linux/include/asm-um, branch v2.6.26.4

uml: activate_mm: remove the dead PF_BORROWED_MM check

2008-06-06T18:36:22Z

use_mm() was changed to use switch_mm() instead of activate_mm(), since then nobody calls (and nobody should call) activate_mm() with PF_BORROWED_MM bit set. As Jeff Dike pointed out, we can also remove the "old != new" check, it is always true. Signed-off-by: Oleg Nesterov Cc: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

asm-{alpha,h8300,um,v850,xtensa}/param.h: unbreak HZ for userspace

2008-05-15T02:11:14Z

I noticed this because alpha was broken due to the recent commit commit bdc807871d58285737d50dc6163d0feb72cb0dc2 ("avoid overflows in kernel/time.c"). Most arches do something like this in their asm/param.h: #ifdef __KERNEL__ # define HZ CONFIG_HZ #else # define HZ 100 #endif A few arches though (namely alpha/h8300/um/v850/xtensa) either do no set HZ at all for !__KERNEL__, or they set it wrongly. This should bring all arches in line by setting up HZ for userspace. Without this currently perl 5.10 doesn't build on alpha: perl.c: In function 'perl_construct': perl.c:388: error: 'CONFIG_HZ' undeclared (first use in this function) -> http://buildd.debian.org/fetch.cgi?pkg=perl;ver=5.10.0-10;arch=alpha;stamp=1210252894 Signed-off-by: Mike Frysinger Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Yoshinori Sato Cc: Jeff Dike Cc: Chris Zankel Cc: maximilian attems Signed-off-by: Andrew Morton [ HZ on alpha is 1024 for historical reasons. - Linus ] Signed-off-by: Linus Torvalds

uml: random driver fixes

2008-05-13T15:02:22Z

The random driver would essentially hang if the host's /dev/random returned -EAGAIN. There was a test of need_resched followed by a schedule inside the loop, but that didn't help and it's the wrong way to work anyway. The right way is to ask for an interrupt when there is input available from the host and handle it then rather than polling. Now, when the host's /dev/random returns -EAGAIN, the driver asks for a wakeup when there's randomness available again and sleeps. The interrupt routine just wakes up whatever processes are sleeping on host_read_wait. There is an atomic_t, host_sleep_count, which counts the number of processes waiting for randomness. When this reaches zero, the interrupt is disabled. An added complication is that async I/O notification was only recently added to /dev/random (by me), so essentially all hosts will lack it. So, we use the sigio workaround here, which is to have a separate thread poll on the descriptor and send an interrupt when there is input on it. This mechanism is activated when a process gets -EAGAIN (activating this multiple times is harmless, if a bit wasteful) and deactivated by the last process still waiting. The module name was changed from "random" to "hw_random" in order for udev to recognize it. The sigio workaround needed some changes. sigio_broken was added for cases when we know that async notification doesn't work. This is now called from maybe_sigio_broken, which deals with pts devices. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

uml: use PAGE_SIZE in linker scripts

2008-05-13T15:02:22Z

This patch includes page.h header into linker scripts that allow us to use PAGE_SIZE macro instead of numeric constant. To be able to include page.h into linker scripts page.h is needed for some modification - i.e. we need to use __ASSEMBLY__ and _AC macro [jdike@linux.intel.com - fixed conflict with as-layout.h] Signed-off-by: Cyrill Gorcunov Signed-off-by: Jeff Dike Cc: WANG Cong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

uml: remove unused header

2008-05-13T15:02:22Z

From: Adrian Bunk This patch removes the unused and broken (the normal asm/keyboard.h files no longer exists) include/asm-um/keyboard.h Signed-off-by: Adrian Bunk Signed-off-by: Jeff Dike Cc: WANG Cong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

rename div64_64 to div64_u64

2008-05-01T15:03:58Z

Rename div64_64 to div64_u64 to make it consistent with the other divide functions, so it clearly includes the type of the divide. Move its definition to math64.h as currently no architecture overrides the generic implementation. They can still override it of course, but the duplicated declarations are avoided. Signed-off-by: Roman Zippel Cc: Avi Kivity Cc: Russell King Cc: Geert Uytterhoeven Cc: Ralf Baechle Cc: David Howells Cc: Jeff Dike Cc: Ingo Molnar Cc: "David S. Miller" Cc: Patrick McHardy Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernel: Move arches to use common unaligned access

2008-04-29T15:06:27Z

Unaligned access is ok for the following arches: cris, m68k, mn10300, powerpc, s390, x86 Arches that use the memmove implementation for native endian, and the byteshifting for the opposite endianness. h8300, m32r, xtensa Packed struct for native endian, byteshifting for other endian: alpha, blackfin, ia64, parisc, sparc, sparc64, mips, sh m86knommu is generic_be for Coldfire, otherwise unaligned access is ok. frv, arm chooses endianness based on compiler settings, uses the byteshifting versions. Remove the unaligned trap handler from frv as it is now unused. v850 is le, uses the byteshifting versions for both be and le. Remove the now unused asm-generic implementation. Signed-off-by: Harvey Harrison Acked-by: David S. Miller Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

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

Generic semaphore implementation

2008-04-17T14:42:34Z

Semaphores are no longer performance-critical, so a generic C implementation is better for maintainability, debuggability and extensibility. Thanks to Peter Zijlstra for fixing the lockdep warning. Thanks to Harvey Harrison for pointing out that the unlikely() was unnecessary. Signed-off-by: Matthew Wilcox Acked-by: Ingo Molnar

uml: compile error fix

2008-04-16T02:35:40Z

This patch fixes this error: In file included from /home/wangcong/projects/linux-2.6/arch/um/kernel/smp.c:9: include2/asm/tlb.h: In function `tlb_remove_page': include2/asm/tlb.h:101: error: implicit declaration of function `page_cache_release' And since including in will break sparc, we add this #include in uml's own header. Acked-by: Jeff Dike Signed-off-by: WANG Cong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds