kern/kmem: rework buffer-to-slab lookup

Instead of using a red-black tree, rely on the VM system to store kmem
specific private data.

4 files changed, 21 insertions, 0 deletions

diff --git a/vm/vm_kmem.c b/vm/vm_kmem.c
index d51b2ced..5cc7374a 100644
--- a/vm/vm_kmem.c
+++ b/vm/vm_kmem.c
@@ -80,6 +80,19 @@ vm_kmem_boot_space(unsigned long *start, unsigned long *end)
     *end = vm_kmem_boot_start;
 }
 
+struct vm_page *
+vm_kmem_lookup_page(unsigned long va)
+{
+    phys_addr_t pa;
+
+    pa = pmap_kextract(va);
+
+    if (pa == 0)
+        return NULL;
+
+    return vm_phys_lookup_page(pa);
+}
+
 static int
 vm_kmem_alloc_check(size_t size)
 {
diff --git a/vm/vm_kmem.h b/vm/vm_kmem.h
index 6ecf8e17..d0da49f3 100644
--- a/vm/vm_kmem.h
+++ b/vm/vm_kmem.h
@@ -52,6 +52,12 @@ unsigned long vm_kmem_bootalloc(size_t size);
 void vm_kmem_boot_space(unsigned long *start, unsigned long *end);
 
 /*
+ * Return the page descriptor for the physical page mapped at va in kernel
+ * space. The given address must be mapped and valid.
+ */
+struct vm_page * vm_kmem_lookup_page(unsigned long va);
+
+/*
  * Allocate memory from the kernel map.
  */
 unsigned long vm_kmem_alloc(size_t size);
diff --git a/vm/vm_page.h b/vm/vm_page.h
index e5ad8fc5..205f3d2f 100644
--- a/vm/vm_page.h
+++ b/vm/vm_page.h
@@ -42,6 +42,7 @@ struct vm_page {
     unsigned short seg_index;
     unsigned short order;
     phys_addr_t phys_addr;
+    void *slab_priv;
 };
 
 static inline phys_addr_t
diff --git a/vm/vm_phys.c b/vm/vm_phys.c
index 14abf90e..cba286a2 100644
--- a/vm/vm_phys.c
+++ b/vm/vm_phys.c
@@ -155,6 +155,7 @@ vm_phys_init_page(struct vm_page *page, unsigned short seg_index,
     page->seg_index = seg_index;
     page->order = order;
     page->phys_addr = pa;
+    page->slab_priv = NULL;
 }
 
 static void __init