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2015-02-21Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds1-2/+26
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull misc x86 fixes from Ingo Molnar: "This contains: - EFI fixes - a boot printout fix - ASLR/kASLR fixes - intel microcode driver fixes - other misc fixes Most of the linecount comes from an EFI revert" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/ASLR: Avoid PAGE_SIZE redefinition for UML subarch x86/microcode/intel: Handle truncated microcode images more robustly x86/microcode/intel: Guard against stack overflow in the loader x86, mm/ASLR: Fix stack randomization on 64-bit systems x86/mm/init: Fix incorrect page size in init_memory_mapping() printks x86/mm/ASLR: Propagate base load address calculation Documentation/x86: Fix path in zero-page.txt x86/apic: Fix the devicetree build in certain configs Revert "efi/libstub: Call get_memory_map() to obtain map and desc sizes" x86/efi: Avoid triple faults during EFI mixed mode calls
2015-02-19x86/mm/init: Fix incorrect page size in init_memory_mapping() printksDave Hansen1-2/+26
With 32-bit non-PAE kernels, we have 2 page sizes available (at most): 4k and 4M. Enabling PAE replaces that 4M size with a 2M one (which 64-bit systems use too). But, when booting a 32-bit non-PAE kernel, in one of our early-boot printouts, we say: init_memory_mapping: [mem 0x00000000-0x000fffff] [mem 0x00000000-0x000fffff] page 4k init_memory_mapping: [mem 0x37000000-0x373fffff] [mem 0x37000000-0x373fffff] page 2M init_memory_mapping: [mem 0x00100000-0x36ffffff] [mem 0x00100000-0x003fffff] page 4k [mem 0x00400000-0x36ffffff] page 2M init_memory_mapping: [mem 0x37400000-0x377fdfff] [mem 0x37400000-0x377fdfff] page 4k Which is obviously wrong. There is no 2M page available. This is probably because of a badly-named variable: in the map_range code: PG_LEVEL_2M. Instead of renaming all the PG_LEVEL_2M's. This patch just fixes the printout: init_memory_mapping: [mem 0x00000000-0x000fffff] [mem 0x00000000-0x000fffff] page 4k init_memory_mapping: [mem 0x37000000-0x373fffff] [mem 0x37000000-0x373fffff] page 4M init_memory_mapping: [mem 0x00100000-0x36ffffff] [mem 0x00100000-0x003fffff] page 4k [mem 0x00400000-0x36ffffff] page 4M init_memory_mapping: [mem 0x37400000-0x377fdfff] [mem 0x37400000-0x377fdfff] page 4k BRK [0x03206000, 0x03206fff] PGTABLE Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20150210212030.665EC267@viggo.jf.intel.com Signed-off-by: Borislav Petkov <bp@suse.de>
2015-02-16Merge branch 'perf-core-for-linus' of ↵Linus Torvalds1-2/+11
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 perf updates from Ingo Molnar: "This series tightens up RDPMC permissions: currently even highly sandboxed x86 execution environments (such as seccomp) have permission to execute RDPMC, which may leak various perf events / PMU state such as timing information and other CPU execution details. This 'all is allowed' RDPMC mode is still preserved as the (non-default) /sys/devices/cpu/rdpmc=2 setting. The new default is that RDPMC access is only allowed if a perf event is mmap-ed (which is needed to correctly interpret RDPMC counter values in any case). As a side effect of these changes CR4 handling is cleaned up in the x86 code and a shadow copy of the CR4 value is added. The extra CR4 manipulation adds ~ <50ns to the context switch cost between rdpmc-capable and rdpmc-non-capable mms" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86: Add /sys/devices/cpu/rdpmc=2 to allow rdpmc for all tasks perf/x86: Only allow rdpmc if a perf_event is mapped perf: Pass the event to arch_perf_update_userpage() perf: Add pmu callbacks to track event mapping and unmapping x86: Add a comment clarifying LDT context switching x86: Store a per-cpu shadow copy of CR4 x86: Clean up cr4 manipulation
2015-02-10Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree changes from Jiri Kosina: "Patches from trivial.git that keep the world turning around. Mostly documentation and comment fixes, and a two corner-case code fixes from Alan Cox" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: kexec, Kconfig: spell "architecture" properly mm: fix cleancache debugfs directory path blackfin: mach-common: ints-priority: remove unused function doubletalk: probe failure causes OOPS ARM: cache-l2x0.c: Make it clear that cache-l2x0 handles L310 cache controller msdos_fs.h: fix 'fields' in comment scsi: aic7xxx: fix comment ARM: l2c: fix comment ibmraid: fix writeable attribute with no store method dynamic_debug: fix comment doc: usbmon: fix spelling s/unpriviledged/unprivileged/ x86: init_mem_mapping(): use capital BIOS in comment
2015-02-04x86: Store a per-cpu shadow copy of CR4Andy Lutomirski1-0/+9
Context switches and TLB flushes can change individual bits of CR4. CR4 reads take several cycles, so store a shadow copy of CR4 in a per-cpu variable. To avoid wasting a cache line, I added the CR4 shadow to cpu_tlbstate, which is already touched in switch_mm. The heaviest users of the cr4 shadow will be switch_mm and __switch_to_xtra, and __switch_to_xtra is called shortly after switch_mm during context switch, so the cacheline is likely to be hot. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Kees Cook <keescook@chromium.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Vince Weaver <vince@deater.net> Cc: "hillf.zj" <hillf.zj@alibaba-inc.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/3a54dd3353fffbf84804398e00dfdc5b7c1afd7d.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-04x86: Clean up cr4 manipulationAndy Lutomirski1-2/+2
CR4 manipulation was split, seemingly at random, between direct (write_cr4) and using a helper (set/clear_in_cr4). Unfortunately, the set_in_cr4 and clear_in_cr4 helpers also poke at the boot code, which only a small subset of users actually wanted. This patch replaces all cr4 access in functions that don't leave cr4 exactly the way they found it with new helpers cr4_set_bits, cr4_clear_bits, and cr4_set_bits_and_update_boot. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Vince Weaver <vince@deater.net> Cc: "hillf.zj" <hillf.zj@alibaba-inc.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/495a10bdc9e67016b8fd3945700d46cfd5c12c2f.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-22x86, mm: Change cachemode exports to non-gplJuergen Gross1-2/+2
Commit 281d4078bec3 ("x86: Make page cache mode a real type") introduced the symbols __cachemode2pte_tbl and __pte2cachemode_tbl and exported them via EXPORT_SYMBOL_GPL. The exports are part of a replacement of code which has been EXPORT_SYMBOL before these changes resulting in build breakage of out-of-tree non-gpl modules. Change EXPORT_SYMBOL_GPL to EXPORT-SYMBOL for these two symbols. Fixes: 281d4078bec3 "x86: Make page cache mode a real type" Reported-and-tested-by: Steven Noonan <steven@uplinklabs.net> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Toshi Kani <toshi.kani@hp.com> Link: http://lkml.kernel.org/r/1421926997-28615-1-git-send-email-jgross@suse.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-01-02x86: init_mem_mapping(): use capital BIOS in commentPavel Machek1-1/+1
Use capital BIOS in comment. Its cleaner, and allows diference between BIOS and BIOs. Signed-off-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-12-23x86: Fix step size adjustment during initial memory mappingJan Beulich1-20/+17
The old scheme can lead to failure in certain cases - the problem is that after bumping step_size the next (non-final) iteration is only guaranteed to make available a memory block the size of what step_size was before. E.g. for a memory block [0,3004600000) we'd have: iter start end step amount 1 3004400000 30045fffff 2M 2M 2 3004000000 30043fffff 64M 4M 3 3000000000 3003ffffff 2G 64M 4 2000000000 2fffffffff 64G 64G Yet to map 64G with 4k pages (as happens e.g. under PV Xen) we need slightly over 128M, but the first three iterations made only about 70M available. The condition (new_mapped_ram_size > mapped_ram_size) for bumping step_size is just not suitable. Instead we want to bump it when we know we have enough memory available to cover a block of the new step_size. And rather than making that condition more complicated than needed, simply adjust step_size by the largest possible factor we know we can cover at that point - which is shifting it left by one less than the difference between page table level shifts. (Interestingly the original STEP_SIZE_SHIFT definition had a comment hinting at that having been the intention, just that it should have been PUD_SHIFT-PMD_SHIFT-1 instead of (PUD_SHIFT-PMD_SHIFT)/2, and of course for non-PAE 32-bit we can't really use these two constants as they're equal there.) Furthermore the comment in get_new_step_size() didn't get updated when the bottom-down mapping logic got added. Yet while an overflow (flushing step_size to zero) of the shift doesn't matter for the top-down method, it does for bottom-up because round_up(x, 0) = 0, and an upper range boundary of zero can't really work well. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/54945C1E020000780005114E@mail.emea.novell.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-12-14Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Misc fixes (mainly Andy's TLS fixes), plus a cleanup" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/tls: Disallow unusual TLS segments x86/tls: Validate TLS entries to protect espfix MAINTAINERS: Add me as x86 VDSO submaintainer x86/asm: Unify segment selector defines x86/asm: Guard against building the 32/64-bit versions of the asm-offsets*.c file directly x86_64, switch_to(): Load TLS descriptors before switching DS and ES x86/mm: Use min() instead of min_t() in the e820 printout code x86/mm: Fix zone ranges boot printout x86/doc: Update documentation after file shuffling
2014-12-11x86/mm: Fix zone ranges boot printoutXishi Qiu1-2/+2
