From 3fe719f467530b7c8ac0797881ff4b66d1357c18 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Wed, 12 Sep 2012 16:57:21 +0000 Subject: pseries: Fix semantics of RTAS int-on, int-off and set-xive functions Currently the ibm,int-on and ibm,int-off RTAS functions are implemented as no-ops. This is because when implemented as specified in PAPR they caused Linux (which calls both int-on/off and set-xive) to end up with interrupts masked when they should not be. Since Linux's set-xive calls make the int-on/off calls redundant, making them nops worked around the problem. In fact, the problem was caused because there was a subtle bug in set-xive, PAPR specifies that as well as updating the current priority, it also needs to update the saved priority used by int-on/off. With this bug fixed the problem goes away. This patch implements this more correct fix. Signed-off-by: David Gibson Signed-off-by: Alexander Graf --- hw/xics.c | 25 ++++++++----------------- 1 file changed, 8 insertions(+), 17 deletions(-) (limited to 'hw/xics.c') diff --git a/hw/xics.c b/hw/xics.c index 75c8cca41d..ce88aa750b 100644 --- a/hw/xics.c +++ b/hw/xics.c @@ -270,13 +270,14 @@ static void write_xive_lsi(struct ics_state *ics, int srcno) } static void ics_write_xive(struct ics_state *ics, int nr, int server, - uint8_t priority) + uint8_t priority, uint8_t saved_priority) { int srcno = nr - ics->offset; struct ics_irq_state *irq = ics->irqs + srcno; irq->server = server; irq->priority = priority; + irq->saved_priority = saved_priority; if (irq->lsi) { write_xive_lsi(ics, srcno); @@ -405,7 +406,7 @@ static void rtas_set_xive(sPAPREnvironment *spapr, uint32_t token, return; } - ics_write_xive(ics, nr, server, priority); + ics_write_xive(ics, nr, server, priority, priority); rtas_st(rets, 0, 0); /* Success */ } @@ -453,14 +454,8 @@ static void rtas_int_off(sPAPREnvironment *spapr, uint32_t token, return; } - /* This is a NOP for now, since the described PAPR semantics don't - * seem to gel with what Linux does */ -#if 0 - struct ics_irq_state *irq = xics->irqs + (nr - xics->offset); - - irq->saved_priority = irq->priority; - ics_write_xive_msi(xics, nr, irq->server, 0xff); -#endif + ics_write_xive(ics, nr, ics->irqs[nr - ics->offset].server, 0xff, + ics->irqs[nr - ics->offset].priority); rtas_st(rets, 0, 0); /* Success */ } @@ -484,13 +479,9 @@ static void rtas_int_on(sPAPREnvironment *spapr, uint32_t token, return; } - /* This is a NOP for now, since the described PAPR semantics don't - * seem to gel with what Linux does */ -#if 0 - struct ics_irq_state *irq = xics->irqs + (nr - xics->offset); - - ics_write_xive_msi(xics, nr, irq->server, irq->saved_priority); -#endif + ics_write_xive(ics, nr, ics->irqs[nr - ics->offset].server, + ics->irqs[nr - ics->offset].saved_priority, + ics->irqs[nr - ics->offset].saved_priority); rtas_st(rets, 0, 0); /* Success */ } -- cgit v1.2.3