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path: root/arch/powerpc/kernel/entry_64.S
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2006-06-15[POWERPC] system call micro optimisationAnton Blanchard
In the syscall path we currently have: crclr so mfcr r9 If we shift the crclr up we can avoid a stall on some CPUs. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-28[PATCH] powerpc: Workaround for pSeries RTAS bugMike Kravetz
A bug in the RTAS services incorrectly interprets some bits in the CR when called from the OS. Specifically, bits in CR4. The result could be a firmware crash that also takes down the partition. A firmware fix is in the works. We have seen this situation when performing DLPAR operations. As a temporary workaround, clear the CR in enter_rtas(). Note that enter_rtas() will not set any bits in CR4 before calling RTAS. Also note that the 32 bit version of enter_rtas() should have the same work around even though the chances of hitting the bug are much smaller due to the lack of DLPAR on 32 bit kernels. However, my assembly skills are a bit rusty and the 32 bit code doesn't seem to follow the conventions for where things should be saved. In addition, I don't have a system to test 32 bit kernels. Help creating and at least touch testing the same workaround for 32 bit would be appreciated. Signed-off-by: Mike Kravetz <kravetz@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-09Merge ../linux-2.6Paul Mackerras
2006-03-08powerpc: Fix various syscall/signal/swapcontext bugsPaul Mackerras
A careful reading of the recent changes to the system call entry/exit paths revealed several problems, plus some things that could be simplified and improved: * 32-bit wasn't testing the _TIF_NOERROR bit in the syscall fast exit path, so it was only doing anything with it once it saw some other bit being set. In other words, the noerror behaviour would apply to the next system call where we had to reschedule or deliver a signal, which is not necessarily the current system call. * 32-bit wasn't doing the call to ptrace_notify in the syscall exit path when the _TIF_SINGLESTEP bit was set. * _TIF_RESTOREALL was in both _TIF_USER_WORK_MASK and _TIF_PERSYSCALL_MASK, which is odd since _TIF_RESTOREALL is only set by system calls. I took it out of _TIF_USER_WORK_MASK. * On 64-bit, _TIF_RESTOREALL wasn't causing the non-volatile registers to be restored (unless perhaps a signal was delivered or the syscall was traced or single-stepped). Thus the non-volatile registers weren't restored on exit from a signal handler. We probably got away with it mostly because signal handlers written in C wouldn't alter the non-volatile registers. * On 32-bit I simplified the code and made it more like 64-bit by making the syscall exit path jump to ret_from_except to handle preemption and signal delivery. * 32-bit was calling do_signal unnecessarily when _TIF_RESTOREALL was set - but I think because of that 32-bit was actually restoring the non-volatile registers on exit from a signal handler. * I changed the order of enabling interrupts and saving the non-volatile registers before calling do_syscall_trace_leave; now we enable interrupts first. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-24powerpc: Implement accurate task and CPU time accountingPaul Mackerras
This implements accurate task and cpu time accounting for 64-bit powerpc kernels. Instead of accounting a whole jiffy of time to a task on a timer interrupt because that task happened to be running at the time, we now account time in units of timebase ticks according to the actual time spent by the task in user mode and kernel mode. We also count the time spent processing hardware and software interrupts accurately. This is conditional on CONFIG_VIRT_CPU_ACCOUNTING. If that is not set, we do tick-based approximate accounting as before. To get this accurate information, we read either the PURR (processor utilization of resources register) on POWER5 machines, or the timebase on other machines on * each entry to the kernel from usermode * each exit to usermode * transitions between process context, hard irq context and soft irq context in kernel mode * context switches. On POWER5 systems with shared-processor logical partitioning we also read both the PURR and the timebase at each timer interrupt and context switch in order to determine how much time has been taken by the hypervisor to run other partitions ("steal" time). Unfortunately, since we need values of the PURR on both threads at the same time to accurately calculate the steal time, and since we can only calculate steal time on a per-core basis, the apportioning of the steal time between idle time (time which we ceded to the hypervisor in the idle loop) and actual stolen time is somewhat approximate at the moment. This is all based quite heavily on what s390 does, and it uses the generic interfaces that were added by the s390 developers, i.e. account_system_time(), account_user_time(), etc. This patch doesn't add any new interfaces between the kernel and userspace, and doesn't change the units in which time is reported to userspace by things such as /proc/stat, /proc/<pid>/stat, getrusage(), times(), etc. Internally the various task and cpu times are stored in timebase units, but they are converted to USER_HZ units (1/100th of a second) when reported to userspace. Some precision is therefore lost but there should not be any accumulating error, since the internal accumulation is at full precision. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-10[PATCH] powerpc: trivial: modify comments to refer to new location of filesJon Mason
This patch removes all self references and fixes references to files in the now defunct arch/ppc64 tree. I think this accomplises everything wanted, though there might be a few references I missed. Signed-off-by: Jon Mason <jdmason@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-18[PATCH] TIF_RESTORE_SIGMASK support for arch/powerpcDavid Woodhouse
Implement the TIF_RESTORE_SIGMASK flag in the new arch/powerpc kernel, for both 32-bit and 64-bit system call paths. Signed-off-by: David Woodhouse <dwmw2@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-13[PATCH] powerpc: Remove lppaca structure from the PACADavid Gibson