This is the usual physical memory layout boot printout: ... [ 0.000000] Zone ranges: [ 0.000000] DMA [mem 0x00001000-0x00ffffff] [ 0.000000] DMA32 [mem 0x01000000-0xffffffff] [ 0.000000] Normal [mem 0x100000000-0xc3fffffff] [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x00001000-0x00099fff] [ 0.000000] node 0: [mem 0x00100000-0xbf78ffff] [ 0.000000] node 0: [mem 0x100000000-0x63fffffff] [ 0.000000] node 1: [mem 0x640000000-0xc3fffffff] ... This is the log when we set "mem=2G" on the boot cmdline: ... [ 0.000000] Zone ranges: [ 0.000000] DMA [mem 0x00001000-0x00ffffff] [ 0.000000] DMA32 [mem 0x01000000-0xffffffff] // should be 0x7fffffff, right? [ 0.000000] Normal empty [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x00001000-0x00099fff] [ 0.000000] node 0: [mem 0x00100000-0x7fffffff] ... This patch fixes the printout, the following log shows the right ranges: ... [ 0.000000] Zone ranges: [ 0.000000] DMA [mem 0x00001000-0x00ffffff] [ 0.000000] DMA32 [mem 0x01000000-0x7fffffff] [ 0.000000] Normal empty [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x00001000-0x00099fff] [ 0.000000] node 0: [mem 0x00100000-0x7fffffff] ... Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Cc: Linux MM <linux-mm@kvack.org> Cc: <dave@sr71.net> Cc: Rik van Riel <riel@redhat.com> Link: http://lkml.kernel.org/r/5487AB3D.6070306@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-16x86: Enable PAT to use cache mode translation tablesJuergen Gross1-0/+8
Update the translation tables from cache mode to pgprot values according to the PAT settings. This enables changing the cache attributes of a PAT index in just one place without having to change at the users side. With this change it is possible to use the same kernel with different PAT configurations, e.g. supporting Xen. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Toshi Kani <toshi.kani@hp.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: stefan.bader@canonical.com Cc: xen-devel@lists.xensource.com Cc: ville.syrjala@linux.intel.com Cc: david.vrabel@citrix.com Cc: jbeulich@suse.com Cc: plagnioj@jcrosoft.com Cc: tomi.valkeinen@ti.com Cc: bhelgaas@google.com Link: http://lkml.kernel.org/r/1415019724-4317-18-git-send-email-jgross@suse.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-11-16x86: Make page cache mode a real typeJuergen Gross1-0/+29
At the moment there are a lot of places that handle setting or getting the page cache mode by treating the pgprot bits equal to the cache mode. This is only true because there are a lot of assumptions about the setup of the PAT MSR. Otherwise the cache type needs to get translated into pgprot bits and vice versa. This patch tries to prepare for that by introducing a separate type for the cache mode and adding functions to translate between those and pgprot values. To avoid too much performance penalty the translation between cache mode and pgprot values is done via tables which contain the relevant information. Write-back cache mode is hard-wired to be 0, all other modes are configurable via those tables. For large pages there are translation functions as the PAT bit is located at different positions in the ptes of 4k and large pages. Based-on-patch-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: stefan.bader@canonical.com Cc: xen-devel@lists.xensource.com Cc: konrad.wilk@oracle.com Cc: ville.syrjala@linux.intel.com Cc: david.vrabel@citrix.com Cc: jbeulich@suse.com Cc: toshi.kani@hp.com Cc: plagnioj@jcrosoft.com Cc: tomi.valkeinen@ti.com Cc: bhelgaas@google.com Link: http://lkml.kernel.org/r/1415019724-4317-2-git-send-email-jgross@suse.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-07-31x86/mm: Add tracepoints for TLB flushesDave Hansen1-0/+7
We don't have any good way to figure out what kinds of flushes are being attempted. Right now, we can try to use the vm counters, but those only tell us what we actually did with the hardware (one-by-one vs full) and don't tell us what was actually _requested_. This allows us to select out "interesting" TLB flushes that we might want to optimize (like the ranged ones) and ignore the ones that we have very little control over (the ones at context switch). Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: http://lkml.kernel.org/r/20140731154059.4C96CBA5@viggo.jf.intel.com Acked-by: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-11-13arch/x86/mm/init.c: fix incorrect function name in alloc_low_pages()Zhi Yong Wu1-2/+2
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13x86/mem-hotplug: support initialize page tables in bottom-upTang Chen1-2/+64
The Linux kernel cannot migrate pages used by the kernel. As a result, kernel pages cannot be hot-removed. So we cannot allocate hotpluggable memory for the kernel. In a memory hotplug system, any numa node the kernel resides in should be unhotpluggable. And for a modern server, each node could have at least 16GB memory. So memory around the kernel image is highly likely unhotpluggable. ACPI SRAT (System Resource Affinity Table) contains the memory hotplug info. But before SRAT is parsed, memblock has already started to allocate memory for the kernel. So we need to prevent memblock from doing this. So direct memory mapping page tables setup is the case. init_mem_mapping() is called before SRAT is parsed. To prevent page tables being allocated within hotpluggable memory, we will use bottom-up direction to allocate page tables from the end of kernel image to the higher memory. Note: As for allocating page tables in lower memory, TJ said: : This is an optional behavior which is triggered by a very specific kernel : boot param, which I suspect is gonna need to stick around to support : memory hotplug in the current setup unless we add another layer of address : translation to support memory hotplug. As for page tables may occupy too much lower memory if using 4K mapping (CONFIG_DEBUG_PAGEALLOC and CONFIG_KMEMCHECK both disable using >4k pages), TJ said: : But as I said in the same paragraph, parsing SRAT earlier doesn't solve : the problem in itself either. Ignoring the option if 4k mapping is : required and memory consumption would be prohibitive should work, no? : Something like that would be necessary if we're gonna worry about cases : like this no matter how we implement it, but, frankly, I'm not sure this : is something worth worrying about. Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Toshi Kani <toshi.kani@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Thomas Renninger <trenn@suse.de> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Taku Izumi <izumi.taku@jp.fujitsu.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13x86/mm: factor out of top-down direct mapping setupTang Chen1-20/+39
Create a new function memory_map_top_down to factor out of the top-down direct memory mapping pagetable setup. This is also a preparation for the following patch, which will introduce the bottom-up memory mapping. That said, we will put the two ways of pagetable setup into separate functions, and choose to use which way in init_mem_mapping, which makes the code more clear. Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Toshi Kani <toshi.kani@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Thomas Renninger <trenn@suse.de> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Taku Izumi <izumi.taku@jp.fujitsu.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-10x86/mm: Add 'step_size' comments to init_mem_mapping()Yinghai Lu1-3/+20
Current code uses macro to shift by 5, but there is no explanation why there's no worry about an overflow there. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Jacob Shin <jacob.shin@amd.com> Link: http://lkml.kernel.org/r/1378519629-10433-1-git-send-email-yinghai@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-08-20x86/mm: Fix boot crash with DEBUG_PAGE_ALLOC=y and more than 512G RAMYinghai Lu1-2/+2
Dave Hansen reported that systems between 500G and 600G RAM crash early if DEBUG_PAGEALLOC is selected. > [ 0.000000] init_memory_mapping: [mem 0x00000000-0x000fffff] > [ 0.000000] [mem 0x00000000-0x000fffff] page 4k > [ 0.000000] BRK [0x02086000, 0x02086fff] PGTABLE > [ 0.000000] BRK [0x02087000, 0x02087fff] PGTABLE > [ 0.000000] BRK [0x02088000, 0x02088fff] PGTABLE > [ 0.000000] init_memory_mapping: [mem 0xe80ee00000-0xe80effffff] > [ 0.000000] [mem 0xe80ee00000-0xe80effffff] page 4k > [ 0.000000] BRK [0x02089000, 0x02089fff] PGTABLE > [ 0.000000] BRK [0x0208a000, 0x0208afff] PGTABLE > [ 0.000000] Kernel panic - not syncing: alloc_low_page: ran out of memory It turns out that we missed increasing needed pages in BRK to mapping initial 2M and [0,1M) when we switched to use the #PF handler to set memory mappings: > commit 8170e6bed465b4b0c7687f93e9948aca4358a33b > Author: H. Peter Anvin <hpa@zytor.com> > Date: Thu Jan 24 12:19:52 2013 -0800 > > x86, 64bit: Use a #PF handler to materialize early mappings on demand Before that, we had the maping from [0,512M) in head_64.S, and we can spare two pages [0-1M). After that change, we can not reuse pages anymore. When we have more than 512M ram, we need an extra page for pgd page with [512G, 1024g). Increase pages in BRK for page table to solve the boot crash. Reported-by: Dave Hansen <dave.hansen@intel.com> Bisected-by: Dave Hansen <dave.hansen@intel.com> Tested-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: <stable@vger.kernel.org> # v3.9 and later Link: http://lkml.kernel.org/r/1376351004-4015-1-git-send-email-yinghai@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-03mm/x86: use free_reserved_area() to simplify codeJiang Liu1-11/+3
Use common help function free_reserved_area() to simplify code. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: <sworddragon2@aol.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Michel Lespinasse <walken@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Tejun Heo <tj@kernel.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-31x86: Fix adjust_range_size_mask calling positionYinghai Lu1-3/+3
