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[src/trunk]: src/sys add experimental new function uvm_direct_process(), to a...
details: https://anonhg.NetBSD.org/src/rev/38d9c3d382c6
branches: trunk
changeset: 361942:38d9c3d382c6
user: jdolecek <jdolecek%NetBSD.org@localhost>
date: Sat May 19 15:03:26 2018 +0000
description:
add experimental new function uvm_direct_process(), to allow of read/writes
of contents of uvm pages without mapping them into kernel, using
direct map or moral equivalent; pmaps supporting the interface need
to provide pmap_direct_process() and define PMAP_DIRECT
implement the new interface for amd64; I hear alpha and mips might be relatively
easy to add too, but I lack the knowledge
part of resolution for PR kern/53124
diffstat:
sys/arch/amd64/include/pmap.h | 16 +++++++++++++-
sys/uvm/uvm_page.c | 49 +++++++++++++++++++++++++++++++++++++++++-
sys/uvm/uvm_page.h | 7 +++++-
sys/uvm/uvm_pmap.h | 9 +++++++-
4 files changed, 76 insertions(+), 5 deletions(-)
diffs (144 lines):
diff -r e20ff8ef9c9e -r 38d9c3d382c6 sys/arch/amd64/include/pmap.h
--- a/sys/arch/amd64/include/pmap.h Sat May 19 14:15:39 2018 +0000
+++ b/sys/arch/amd64/include/pmap.h Sat May 19 15:03:26 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.h,v 1.45 2018/02/22 13:27:18 maxv Exp $ */
+/* $NetBSD: pmap.h,v 1.46 2018/05/19 15:03:26 jdolecek Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -318,6 +318,20 @@
}
#endif
+#ifdef __HAVE_DIRECT_MAP
+#define PMAP_DIRECT
+
+static __inline int
+pmap_direct_process(paddr_t pa, voff_t pgoff, size_t len,
+ int (*process)(void *, size_t, void *), void *arg)
+{
+ vaddr_t va = PMAP_DIRECT_MAP(pa);
+
+ return process((void *)(va + pgoff), len, arg);
+}
+
+#endif /* __HAVE_DIRECT_MAP */
+
void pmap_changeprot_local(vaddr_t, vm_prot_t);
#include <x86/pmap_pv.h>
diff -r e20ff8ef9c9e -r 38d9c3d382c6 sys/uvm/uvm_page.c
--- a/sys/uvm/uvm_page.c Sat May 19 14:15:39 2018 +0000
+++ b/sys/uvm/uvm_page.c Sat May 19 15:03:26 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: uvm_page.c,v 1.197 2018/05/19 11:02:33 jdolecek Exp $ */
+/* $NetBSD: uvm_page.c,v 1.198 2018/05/19 15:03:26 jdolecek Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -66,7 +66,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_page.c,v 1.197 2018/05/19 11:02:33 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_page.c,v 1.198 2018/05/19 15:03:26 jdolecek Exp $");
#include "opt_ddb.h"
#include "opt_uvm.h"
@@ -1758,6 +1758,51 @@
return true;
}
+#ifdef PMAP_DIRECT
+/*
+ * Call pmap to translate physical address into a virtual and to run a callback
+ * for it. Used to avoid actually mapping the pages, pmap most likely uses direct map
+ * or equivalent.
+ */
+int
+uvm_direct_process(struct vm_page **pgs, u_int npages, voff_t off, vsize_t len,
+ int (*process)(void *, size_t, void *), void *arg)
+{
+ int error = 0;
+ paddr_t pa;
+ size_t todo;
+ voff_t pgoff = (off & PAGE_MASK);
+ struct vm_page *pg;
+
+ KASSERT(npages > 0 && len > 0);
+
+ for (int i = 0; i < npages; i++) {
+ pg = pgs[i];
+
+ KASSERT(len > 0);
+
+ /*
+ * Caller is responsible for ensuring all the pages are
+ * available.
+ */
+ KASSERT(pg != NULL && pg != PGO_DONTCARE);
+
+ pa = VM_PAGE_TO_PHYS(pg);
+ todo = MIN(len, PAGE_SIZE - pgoff);
+
+ error = pmap_direct_process(pa, pgoff, todo, process, arg);
+ if (error)
+ break;
+
+ pgoff = 0;
+ len -= todo;
+ }
+
+ KASSERTMSG(error != 0 || len == 0, "len %lu != 0 for non-error", len);
+ return error;
+}
+#endif /* PMAP_DIRECT */
+
#if defined(DDB) || defined(DEBUGPRINT)
/*
diff -r e20ff8ef9c9e -r 38d9c3d382c6 sys/uvm/uvm_page.h
--- a/sys/uvm/uvm_page.h Sat May 19 14:15:39 2018 +0000
+++ b/sys/uvm/uvm_page.h Sat May 19 15:03:26 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: uvm_page.h,v 1.82 2017/11/14 06:43:23 mrg Exp $ */
+/* $NetBSD: uvm_page.h,v 1.83 2018/05/19 15:03:26 jdolecek Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -336,6 +336,11 @@
struct vm_page *uvm_phys_to_vm_page(paddr_t);
paddr_t uvm_vm_page_to_phys(const struct vm_page *);
+#if defined(PMAP_DIRECT)
+int uvm_direct_process(struct vm_page **, u_int, voff_t, vsize_t,
+ int (*)(void *, size_t, void *), void *);
+#endif
+
/*
* macros
*/
diff -r e20ff8ef9c9e -r 38d9c3d382c6 sys/uvm/uvm_pmap.h
--- a/sys/uvm/uvm_pmap.h Sat May 19 14:15:39 2018 +0000
+++ b/sys/uvm/uvm_pmap.h Sat May 19 15:03:26 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: uvm_pmap.h,v 1.38 2013/02/02 14:06:58 matt Exp $ */
+/* $NetBSD: uvm_pmap.h,v 1.39 2018/05/19 15:03:26 jdolecek Exp $ */
/*
* Copyright (c) 1991, 1993
@@ -212,6 +212,13 @@
#if defined(PMAP_FORK)
void pmap_fork(pmap_t, pmap_t);
#endif
+
+#if defined(PMAP_DIRECT)
+int pmap_direct_process(paddr_t, voff_t, size_t,
+ int (*)(void *, size_t, void *),
+ void *);
+#endif
+
#endif /* kernel*/
#endif /* PMAP_EXCLUDE_DECLS */
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