From fe105d45a2337d85cfb6ebb9bc7323f5efc35a0a Mon Sep 17 00:00:00 2001
From: Alan Cox <alc@FreeBSD.org>
Date: Fri, 18 Sep 2009 17:04:57 +0000
Subject: [PATCH] Add a new sysctl for reporting all of the supported page
 sizes.

Reviewed by:	jhb
MFC after:	3 weeks
---
 sys/amd64/include/param.h   |  2 ++
 sys/arm/include/param.h     |  2 ++
 sys/i386/include/param.h    |  2 ++
 sys/ia64/include/param.h    |  2 ++
 sys/kern/kern_mib.c         | 27 +++++++++++++++++++++++++++
 sys/mips/include/param.h    |  2 ++
 sys/powerpc/include/param.h |  2 ++
 sys/sparc64/include/param.h |  2 ++
 sys/sun4v/include/param.h   |  2 ++
 sys/sys/systm.h             |  1 +
 10 files changed, 44 insertions(+)

diff --git a/sys/amd64/include/param.h b/sys/amd64/include/param.h
index f9b6bd81d6fe..3ede6014adcc 100644
--- a/sys/amd64/include/param.h
+++ b/sys/amd64/include/param.h
@@ -108,6 +108,8 @@
 #define	NBPML4		(1ul<<PML4SHIFT)/* bytes/page map lev4 table */
 #define	PML4MASK	(NBPML4-1)
 
+#define	MAXPAGESIZES	3	/* maximum number of supported page sizes */
+
 #define IOPAGES	2		/* pages of i/o permission bitmap */
 
 #ifndef	KSTACK_PAGES
diff --git a/sys/arm/include/param.h b/sys/arm/include/param.h
index 2161103a52e7..1694bc43c5ed 100644
--- a/sys/arm/include/param.h
+++ b/sys/arm/include/param.h
@@ -92,6 +92,8 @@
 #define NBPDR		(1 << PDR_SHIFT)
 #define NPDEPG          (1 << (32 - PDR_SHIFT))
 
+#define	MAXPAGESIZES	1		/* maximum number of supported page sizes */
+
 #ifndef KSTACK_PAGES
 #define KSTACK_PAGES    2
 #endif /* !KSTACK_PAGES */
diff --git a/sys/i386/include/param.h b/sys/i386/include/param.h
index b6a527dba054..11ac12efac70 100644
--- a/sys/i386/include/param.h
+++ b/sys/i386/include/param.h
@@ -110,6 +110,8 @@
 #define NBPDR		(1<<PDRSHIFT)	/* bytes/page dir */
 #define PDRMASK		(NBPDR-1)
 
+#define	MAXPAGESIZES	2	/* maximum number of supported page sizes */
+
 #define IOPAGES	2		/* pages of i/o permission bitmap */
 
 #ifndef KSTACK_PAGES
diff --git a/sys/ia64/include/param.h b/sys/ia64/include/param.h
index 8518020a9240..331af7aacf40 100644
--- a/sys/ia64/include/param.h
+++ b/sys/ia64/include/param.h
@@ -89,6 +89,8 @@
 #define PAGE_MASK	(PAGE_SIZE-1)
 #define NPTEPG		(PAGE_SIZE/(sizeof (pt_entry_t)))
 
+#define	MAXPAGESIZES	1		/* maximum number of supported page sizes */
+
 #ifndef	KSTACK_PAGES
 #define	KSTACK_PAGES	4		/* pages of kernel stack */
 #endif
diff --git a/sys/kern/kern_mib.c b/sys/kern/kern_mib.c
index d42d31d651f5..04e4dc0437b7 100644
--- a/sys/kern/kern_mib.c
+++ b/sys/kern/kern_mib.c
@@ -204,6 +204,33 @@ SYSCTL_PROC(_hw, HW_USERMEM, usermem, CTLTYPE_ULONG | CTLFLAG_RD,
 
 SYSCTL_ULONG(_hw, OID_AUTO, availpages, CTLFLAG_RD, &physmem, 0, "");
 
