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2008-05-20[POWERPC] powerpc/mm/hash_low_32.S: Remove CVS keywordAdrian Bunk
This removes a CVS keyword that wasn't updated for a long time from a comment. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-05-15[POWERPC] vmemmap fixes to use smaller pagesBenjamin Herrenschmidt
This changes vmemmap to use a different region (region 0xf) of the address space, and to configure the page size of that region dynamically at boot. The problem with the current approach of always using 16M pages is that it's not well suited to machines that have small amounts of memory such as small partitions on pseries, or PS3's. In fact, on the PS3, failure to allocate the 16M page backing vmmemmap tends to prevent hotplugging the HV's "additional" memory, thus limiting the available memory even more, from my experience down to something like 80M total, which makes it really not very useable. The logic used by my match to choose the vmemmap page size is: - If 16M pages are available and there's 1G or more RAM at boot, use that size. - Else if 64K pages are available, use that - Else use 4K pages I've tested on a POWER6 (16M pages) and on an iSeries POWER3 (4K pages) and it seems to work fine. Note that I intend to change the way we organize the kernel regions & SLBs so the actual region will change from 0xf back to something else at one point, as I simplify the SLB miss handler, but that will be for a later patch. Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-05-02[POWERPC] Bolt in SLB entry for kernel stack on secondary cpusPaul Mackerras
This fixes a regression reported by Kamalesh Bulabel where a POWER4 machine would crash because of an SLB miss at a point where the SLB miss exception was unrecoverable. This regression is tracked at: http://bugzilla.kernel.org/show_bug.cgi?id=10082 SLB misses at such points shouldn't happen because the kernel stack is the only memory accessed other than things in the first segment of the linear mapping (which is mapped at all times by entry 0 of the SLB). The context switch code ensures that SLB entry 2 covers the kernel stack, if it is not already covered by entry 0. None of entries 0 to 2 are ever replaced by the SLB miss handler. Where this went wrong is that the context switch code assumes it doesn't have to write to SLB entry 2 if the new kernel stack is in the same segment as the old kernel stack, since entry 2 should already be correct. However, when we start up a secondary cpu, it calls slb_initialize, which doesn't set up entry 2. This is correct for the boot cpu, where we will be using a stack in the kernel BSS at this point (i.e. init_thread_union), but not necessarily for secondary cpus, whose initial stack can be allocated anywhere. This doesn't cause any immediate problem since the SLB miss handler will just create an SLB entry somewhere else to cover the initial stack. In fact it's possible for the cpu to go quite a long time without SLB entry 2 being valid. Eventually, though, the entry created by the SLB miss handler will get overwritten by some other entry, and if the next access to the stack is at an unrecoverable point, we get the crash. This fixes the problem by making slb_initialize create a suitable entry for the kernel stack, if we are on a secondary cpu and the stack isn't covered by SLB entry 0. This requires initializing the get_paca()->kstack field earlier, so I do that in smp_create_idle where the current field is initialized. This also abstracts a bit of the computation that mk_esid_data in slb.c does so that it can be used in slb_initialize. Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-05-02[POWERPC] Fix slb.c compile warningsGeoff Levand
Arrange for a syntax check to always be done on the powerpc/mm/slb.c DBG() macro by defining it to pr_debug() for non-debug builds. Also, fix these related compile warnings: slb.c:273: warning: format '%04x' expects type 'unsigned int', but argument 2 has type 'long unsigned int slb.c:274: warning: format '%04x' expects type 'unsigned int', but argument 2 has type 'long unsigned int' Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-29[POWERPC] Provide walk_memory_resource() for powerpcBadari Pulavarty
Provide walk_memory_resource() for 64-bit powerpc. PowerPC maintains logical memory region mapping in the lmb.memory structure. Walk through these structures and do the callbacks for the contiguous chunks. Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-28hotplug-memory: make online_page() commonJeremy Fitzhardinge