Commit 8d57470d x86, mm: setup page table in top-down causes a kernel panic while setting mem=2G. [mem 0x00000000-0x000fffff] page 4k [mem 0x7fe00000-0x7fffffff] page 1G [mem 0x7c000000-0x7fdfffff] page 1G [mem 0x00100000-0x001fffff] page 4k [mem 0x00200000-0x7bffffff] page 2M for last entry is not what we want, we should have [mem 0x00200000-0x3fffffff] page 2M [mem 0x40000000-0x7bffffff] page 1G Actually we merge the continuous ranges with same page size too early. in this case, before merging we have [mem 0x00200000-0x3fffffff] page 2M [mem 0x40000000-0x7bffffff] page 2M after merging them, will get [mem 0x00200000-0x7bffffff] page 2M even we can use 1G page to map [mem 0x40000000-0x7bffffff] that will cause problem, because we already map [mem 0x7fe00000-0x7fffffff] page 1G [mem 0x7c000000-0x7fdfffff] page 1G with 1G page, aka [0x40000000-0x7fffffff] is mapped with 1G page already. During phys_pud_init() for [0x40000000-0x7bffffff], it will not reuse existing that pud page, and allocate new one then try to use 2M page to map it instead, as page_size_mask does not include PG_LEVEL_1G. At end will have [7c000000-0x7fffffff] not mapped, loop in phys_pmd_init stop mapping at 0x7bffffff. That is right behavoir, it maps exact range with exact page size that we ask, and we should explicitly call it to map [7c000000-0x7fffffff] before or after mapping 0x40000000-0x7bffffff. Anyway we need to make sure ranges' page_size_mask correct and consistent after split_mem_range for each range. Fix that by calling adjust_range_size_mask before merging range with same page size. -v2: update change log. -v3: add more explanation why [7c000000-0x7fffffff] is not mapped, and it causes panic. Bisected-by: "Xie, ChanglongX" <changlongx.xie@intel.com> Bisected-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Reported-and-tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1370015587-20835-1-git-send-email-yinghai@kernel.org Cc: <stable@vger.kernel.org> v3.9 Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-05-10x86/mm: Add missing comments for initial kernel direct mappingZhang Yanfei1-1/+18
Two sets of comments were lost during patch-series shuffling: - comments for init_range_memory_mapping() - comments in init_mem_mapping that is helpful for reminding people that the pagetable is setup top-down The comments were written by Yinghai in his patch in: https://lkml.org/lkml/2012/11/28/620 This patch reintroduces them. Originally-From: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/518BC776.7010506@gmail.com [ Tidied it all up a bit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-29mm/x86: use common help functions to free reserved pagesJiang Liu1-4/+1
Use common help functions to free reserved pages. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-06x86, mm: Make sure to find a 2M free block for the first mapped areaYinghai Lu1-3/+2
Henrik reported that his MacAir 3.1 would not boot with | commit 8d57470d8f859635deffe3919d7d4867b488b85a | Date: Fri Nov 16 19:38:58 2012 -0800 | | x86, mm: setup page table in top-down It turns out that we do not calculate the real_end properly: We try to get 2M size with 4K alignment, and later will round down to 2M, so we will get less then 2M for first mapping, in extreme case could be only 4K only. In Henrik's system it has (1M-32K) as last usable rage is [mem 0x7f9db000-0x7fef8fff]. The problem is exposed when EFI booting have several holes and it will force mapping to use PTE instead as we only map usable areas. To fix it, just make it be 2M aligned, so we can be guaranteed to be able to use large pages to map it. Reported-by: Henrik Rydberg <rydberg@euromail.se> Bisected-by: Henrik Rydberg <rydberg@euromail.se> Tested-by: Henrik Rydberg <rydberg@euromail.se> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/CAE9FiQX4nQ7_1kg5RL_vh56rmcSHXUi1ExrZX7CwED4NGMnHfg@mail.gmail.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2013-01-31x86/mm/init.c: Copy ucode from initrd image to kernel memoryFenghua Yu1-0/+10
Before initrd image is freed, copy valid ucode patches from initrd image to kernel memory. The saved ucode will be used to update AP in resume or hotplug. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Link: http://lkml.kernel.org/r/1356075872-3054-12-git-send-email-fenghua.yu@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-01-29x86, kexec, 64bit: Only set ident mapping for ram.Yinghai Lu1-2/+2
We should set mappings only for usable memory ranges under max_pfn Otherwise causes same problem that is fixed by x86, mm: Only direct map addresses that are marked as E820_RAM This patch exposes pfn_mapped array, and only sets ident mapping for ranges in that array. This patch relies on new kernel_ident_mapping_init that could handle existing pgd/pud between different calls. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1359058816-7615-25-git-send-email-yinghai@kernel.org Cc: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-01-29x86, 64bit: Use a #PF handler to materialize early mappings on demandH. Peter Anvin1-1/+2
