From 4be518d838809e21354f32087aa9c26efc50b410 Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Tue, 16 Feb 2021 14:33:07 +1100 Subject: powerpc/iommu: Do not immediately panic when failed IOMMU table allocation Most platforms allocate IOMMU table structures (specifically it_map) at the boot time and when this fails - it is a valid reason for panic(). However the powernv platform allocates it_map after a device is returned to the host OS after being passed through and this happens long after the host OS booted. It is quite possible to trigger the it_map allocation panic() and kill the host even though it is not necessary - the host OS can still use the DMA bypass mode (requires a tiny fraction of it_map's memory) and even if that fails, the host OS is runnnable as it was without the device for which allocating it_map causes the panic. Instead of immediately crashing in a powernv/ioda2 system, this prints an error and continues. All other platforms still call panic(). Signed-off-by: Alexey Kardashevskiy Reviewed-by: David Gibson Reviewed-by: Leonardo Bras Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210216033307.69863-3-aik@ozlabs.ru --- arch/powerpc/platforms/cell/iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/powerpc/platforms/cell/iommu.c') diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c index 2124831cf57c..fa08699aedeb 100644 --- a/arch/powerpc/platforms/cell/iommu.c +++ b/arch/powerpc/platforms/cell/iommu.c @@ -486,7 +486,8 @@ cell_iommu_setup_window(struct cbe_iommu *iommu, struct device_node *np, window->table.it_size = size >> window->table.it_page_shift; window->table.it_ops = &cell_iommu_ops; - iommu_init_table(&window->table, iommu->nid, 0, 0); + if (!iommu_init_table(&window->table, iommu->nid, 0, 0)) + panic("Failed to initialize iommu table"); pr_debug("\tioid %d\n", window->ioid); pr_debug("\tblocksize %ld\n", window->table.it_blocksize); -- cgit