From 18c389411a0f6283c1b6dffc78bbcfcb237e367b Mon Sep 17 00:00:00 2001
From: Jon Santmyer <jon@jonsantmyer.com>
Date: Tue, 19 Aug 2025 16:16:10 -0400
Subject: move pager to libjove

---
 lib/libjove/arch/x86_64/invoke-pagemap.c |  6 +--
 lib/libjove/arch/x86_64/object/pagemap.c |  4 --
 lib/libjove/arch/x86_64/pager/ensure.c   | 88 ++++++++++++++++++++++++++++++++
 3 files changed, 91 insertions(+), 7 deletions(-)
 create mode 100644 lib/libjove/arch/x86_64/pager/ensure.c

(limited to 'lib/libjove/arch/x86_64')

diff --git a/lib/libjove/arch/x86_64/invoke-pagemap.c b/lib/libjove/arch/x86_64/invoke-pagemap.c
index e3f3dff..131b22a 100644
--- a/lib/libjove/arch/x86_64/invoke-pagemap.c
+++ b/lib/libjove/arch/x86_64/invoke-pagemap.c
@@ -10,7 +10,7 @@
 int
 _syscall_invoke_mapping_exists(KernelObjectPageMap *map, uint8_t depth, uint16_t *path)
 {
-    uint8_t *syscallData = _syscall_message_ptr;
+    uint8_t *syscallData = __jove_syscall_ptr;
     int syscall_at = 0;
 
     SYSCALL_PAYLOAD_PUTOBJ(syscallData, syscall_at, map);
@@ -23,7 +23,7 @@ _syscall_invoke_mapping_exists(KernelObjectPageMap *map, uint8_t depth, uint16_t
 int
 _syscall_invoke_mapping_map(KernelObjectPageMap *map, uint8_t depth, uint16_t *path, KernelObjectUntyped *untyped)
 {
-    uint8_t *syscallData = _syscall_message_ptr;
+    uint8_t *syscallData = __jove_syscall_ptr;
     int syscall_at = 0;
 
     SYSCALL_PAYLOAD_PUTOBJ(syscallData, syscall_at, map);
@@ -37,7 +37,7 @@ _syscall_invoke_mapping_map(KernelObjectPageMap *map, uint8_t depth, uint16_t *p
 int
 _syscall_invoke_mapping_unmap(KernelObjectPageMap *map, uint8_t depth, uint16_t *path, KernelObjectUntyped *dest)
 {
-    uint8_t *syscallData = _syscall_message_ptr;
+    uint8_t *syscallData = __jove_syscall_ptr;
     int syscall_at = 0;
 
     SYSCALL_PAYLOAD_PUTOBJ(syscallData, syscall_at, map);
diff --git a/lib/libjove/arch/x86_64/object/pagemap.c b/lib/libjove/arch/x86_64/object/pagemap.c
index c58d7c6..0c03028 100644
--- a/lib/libjove/arch/x86_64/object/pagemap.c
+++ b/lib/libjove/arch/x86_64/object/pagemap.c
@@ -59,10 +59,6 @@ jove_pagemap_exists(
         uint16_t *path
         )
 {
-    if(!_jove_alloc) {
-        jove_errno = EJOVE_NOALLOC;
-        return 0;
-    }
     int kerr = _syscall_invoke_mapping_exists(map, depth, path);
     if(kerr == KE_DNE) return 0;
 
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;
+}
-- 
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