Linear mode (CR0.PG = 0) is mutually exclusive with 64-bit mode; all 64-bit code has to use page tables. This makes it awkward before we have first set up properly all-covering page tables to access objects that are outside the static kernel range. So far we have dealt with that simply by mapping a fixed amount of low memory, but that fails in at least two upcoming use cases: 1. We will support load and run kernel, struct boot_params, ramdisk, command line, etc. above the 4 GiB mark. 2. need to access ramdisk early to get microcode to update that as early possible. We could use early_iomap to access them too, but it will make code to messy and hard to be unified with 32 bit. Hence, set up a #PF table and use a fixed number of buffers to set up page tables on demand. If the buffers fill up then we simply flush them and start over. These buffers are all in __initdata, so it does not increase RAM usage at runtime. Thus, with the help of the #PF handler, we can set the final kernel mapping from blank, and switch to init_level4_pgt later. During the switchover in head_64.S, before #PF handler is available, we use three pages to handle kernel crossing 1G, 512G boundaries with sharing page by playing games with page aliasing: the same page is mapped twice in the higher-level tables with appropriate wraparound. The kernel region itself will be properly mapped; other mappings may be spurious. early_make_pgtable is using kernel high mapping address to access pages to set page table. -v4: Add phys_base offset to make kexec happy, and add init_mapping_kernel() - Yinghai -v5: fix compiling with xen, and add back ident level3 and level2 for xen also move back init_level4_pgt from BSS to DATA again. because we have to clear it anyway. - Yinghai -v6: switch to init_level4_pgt in init_mem_mapping. - Yinghai -v7: remove not needed clear_page for init_level4_page it is with fill 512,8,0 already in head_64.S - Yinghai -v8: we need to keep that handler alive until init_mem_mapping and don't let early_trap_init to trash that early #PF handler. So split early_trap_pf_init out and move it down. - Yinghai -v9: switchover only cover kernel space instead of 1G so could avoid touch possible mem holes. - Yinghai -v11: change far jmp back to far return to initial_code, that is needed to fix failure that is reported by Konrad on AMD systems. - Yinghai Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1359058816-7615-12-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-01-29x86, mm: Fix page table early allocation offset checkingYinghai Lu1-1/+12
During debugging loading kernel above 4G, found that one page is not used in pre-allocated BRK area for early page allocation. pgt_buf_top is address that can not be used, so should check if that new end is above that top, otherwise last page will not be used. Fix that checking and also add print out for allocation from pre-allocated BRK area to catch possible bugs later. But after we get back that page for pgt, it tiggers one bug in pgt allocation with xen: We need to avoid to use page as pgt to map range that is overlapping with that pgt page. Add checking about overlapping, when it happens, use memblock allocation instead. That fixes crash on Xen PV guest with 2G that Stefan found. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1359058816-7615-2-git-send-email-yinghai@kernel.org Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Tested-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Use clamp_t() in init_range_memory_mappingYinghai Lu1-16/+5
save some lines, and make code more readable. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-42-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Unifying after_bootmem for 32bit and 64bitYinghai Lu1-2/+0
after_bootmem has different meaning in 32bit and 64bit. 32bit: after bootmem is ready 64bit: after bootmem is distroyed Let's merget them make 32bit the same as 64bit. for 32bit, it is mixing alloc_bootmem_pages, and alloc_low_page under after_bootmem is set or not set. alloc_bootmem is just wrapper for memblock for x86. Now we have alloc_low_page() with memblock too. We can drop bootmem path now, and only alloc_low_page only. At the same time, we make alloc_low_page could handle real after_bootmem for 32bit, because alloc_bootmem_pages could fallback to use slab too. At last move after_bootmem set position for 32bit the same as 64bit. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-40-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: use limit_pfn for end pfnYinghai Lu1-9/+11
instead of shifting end to get that. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-39-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: use pfn instead of pos in split_mem_rangeYinghai Lu1-15/+14
could save some bit shifting operations. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-38-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: use PFN_DOWN in split_mem_range()Yinghai Lu1-22/+22
to replace own inline version for shifting. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-37-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: use round_up/down in split_mem_range()Yinghai Lu1-18/+12
to replace own inline version for those roundup and rounddown. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-36-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Move init_gbpages() out of setup.cYinghai Lu1-0/+12
