forked from Minki/linux
8c0d51592f
On LoPAR "DMA Window Manipulation Calls", it's recommended to remove the default DMA window for the device, before attempting to configure a DDW, in order to make the maximum resources available for the next DDW to be created. This is a requirement for using DDW on devices in which hypervisor allows only one DMA window. If setting up a new DDW fails anywhere after the removal of this default DMA window, it's needed to restore the default DMA window. For this, an implementation of ibm,reset-pe-dma-windows rtas call is needed: Platforms supporting the DDW option starting with LoPAR level 2.7 implement ibm,ddw-extensions. The first extension available (index 2) carries the token for ibm,reset-pe-dma-windows rtas call, which is used to restore the default DMA window for a device, if it has been deleted. It does so by resetting the TCE table allocation for the PE to it's boot time value, available in "ibm,dma-window" device tree node. Signed-off-by: Leonardo Bras <leobras.c@gmail.com> Tested-by: David Dai <zdai@linux.vnet.ibm.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200805030455.123024-5-leobras.c@gmail.com |
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| math-emu | ||
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| net | ||
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| perf | ||
| platforms | ||
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