habanalabs: prevent CPU soft lockup on Palladium (e850b89f) · Commits · 戴 / test

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>

drivers/misc/habanalabs/memory.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -1046,11 +1046,18 @@ 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);

		/* 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);

		mutex_unlock(&ctx->mmu_lock);

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