Put it in mm/init.c, and call it from probe_page_mask(). init_mem_mapping is calling probe_page_mask at first. So calling sequence is not changed. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-32-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Move back pgt_buf_* to mm/init.cYinghai Lu1-3/+3
Also change them to static. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-31-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: only call early_ioremap_page_table_range_init() onceYinghai Lu1-8/+5
On 32bit, before patcheset that only set page table for ram, we only call that one time. Now, we are calling that during every init_memory_mapping if we have holes under max_low_pfn. We should only call it one time after all ranges under max_low_page get mapped just like we did before. Also that could avoid the risk to run out of pgt_buf in BRK. Need to update page_table_range_init() to count the pages for kmap page table at first, and use new added alloc_low_pages() to get pages in sequence. That will conform to the requirement that pages need to be in low to high order. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-30-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Add pointer about Xen mmu requirement for alloc_low_pagesStefano Stabellini1-0/+9
Add link for more information 279b706 x86,xen: introduce x86_init.mapping.pagetable_reserve -v2: updated to commets from hpa to include commit name. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-29-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Add alloc_low_pages(num)Yinghai Lu1-12/+21
32bit kmap mapping needs pages to be used for low to high. At this point those pages are still from pgt_buf_* from BRK, so it is ok now. But we want to move early_ioremap_page_table_range_init() out of init_memory_mapping() and only call it one time later, that will make page_table_range_init/page_table_kmap_check/alloc_low_page to use memblock to get page. memblock allocation for pages are from high to low. So will get panic from page_table_kmap_check() that has BUG_ON to do ordering checking. This patch add alloc_low_pages to make it possible to allocate serveral pages at first, and hand out pages one by one from low to high. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-28-git-send-email-yinghai@kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm, Xen: Remove mapping_pagetable_reserve()Yinghai Lu1-4/+0
Page table area are pre-mapped now after x86, mm: setup page table in top-down x86, mm: Remove early_memremap workaround for page table accessing on 64bit mapping_pagetable_reserve is not used anymore, so remove it. Also remove operation in mask_rw_pte(), as modified allow_low_page always return pages that are already mapped, moreover xen_alloc_pte_init, xen_alloc_pmd_init, etc, will mark the page RO before hooking it into the pagetable automatically. -v2: add changelog about mask_rw_pte() from Stefano. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-27-git-send-email-yinghai@kernel.org Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Move min_pfn_mapped back to mm/init.cYinghai Lu1-0/+2
Also change it to static. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-26-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Merge alloc_low_page between 64bit and 32bitYinghai Lu1-0/+34
They are almost same except 64 bit need to handle after_bootmem case. Add mm_internal.h to make that alloc_low_page() only to be accessible from arch/x86/mm/init*.c Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-25-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: setup page table in top-downYinghai Lu1-149/+61
Get pgt_buf early from BRK, and use it to map PMD_SIZE from top at first. Then use mapped pages to map more ranges below, and keep looping until all pages get mapped. alloc_low_page will use page from BRK at first, after that buffer is used up, will use memblock to find and reserve pages for page table usage. Introduce min_pfn_mapped to make sure find new pages from mapped ranges, that will be updated when lower pages get mapped. Also add step_size to make sure that don't try to map too big range with limited mapped pages initially, and increase the step_size when we have more mapped pages on hand. We don't need to call pagetable_reserve anymore, reserve work is done in alloc_low_page() directly. At last we can get rid of calculation and find early pgt related code. -v2: update to after fix_xen change, also use MACRO for initial pgt_buf size and add comments with it. -v3: skip big reserved range in memblock.reserved near end. -v4: don't need fix_xen change now. -v5: add changelog about moving about reserving pagetable to alloc_low_page. Suggested-by: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-22-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Break down init_all_memory_mappingYinghai Lu1-22/+19
Will replace that with top-down page table initialization. New API need to take range: init_range_memory_mapping() Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-21-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Use big page size for small memory rangeYinghai Lu1-0/+37
