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authorAlexey Kardashevskiy <aik@ozlabs.ru>2021-02-16 06:33:07 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2021-04-22 18:38:04 +0300
commit4be518d838809e21354f32087aa9c26efc50b410 (patch)
tree5e7dc1d62e3a58ab8a49847016310e7cfcaf3f78 /arch/powerpc/sysdev
parent7f1fa82d79947dfabb4046e1d787da9db2bc1c20 (diff)
downloadlinux-4be518d838809e21354f32087aa9c26efc50b410.tar.xz
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/sysdev')
-rw-r--r--arch/powerpc/sysdev/dart_iommu.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/powerpc/sysdev/dart_iommu.c b/arch/powerpc/sysdev/dart_iommu.c
index 6b4a34b36d98..1d33b7a5ea83 100644
--- a/arch/powerpc/sysdev/dart_iommu.c
+++ b/arch/powerpc/sysdev/dart_iommu.c
@@ -344,7 +344,8 @@ static void iommu_table_dart_setup(void)
iommu_table_dart.it_index = 0;
iommu_table_dart.it_blocksize = 1;
iommu_table_dart.it_ops = &iommu_dart_ops;
- iommu_init_table(&iommu_table_dart, -1, 0, 0);
+ if (!iommu_init_table(&iommu_table_dart, -1, 0, 0))
+ panic("Failed to initialize iommu table");
/* Reserve the last page of the DART to avoid possible prefetch
* past the DART mapped area