From 40bfb8eedf1e7fa0535c685ff1000c05bcf7a637 Mon Sep 17 00:00:00 2001 From: Dimitri Sivanich Date: Fri, 29 Apr 2016 16:54:22 -0500 Subject: x86/platform/UV: Remove Obsolete GRU MMR address translation Use no-op messages in place of cross-partition interrupts when nacking a put message in the GRU. This allows us to remove MMR's as a destination from the GRU driver. Tested-by: John Estabrook Tested-by: Gary Kroening Tested-by: Nathan Zimmer Signed-off-by: Dimitri Sivanich Signed-off-by: Mike Travis Cc: Andrew Banman Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Len Brown Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Russ Anderson Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20160429215406.012228480@asylum.americas.sgi.com Signed-off-by: Ingo Molnar --- drivers/misc/sgi-gru/grukservices.c | 38 +++++++++++++++++++++---------------- 1 file changed, 22 insertions(+), 16 deletions(-) (limited to 'drivers/misc') diff --git a/drivers/misc/sgi-gru/grukservices.c b/drivers/misc/sgi-gru/grukservices.c index 967b9dd24fe9..030769018461 100644 --- a/drivers/misc/sgi-gru/grukservices.c +++ b/drivers/misc/sgi-gru/grukservices.c @@ -718,8 +718,8 @@ cberr: static int send_message_put_nacked(void *cb, struct gru_message_queue_desc *mqd, void *mesg, int lines) { - unsigned long m, *val = mesg, gpa, save; - int ret; + unsigned long m; + int ret, loops = 200; /* experimentally determined */ m = mqd->mq_gpa + (gru_get_amo_value_head(cb) << 6); if (lines == 2) { @@ -735,22 +735,28 @@ static int send_message_put_nacked(void *cb, struct gru_message_queue_desc *mqd, return MQE_OK; /* - * Send a cross-partition interrupt to the SSI that contains the target - * message queue. Normally, the interrupt is automatically delivered by - * hardware but some error conditions require explicit delivery. - * Use the GRU to deliver the interrupt. Otherwise partition failures + * Send a noop message in order to deliver a cross-partition interrupt + * to the SSI that contains the target message queue. Normally, the + * interrupt is automatically delivered by hardware following mesq + * operations, but some error conditions require explicit delivery. + * The noop message will trigger delivery. Otherwise partition failures * could cause unrecovered errors. */ - gpa = uv_global_gru_mmr_address(mqd->interrupt_pnode, UVH_IPI_INT); - save = *val; - *val = uv_hub_ipi_value(mqd->interrupt_apicid, mqd->interrupt_vector, - dest_Fixed); - gru_vstore_phys(cb, gpa, gru_get_tri(mesg), IAA_REGISTER, IMA); - ret = gru_wait(cb); - *val = save; - if (ret != CBS_IDLE) - return MQE_UNEXPECTED_CB_ERR; - return MQE_OK; + do { + ret = send_noop_message(cb, mqd, mesg); + } while ((ret == MQIE_AGAIN || ret == MQE_CONGESTION) && (loops-- > 0)); + + if (ret == MQIE_AGAIN || ret == MQE_CONGESTION) { + /* + * Don't indicate to the app to resend the message, as it's + * already been successfully sent. We simply send an OK + * (rather than fail the send with MQE_UNEXPECTED_CB_ERR), + * assuming that the other side is receiving enough + * interrupts to get this message processed anyway. + */ + ret = MQE_OK; + } + return ret; } /* -- cgit v1.2.3