[PATCH 3/6] add L4 kmem cache for x86_64

[Luca Dariz]

* i386/intel/pmap.c: allocate the L4 page table from a dedicate kmem
  cache instead of the generic kernel map.
  Also improve readability of nested ifdef's.
---
 i386/intel/pmap.c | 34 +++++++++++++++++++---------------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/i386/intel/pmap.c b/i386/intel/pmap.c
index ccbb03fc..615b0fff 100644
--- a/i386/intel/pmap.c
+++ b/i386/intel/pmap.c
@@ -397,13 +397,14 @@ boolean_t cpu_update_needed[NCPUS];
 struct pmap    kernel_pmap_store;
 pmap_t         kernel_pmap;
 
-struct kmem_cache      pmap_cache;             /* cache of pmap structures */
-struct kmem_cache      pd_cache;               /* cache of page directories */
+struct kmem_cache pmap_cache;  /* cache of pmap structures */
+struct kmem_cache pd_cache;    /* cache of page directories */
 #if PAE
-struct kmem_cache      pdpt_cache;             /* cache of page
-                                                  directory pointer
-                                                  tables */
-#endif
+struct kmem_cache pdpt_cache;  /* cache of page directory pointer tables */
+#ifdef __x86_64__
+struct kmem_cache l4_cache;    /* cache of L4 tables */
+#endif /* __x86_64__ */
+#endif /* PAE */
 
 boolean_t              pmap_debug = FALSE;     /* flag for debugging prints */
 
@@ -1046,7 +1047,12 @@ void pmap_init(void)
        kmem_cache_init(&pdpt_cache, "pdpt",
                        INTEL_PGBYTES, INTEL_PGBYTES, NULL,
                        KMEM_CACHE_PHYSMEM);
-#endif
+#ifdef __x86_64__
+       kmem_cache_init(&l4_cache, "L4",
+                       INTEL_PGBYTES, INTEL_PGBYTES, NULL,
+                       KMEM_CACHE_PHYSMEM);
+#endif /* __x86_64__ */
+#endif /* PAE */
        s = (vm_size_t) sizeof(struct pv_entry);
        kmem_cache_init(&pv_list_cache, "pv_entry", s, 0, NULL, 0);
 
@@ -1287,10 +1293,8 @@ pmap_t pmap_create(vm_size_t size)
                                  );
        }
 #ifdef __x86_64__
-       // FIXME: use kmem_cache_alloc instead
-       if (kmem_alloc_wired(kernel_map,
-                            (vm_offset_t *)&p->l4base, INTEL_PGBYTES)
-                                                       != KERN_SUCCESS)
+       p->l4base = (pt_entry_t *) kmem_cache_alloc(&l4_cache);
+       if (p->l4base == NULL)
                panic("pmap_create");
        memset(p->l4base, 0, INTEL_PGBYTES);
        WRITE_PTE(&p->l4base[0], pa_to_pte(kvtophys((vm_offset_t) p->pdpbase)) 
| INTEL_PTE_VALID | INTEL_PTE_WRITE | INTEL_PTE_USER);
@@ -1426,16 +1430,16 @@ void pmap_destroy(pmap_t p)
        pmap_set_page_readwrite(p->l4base);
        pmap_set_page_readwrite(p->user_l4base);
        pmap_set_page_readwrite(p->user_pdpbase);
-#endif
+#endif /* __x86_64__ */
        pmap_set_page_readwrite(p->pdpbase);
 #endif /* MACH_PV_PAGETABLES */
 #ifdef __x86_64__
-       kmem_free(kernel_map, (vm_offset_t)p->l4base, INTEL_PGBYTES);
+        kmem_cache_free(&l4_cache, (vm_offset_t) p->l4base);
 #ifdef MACH_PV_PAGETABLES
        kmem_free(kernel_map, (vm_offset_t)p->user_l4base, INTEL_PGBYTES);
        kmem_free(kernel_map, (vm_offset_t)p->user_pdpbase, INTEL_PGBYTES);
-#endif
-#endif
+#endif /* MACH_PV_PAGETABLES */
+#endif /* __x86_64__ */
        kmem_cache_free(&pdpt_cache, (vm_offset_t) p->pdpbase);
 #endif /* PAE */
        kmem_cache_free(&pmap_cache, (vm_offset_t) p);
-- 
2.30.2