At present the lppaca - the structure shared with the iSeries hypervisor and phyp - is contained within the PACA, our own low-level per-cpu structure. This doesn't have to be so, the patch below removes it, making a separate array of lppaca structures. This saves approximately 500*NR_CPUS bytes of image size and kernel memory, because we don't need aligning gap between the Linux and hypervisor portions of every PACA. On the other hand it means an extra level of dereference in many accesses to the lppaca. The patch also gets rid of several places where we assign the paca address to a local variable for no particular reason. Signed-off-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13[PATCH] powerpc: Cleanup LOADADDR etc. asm macrosDavid Gibson
This patch consolidates the variety of macros used for loading 32 or 64-bit constants in assembler (LOADADDR, LOADBASE, SET_REG_TO_*). The idea is to make the set of macros consistent across 32 and 64 bit and to make it more obvious which is the appropriate one to use in a given situation. The new macros and their semantics are described in the comments in ppc_asm.h. In the process, we change several places that were unnecessarily using immediate loads on ppc64 to use the GOT/TOC. Likewise we cleanup a couple of places where we were clumsily subtracting PAGE_OFFSET with asm instructions to use assemble-time arithmetic or the toreal() macro instead. Signed-off-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-09[PATCH] powerpc: Separate usage of KERNELBASE and PAGE_OFFSETMichael Ellerman
This patch separates usage of KERNELBASE and PAGE_OFFSET. I haven't looked at any of the PPC32 code, if we ever want to support Kdump on PPC we'll have to do another audit, ditto for iSeries. This patch makes PAGE_OFFSET the constant, it'll always be 0xC * 1 gazillion for 64-bit. To get a physical address from a virtual one you subtract PAGE_OFFSET, _not_ KERNELBASE. KERNELBASE is the virtual address of the start of the kernel, it's often the same as PAGE_OFFSET, but _might not be_. If you want to know something's offset from the start of the kernel you should subtract KERNELBASE. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-09[PATCH] ppc64 syscall_exit_work: call the save_nvgprs function, not its ↵David Woodhouse
descriptor. On Tue, 2005-11-15 at 18:52 +0000, David Woodhouse wrote: > This cleanup patch speeds up the null syscall path on ppc64 by about 3%, > and brings the ppc32 and ppc64 code slightly closer together. Needs this unless your binutils, like mine, are clever enough to notice my stupidity and fix it up automatically... Spotted by Paul. Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-09[PATCH] syscall entry/exit revampDavid Woodhouse
This cleanup patch speeds up the null syscall path on ppc64 by about 3%, and brings the ppc32 and ppc64 code slightly closer together. The ppc64 code was checking current_thread_info()->flags twice in the syscall exit path; once for TIF_SYSCALL_T_OR_A before disabling interrupts, and then again for TIF_SIGPENDING|TIF_NEED_RESCHED etc after disabling interrupts. Now we do the same as ppc32 -- check the flags only once in the fast path, and re-enable interrupts if necessary in the ptrace case. The patch abolishes the 'syscall_noerror' member of struct thread_info and replaces it with a TIF_NOERROR bit in the flags, which is handled in the slow path. This shortens the syscall entry code, which no longer needs to clear syscall_noerror. The patch adds a TIF_SAVE_NVGPRS flag which causes the syscall exit slow path to save the non-volatile GPRs into a signal frame. This removes the need for the assembly wrappers around sys_sigsuspend(), sys_rt_sigsuspend(), et al which existed solely to save those registers in advance. It also means I don't have to add new wrappers for ppoll() and pselect(), which is what I was supposed to be doing when I got distracted into this... Finally, it unifies the ppc64 and ppc32 methods of handling syscall exit directly into a signal handler (as required by sigsuspend et al) by introducing a TIF_RESTOREALL flag which causes _all_ the registers to be reloaded from the pt_regs by taking the ret_from_exception path, instead of the normal syscall exit path which stomps on the callee-saved GPRs. It appears to pass an LTP test run on ppc64, and passes basic testing on ppc32 too. Brief tests of ptrace functionality with strace and gdb also appear OK. I wouldn't send it to Linus for 2.6.15 just yet though :) Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-12-20powerpc: correct register usage in 64-bit syscall exit pathPaul Mackerras
Since we don't restore the volatile registers in the syscall exit path, we need to make sure we don't leak any potentially interesting values from the kernel to userspace. This was already the case for all except r11. This makes it use r11 for an MSR value, so r11 will have an (uninteresting) MSR value in it on return to userspace. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-01[PATCH] audit_sysctl_exit can only be used with CONF_AUDIT_SYSCTLHorms
This section of code calls .audit_syscal_exit, but is inside CONFIG_AUDIT, so it will fail to build if CONFIG_AUDITSYSCALL is not defined. After discussion with David Woodhouse, change the ifdef to CONFIG_AUDITSYSCALL Signed-off-by: Horms <horms@verge.net.au> Acked-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-18powerpc: change sys32_ to compat_sys_Stephen Rothwell
This allows us to get rid of one type of entry in systbl.S. In passing we remove the duplicate compat_sys_getdents and compat_sys_utimes for which there are generic versions. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
2005-10-10powerpc: Introduce entry_{32,64}.S, misc_{32,64}.S, systbl.SPaul Mackerras
The system call table has been consolidated into systbl.S. We have separate 32-bit and 64-bit versions of entry.S and misc.S since the code is mostly sufficiently different to be not worth merging. There are some common bits that will be extracted in future. Signed-off-by: Paul Mackerras <paulus@samba.org>