wireguard-linux/include/asm-um/pgtable.h, branch stable

x86, um: initial part of asm-um move

2008-10-23T05:55:19Z

Signed-off-by: Al Viro Signed-off-by: H. Peter Anvin

mm: introduce pte_special pte bit

2008-04-28T15:58:23Z

s390 for one, cannot implement VM_MIXEDMAP with pfn_valid, due to their memory model (which is more dynamic than most). Instead, they had proposed to implement it with an additional path through vm_normal_page(), using a bit in the pte to determine whether or not the page should be refcounted: vm_normal_page() { ... if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) { if (vma->vm_flags & VM_MIXEDMAP) { #ifdef s390 if (!mixedmap_refcount_pte(pte)) return NULL; #else if (!pfn_valid(pfn)) return NULL; #endif goto out; } ... } This is fine, however if we are allowed to use a bit in the pte to determine refcountedness, we can use that to _completely_ replace all the vma based schemes. So instead of adding more cases to the already complex vma-based scheme, we can have a clearly seperate and simple pte-based scheme (and get slightly better code generation in the process): vm_normal_page() { #ifdef s390 if (!mixedmap_refcount_pte(pte)) return NULL; return pte_page(pte); #else ... #endif } And finally, we may rather make this concept usable by any architecture rather than making it s390 only, so implement a new type of pte state for this. Unfortunately the old vma based code must stay, because some architectures may not be able to spare pte bits. This makes vm_normal_page a little bit more ugly than we would like, but the 2 cases are clearly seperate. So introduce a pte_special pte state, and use it in mm/memory.c. It is currently a noop for all architectures, so this doesn't actually result in any compiled code changes to mm/memory.o. BTW: I haven't put vm_normal_page() into arch code as-per an earlier suggestion. The reason is that, regardless of where vm_normal_page is actually implemented, the *abstraction* is still exactly the same. Also, while it depends on whether the architecture has pte_special or not, that is the only two possible cases, and it really isn't an arch specific function -- the role of the arch code should be to provide primitive functions and accessors with which to build the core code; pte_special does that. We do not want architectures to know or care about vm_normal_page itself, and we definitely don't want them being able to invent something new there out of sight of mm/ code. If we made vm_normal_page an arch function, then we have to make vm_insert_mixed (next patch) an arch function too. So I don't think moving it to arch code fundamentally improves any abstractions, while it does practically make the code more difficult to follow, for both mm and arch developers, and easier to misuse. [akpm@linux-foundation.org: build fix] Signed-off-by: Nick Piggin Acked-by: Carsten Otte Cc: Jared Hulbert Cc: Martin Schwidefsky Cc: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

uml: 64-bit tlb fixes

2008-02-05T17:44:29Z

Some 64-bit tlb fixes - moved pmd_page_vaddr to pgtable.h since it's the same for both 2-level and 3-level page tables fixed a bogus cast on pud_page_vaddr made the address checking in update_*_range more careful Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

uml: add virt_to_pte

2008-02-05T17:44:28Z

Turn um_virt_to_phys into virt_to_pte, cleaning up a horrid interface. It's also made non-static and declared in pgtable.h because it'll be needed when the stubs get a vma. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

uml: fix page table data sizes

2008-02-05T17:44:28Z

Get the sizes of various pieces of data right when using three-level page tables. pgd and pmd entries remain at 32 bits in a 32-bit compilation because page tables will remain in low memory. So, PGDIR_SHIFT, the PTRS_PER_* values, set_pud, set_pmd are conditional on 64BIT. More use of phys_t is made when there are physical memory addresses floating around. ObCheckpatchViolationJustification - the new typedef is an alternate definition of pmd_t, which I can't really live without. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

uml: header untangling

2008-02-05T17:44:28Z

Untangle UML headers somewhat and add some includes where they were needed explicitly, but gotten accidentally via some other header. arch/um/include/um_uaccess.h loses asm/fixmap.h because it uses no fixmap stuff and gains elf.h, because it needs FIXADDR_USER_*, and archsetjmp.h, because it needs jmp_buf. pmd_alloc_one is uninlined because it needs mm_struct, and that's inconvenient to provide in asm-um/pgtable-3level.h. elf_core_copy_fpregs is also uninlined from elf-i386.h and elf-x86_64.h, which duplicated the code anyway, to arch/um/kernel/process.c, so that the reference to current_thread doesn't pull sched.h or anything related into asm/elf.h. arch/um/sys-i386/ldt.c, arch/um/kernel/tlb.c and arch/um/kernel/skas/uaccess.c got sched.h because they dereference task_structs. Its includes of linux and asm headers got turned from "" to <>. arch/um/sys-i386/bug.c gets asm/errno.h because it needs errno constants. asm/elf-i386 gets asm/user.h because it needs user_regs_struct. asm/fixmap.h gets page.h because it needs PAGE_SIZE and PAGE_MASK and system.h for BUG_ON. asm/pgtable doesn't need sched.h. asm/processor-generic.h defined mm_segment_t, but didn't use it. So, that definition is moved to uaccess.h, which defines a bunch of mm_segment_t-related stuff. thread_info.h uses mm_segment_t, and includes uaccess.h, which causes a recursion. So, the definition is placed above the include of thread_info. in uaccess.h. thread_info.h also gets page.h because it needs PAGE_SIZE. ObCheckpatchViolationJustification - I'm not adding a typedef; I'm moving mm_segment_t from one place to another. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

uml: move um_virt_to_phys

2008-02-05T17:44:28Z

This patchset makes UML build and run with three-level page tables on 32-bit hosts. This is an uncommon use case, but the code here needed fixing and cleaning up, so 32-bit three-level pages tables were tested to make sure the changes are good. Patch 1 - code movement Patch 2 - header untangling Patch 3 - style fixups in files affected so far Patch 4 - clean up use of current.h Patch 5 - fix sizes of types that are different between 2 and 3-level page tables - three-level page table support should build at this point Patch 6 - tidy (i.e. eliminate much of) the code that figures out how big the address space is Patch 7 - change um_virt_to_phys into virt_to_pte, clean its interface, and clean its (so far) one caller Patch 8 - the stub pages are covered with a VMA, allowing some nasty code to be thrown out - three-level page tables now work This patch: um_virt_to_phys only has one user, so it can be moved to the same file and made static. Its declarations in pgtable.h and ksyms.c are also gone. current_cmd was another apparent user, but it itself isn't used, so it is deleted. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

UML - Fix build in 2.6.24-rc2-mm1

2008-02-05T17:44:26Z

The earlier pgtable.h tidying patch made things a bit too tidy. Add back a header which is needed in VMALLOC_START and friend. Also add back a definition of pmd_page_vaddr, which is needed on x86_64. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

uml: tidy pgtable.h

2008-02-05T17:44:26Z

Large pieces of include/asm/pgtable.h were unused cruft. This uncovered arch/um/kernel/trap.c needing skas.h in order to get ptrace_faultinfo. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

page table handling cleanup

2007-07-16T16:05:36Z

Kill pte_rdprotect(), pte_exprotect(), pte_mkread(), pte_mkexec(), pte_read(), pte_exec(), and pte_user() except where arch-specific code is making use of them. Signed-off-by: Jan Beulich Cc: Andi Kleen Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds