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| author | Alexey Kardashevskiy <aik@ozlabs.ru> | 2021-02-16 14:33:07 +1100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-04-23 01:38:04 +1000 |
| commit | 4be518d838809e21354f32087aa9c26efc50b410 (patch) | |
| tree | 5e7dc1d62e3a58ab8a49847016310e7cfcaf3f78 /arch/powerpc/platforms/cell | |
| parent | 7f1fa82d79947dfabb4046e1d787da9db2bc1c20 (diff) | |
| download | lwn-4be518d838809e21354f32087aa9c26efc50b410.tar.gz lwn-4be518d838809e21354f32087aa9c26efc50b410.zip | |
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 <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Leonardo Bras <leobras.c@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210216033307.69863-3-aik@ozlabs.ru
Diffstat (limited to 'arch/powerpc/platforms/cell')
| -rw-r--r-- | arch/powerpc/platforms/cell/iommu.c | 3 |
1 files changed, 2 insertions, 1 deletions
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); |