[PATCH kernel] powerpc/powernv/ioda2: Reduce upper limit for DMA window size (retry)

2018-09-10 Thread Alexey Kardashevskiy
We use PHB in mode1 which uses bit 59 to select a correct DMA window. However there is mode2 which uses bits 59:55 and allows up to 32 DMA windows per a PE. Even though documentation does not clearly specify that, it seems that the actual hardware does not support bits 59:55 even in mode1, in

Re: [PATCH kernel] powerpc/powernv/ioda2: Reduce upper limit for DMA window size

2018-06-28 Thread Michael Ellerman
Alexey Kardashevskiy writes: > We use PHB in mode1 which uses bit 59 to select a correct DMA window. > However there is mode2 which uses bits 59:55 and allows up to 32 DMA > windows per a PE. Do we ever use mode2? > Even though documentation does not clearly specify that, it seems that > the

Re: [PATCH kernel] powerpc/powernv/ioda2: Reduce upper limit for DMA window size

2018-06-25 Thread Alexey Kardashevskiy
On Fri, 1 Jun 2018 18:06:16 +1000 Alexey Kardashevskiy wrote: > We use PHB in mode1 which uses bit 59 to select a correct DMA window. > However there is mode2 which uses bits 59:55 and allows up to 32 DMA > windows per a PE. > > Even though documentation does not clearly specify that, it seems

[PATCH kernel] powerpc/powernv/ioda2: Reduce upper limit for DMA window size

2018-06-01 Thread Alexey Kardashevskiy
We use PHB in mode1 which uses bit 59 to select a correct DMA window. However there is mode2 which uses bits 59:55 and allows up to 32 DMA windows per a PE. Even though documentation does not clearly specify that, it seems that the actual hardware does not support bits 59:55 even in mode1, in