All architectures use an effectively identical definition of online_page(), so just make it common code. x86-64, ia64, powerpc and sh are actually identical; x86-32 is slightly different. x86-32's differences arise because it puts its hotplug pages in the highmem zone. We can handle this in the generic code by inspecting the page to see if its in highmem, and update the totalhigh_pages count appropriately. This leaves init_32.c:free_new_highpage with a single caller, so I folded it into add_one_highpage_init. I also removed an incorrect comment referring to the NUMA case; any NUMA details have already been dealt with by the time online_page() is called. [akpm@linux-foundation.org: fix indenting] Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Dave Hansen <dave@linux.vnet.ibm.com> Reviewed-by: KAMEZAWA Hiroyuki <kamez.hiroyu@jp.fujitsu.com> Tested-by: KAMEZAWA Hiroyuki <kamez.hiroyu@jp.fujitsu.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Christoph Lameter <clameter@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-24[POWERPC] Clean up access to thread_info in assemblyKumar Gala
Use (31-THREAD_SHIFT) to get to thread_info from stack pointer. This makes the code a bit easier to read and more robust if we ever change THREAD_SHIFT. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-24[POWERPC] Port fixmap from x86 and use for kmap_atomicKumar Gala
The fixmap code from x86 allows us to have compile time virtual addresses that we change the physical addresses of at run time. This is useful for applications like kmap_atomic, PCI config that is done via direct memory map, kexec/kdump. We got ride of CONFIG_HIGHMEM_START as we can now determine a more optimal location for PKMAP_BASE based on where the fixmap addresses start and working back from there. Additionally, the kmap code in asm-powerpc/highmem.h always had debug enabled. Moved to using CONFIG_DEBUG_HIGHMEM to determine if we should have the extra debug checking. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-24[POWERPC] 85xx: Add support for relocatable kernel (and booting at non-zero)Kumar Gala
Added support to allow an 85xx kernel to be run from a non-zero physical address (useful for cooperative asymmetric multiprocessing situations and kdump). The support can be configured at compile time by setting CONFIG_PAGE_OFFSET, CONFIG_KERNEL_START, and CONFIG_PHYSICAL_START as desired. Alternatively, the kernel build can set CONFIG_RELOCATABLE. Setting this config option causes the kernel to determine at runtime the physical addresses of CONFIG_PAGE_OFFSET and CONFIG_KERNEL_START. If CONFIG_RELOCATABLE is set, then CONFIG_PHYSICAL_START has no meaning. However, CONFIG_PHYSICAL_START will always be used to set the LOAD program header physical address field in the resulting ELF image. Currently we are limited to running at a physical address that is a multiple of 256M. This is due to how we map TLBs to cover lowmem. This should be fixed to allow 64M or maybe even 16M alignment in the future. It is considered an error to try and run a kernel at a non-aligned physical address. All the magic for this support is accomplished by proper initialization of the kernel memory subsystem and use of ARCH_PFN_OFFSET. The use of ARCH_PFN_OFFSET only affects normal memory and not IO mappings. ioremap uses map_page and isn't affected by ARCH_PFN_OFFSET. /dev/mem continues to allow access to any physical address in the system regardless of how CONFIG_PHYSICAL_START is set. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-24[POWERPC] Add include of linux/of.h to numa.cMichael Ellerman
numa.c requires routines declared in linux/of.h, so should include it. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-18[POWERPC] Remove unused __max_memory variableOlof Johansson
Remove the __max_memory variable, as it is not referenced anywhere in the tree besides some code in arch/ppc. Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-17[POWERPC] Remove unused machine call outsKumar Gala
When we moved to arch/powerpc we actively tried to avoid using the ppc_md.setup_io_mappings(). Currently no board ports use it so let's remove it to avoid any new boards using it. Also, remove early_serial_map() since we don't even have a call out for it in arch/powerpc. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-17[POWERPC] Rename __initial_memory_limit to __initial_memory_limit_addrKumar Gala
We always use __initial_memory_limit as an address so rename it to be clear. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-17[POWERPC] 85xx: Cleanup TLB initializationKumar Gala
* Determine the RPN we are running the kernel at runtime rather than using compile time constant for initial TLB * Cleanup adjust_total_lowmem() to respect memstart_addr and be a bit more clear on variables that are sizes vs addresses. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-17[POWERPC] Introduce lowmem_end_addr to distinguish from total_lowmemKumar Gala
total_lowmem represents the amount of low memory, not the physical address that low memory ends at. If the start of memory is at 0 it happens that total_lowmem can be used as both the size and the address that lowmem ends at (or more specifically one byte beyond the end). To make the code a bit more clear and deal with the case when the start of memory isn't at physical 0, we introduce lowmem_end_addr that represents one byte beyond the last physical address in the lowmem region. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-17[POWERPC] Remove and replace uses of PPC_MEMSTART with memstart_addrKumar Gala
