kernel: Add preliminary C support for many headers

This commit fixes up a variety of headers for C support on things such
as filesystem drivers. It has a couple of hacks, and some stuff just
isn't there yet (struct process, for one).

Signed-off-by: Pedro Falcato <pedro.falcato@gmail.com>

kernel/include/onyx/atomic.hpp

@@ -9,10 +9,6 @@
 
 #include <stddef.h>
 
-#include <onyx/conditional.h>
-#include <onyx/enable_if.h>
-#include <onyx/is_integral.h>
-
 #ifdef __GNUG__
 enum class mem_order : int
 {
@@ -38,16 +34,17 @@ enum class mem_order : int
 #endif
 
 template <typename type>
-class atomic_primitive
+class atomic
 {
 protected:
     type val;
 
 public:
-    constexpr atomic_primitive(type v) : val{v}
+    constexpr atomic(type v) : val{v}
     {
     }
-    constexpr atomic_primitive() : val{}
+
+    constexpr atomic() : val{}
     {
     }
 
@@ -134,47 +131,6 @@ class atomic_primitive
         return __atomic_compare_exchange_n(&val, &expected, desired, false, (int) order,
                                            (int) order);
     }
-};
-
-template <typename type>
-class atomic_complex_type
-{
-protected:
-    type val;
-
-public:
-    virtual type load(mem_order order = mem_order::seq_cst) = 0;
-
-    virtual void store(type t, mem_order order = mem_order::seq_cst) = 0;
-
-    virtual type add_fetch(type v, mem_order order = mem_order::seq_cst) = 0;
-    virtual type fetch_add(type v, mem_order order = mem_order::seq_cst) = 0;
-    virtual type sub_fetch(type v, mem_order order = mem_order::seq_cst) = 0;
-    virtual type fetch_sub(type v, mem_order order = mem_order::seq_cst) = 0;
-    virtual type and_fetch(type v, mem_order order = mem_order::seq_cst) = 0;
-    virtual type fetch_and(type v, mem_order order = mem_order::seq_cst) = 0;
-    virtual type or_fetch(type v, mem_order order = mem_order::seq_cst) = 0;
-    virtual type fetch_or(type v, mem_order order = mem_order::seq_cst) = 0;
-    virtual type xor_fetch(type v, mem_order order = mem_order::seq_cst) = 0;
-    virtual type fetch_xor(type v, mem_order order = mem_order::seq_cst) = 0;
-};
-
-template <typename type>
-class atomic : public conditional<is_integral_v<type>, atomic_primitive<type>,
-                                  atomic_complex_type<type>>::type
-{
-private:
-public:
-    constexpr atomic(type v)
-        : conditional<is_integral_v<type>, atomic_primitive<type>, atomic_complex_type<type>>::type(
-              v)
-    {
-    }
-    constexpr atomic()
-        : conditional<is_integral_v<type>, atomic_primitive<type>,
-                      atomic_complex_type<type>>::type()
-    {
-    }
 
     /* pre increment */
     type operator++()

kernel/include/onyx/bio.h

@@ -33,7 +33,7 @@ void bio_free(struct bio_req *req);
 
 static inline void bio_init(struct bio_req *req)
 {
-    *req = {};
+    *req = (struct bio_req){};
     req->b_ref = 1;
 }
 
@@ -57,6 +57,8 @@ static inline void bio_put(struct bio_req *req)
  */
 int bio_submit_req_wait(struct blockdev *dev, struct bio_req *req);
 
+int bio_submit_request(struct blockdev *dev, struct bio_req *req);
+
 /**
  * @brief Complete a bio req
  * Callable from softirq context, and lower

kernel/include/onyx/block.h

@@ -104,8 +104,6 @@ int blkdev_flush(struct blockdev *dev);
  */
 int blkdev_power(int op, struct blockdev *dev);
 
-int bio_submit_request(struct blockdev *dev, struct bio_req *req);
-
 static inline bool block_get_device_letter_from_id(unsigned int id, cul::slice<char> buffer)
 {
     if (id > 26)

kernel/include/onyx/buffer.h

@@ -13,6 +13,8 @@
 #include <onyx/mm/flush.h>
 #include <onyx/page.h>
 
+__BEGIN_CDECLS
+
 /* block_buf represents a filesystem block(works kind of like a buffer_head in linux).
  * It keeps information like whether the block is dirty, the page it's stored on, the offset, etc.
  * It's supposed to be used by filesystems only, for metadata.
@@ -136,10 +138,12 @@ void block_buf_dirty_inode(struct block_buf *buf, struct inode *inode);
  */
 void block_buf_tear_down_assoc(struct vm_object *object);
 
-#ifdef __cplusplus
-
 void page_remove_block_buf(struct page *page, size_t offset, size_t end);
 
+__END_CDECLS
+
+#ifdef __cplusplus
+
 class auto_block_buf
 {
 private:

kernel/include/onyx/compiler.h

@@ -166,4 +166,10 @@ inline void write_once(const Type& t, Type val)
 #define __nocov
 #endif
 
+#ifdef __cplusplus
+#define __deprecated [[deprecated]]
+#else
+#define __deprecated
+#endif
+
 #endif /* COMPILER_H */

kernel/include/onyx/cpu.h

@@ -241,7 +241,7 @@
 #define X86_CPU_MANUFACTURER_AMD     1
 #define X86_CPU_MANUFACTURER_UNKNOWN 3
 