+u_long pagesizes[MAXPAGESIZES] = { PAGE_SIZE };
+
+static int
+sysctl_hw_pagesizes(SYSCTL_HANDLER_ARGS)
+{
+	int error;
+#ifdef SCTL_MASK32
+	int i;
+	uint32_t pagesizes32[MAXPAGESIZES];
+
+	if (req->flags & SCTL_MASK32) {
+		/*
+		 * Recreate the "pagesizes" array with 32-bit elements.  Truncate
+		 * any page size greater than UINT32_MAX to zero.
+		 */
+		for (i = 0; i < MAXPAGESIZES; i++)
+			pagesizes32[i] = (uint32_t)pagesizes[i];
+
+		error = SYSCTL_OUT(req, pagesizes32, sizeof(pagesizes32));
+	} else
+#endif
+		error = SYSCTL_OUT(req, pagesizes, sizeof(pagesizes));
+	return (error);
+}
+SYSCTL_PROC(_hw, OID_AUTO, pagesizes, CTLTYPE_ULONG | CTLFLAG_RD,
+    NULL, 0, sysctl_hw_pagesizes, "LU", "Supported page sizes");
+
 static char	machine_arch[] = MACHINE_ARCH;
 SYSCTL_STRING(_hw, HW_MACHINE_ARCH, machine_arch, CTLFLAG_RD,
     machine_arch, 0, "System architecture");
diff --git a/sys/mips/include/param.h b/sys/mips/include/param.h
index 10f348a7cf8f..b81864940467 100644
--- a/sys/mips/include/param.h
+++ b/sys/mips/include/param.h
@@ -115,6 +115,8 @@
 #define	SEGOFSET	(NBSEG-1)	/* byte offset into segment */
 #define	SEGSHIFT	22		/* LOG2(NBSEG) */
 
+#define	MAXPAGESIZES	1		/* maximum number of supported page sizes */
+
 /* XXXimp: This has moved to vmparam.h */
 /* Also, this differs from the mips2 definition, but likely is better */
 /* since this means the kernel won't chew up TLBs when it is executing */
diff --git a/sys/powerpc/include/param.h b/sys/powerpc/include/param.h
index 160cd782a7d8..6c3edf9c92a0 100644
--- a/sys/powerpc/include/param.h
+++ b/sys/powerpc/include/param.h
@@ -86,6 +86,8 @@
 #define	PAGE_MASK	(PAGE_SIZE - 1)
 #define	NPTEPG		(PAGE_SIZE/(sizeof (pt_entry_t)))
 
+#define	MAXPAGESIZES	1		/* maximum number of supported page sizes */
+
 #ifndef KSTACK_PAGES
 #define	KSTACK_PAGES		4		/* includes pcb */
 #endif
diff --git a/sys/sparc64/include/param.h b/sys/sparc64/include/param.h
index 90864b0556f7..af026b293f29 100644
--- a/sys/sparc64/include/param.h
+++ b/sys/sparc64/include/param.h
@@ -109,6 +109,8 @@
 #define PAGE_SIZE_MAX	PAGE_SIZE_4M
 #define PAGE_MASK_MAX	PAGE_MASK_4M
 
+#define	MAXPAGESIZES	1		/* maximum number of supported page sizes */
+
 #ifndef KSTACK_PAGES
 #define KSTACK_PAGES		4	/* pages of kernel stack (with pcb) */
 #endif
diff --git a/sys/sun4v/include/param.h b/sys/sun4v/include/param.h
index 069ab548d57f..2ca699e838a3 100644
--- a/sys/sun4v/include/param.h
+++ b/sys/sun4v/include/param.h
@@ -104,6 +104,8 @@
 #define PAGE_SIZE_MAX	PAGE_SIZE_4M
 #define PAGE_MASK_MAX	PAGE_MASK_4M
 
+#define	MAXPAGESIZES	1		/* maximum number of supported page sizes */
+
 #ifndef KSTACK_PAGES
 #define KSTACK_PAGES		4	/* pages of kernel stack (with pcb) */
 #endif
diff --git a/sys/sys/systm.h b/sys/sys/systm.h
index 96222da91522..397976fd564f 100644
--- a/sys/sys/systm.h
+++ b/sys/sys/systm.h
@@ -54,6 +54,7 @@ extern int kstack_pages;	/* number of kernel stack pages */
 
 extern int nswap;		/* size of swap space */
 
+extern u_long pagesizes[];	/* supported page sizes */
 extern long physmem;		/* physical memory */
 extern long realmem;		/* 'real' memory */