From 446fa65eb57947481583df043bc613a164172131 Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Fri, 8 Dec 2023 13:22:58 -0800 Subject: [PATCH] lib: sbi_ipi: Process self-IPIs in sbi_ipi_send() An IPI sent to the local hart can be processed directly instead of triggering the IPI device. This is more efficient, and it avoids a deadlock when the .sync callback is defined. Since interrupts are disabled while handling an ecall, the IPI would not get delivered until the next mret, but sbi_ipi_sync() is called before then. Signed-off-by: Samuel Holland Reviewed-by: Anup Patel Reviewed-by: Xiang W --- lib/sbi/sbi_ipi.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/lib/sbi/sbi_ipi.c b/lib/sbi/sbi_ipi.c index 56ba743..bbc97f7 100644 --- a/lib/sbi/sbi_ipi.c +++ b/lib/sbi/sbi_ipi.c @@ -60,6 +60,14 @@ static int sbi_ipi_send(struct sbi_scratch *scratch, u32 remote_hartindex, remote_hartindex, data); if (ret != SBI_IPI_UPDATE_SUCCESS) return ret; + } else if (scratch == remote_scratch) { + /* + * IPI events with an update() callback are expected to return + * SBI_IPI_UPDATE_BREAK for self-IPIs. For other events, check + * for self-IPI and execute the callback directly here. + */ + ipi_ops->process(scratch); + return 0; } /*