[PATCH v2 6/6] x86/platform/uv/BAU: Implement uv4_wait_completion with read_status

From: Andrew Banman
Date: Fri Feb 17 2017 - 17:07:33 EST


UV4 does not employ a software-timeout as in previous generations so a new
wait_completion routine without this logic is required. Certain completion
statuses require the AUX status bit in addition to ERROR and BUSY.

Add the read_status routine to construct the full completion status. Use
read_status in the uv4_wait_completion routine to handle all possible
completion statuses.

Signed-off-by: Andrew Banman <abanman@xxxxxxx>
Acked-by: Mike Travis <mike.travis@xxxxxxx>
---
arch/x86/platform/uv/tlb_uv.c | 58 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 57 insertions(+), 1 deletion(-)

diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c
index 2a826dd..42e65fe 100644
--- a/arch/x86/platform/uv/tlb_uv.c
+++ b/arch/x86/platform/uv/tlb_uv.c
@@ -687,6 +687,62 @@ static int uv2_3_wait_completion(struct bau_desc *bau_desc,
}

/*
+ * Returns the status of current BAU message for cpu desc as a bit field
+ * [Error][Busy][Aux]
+ */
+static u64 read_status(u64 status_mmr, int index, int desc)
+{
+ u64 stat;
+
+ stat = ((read_lmmr(status_mmr) >> index) & UV_ACT_STATUS_MASK) << 1;
+ stat |= (read_lmmr(UVH_LB_BAU_SB_ACTIVATION_STATUS_2) >> desc) & 0x1;
+
+ return stat;
+}
+
+static int uv4_wait_completion(struct bau_desc *bau_desc,
+ struct bau_control *bcp, long try)
+{
+ struct ptc_stats *stat = bcp->statp;
+ u64 descriptor_stat;
+ u64 mmr = bcp->status_mmr;
+ int index = bcp->status_index;
+ int desc = bcp->uvhub_cpu;
+
+ descriptor_stat = read_status(mmr, index, desc);
+
+ /* spin on the status MMR, waiting for it to go idle */
+ while (descriptor_stat != UV2H_DESC_IDLE) {
+ switch (descriptor_stat) {
+ case UV2H_DESC_SOURCE_TIMEOUT:
+ stat->s_stimeout++;
+ return FLUSH_GIVEUP;
+
+ case UV2H_DESC_DEST_TIMEOUT:
+ stat->s_dtimeout++;
+ bcp->conseccompletes = 0;
+ return FLUSH_RETRY_TIMEOUT;
+
+ case UV2H_DESC_DEST_STRONG_NACK:
+ stat->s_plugged++;
+ bcp->conseccompletes = 0;
+ return FLUSH_RETRY_PLUGGED;
+
+ case UV2H_DESC_DEST_PUT_ERR:
+ bcp->conseccompletes = 0;
+ return FLUSH_GIVEUP;
+
+ default:
+ /* descriptor_stat is still BUSY */
+ cpu_relax();
+ }
+ descriptor_stat = read_status(mmr, index, desc);
+ }
+ bcp->conseccompletes++;
+ return FLUSH_COMPLETE;
+}
+
+/*
* Our retries are blocked by all destination sw ack resources being
* in use, and a timeout is pending. In that case hardware immediately
* returns the ERROR that looks like a destination timeout.
@@ -2157,7 +2213,7 @@ static int __init init_per_cpu(int nuvhubs, int base_part_pnode)
.write_g_sw_ack = write_gmmr_proc_sw_ack,
.write_payload_first = write_mmr_proc_payload_first,
.write_payload_last = write_mmr_proc_payload_last,
- .wait_completion = uv2_3_wait_completion,
+ .wait_completion = uv4_wait_completion,
};

/*
--
1.8.2.1