user(buffer, offset, c, len);
+}
+
+static inline __always_inline size_t
+UACCESS_INLINE(linux, strlen_user)(userptr_t buffer, off_t offset)
+{
+	return trivial_strlen_user(buffer, offset);
+}
+
+static inline __always_inline off_t
+UACCESS_INLINE(linux, memchr_user)(userptr_t buffer, off_t offset, int c, size_t len)
+{
+	return trivial_memchr_user(buffer, offset, c, len);
+}
+
+#endif /* _IPXE_LINUX_UACCESS_H */

src/include/ipxe/uaccess.h

@@ -189,6 +189,7 @@ trivial_memchr_user ( userptr_t buffer, off_t offset, int c, size_t len ) {
 
 /* Include all architecture-independent user access API headers */
 #include <ipxe/efi/efi_uaccess.h>
+#include <ipxe/linux/linux_uaccess.h>
 
 /* Include all architecture-dependent user access API headers */
 #include <bits/uaccess.h>

src/interface/linux/linux_uaccess.c

@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2010 Piotr Jaroszyński <p.jaroszynski@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE(GPL2_OR_LATER);
+
+#include <ipxe/uaccess.h>
+
+/** @file
+ *
+ * iPXE user access API for linux
+ *
+ */
+
+PROVIDE_UACCESS_INLINE(linux, phys_to_user);
+PROVIDE_UACCESS_INLINE(linux, user_to_phys);
+PROVIDE_UACCESS_INLINE(linux, virt_to_user);
+PROVIDE_UACCESS_INLINE(linux, user_to_virt);
+PROVIDE_UACCESS_INLINE(linux, userptr_add);
+PROVIDE_UACCESS_INLINE(linux, memcpy_user);
+PROVIDE_UACCESS_INLINE(linux, memmove_user);
+PROVIDE_UACCESS_INLINE(linux, memset_user);
+PROVIDE_UACCESS_INLINE(linux, strlen_user);
+PROVIDE_UACCESS_INLINE(linux, memchr_user);