Rework pmap so that it separates the PTE structure from the pv_entry

structure. This makes it possible to pre-allocate PTEs for the kernel,
which is necessary for a reliable implementation of pmap_kenter(). This
also avoids wasting space (about 48 bytes per page) for kernel mappings
and user mappings of memory-mapped devices.

This also fixes a bug with the previous version where the implementation
required the pv_entry structure to be physically contiguous but did not
enforce this (the structure size was not a power of two). This meant
that the pv_entry free list was quickly corrupted as soon as the system
was even mildly loaded.

1 files changed, 6 insertions, 1 deletions

diff --git a/sys/ia64/include/pmap.h b/sys/ia64/include/pmap.h
index e7fd258..0aa9a46 100644
--- a/sys/ia64/include/pmap.h
+++ b/sys/ia64/include/pmap.h
@@ -54,6 +54,12 @@
 
 #ifdef _KERNEL
 
+#ifndef NKPT
+#define	NKPT		30	/* initial number of kernel page tables */
+#endif
+#define MAXKPT		(PAGE_SIZE/sizeof(vm_offset_t))
+
+
 /*
  *	Routine:	pmap_kextract
  *	Function:
@@ -106,7 +112,6 @@ extern pmap_t		kernel_pmap;
  * mappings of that page.  An entry is a pv_entry_t, the list is pv_table.
  */
 typedef struct pv_entry {
-	struct ia64_lpte pv_pte;	/* pte for collision walker */
 	pmap_t		pv_pmap;	/* pmap where mapping lies */
 	vm_offset_t	pv_va;		/* virtual address for mapping */
 	TAILQ_ENTRY(pv_entry)	pv_list;