From: tip-bot for Andy Lutomirski <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: oleg@redhat.com, mingo@kernel.org, linux-kernel@vger.kernel.org,
tglx@linutronix.de, keescook@chromium.org, luto@kernel.org,
dave.hansen@linux.intel.com, fenghua.yu@intel.com,
luto@amacapital.net, peterz@infradead.org,
quentin.casasnovas@oracle.com, torvalds@linux-foundation.org,
bp@alien8.de, akpm@linux-foundation.org, hpa@zytor.com
Subject: [tip:x86/asm] mm: Add vm_insert_pfn_prot()
Date: Tue, 12 Jan 2016 04:02:59 -0800 [thread overview]
Message-ID: <tip-1745cbc5d0dee0749a6bc0ea8e872c5db0074061@git.kernel.org> (raw)
In-Reply-To: <d2938d1eb37be7a5e4f86182db646551f11e45aa.1451446564.git.luto@kernel.org>
Commit-ID: 1745cbc5d0dee0749a6bc0ea8e872c5db0074061
Gitweb: http://git.kernel.org/tip/1745cbc5d0dee0749a6bc0ea8e872c5db0074061
Author: Andy Lutomirski <luto@kernel.org>
AuthorDate: Tue, 29 Dec 2015 20:12:20 -0800
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 12 Jan 2016 11:59:34 +0100
mm: Add vm_insert_pfn_prot()
The x86 vvar vma contains pages with differing cacheability
flags. x86 currently implements this by manually inserting all
the ptes using (io_)remap_pfn_range when the vma is set up.
x86 wants to move to using .fault with VM_FAULT_NOPAGE to set up
the mappings as needed. The correct API to use to insert a pfn
in .fault is vm_insert_pfn(), but vm_insert_pfn() can't override the
vma's cache mode, and the HPET page in particular needs to be
uncached despite the fact that the rest of the VMA is cached.
Add vm_insert_pfn_prot() to support varying cacheability within
the same non-COW VMA in a more sane manner.
x86 could alternatively use multiple VMAs, but that's messy,
would break CRIU, and would create unnecessary VMAs that would
waste memory.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/d2938d1eb37be7a5e4f86182db646551f11e45aa.1451446564.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
include/linux/mm.h | 2 ++
mm/memory.c | 25 +++++++++++++++++++++++--
2 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 00bad77..87ef1d7 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2080,6 +2080,8 @@ int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn);
+int vm_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
+ unsigned long pfn, pgprot_t pgprot);
int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn);
int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
diff --git a/mm/memory.c b/mm/memory.c
index c387430..a29f0b9 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1564,8 +1564,29 @@ out:
int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn)
{
+ return vm_insert_pfn_prot(vma, addr, pfn, vma->vm_page_prot);
+}
+EXPORT_SYMBOL(vm_insert_pfn);
+
+/**
+ * vm_insert_pfn_prot - insert single pfn into user vma with specified pgprot
+ * @vma: user vma to map to
+ * @addr: target user address of this page
+ * @pfn: source kernel pfn
+ * @pgprot: pgprot flags for the inserted page
+ *
+ * This is exactly like vm_insert_pfn, except that it allows drivers to
+ * to override pgprot on a per-page basis.
+ *
+ * This only makes sense for IO mappings, and it makes no sense for
+ * cow mappings. In general, using multiple vmas is preferable;
+ * vm_insert_pfn_prot should only be used if using multiple VMAs is
+ * impractical.
+ */
+int vm_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
+ unsigned long pfn, pgprot_t pgprot)
+{
int ret;
- pgprot_t pgprot = vma->vm_page_prot;
/*
* Technically, architectures with pte_special can avoid all these
* restrictions (same for remap_pfn_range). However we would like
@@ -1587,7 +1608,7 @@ int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
return ret;
}
-EXPORT_SYMBOL(vm_insert_pfn);
+EXPORT_SYMBOL(vm_insert_pfn_prot);
int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn)
next prev parent reply other threads:[~2016-01-12 12:04 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-30 4:12 [PATCH v3 0/7] mm, x86/vdso: Special IO mapping improvements Andy Lutomirski
2015-12-30 4:12 ` [PATCH v3 1/7] x86/vsdo: Fix build on PARAVIRT_CLOCK=y, KVM_GUEST=n Andy Lutomirski
2016-01-05 19:21 ` Borislav Petkov
2016-01-06 9:54 ` [tip:x86/asm] x86/vsdo: Fix build on PARAVIRT_CLOCK=y, KVM_GUEST= n tip-bot for Andy Lutomirski
2015-12-30 4:12 ` [PATCH v3 2/7] mm: Add a vm_special_mapping .fault method Andy Lutomirski
2016-01-12 12:02 ` [tip:x86/asm] mm: Add a vm_special_mapping.fault() method tip-bot for Andy Lutomirski
2015-12-30 4:12 ` [PATCH v3 3/7] mm: Add vm_insert_pfn_prot Andy Lutomirski
2016-01-12 12:02 ` tip-bot for Andy Lutomirski [this message]
2015-12-30 4:12 ` [PATCH v3 4/7] x86/vdso: Track each mm's loaded vdso image as well as its base Andy Lutomirski
2016-01-12 12:03 ` [tip:x86/asm] x86/vdso: Track each mm' s loaded vDSO " tip-bot for Andy Lutomirski
2015-12-30 4:12 ` [PATCH v3 5/7] x86,vdso: Use .fault for the vdso text mapping Andy Lutomirski
2016-01-12 12:03 ` [tip:x86/asm] x86/vdso: Use .fault for the vDSO " tip-bot for Andy Lutomirski
2015-12-30 4:12 ` [PATCH v3 6/7] x86,vdso: Use .fault instead of remap_pfn_range for the vvar mapping Andy Lutomirski
2016-01-12 12:04 ` [tip:x86/asm] x86/vdso: Use ->fault() instead of remap_pfn_range( ) " tip-bot for Andy Lutomirski
2015-12-30 4:12 ` [PATCH v3 7/7] x86/vdso: Disallow vvar access to vclock IO for never-used vclocks Andy Lutomirski
2016-01-12 12:04 ` [tip:x86/asm] " tip-bot for Andy Lutomirski
2016-01-05 0:02 ` [PATCH v3 0/7] mm, x86/vdso: Special IO mapping improvements Kees Cook
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