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habanalabs: prevent CPU soft lockup on Palladium

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>
hifive-unleashed-5.2
Oded Gabbay 2019-03-31 21:37:42 +03:00
parent 9336c02167
commit e850b89f50
1 changed files with 9 additions and 2 deletions

View File

@ -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);