[PATCH liburing v1 3/4] lib.h: Split off lib header for arch specific and generic

[Ammar Faizi <ammarfaizi2@gnuweeb.org>]

1) Clean up #ifdef/#endif for get_page_size().

2) Always use arch specific code for x86-64 to reduce libc usage.

3) For other archs, we will use src/arch/generic/lib.h header that
   contains libc wrapper.

At this point, on x86-64, we only use libc for memset(), malloc() and
free().

Cc: Nugra <richiisei@gmail.com>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
---
 src/arch/generic/lib.h | 21 ++++++++++++++++++++
 src/arch/x86/lib.h     | 20 ++++++++++++-------
 src/lib.h              | 45 ++++++++++++++++++------------------------
 3 files changed, 53 insertions(+), 33 deletions(-)
 create mode 100644 src/arch/generic/lib.h

diff --git a/src/arch/generic/lib.h b/src/arch/generic/lib.h
new file mode 100644
index 0000000..737e795
--- /dev/null
+++ b/src/arch/generic/lib.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: MIT */
+
+#ifndef __INTERNAL__LIBURING_LIB_H
+	#error "This file should be included from src/lib.h (liburing)"
+#endif
+
+#ifndef LIBURING_ARCH_GENERIC_LIB_H
+#define LIBURING_ARCH_GENERIC_LIB_H
+
+static inline long get_page_size(void)
+{
+	long page_size;
+
+	page_size = sysconf(_SC_PAGESIZE);
+	if (page_size < 0)
+		page_size = 4096;
+
+	return page_size;
+}
+
+#endif /* #ifndef LIBURING_ARCH_GENERIC_LIB_H */
diff --git a/src/arch/x86/lib.h b/src/arch/x86/lib.h
index 65ad396..bacf74e 100644
--- a/src/arch/x86/lib.h
+++ b/src/arch/x86/lib.h
@@ -1,15 +1,15 @@
 /* SPDX-License-Identifier: MIT */
 
+#ifndef __INTERNAL__LIBURING_LIB_H
+	#error "This file should be included from src/lib.h (liburing)"
+#endif
+
 #ifndef LIBURING_ARCH_X86_LIB_H
 #define LIBURING_ARCH_X86_LIB_H
 
-#ifndef LIBURING_LIB_H
-#  error "This file should be included from src/lib.h (liburing)"
-#endif
-
 #if defined(__x86_64__)
 
-static inline long __arch_impl_get_page_size(void)
+static inline long get_page_size(void)
 {
 	return 4096;
 }
@@ -17,9 +17,15 @@ static inline long __arch_impl_get_page_size(void)
 #else /* #if defined(__x86_64__) */
 
 /*
- * TODO: Add x86 (32-bit) support here.
+ * For x86 (32-bit), fallback to libc wrapper.
+ * We can't use CONFIG_NOLIBC for x86 (32-bit) at the moment.
+ *
+ * TODO: Add x86 (32-bit) nolibc support.
  */
-#error "x86 (32-bit) is currently not supported for nolibc builds"
+#ifdef CONFIG_NOLIBC
+	#error "x86 (32-bit) is currently not supported for nolibc builds"
+#endif
+#include "../generic/lib.h"
 
 #endif /* #if defined(__x86_64__) */
 
diff --git a/src/lib.h b/src/lib.h
index bd02805..6672cc5 100644
--- a/src/lib.h
+++ b/src/lib.h
@@ -6,23 +6,31 @@
 #include <string.h>
 #include <unistd.h>
 
-#ifdef CONFIG_NOLIBC
-#  if defined(__x86_64__) || defined(__i386__)
-#    include "arch/x86/lib.h"
-#  else
-#    error "This arch doesn't support building liburing without libc"
-#  endif
+#define __INTERNAL__LIBURING_LIB_H
+#if defined(__x86_64__) || defined(__i386__)
+	#include "arch/x86/lib.h"
+#else
+	/*
+	 * We don't have nolibc support for this arch. Must use libc!
+	 */
+	#ifdef CONFIG_NOLIBC
+		#error "This arch doesn't support building liburing without libc"
+	#endif
+	/* libc wrappers. */
+	#include "arch/generic/lib.h"
 #endif
+#undef __INTERNAL__LIBURING_LIB_H
+
 
 #ifndef offsetof
-# define offsetof(TYPE, FIELD) ((size_t) &((TYPE *)0)->FIELD)
+	#define offsetof(TYPE, FIELD) ((size_t) &((TYPE *)0)->FIELD)
 #endif
 
 #ifndef container_of
-# define container_of(PTR, TYPE, FIELD) ({				\
-	__typeof__(((TYPE *)0)->FIELD) *__FIELD_PTR = (PTR);		\
-	(TYPE *)((char *) __FIELD_PTR - offsetof(TYPE, FIELD));		\
-})
+	#define container_of(PTR, TYPE, FIELD) ({			\
+		__typeof__(((TYPE *)0)->FIELD) *__FIELD_PTR = (PTR);	\
+		(TYPE *)((char *) __FIELD_PTR - offsetof(TYPE, FIELD));	\
+	})
 #endif
 
 void *__uring_malloc(size_t len);
@@ -46,19 +54,4 @@ static inline void uring_free(void *ptr)
 #endif
 }
 
-static inline long get_page_size(void)
-{
-#ifdef CONFIG_NOLIBC
-	return __arch_impl_get_page_size();
-#else
-	long page_size;
-
-	page_size = sysconf(_SC_PAGESIZE);
-	if (page_size < 0)
-		page_size = 4096;
-
-	return page_size;
-#endif
-}
-
 #endif /* #ifndef LIBURING_LIB_H */
-- 
2.32.0