| From b63f751b52eecd629f92d4c53cf24bca48c946ce Mon Sep 17 00:00:00 2001 |
| From: Oded Gabbay <oded.gabbay@gmail.com> |
| Date: Sun, 31 Mar 2019 21:37:42 +0300 |
| Subject: habanalabs: prevent CPU soft lockup on Palladium |
| |
| [ Upstream commit e850b89f50d2c1439f58d547b888ee6e43312dea ] |
| |
| Unmapping ptes in the device MMU on Palladium can take a long time, which |
| can cause a kernel BUG of CPU soft lockup. |
| |
| This patch minimize the chances for this bug by sleeping a little between |
| unmapping ptes. |
| |
| Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/misc/habanalabs/memory.c | 11 +++++++++-- |
| 1 file changed, 9 insertions(+), 2 deletions(-) |
| |
| diff --git a/drivers/misc/habanalabs/memory.c b/drivers/misc/habanalabs/memory.c |
| index ce1fda40a8b81..fadaf557603f5 100644 |
| --- a/drivers/misc/habanalabs/memory.c |
| +++ b/drivers/misc/habanalabs/memory.c |
| @@ -1046,10 +1046,17 @@ static int unmap_device_va(struct hl_ctx *ctx, u64 vaddr) |
| |
| mutex_lock(&ctx->mmu_lock); |
| |
| - for (i = 0 ; i < phys_pg_pack->npages ; i++, next_vaddr += page_size) |
| + for (i = 0 ; i < phys_pg_pack->npages ; i++, next_vaddr += page_size) { |
| if (hl_mmu_unmap(ctx, next_vaddr, page_size)) |
| dev_warn_ratelimited(hdev->dev, |
| - "unmap failed for vaddr: 0x%llx\n", next_vaddr); |
| + "unmap failed for vaddr: 0x%llx\n", next_vaddr); |
| + |
| + /* unmapping on Palladium can be really long, so avoid a CPU |
| + * soft lockup bug by sleeping a little between unmapping pages |
| + */ |
| + if (hdev->pldm) |
| + usleep_range(500, 1000); |
| + } |
| |
| hdev->asic_funcs->mmu_invalidate_cache(hdev, true); |
| |
| -- |
| 2.20.1 |
| |