A number of users of PPC_MEMSTART (40x, ppc_mmu_32) can just always use 0 as we don't support booting these kernels at non-zero physical addresses since their exception vectors must be at 0 (or 0xfffx_xxxx). For the sub-arches that support relocatable interrupt vectors (book-e), it's reasonable to have memory start at a non-zero physical address. For those cases use the variable memstart_addr instead of the #define PPC_MEMSTART since the only uses of PPC_MEMSTART are for initialization and in the future we can set memstart_addr at runtime to have a relocatable kernel. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-14Merge branch 'linux-2.6'Paul Mackerras
2008-04-07[POWERPC] htab_remove_mapping is only used by MEMORY_HOTPLUGStephen Rothwell
This eliminates a warning in builds that don't define CONFIG_MEMORY_HOTPLUG. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-03[POWERPC] Fix deadlock with mmu_hash_lock in hash_page_syncBenjamin Herrenschmidt
hash_page_sync() takes and releases the low level mmu hash lock in order to sync with other processors disposing of page tables. Because that lock can be needed to service hash misses triggered by interrupt handlers, taking it must be done with interrupts off. However, hash_page_sync() appears to be called with interrupts enabled, thus causing occasional deadlocks. We fix it by making sure hash_page_sync() masks interrupts while holding the lock. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-01[POWERPC] Remove redundant display of free swap space in show_mem()Johannes Weiner
show_mem() has no need to print the amount of free swap space manually because show_free_areas() does this already and is called by the former. The two outputs only differ in text formatting: printk("Free swap = %lukB\n", ...); printk("Free swap: %6ldkB\n", ...); Signed-off-by: Johannes Weiner <hannes@saeurebad.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-01[POWERPC] Replace remaining __FUNCTION__ occurrencesHarvey Harrison
__FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-01[POWERPC] arch_add_memory() cannot be __devinitGeert Uytterhoeven
WARNING: vmlinux.o(.text+0xb41b0): Section mismatch in reference from the function .add_memory() to the function .devinit.text:.arch_add_memory() The function .add_memory() references the function __devinit .arch_add_memory(). This is often because .add_memory lacks a __devinit annotation or the annotation of .arch_add_memory is wrong. arch_add_memory() is also not __devinit on other architectures Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-01[POWERPC] Add error return from htab_remove_mapping()Badari Pulavarty
If the platform doesn't support hpte_removebolted(), gracefully return failure rather than success. Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-03-26Merge branch 'linux-2.6'Paul Mackerras
2008-03-24[POWERPC] Don't use 64k pages for ioremap on pSeriesPaul Mackerras
On pSeries, the hypervisor doesn't let us map in the eHEA ethernet adapter using 64k pages, and thus the ehea driver will fail if 64k pages are configured. This works around the problem by always using 4k pages for ioremap on pSeries (but not on other platforms). A better fix would be to check whether the partition could ever have an eHEA adapter, and only force 4k pages if it could, but this will do for 2.6.25. This is based on an earlier patch by Tony Breeds. Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-03-20[POWERPC] Fix PMU + soft interrupt disable bugAnton Blanchard
Since the PMU is an NMI now, it can come at any time we are only soft disabled. We must hard disable around the two places we allow the kernel stack SLB and r1 to go out of sync. Otherwise the PMU exception can force a kernel stack SLB into another slot, which can lead to it getting evicted, which can lead to a nasty unrecoverable SLB miss in the exception entry code. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-03-13Merge branch 'linux-2.6'Paul Mackerras
2008-03-13[POWERPC] Fix large hash table allocation on Cell bladesMichael Ellerman
My recent hack to allocate the hash table under 1GB on cell was poorly tested, *cough*. It turns out on blades with large amounts of memory we fail to allocate the hash table at all. This is because RTAS has been instantiated just below 768MB, and 0-x MB are used by the kernel, leaving no areas that are both large enough and also naturally-aligned. For the cell IOMMU hack the page tables must be under 2GB, so use that as the limit instead. This has been tested on real hardware and boots happily. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-02-26[POWERPC] Add code for removing HPTEs for parts of the linear mappingBadari Pulavarty
