kernel.git/arch/powerpc/kernel/head_64.S, branch linux-2.6.37.y

KVM: PPC: Move KVM trampolines before __end_interrupts

2010-10-24T08:50:59Z

When using a relocatable kernel we need to make sure that the trampline code and the interrupt handlers are both copied to low memory. The only way to do this reliably is to put them in the copied section. This patch should make relocated kernels work with KVM. KVM-Stable-Tag Signed-off-by: Alexander Graf Signed-off-by: Avi Kivity

powerpc: Don't use kernel stack with translation off

2010-08-31T01:35:13Z

In f761622e59433130bc33ad086ce219feee9eb961 we changed early_setup_secondary so it's called using the proper kernel stack rather than the emergency one. Unfortunately, this stack pointer can't be used when translation is off on PHYP as this stack pointer might be outside the RMO. This results in the following on all non zero cpus: cpu 0x1: Vector: 300 (Data Access) at [c00000001639fd10] pc: 000000000001c50c lr: 000000000000821c sp: c00000001639ff90 msr: 8000000000001000 dar: c00000001639ffa0 dsisr: 42000000 current = 0xc000000016393540 paca = 0xc000000006e00200 pid = 0, comm = swapper The original patch was only tested on bare metal system, so it never caught this problem. This changes __secondary_start so that we calculate the new stack pointer but only start using it after we've called early_setup_secondary. With this patch, the above problem goes away. Signed-off-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt

powerpc: Initialise paca->kstack before early_setup_secondary

2010-08-24T05:26:31Z

As early setup calls down to slb_initialize(), we must have kstack initialised before checking "should we add a bolted SLB entry for our kstack?" Failing to do so means stack access requires an SLB miss exception to refill an entry dynamically, if the stack isn't accessible via SLB(0) (kernel text & static data). It's not always allowable to take such a miss, and intermittent crashes will result. Primary CPUs don't have this issue; an SLB entry is not bolted for their stack anyway (as that lives within SLB(0)). This patch therefore only affects the init of secondaries. Signed-off-by: Matt Evans Cc: stable Signed-off-by: Benjamin Herrenschmidt

KVM: PPC: Name generic 64-bit code generic

2010-05-17T09:18:14Z

We have quite some code that can be used by Book3S_32 and Book3S_64 alike, so let's call it "Book3S" instead of "Book3S_64", so we can later on use it from the 32 bit port too. Signed-off-by: Alexander Graf Signed-off-by: Avi Kivity

powerpc: Reset kernel stack on cpu online from cede state

2010-03-09T00:57:10Z

Cpu hotplug (offline) without dlpar operation will place cpu in cede state and the extended_cede_processor() function will return when resumed. Kernel stack pointer needs to be reset before start_secondary() is called to continue the online operation. Added new function start_secondary_resume() to do the above steps. Signed-off-by: Vaidyanathan Srinivasan Cc: Gautham R Shenoy Signed-off-by: Benjamin Herrenschmidt

powerpc: Dynamically allocate pacas

2010-03-09T00:52:52Z

On 64-bit kernels we currently have a 512 byte struct paca_struct for each cpu (usually just called "the paca"). Currently they are statically allocated, which means a kernel built for a large number of cpus will waste a lot of space if it's booted on a machine with few cpus. We can avoid that by only allocating the number of pacas we need at boot. However this is complicated by the fact that we need to access the paca before we know how many cpus there are in the system. The solution is to dynamically allocate enough space for NR_CPUS pacas, but then later in boot when we know how many cpus we have, we free any unused pacas. Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt

Make head_64.S aware of KVM real mode code

2009-11-05T05:49:57Z

We need to run some KVM trampoline code in real mode. Unfortunately, real mode only covers 8MB on Cell so we need to squeeze ourselves as low as possible. Also, we need to trap interrupts to get us back from guest state to host state without telling Linux about it. This patch adds interrupt traps and includes the KVM code that requires real mode in the real mode parts of Linux. Signed-off-by: Alexander Graf Signed-off-by: Benjamin Herrenschmidt

powerpc: Remaining 64-bit Book3E support

2009-08-20T00:25:11Z

This contains all the bits that didn't fit in previous patches :-) This includes the actual exception handlers assembly, the changes to the kernel entry, other misc bits and wiring it all up in Kconfig. Signed-off-by: Benjamin Herrenschmidt

powerpc: Use names rather than numbers for SPRGs (v2)

2009-08-20T00:12:27Z

The kernel uses SPRG registers for various purposes, typically in low level assembly code as scratch registers or to hold per-cpu global infos such as the PACA or the current thread_info pointer. We want to be able to easily shuffle the usage of those registers as some implementations have specific constraints realted to some of them, for example, some have userspace readable aliases, etc.. and the current choice isn't always the best. This patch should not change any code generation, and replaces the usage of SPRN_SPRGn everywhere in the kernel with a named replacement and adds documentation next to the definition of the names as to what those are used for on each processor family. The only parts that still use the original numbers are bits of KVM or suspend/resume code that just blindly needs to save/restore all the SPRGs. Signed-off-by: Benjamin Herrenschmidt

powerpc: Rename exception.h to exception-64s.h

2009-08-20T00:12:26Z

The file include/asm/exception.h contains definitions that are specific to exception handling on 64-bit server type processors. This renames the file to exception-64s.h to reflect that fact and avoid confusion. Signed-off-by: Benjamin Herrenschmidt