kernel/linux.git/arch/powerpc/include/asm/dbell.h, branch linux-4.16.y

powerpc/64s: msgclr when handling doorbell exceptions from system reset

2017-06-19T09:46:27+00:00

msgsnd doorbell exceptions are cleared when the doorbell interrupt is taken. However if a doorbell exception causes a system reset interrupt wake from power saving state, the message is not cleared. Processing the doorbell from the system reset interrupt requires msgclr to avoid taking the exception again. Testing this plus the previous wakup direct patch gives: original wakeup direct msgclr Different threads, same core: 315k/s 264k/s 345k/s Different cores: 235k/s 242k/s 242k/s Net speedup is +10% for same core, and +3% for different core. Reviewed-by: Gautham R. Shenoy Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman

powerpc/powernv: POWER9 support for msgsnd/doorbell IPI

2017-04-13T13:34:34+00:00

POWER9 requires msgsync for receiver-side synchronization, and a DD1 workaround restricts IPIs to core-local. Signed-off-by: Nicholas Piggin [mpe: Drop no longer needed asm feature macro changes] Signed-off-by: Michael Ellerman

powerpc/64s: Avoid a branch for ppc_msgsnd

2017-04-13T13:34:34+00:00

IPIs are a pretty hot path and we already have the ability to do asm feature patching, so use it. Signed-off-by: Nicholas Piggin [mpe: Change log detail] Signed-off-by: Michael Ellerman

powerpc: Introduce msgsnd/doorbell barrier primitives

2017-04-13T13:34:33+00:00

POWER9 changes requirements and adds new instructions for synchronization. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman

powerpc: Change the doorbell IPI calling convention

2017-04-13T13:34:33+00:00

Change the doorbell callers to know about their msgsnd addressing, rather than have them set a per-cpu target data tag at boot that gets sent to the cause_ipi functions. The data is only used for doorbell IPI functions, no other IPI types, so it makes sense to keep that detail local to doorbell. Have the platform code understand doorbell IPIs, rather than the interrupt controller code understand them. Platform code can look at capabilities it has available and decide which to use. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman

powerpc: Move cpu_has_feature() to a separate file

2016-08-01T01:15:03+00:00

We plan to use jump label for cpu_has_feature(). In order to implement this we need to include the linux/jump_label.h in asm/cputable.h. Unfortunately if we do that it leads to an include loop. The root of the problem seems to be that reg.h needs cputable.h (for CPU_FTRs), and then cputable.h via jump_label.h eventually pulls in hw_irq.h which needs reg.h (for MSR_EE). So move cpu_has_feature() to a separate file on its own. Signed-off-by: Kevin Hao Signed-off-by: Aneesh Kumar K.V [mpe: Rename to cpu_has_feature.h and flesh out change log] Signed-off-by: Michael Ellerman

powerpc: Select either privileged or hypervisor doorbell when sending

2013-01-10T04:09:06+00:00

On book3s we have two msgsnd instructions with differing privilege levels. This patch selects the appropriate instruction to use whenever we send a doorbell interrupt. Signed-off-by: Ian Munsie Tested-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt

powerpc: Define differences between doorbells on book3e and book3s

2013-01-10T04:09:05+00:00

There are a few key differences between doorbells on server compared with embedded that we care about on Linux, namely: - We have a new msgsndp instruction for directed privileged doorbells. msgsnd is used for directed hypervisor doorbells. - The tag we use in the instruction is the Thread Identification Register of the recipient thread (since server doorbells can only occur between threads within a single core), and is only 7 bits wide. - A new message type is introduced for server doorbells (none of the existing book3e message types are currently supported on book3s). Signed-off-by: Ian Munsie Tested-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix typos in Freescale copyright claims

2012-11-15T02:00:58+00:00

There are many cases that Semiconductor is misspelled. The patch fix these typos. Signed-off-by: Li Yang Acked-by: Timur Tabi Signed-off-by: Benjamin Herrenschmidt

KVM: PPC: e500mc: Add doorbell emulation support

2012-04-08T09:54:50+00:00

When one vcpu wants to kick another, it can issue a special IPI instruction called msgsnd. This patch emulates this instruction, its clearing counterpart and the infrastructure required to actually trigger that interrupt inside a guest vcpu. With this patch, SMP guests on e500mc work. Signed-off-by: Alexander Graf Signed-off-by: Avi Kivity