For memory remove, we need to clean up htab mappings for the section of the memory we are removing. This implements support for removing htab bolted mappings for pSeries logical partitions. Other sub-archs may need to implement similar functionality for hotplug memory remove to work on them. Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-02-13[LIB]: Make PowerPC LMB code generic so sparc64 can use it too.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-02-08Merge branch 'for-2.6.25' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc * 'for-2.6.25' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: [POWERPC] Add arch-specific walk_memory_remove() for 64-bit powerpc [POWERPC] Enable hotplug memory remove for 64-bit powerpc [POWERPC] Add remove_memory() for 64-bit powerpc [POWERPC] Make cell IOMMU fixed mapping printk more useful [POWERPC] Fix potential cell IOMMU bug when switching back to default DMA ops [POWERPC] Don't enable cell IOMMU fixed mapping if there are no dma-ranges [POWERPC] Fix cell IOMMU null pointer explosion on old firmwares [POWERPC] spufs: Fix timing dependent false return from spufs_run_spu [POWERPC] spufs: No need to have a runnable SPU for libassist update [POWERPC] spufs: Update SPU_Status[CISHP] in backing runcntl write [POWERPC] spufs: Fix state_mutex leaks [POWERPC] Disable G5 NAP mode during SMU commands on U3
2008-02-08CONFIG_HIGHPTE vs. sub-page page tables.Martin Schwidefsky
Background: I've implemented 1K/2K page tables for s390. These sub-page page tables are required to properly support the s390 virtualization instruction with KVM. The SIE instruction requires that the page tables have 256 page table entries (pte) followed by 256 page status table entries (pgste). The pgstes are only required if the process is using the SIE instruction. The pgstes are updated by the hardware and by the hypervisor for a number of reasons, one of them is dirty and reference bit tracking. To avoid wasting memory the standard pte table allocation should return 1K/2K (31/64 bit) and 2K/4K if the process is using SIE. Problem: Page size on s390 is 4K, page table size is 1K or 2K. That means the s390 version for pte_alloc_one cannot return a pointer to a struct page. Trouble is that with the CONFIG_HIGHPTE feature on x86 pte_alloc_one cannot return a pointer to a pte either, since that would require more than 32 bit for the return value of pte_alloc_one (and the pte * would not be accessible since its not kmapped). Solution: The only solution I found to this dilemma is a new typedef: a pgtable_t. For s390 pgtable_t will be a (pte *) - to be introduced with a later patch. For everybody else it will be a (struct page *). The additional problem with the initialization of the ptl lock and the NR_PAGETABLE accounting is solved with a constructor pgtable_page_ctor and a destructor pgtable_page_dtor. The page table allocation and free functions need to call these two whenever a page table page is allocated or freed. pmd_populate will get a pgtable_t instead of a struct page pointer. To get the pgtable_t back from a pmd entry that has been installed with pmd_populate a new function pmd_pgtable is added. It replaces the pmd_page call in free_pte_range and apply_to_pte_range. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08[POWERPC] Add arch-specific walk_memory_remove() for 64-bit powerpcBadari Pulavarty
walk_memory_resource() verifies if there are holes in a given memory range, by checking against /proc/iomem. On x86/ia64 system memory is represented in /proc/iomem. On powerpc, we don't show system memory as IO resource in /proc/iomem - instead it's maintained in /proc/device-tree. This provides a way for an architecture to provide its own walk_memory_resource() function. On powerpc, the memory region is small (16MB), contiguous and non-overlapping. So extra checking against the device-tree is not needed. Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Kumar Gala <galak@gate.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-02-08[POWERPC] Add remove_memory() for 64-bit powerpcBadari Pulavarty
Supply remove_memory() function for 64-bit powerpc. This is still not quite complete as it needs to do some more arch-specific stuff, which will be added in a later patch. Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-02-07Merge branch 'for-2.6.25' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc * 'for-2.6.25' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (69 commits) [POWERPC] Add SPE registers to core dumps [POWERPC] Use regset code for compat PTRACE_*REGS* calls [POWERPC] Use generic compat_sys_ptrace [POWERPC] Use generic compat_ptrace_request [POWERPC] Use generic ptrace peekdata/pokedata [POWERPC] Use regset code for PTRACE_*REGS* requests [POWERPC] Switch to generic compat_binfmt_elf code [POWERPC] Switch to using user_regset-based core dumps [POWERPC] Add user_regset compat support [POWERPC] Add user_regset_view definitions [POWERPC] Use user_regset accessors for GPRs [POWERPC] ptrace accessors for special regs MSR and TRAP [POWERPC] Use user_regset accessors for SPE regs [POWERPC] Use user_regset accessors for altivec regs [POWERPC] Use user_regset accessors for FP regs [POWERPC] mpc52xx: fix compile error introduce when rebasing patch [POWERPC] 4xx: PCIe indirect DCR spinlock fix. [POWERPC] Add missing native dcr dcr_ind_lock spinlock [POWERPC] 4xx: Fix offset value on Warp board [POWERPC] 4xx: Add 440EPx Sequoia ehci dts entry ...
