These macros are using integers where they could be using logical names since they take registers. We are going to enforce this soon, so fix these up now. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
move lbz/stbciz to ppc-opcode.h. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Anything that uses a constructed instruction (ie. from ppc-opcode.h), need to use the new R0 macro, as %r0 is not going to work. Also convert usages of macros where we are just determining an offset (usually for a load/store), like: std r14,STK_REG(r14)(r1) Can't use STK_REG(r14) as %r14 doesn't work in the STK_REG macro since it's just calculating an offset. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Enable functions used to access SCOM if PPC_MAPLE is defined: they are used by cpufreq driver to control hardware. Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Commit 1fc711f7ffb01089efc58042cfdbac8573d1b59a (powerpc/kexec: Fix race in kexec shutdown) moved the write to signal the cpu had exited the kernel from before the transition to real mode in kexec_smp_wait to kexec_wait. Unfornately it missed that kexec_wait is used both by cpus leaving the kernel and by secondary slave cpus that were not allocated a paca for what ever reason -- they could be beyond nr_cpus or not described in the current device tree for whatever reason (for example, kexec-load was not refreshed after a cpu hotplug operation). Cpus coming through that path they will write to paca[NR_CPUS] which is beyond the space allocated for the paca data and overwrite memory not allocated to pacas but very likely still real mode accessable). Move the write back to kexec_smp_wait, which is used only by cpus that found their paca, but after the transition to real mode. Signed-off-by: Milton Miller <miltonm@bga.com> Cc: <stable@kernel.org> # (1fc711f was backported to 2.6.32) Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Since STACK_FRAME_OVERHEAD is defined in asm/ptrace.h and that is ASSEMBER safe, we can just include that instead of going via asm-offsets.h. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Irq stacks provide an essential protection from stack overflows through external interrupts, at the cost of two additionals stacks per CPU. Enable them unconditionally to simplify the kernel build and prevent people from accidentally disabling them. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In kexec_prepare_cpus, the primary CPU IPIs the secondary CPUs to kexec_smp_down(). kexec_smp_down() calls kexec_smp_wait() which sets the hw_cpu_id() to -1. The primary does this while leaving IRQs on which means the primary can take a timer interrupt which can lead to the IPIing one of the secondary CPUs (say, for a scheduler re-balance) but since the secondary CPU now has a hw_cpu_id = -1, we IPI CPU -1... Kaboom! We are hitting this case regularly on POWER7 machines. There is also a second race, where the primary will tear down the MMU mappings before knowing the secondaries have entered real mode. Also, the secondaries are clearing out any pending IPIs before guaranteeing that no more will be received. This changes kexec_prepare_cpus() so that we turn off IRQs in the primary CPU much earlier. It adds a paca flag to say that the secondaries have entered the kexec_smp_down() IPI and turned off IRQs, rather than overloading hw_cpu_id with -1. This new paca flag is again used to in indicate when the secondaries has entered real mode. It also ensures that all CPUs have their IRQs off before we clear out any pending IPI requests (in kexec_cpu_down()) to ensure there are no trailing IPIs left unacknowledged. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently, load_up_altivec and give_up_altivec are duplicated in 32-bit and 64-bit. This creates a common implementation that is moved away from head_32.S, head_64.S and misc_64.S and into vector.S, using the same macros we already use for our common implementation of load_up_fpu. I also moved the VSX code over to vector.S though in that case I didn't make it build on 32-bit (yet). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When we call giveup_fpu, we need to need to turn off VSX for the
current process. If we don't, on return to userspace it may execute a
VSX instruction before the next FP instruction, and not have its
register state refreshed correctly from the thread_struct. Ditto for
altivec.
This caused a bug where an unaligned lfs or stfs results in
fix_alignment calling giveup_fpu so it can use the FPRs (in order to
do a single <-> double conversion), and then returning to userspace
with FP off but VSX on. Then if a VSX instruction is executed, before
another FP instruction, it will proceed without another exception and
hence have the incorrect register state for VSX registers 0-31.
lfs unaligned <- alignment exception turns FP off but leaves VSX on
VSX instruction <- no exception since VSX on, hence we get the
wrong VSX register values for VSX registers 0-31,
which overlap the FPRs.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>