We could map small range in the middle of big range at first, so should use big page size at first to avoid using small page size to break down page table. Only can set big page bit when that range has ram area around it. -v2: fix 32bit boundary checking. We can not count ram above max_low_pfn for 32 bit. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-19-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Only direct map addresses that are marked as E820_RAMJacob Shin1-11/+109
Currently direct mappings are created for [ 0 to max_low_pfn<<PAGE_SHIFT ) and [ 4GB to max_pfn<<PAGE_SHIFT ), which may include regions that are not backed by actual DRAM. This is fine for holes under 4GB which are covered by fixed and variable range MTRRs to be UC. However, we run into trouble on higher memory addresses which cannot be covered by MTRRs. Our system with 1TB of RAM has an e820 that looks like this: BIOS-e820: [mem 0x0000000000000000-0x00000000000983ff] usable BIOS-e820: [mem 0x0000000000098400-0x000000000009ffff] reserved BIOS-e820: [mem 0x00000000000d0000-0x00000000000fffff] reserved BIOS-e820: [mem 0x0000000000100000-0x00000000c7ebffff] usable BIOS-e820: [mem 0x00000000c7ec0000-0x00000000c7ed7fff] ACPI data BIOS-e820: [mem 0x00000000c7ed8000-0x00000000c7ed9fff] ACPI NVS BIOS-e820: [mem 0x00000000c7eda000-0x00000000c7ffffff] reserved BIOS-e820: [mem 0x00000000fec00000-0x00000000fec0ffff] reserved BIOS-e820: [mem 0x00000000fee00000-0x00000000fee00fff] reserved BIOS-e820: [mem 0x00000000fff00000-0x00000000ffffffff] reserved BIOS-e820: [mem 0x0000000100000000-0x000000e037ffffff] usable BIOS-e820: [mem 0x000000e038000000-0x000000fcffffffff] reserved BIOS-e820: [mem 0x0000010000000000-0x0000011ffeffffff] usable and so direct mappings are created for huge memory hole between 0x000000e038000000 to 0x0000010000000000. Even though the kernel never generates memory accesses in that region, since the page tables mark them incorrectly as being WB, our (AMD) processor ends up causing a MCE while doing some memory bookkeeping/optimizations around that area. This patch iterates through e820 and only direct maps ranges that are marked as E820_RAM, and keeps track of those pfn ranges. Depending on the alignment of E820 ranges, this may possibly result in using smaller size (i.e. 4K instead of 2M or 1G) page tables. -v2: move changes from setup.c to mm/init.c, also use for_each_mem_pfn_range instead. - Yinghai Lu -v3: add calculate_all_table_space_size() to get correct needed page table size. - Yinghai Lu -v4: fix add_pfn_range_mapped() to get correct max_low_pfn_mapped when mem map does have hole under 4g that is found by Konard on xen domU with 8g ram. - Yinghai Signed-off-by: Jacob Shin <jacob.shin@amd.com> Link: http://lkml.kernel.org/r/1353123563-3103-16-git-send-email-yinghai@kernel.org Signed-off-by: Yinghai Lu <yinghai@kernel.org> Reviewed-by: Pekka Enberg <penberg@kernel.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Separate out calculate_table_space_size()Yinghai Lu1-11/+27
It should take physical address range that will need to be mapped. find_early_table_space should take range that pgt buff should be in. Separating page table size calculating and finding early page table to reduce confusing. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-9-git-send-email-yinghai@kernel.org Reviewed-by: Pekka Enberg <penberg@kernel.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Find early page table buffer togetherYinghai Lu1-32/+34
We should not do that in every calling of init_memory_mapping. At the same time need to move down early_memtest, and could remove after_bootmem checking. -v2: fix one early_memtest with 32bit by passing max_pfn_mapped instead. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-8-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Change find_early_table_space() paramtersYinghai Lu1-3/+9
call split_mem_range inside the function. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-7-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Revert back good_end setting for 64bitYinghai Lu1-1/+1
After | commit 8548c84da2f47e71bbbe300f55edb768492575f7 | Author: Takashi Iwai <tiwai@suse.de> | Date: Sun Oct 23 23:19:12 2011 +0200 | | x86: Fix S4 regression | | Commit 4b239f458 ("x86-64, mm: Put early page table high") causes a S4 | regression since 2.6.39, namely the machine reboots occasionally at S4 | resume. It doesn't happen always, overall rate is about 1/20. But, | like other bugs, once when this happens, it continues to happen. | | This patch fixes the problem by essentially reverting the memory | assignment in the older way. Have some page table around 512M again, that will prevent kdump to find 512M under 768M. We need revert that reverting, so we could put page table high again for 64bit. Takashi agreed that S4 regression could be something else. https://lkml.org/lkml/2012/6/15/182 Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-6-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>