2008-02-07Introduce flags for reserve_bootmem()Bernhard Walle
This patchset adds a flags variable to reserve_bootmem() and uses the BOOTMEM_EXCLUSIVE flag in crashkernel reservation code to detect collisions between crashkernel area and already used memory. This patch: Change the reserve_bootmem() function to accept a new flag BOOTMEM_EXCLUSIVE. If that flag is set, the function returns with -EBUSY if the memory already has been reserved in the past. This is to avoid conflicts. Because that code runs before SMP initialisation, there's no race condition inside reserve_bootmem_core(). [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix powerpc build] Signed-off-by: Bernhard Walle <bwalle@suse.de> Cc: <linux-arch@vger.kernel.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07[POWERPC] Fake NUMA emulation for PowerPCBalbir Singh
Here's a dumb simple implementation of fake NUMA nodes for PowerPC. Fake NUMA nodes can be specified using the following command line option numa=fake=<node range> node range is of the format <range1>,<range2>,...<rangeN> Each of the rangeX parameters is passed using memparse(). I find the patch useful for fake NUMA emulation on my simple PowerPC machine. I've tested it on a numa box with the following arguments numa=fake=512M numa=fake=512M,768M numa=fake=256M,512M mem=512M numa=fake=1G mem=768M numa=fake= without any numa= argument The other side-effect introduced by this patch is that; in the case where we don't have NUMA information, we now set a node online after adding each LMB. This node could very well be node 0, but in the case that we enable fake NUMA nodes, when we cross node boundaries, we need to set the new node online. Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-02-06[POWERPC] update_mmu_cache: Don't cache-flush non-readable pagesScott Wood
Currently, update_mmu_cache will crash if given a no-access PTE. There's no need to synchronize dcache/icache unless it's an exec mapping -- however, due to the existence of older glibc versions that execute out of a read-but-no-exec page, readability is tested instead. This assumes no exec-only mappings; if such mappings become supported, they will need to go through the kmap_atomic() version of dcache/icache synchronization. This fixes a bug reported by some users where the kernel would crash while dumping core on a threaded program. Signed-off-by: Scott Wood <scottwood@freescale.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-02-05add mm argument to pte/pmd/pud/pgd_freeBenjamin Herrenschmidt
(with Martin Schwidefsky <schwidefsky@de.ibm.com>) The pgd/pud/pmd/pte page table allocation functions get a mm_struct pointer as first argument. The free functions do not get the mm_struct argument. This is 1) asymmetrical and 2) to do mm related page table allocations the mm argument is needed on the free function as well. [kamalesh@linux.vnet.ibm.com: i386 fix] [akpm@linux-foundation.org: coding-syle fixes] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-31[POWERPC] Allocate the hash table under 1G on cellMichael Ellerman
In order to support the fixed IOMMU mapping (in a subsequent patch), we need the hash table to be inside the IOMMUs DMA window. This is usually 2G, but let's make sure the hash table is under 1G as that will satisfy the IOMMU requirements and also means the hash table will be on node 0. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-26Revert "[POWERPC] Fake NUMA emulation for PowerPC"Paul Mackerras
This reverts commit 5c3f5892a2db6757a72ce8b27cba90db06683e1d, basically because it changes behaviour even when no fake NUMA information is specified on the kernel command line. Firstly, it changes the nid, thus destroying the real NUMA information. Secondly, it also changes behaviour in that if a node ends up with no memory in it because of the memory limit, we used to set it online and now we don't. Also, in the non-NUMA case with no fake NUMA information, we do node_set_online once for each LMB now, whereas previously we only did it once. I don't know if that is actually a problem, but it does seem unnecessary. Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-25[POWERPC] Make setjmp/longjmp code usable outside of xmonMichael Neuling
This makes the setjmp/longjmp code used by xmon, generically available to other code. It also removes the requirement for debugger hooks to be only called on 0x300 (data storage) exception. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-24Merge branch 'for-2.6.25' of ↵Paul Mackerras
master.kernel.org:/pub/scm/linux/kernel/git/galak/powerpc into for-2.6.25
2008-01-23[POWERPC] 85xx: Respect KERNELBASE, PAGE_OFFSET, and PHYSICAL_START on e500Dale Farnsworth
The e500 MMU init code previously assumed KERNELBASE always equaled PAGE_OFFSET and PHYSICAL_START was 0. This is useful for kdump support as well as asymetric multicore. For the initial kdump support the secondary kernel will run at 32M but need access to all of memory so we bump the initial TLB up to 64M. This also matches with the forth coming ePAPR spec. Signed-off-by: Dale Farnsworth <dale@farnsworth.org> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2008-01-23[POWERPC] Fix handling of memreserve if the range lands in highmemKumar Gala