-using cpu_t = struct cpu
+typedef struct cpu
 {
     char manuid[13];
     char brandstr[48];
@@ -254,7 +254,7 @@ using cpu_t = struct cpu
     unsigned long manufacturer;
     /* Add more as needed */
     uint64_t caps[8];
-};
+} cpu_t;
 
 __attribute__((hot)) bool x86_has_cap(int cap);
 bool x86_has_usable_tsc(void);

kernel/include/onyx/file.h

@@ -7,13 +7,16 @@
 #define _ONYX_FILE_H
 
 #include <errno.h>
-#include <uapi/fcntl.h>
 
 #include <onyx/panic.h>
 #include <onyx/vfs.h>
 
+#include <uapi/fcntl.h>
+
 struct ioctx;
 
+__BEGIN_CDECLS
+
 void file_do_cloexec(struct ioctx *ctx);
 int open_with_vnode(struct file *node, int flags);
 struct file *get_file_description(int fd);
@@ -31,7 +34,7 @@ void file_cache_init();
  *
  * @return Pointer to struct file, or nullptr
  */
-file *file_alloc();
+struct file *file_alloc();
 
 /**
  * @brief Free a struct file
@@ -43,7 +46,7 @@ void file_free(struct file *file);
 int allocate_file_descriptor_table(struct process *process);
 int copy_file_descriptors(struct process *process, struct ioctx *ctx);
 struct file *get_dirfd_file(int dirfd);
-void process_destroy_file_descriptors(process *process);
+void process_destroy_file_descriptors(struct process *process);
 
 #define OPEN_FLAGS_ACCESS_MODE(flags) (flags & 0x3)
 
@@ -64,6 +67,8 @@ static inline unsigned int open_to_file_access_flags(int open_flgs)
 
 bool fd_may_access(struct file *f, unsigned int access);
 
+__END_CDECLS
+
 #ifdef __cplusplus
 
 class auto_file

kernel/include/onyx/filemap.h

@@ -16,6 +16,7 @@
 
 struct file;
 struct page;
+struct iovec_iter;
 
 /**
  * @brief Read from a generic file (using the page cache) using iovec_iter
@@ -26,7 +27,8 @@ struct page;
  * @param flags Flags
  * @return Read bytes, or negative error code
  */
-ssize_t filemap_read_iter(struct file *filp, size_t off, iovec_iter *iter, unsigned int flags);
+ssize_t filemap_read_iter(struct file *filp, size_t off, struct iovec_iter *iter,
+                          unsigned int flags);
 
 /**
  * @brief Write to a generic file (using the page cache) using iovec_iter
@@ -37,7 +39,8 @@ ssize_t filemap_read_iter(struct file *filp, size_t off, iovec_iter *iter, unsig
  * @param flags Flags
  * @return Written bytes, or negative error code
  */
-ssize_t filemap_write_iter(struct file *filp, size_t off, iovec_iter *iter, unsigned int flags);
+ssize_t filemap_write_iter(struct file *filp, size_t off, struct iovec_iter *iter,
+                           unsigned int flags);
 
 #define FILEMAP_MARK_DIRTY RA_MARK_0
 

kernel/include/onyx/mm/slab.h

@@ -14,17 +14,28 @@
 #include <onyx/mm/kasan.h>
 #include <onyx/spinlock.h>
 
+#ifndef CONFIG_SMP_NR_CPUS
+#define CONFIG_SMP_NR_CPUS 64
+#endif
+
+#ifdef __cplusplus
 #include <onyx/atomic.hpp>
+#define ATOMIC_TYPE(type) atomic<type>
+#else
+#define ATOMIC_TYPE(type) type
+#endif
 
 #define SLAB_CACHE_PERCPU_MAGAZINE_SIZE 128
 
 struct slab_cache_percpu_context
 {
     void *magazine[SLAB_CACHE_PERCPU_MAGAZINE_SIZE];
     int size;
-    atomic<int> touched;
+    ATOMIC_TYPE(int) touched;
 } __align_cache;
 
+#undef ATOMIC_TYPE
+
 struct slab_cache
 {
     const char *name;
@@ -42,14 +53,16 @@ struct slab_cache
     size_t nfullslabs;
     struct list_head cache_list_node;
     unsigned int flags;
-    spinlock lock;
+    struct spinlock lock;
     void (*ctor)(void *);
     int mag_limit;
     // TODO: This is horrible. We need a way to allocate percpu memory,
     // and then either trim it or grow it when CPUs come online.
     struct slab_cache_percpu_context pcpu[CONFIG_SMP_NR_CPUS] __align_cache;
 };
 
+__BEGIN_CDECLS
+
 #define KMEM_CACHE_HWALIGN (1 << 0)
 #define KMEM_CACHE_VMALLOC (1 << 1)
 #define KMEM_CACHE_NOPCPU  (1 << 2)
@@ -143,4 +156,6 @@ void kmem_cache_print_slab_info_kasan(void *mem, struct slab *slab);
  */
 void slab_shrink_caches(unsigned long target_freep);
 
+__END_CDECLS
+
 #endif