move pager to libjove

1 files changed, 88 insertions, 0 deletions

diff --git a/lib/libjove/arch/x86_64/pager/ensure.c b/lib/libjove/arch/x86_64/pager/ensure.c
new file mode 100644
index 0000000..bfe68ff
--- /dev/null
+++ b/lib/libjove/arch/x86_64/pager/ensure.c
@@ -0,0 +1,88 @@
+#include "arch/x86_64/pager.h"
+#include "object-untyped.h"
+#include "jove.h"
+#include <stdbool.h>
+
+KernelObjectPageMap __jove_pagemap;
+static unsigned d_cache[3] = { -1, -1, -1 };
+static uintptr_t vptr_cache = 0;
+static KernelObjectUntyped work_untyped;
+
+#define PMLI_SHL(d) (((4 - d) * 9) + 3)
+#define PMLI_DL(v, d) ((v >> PMLI_SHL(d)) % 512)
+
+static uint64_t
+pager_write_path(uintptr_t vptr, uint8_t depth)
+{
+    uint64_t r = 0;
+    if(depth >= 4) return -1;
+
+    uint16_t *path = (uint16_t*)&r;
+    for(uint8_t i = 0; i < depth; i++) path[i] = PMLI_DL(vptr, i);
+    return r;
+}
+
+/* Places new page in work_page. */
+static JoveError
+pager_alloc_page_untyped(void)
+{
+    uint8_t lastmemb = jove_objdir_lastmemb(&__jove_untyped_directory);
+    if(jove_errno) {
+        JoveError err = jove_errno;
+        jove_errno = EJOVE_OK;
+        return err;
+    }
+    
+    KernelObjectUntyped last_untyped;
+    _jove_alloc_untyped_inplace(&last_untyped, &__jove_untyped_directory, lastmemb);
+    
+    if(jove_untyped_size(&last_untyped) == 0x1000) {
+        jove_objdir_move(&__jove_untyped_directory, lastmemb, &__rootdir, __jove_work_obj.membi);
+        return EJOVE_OK;
+    }
+
+    work_untyped.typed = __jove_work_obj;
+    return jove_untyped_split_inplace(&last_untyped, 0x1000, &work_untyped);
+}
+
+static JoveError
+pager_ensure_at_depth(KernelObjectPageMap *map, uint8_t depth, uint16_t *path)
+{
+    int exists = jove_pagemap_exists(map, depth, path);
+    if(exists) {
+        return EJOVE_OK;
+    }
+
+    JoveError pagealloc_err = pager_alloc_page_untyped();
+    if(pagealloc_err) {
+        return pagealloc_err;
+    }
+    return jove_pagemap_map(map, depth, path, &work_untyped);
+}
+
+#define PAGER_CACHE_ENSURE_DEPTH(map, path_seg, d) \
+    if(path_seg[d] != d_cache[d]) { \
+        JoveError d_err = pager_ensure_at_depth(map, d, path_seg); \
+        if(d_err) return d_err; \
+        d_cache[d] = path_seg[d]; \
+    }
+
+JoveError
+jove_pager_ensure_for(KernelObjectPageMap *map, uintptr_t vptr)
+{
+    uint64_t path = pager_write_path(vptr, 3);
+    if(path == -1) return EJOVE_BADARG;
+
+    vptr &= ~0xFFFULL;
+    uint16_t *path_seg = (uint16_t*)&path;
+
+    jove_kprintf("%p Alloc %p : %x:%x:%x:%x\n", map, vptr, path_seg[0], path_seg[1], path_seg[2], path_seg[3]);
+
+    PAGER_CACHE_ENSURE_DEPTH(map, path_seg, 0);
+    PAGER_CACHE_ENSURE_DEPTH(map, path_seg, 1);
+    PAGER_CACHE_ENSURE_DEPTH(map, path_seg, 2);
+    if(vptr != vptr_cache) {
+        return pager_ensure_at_depth(map, 3, path_seg);
+    }
+    return EJOVE_OK;
+}