From 688834a82775540c28ce314579b80964d94aed3c Mon Sep 17 00:00:00 2001
From: jhb <jhb@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Date: Fri, 27 Jun 2014 17:22:18 +0000
Subject: [PATCH] MFC 261781: Don't waste a page of KVA for the boot-time
 memory test on x86.  For amd64, reuse the first page of the crashdumpmap as
 CMAP1/CADDR1.  For i386, remove CMAP1/CADDR1 entirely and reuse CMAP3/CADDR3
 for the memory test.

git-svn-id: svn://svn.freebsd.org/base/stable/10@267964 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
---
 sys/amd64/amd64/pmap.c  | 13 +++++--------
 sys/i386/i386/machdep.c |  4 ++--
 sys/i386/i386/pmap.c    |  8 +++-----
 sys/i386/include/pmap.h |  4 ++--
 sys/i386/xen/pmap.c     |  4 ++--
 sys/pc98/pc98/machdep.c |  4 ++--
 6 files changed, 16 insertions(+), 21 deletions(-)

diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
index 2b6102331..05ae8bb57 100644
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
@@ -812,7 +812,7 @@ void
 pmap_bootstrap(vm_paddr_t *firstaddr)
 {
 	vm_offset_t va;
-	pt_entry_t *pte, *unused;
+	pt_entry_t *pte;
 
 	/*
 	 * Create an initial set of page tables to run the kernel in.
@@ -858,14 +858,11 @@ pmap_bootstrap(vm_paddr_t *firstaddr)
 	pte = vtopte(va);
 
 	/*
-	 * CMAP1 is only used for the memory test.
-	 */
-	SYSMAP(caddr_t, CMAP1, CADDR1, 1)
-
-	/*
-	 * Crashdump maps.
+	 * Crashdump maps.  The first page is reused as CMAP1 for the
+	 * memory test.
 	 */
-	SYSMAP(caddr_t, unused, crashdumpmap, MAXDUMPPGS)
+	SYSMAP(caddr_t, CMAP1, crashdumpmap, MAXDUMPPGS)
+	CADDR1 = crashdumpmap;
 
 	virtual_avail = va;
 
diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index 2e1785b0c..9e25cd983 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -2387,7 +2387,7 @@ getmemsize(int first)
 	phys_avail[pa_indx++] = physmap[0];
 	phys_avail[pa_indx] = physmap[0];
 	dump_avail[da_indx] = physmap[0];
-	pte = CMAP1;
+	pte = CMAP3;
 
 	/*
 	 * Get dcons buffer address
@@ -2409,7 +2409,7 @@ getmemsize(int first)
 			end = trunc_page(physmap[i + 1]);
 		for (pa = round_page(physmap[i]); pa < end; pa += PAGE_SIZE) {
 			int tmp, page_bad, full;
-			int *ptr = (int *)CADDR1;
+			int *ptr = (int *)CADDR3;
 
 			full = FALSE;
 			/*
diff --git a/sys/i386/i386/pmap.c b/sys/i386/i386/pmap.c
index d5f31ec7b..1f9acfe86 100644
--- a/sys/i386/i386/pmap.c
+++ b/sys/i386/i386/pmap.c
@@ -256,11 +256,10 @@ struct sysmaps {
 	caddr_t	CADDR2;
 };
 static struct sysmaps sysmaps_pcpu[MAXCPU];
-pt_entry_t *CMAP1 = 0;
-static pt_entry_t *CMAP3;
+pt_entry_t *CMAP3;
 static pd_entry_t *KPTD;
-caddr_t CADDR1 = 0, ptvmmap = 0;
-static caddr_t CADDR3;
+caddr_t ptvmmap = 0;
+caddr_t CADDR3;
 struct msgbuf *msgbufp = 0;
 
 /*
@@ -434,7 +433,6 @@ pmap_bootstrap(vm_paddr_t firstaddr)
 		SYSMAP(caddr_t, sysmaps->CMAP1, sysmaps->CADDR1, 1)
 		SYSMAP(caddr_t, sysmaps->CMAP2, sysmaps->CADDR2, 1)
 	}
-	SYSMAP(caddr_t, CMAP1, CADDR1, 1)
 	SYSMAP(caddr_t, CMAP3, CADDR3, 1)
 
 	/*
diff --git a/sys/i386/include/pmap.h b/sys/i386/include/pmap.h
index 0303c604b..100475c7b 100644
--- a/sys/i386/include/pmap.h
+++ b/sys/i386/include/pmap.h
@@ -420,8 +420,8 @@ struct pv_chunk {
 
 #ifdef	_KERNEL
 
-extern caddr_t	CADDR1;
-extern pt_entry_t *CMAP1;
+extern caddr_t	CADDR3;
+extern pt_entry_t *CMAP3;
 extern vm_paddr_t phys_avail[];
 extern vm_paddr_t dump_avail[];
 extern int pseflag;
diff --git a/sys/i386/xen/pmap.c b/sys/i386/xen/pmap.c
index 9f3e8bb88..fa9bda813 100644
--- a/sys/i386/xen/pmap.c
+++ b/sys/i386/xen/pmap.c
@@ -249,9 +249,9 @@ struct sysmaps {
 	caddr_t	CADDR2;
 };
 static struct sysmaps sysmaps_pcpu[MAXCPU];
-static pt_entry_t *CMAP3;
+pt_entry_t *CMAP3;
 caddr_t ptvmmap = 0;
-static caddr_t CADDR3;
+caddr_t CADDR3;
 struct msgbuf *msgbufp = 0;
 
 /*
diff --git a/sys/pc98/pc98/machdep.c b/sys/pc98/pc98/machdep.c
index a4887c6a4..a5b799dc7 100644
--- a/sys/pc98/pc98/machdep.c
+++ b/sys/pc98/pc98/machdep.c
@@ -1962,7 +1962,7 @@ getmemsize(int first)
 	phys_avail[pa_indx++] = physmap[0];
 	phys_avail[pa_indx] = physmap[0];
 	dump_avail[da_indx] = physmap[0];
-	pte = CMAP1;
+	pte = CMAP3;
 
 	/*
 	 * Get dcons buffer address
@@ -1983,7 +1983,7 @@ getmemsize(int first)
 			end = trunc_page(physmap[i + 1]);
 		for (pa = round_page(physmap[i]); pa < end; pa += PAGE_SIZE) {
 			int tmp, page_bad, full;
-			int *ptr = (int *)CADDR1;
+			int *ptr = (int *)CADDR3;
 
 			full = FALSE;
 			/*
-- 
2.45.0