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path: root/arch/powerpc/kernel/idle_power4.S
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2007-05-07[POWERPC] powermac: Support G5 CPU hotplugJohannes Berg
This allows "hotplugging" of CPUs on G5 machines. CPUs that are disabled are put into an idle loop with the decrementer frequency set to minimum. To wake them up again we kick them just like when bringing them up. To stop those CPUs from messing with any global state we stop them from entering the timer interrupt. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-10-16[POWERPC] Lazy interrupt disabling for 64-bit machinesPaul Mackerras
This implements a lazy strategy for disabling interrupts. This means that local_irq_disable() et al. just clear the 'interrupts are enabled' flag in the paca. If an interrupt comes along, the interrupt entry code notices that interrupts are supposed to be disabled, and clears the EE bit in SRR1, clears the 'interrupts are hard-enabled' flag in the paca, and returns. This means that interrupts only actually get disabled in the processor when an interrupt comes along. When interrupts are enabled by local_irq_enable() et al., the code sets the interrupts-enabled flag in the paca, and then checks whether interrupts got hard-disabled. If so, it also sets the EE bit in the MSR to hard-enable the interrupts. This has the potential to improve performance, and also makes it easier to make a kernel that can boot on iSeries and on other 64-bit machines, since this lazy-disable strategy is very similar to the soft-disable strategy that iSeries already uses. This version renames paca->proc_enabled to paca->soft_enabled, and changes a couple of soft-disables in the kexec code to hard-disables, which should fix the crash that Michael Ellerman saw. This doesn't yet use a reserved CR field for the soft_enabled and hard_enabled flags. This applies on top of Stephen Rothwell's patches to make it possible to build a combined iSeries/other kernel. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-18powerpc: Use correct sequence for putting CPU into nap modePaul Mackerras
We weren't using the recommended sequence for putting the CPU into nap mode. When I changed the idle loop, for some reason 7447A cpus started hanging when we put them into nap mode. Changing to the recommended sequence fixes that. The complexity here is that the recommended sequence is a loop that keeps putting the cpu back into nap mode. Clearly we need some way to break out of the loop when an interrupt (external interrupt, decrementer, performance monitor) occurs. Here we use a bit in the thread_info struct to indicate that we need this, and the exception entry code notices this and arranges for the exception to return to the value in the link register, thus breaking out of the loop. We use a new `local_flags' field in the thread_info which we can alter without needing to use an atomic update sequence. The PPC970 has the same recommended sequence, so we do the same thing there too. This also fixes a bug in the kernel stack overflow handling code on 32-bit, since it was causing a value that we needed in a register to get trashed. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-28powerpc: Fix goof in 6xx and POWER4 idle power-save functionsPaul Mackerras
This fixes a mistake I made when editing these functions - when I took out the interrupt disabling code (because interrupts are now disabled by the caller) I left the register that is used for the MSR value to be used during doze/nap uninitialized. This fixes it. Also updated some of the comments in idle_power4.S and removed some code that was copied over from idle_6xx.S but is no longer relevant (we don't ever clear the CPU_FTR_CAN_NAP bit at runtime for POWER4). Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-27powerpc: Unify the 32 and 64 bit idle loopsPaul Mackerras
This unifies the 32-bit (ARCH=ppc and ARCH=powerpc) and 64-bit idle loops. It brings over the concept of having a ppc_md.power_save function from 32-bit to ARCH=powerpc, which lets us get rid of native_idle(). With this we will also be able to simplify the idle handling for pSeries and cell. 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>
2005-10-17[PATCH] powerpc: Fix use of LOADBASE in merge treeDavid Gibson
The merge-tree version of LOADBASE actually loads the whole given address from the toc for ppc64. The matching OFF macro adjust for this, using an offset of 0 for ppc64, but we weren't using that in power4_idle. Signed-off-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-01powerpc: merge idle_power4.S and trapc.sStephen Rothwell
Use idle_power4.S from ppc64 as we are not going to support 32 bit power4 in the merged tree. Merge ppc64 traps.c into powerpc traps.c: use ppc64 versions of exception routine names (as they don't have StudlyCaps) make all the versions if die() have the same prototype Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>