[linux] Rewrite headers included in all builds

Rewrite (and relicense) the header files which are included in all
builds of iPXE (including non-Linux builds).

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/include/ipxe/linux/linux_entropy.h

@@ -3,11 +3,11 @@
 
 /** @file
  *
- * iPXE entropy API for linux
+ * /dev/random-based entropy source
  *
  */
 
-FILE_LICENCE(GPL2_OR_LATER_OR_UBDL);
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #ifdef ENTROPY_LINUX
 #define ENTROPY_PREFIX_linux
@@ -23,10 +23,12 @@ FILE_LICENCE(GPL2_OR_LATER_OR_UBDL);
 static inline __always_inline double
 ENTROPY_INLINE ( linux, min_entropy_per_sample ) ( void ) {
 
-	/* We read single bytes from /dev/random and assume that each
-	 * contains full entropy.
+	/* linux_get_noise() reads a single byte from /dev/random,
+	 * which is supposed to block until a sufficient amount of
+	 * entropy is available.  We therefore assume that each sample
+	 * contains exactly 8 bits of entropy.
 	 */
-	return 8;
+	return 8.0;
 }
 
 #endif /* _IPXE_LINUX_ENTROPY_H */

src/include/ipxe/linux/linux_nap.h

@@ -7,7 +7,7 @@
  *
  */
 
-FILE_LICENCE(GPL2_OR_LATER);
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #ifdef NAP_LINUX
 #define NAP_PREFIX_linux

src/include/ipxe/linux/linux_smbios.h

@@ -3,11 +3,11 @@
 
 /** @file
  *
- * iPXE SMBIOS API for linux
+ * iPXE SMBIOS API for Linux
  *
  */
 
-FILE_LICENCE(GPL2_OR_LATER);
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #ifdef SMBIOS_LINUX
 #define SMBIOS_PREFIX_linux

src/include/ipxe/linux/linux_timer.h

@@ -7,7 +7,7 @@
  *
  */
 
-FILE_LICENCE ( GPL2_OR_LATER );
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #ifdef TIMER_LINUX
 #define TIMER_PREFIX_linux

src/include/ipxe/linux/linux_uaccess.h

@@ -1,116 +1,108 @@
-/*
- * 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
+ * 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.
+ * We run with no distinction between internal and external addresses,
+ * so can use trivial_virt_to_user() et al.
+ *
+ * We have no concept of the underlying physical addresses, since
+ * these are not exposed to userspace.  We provide a stub
+ * implementation of user_to_phys() since this is required by
+ * alloc_memblock().  We provide no implementation of phys_to_user();
+ * any code attempting to access physical addresses will therefore
+ * (correctly) fail to link.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
 #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;
-}
-
+/**
+ * Convert user buffer to physical address
+ *
+ * @v userptr		User pointer
+ * @v offset		Offset from user pointer
+ * @ret phys_addr	Physical address
+ */
 static inline __always_inline unsigned long
-UACCESS_INLINE(linux, user_to_phys)(userptr_t userptr, off_t offset)
-{
-	return userptr + offset;
+UACCESS_INLINE ( linux, user_to_phys ) ( userptr_t userptr, off_t offset ) {
+
+	/* We do not know the real underlying physical address.  We
+	 * provide this stub implementation only because it is
+	 * required by alloc_memblock() (which allocates memory with
+	 * specified physical address alignment).  We assume that the
+	 * low-order bits of virtual addresses match the low-order
+	 * bits of physical addresses, and so simply returning the
+	 * virtual address will suffice for the purpose of determining
+	 * alignment.
+	 */
+	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);
+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);
+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);
+UACCESS_INLINE ( linux, userptr_add ) ( userptr_t userptr, off_t offset ) {
+	return trivial_userptr_add ( userptr, offset );
 }
 
 static inline __always_inline off_t
-UACCESS_INLINE(linux, userptr_sub)(userptr_t userptr, userptr_t subtrahend)
-{
+UACCESS_INLINE ( linux, userptr_sub ) ( userptr_t userptr,
+					userptr_t subtrahend ) {
 	return trivial_userptr_sub ( userptr, subtrahend );
 }
 
 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);
+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);
+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 int
-UACCESS_INLINE(linux, memcmp_user)(userptr_t first, off_t first_off, userptr_t second, off_t second_off, size_t len)
-{
-	return trivial_memcmp_user(first, first_off, second, second_off, len);
+UACCESS_INLINE ( linux, memcmp_user ) ( userptr_t first, off_t first_off,
+					userptr_t second, off_t second_off,
+					size_t len ) {
+	return trivial_memcmp_user ( first, first_off, second, second_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);
+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);
+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);
+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/linux/linux_umalloc.h

@@ -1,14 +1,14 @@
 #ifndef _IPXE_LINUX_UMALLOC_H
 #define _IPXE_LINUX_UMALLOC_H
 
-FILE_LICENCE(GPL2_OR_LATER);
-
 /** @file
  *
- * iPXE user memory allocation API for linux
+ * iPXE user memory allocation API for Linux
  *
  */
 
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
 #ifdef UMALLOC_LINUX
 #define UMALLOC_PREFIX_linux
 #else

src/interface/linux/linux_uaccess.c

@@ -27,7 +27,6 @@ FILE_LICENCE(GPL2_OR_LATER);
  *
  */
 
-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);