There were several issues if a memreserve range existed and happened to be in highmem: * The bootmem allocator is only aware of lowmem so calling reserve_bootmem with a highmem address would cause a BUG_ON * All highmem pages were provided to the buddy allocator Added a lmb_is_reserved() api that we now use to determine if a highem page should continue to be PageReserved or provided to the buddy allocator. Also, we incorrectly reported the amount of pages reserved since all highmem pages are initally marked reserved and we clear the PageReserved flag as we "free" up the highmem pages. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2008-01-24Merge branch 'linux-2.6'Paul Mackerras
2008-01-24[POWERPC] Provide a way to protect 4k subpages when using 64k pagesPaul Mackerras
Using 64k pages on 64-bit PowerPC systems makes life difficult for emulators that are trying to emulate an ISA, such as x86, which use a smaller page size, since the emulator can no longer use the MMU and the normal system calls for controlling page protections. Of course, the emulator can emulate the MMU by checking and possibly remapping the address for each memory access in software, but that is pretty slow. This provides a facility for such programs to control the access permissions on individual 4k sub-pages of 64k pages. The idea is that the emulator supplies an array of protection masks to apply to a specified range of virtual addresses. These masks are applied at the level where hardware PTEs are inserted into the hardware page table based on the Linux PTEs, so the Linux PTEs are not affected. Note that this new mechanism does not allow any access that would otherwise be prohibited; it can only prohibit accesses that would otherwise be allowed. This new facility is only available on 64-bit PowerPC and only when the kernel is configured for 64k pages. The masks are supplied using a new subpage_prot system call, which takes a starting virtual address and length, and a pointer to an array of protection masks in memory. The array has a 32-bit word per 64k page to be protected; each 32-bit word consists of 16 2-bit fields, for which 0 allows any access (that is otherwise allowed), 1 prevents write accesses, and 2 or 3 prevent any access. Implicit in this is that the regions of the address space that are protected are switched to use 4k hardware pages rather than 64k hardware pages (on machines with hardware 64k page support). In fact the whole process is switched to use 4k hardware pages when the subpage_prot system call is used, but this could be improved in future to switch only the affected segments. The subpage protection bits are stored in a 3 level tree akin to the page table tree. The top level of this tree is stored in a structure that is appended to the top level of the page table tree, i.e., the pgd array. Since it will often only be 32-bit addresses (below 4GB) that are protected, the pointers to the first four bottom level pages are also stored in this structure (each bottom level page contains the protection bits for 1GB of address space), so the protection bits for addresses below 4GB can be accessed with one fewer loads than those for higher addresses. Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-17[POWERPC] Add hugepagesz boot-time parameterJon Tollefson
This adds the hugepagesz boot-time parameter for ppc64. It lets one pick the size for huge pages. The choices available are 64K and 16M when the base page size is 4k. It defaults to 16M (previously the only only choice) if nothing or an invalid choice is specified. Tested 64K huge pages successfully with the libhugetlbfs 1.2. Signed-off-by: Jon Tollefson <kniht@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-15[POWERPC] Fix boot failure on POWER6Paul Mackerras
Commit 473980a99316c0e788bca50996375a2815124ce1 added a call to clear the SLB shadow buffer before registering it. Unfortunately this means that we clear out the entries that slb_initialize has previously set in there. On POWER6, the hypervisor uses the SLB shadow buffer when doing partition switches, and that means that after the next partition switch, each non-boot CPU has no SLB entries to map the kernel text and data, which causes it to crash. This fixes it by reverting most of 473980a9 and instead clearing the 3rd entry explicitly in slb_initialize. This fixes the problem that 473980a9 was trying to solve, but without breaking POWER6. Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-11[POWERPC] Fix CPU hotplug when using the SLB shadow bufferMichael Neuling
Before we register the SLB shadow buffer, we need to invalidate the entries in the buffer, otherwise we can end up stale entries from when we previously offlined the CPU. This does this invalidate as well as unregistering the buffer with PHYP before we offline the cpu. Tested and fixes crashes seen on 970MP (thanks to tonyb) and POWER5. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>