From: Christoph Hellwig <hch@lst.de>
To: Reza Arbab <arbab@linux.ibm.com>
Cc: Andrew Donnellan <ajd@linux.ibm.com>,
Alexey Kardashevskiy <aik@ozlabs.ru>,
Paul Mackerras <paulus@samba.org>,
Alistair Popple <alistair@popple.id.au>,
Oliver O'Halloran <oohall@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
linuxppc-dev@lists.ozlabs.org, Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH 00/11] powerpv/powernv: Restore pnv_npu_try_dma_set_bypass()
Date: Wed, 30 Oct 2019 18:53:41 +0100 [thread overview]
Message-ID: <20191030175341.GA19166@lst.de> (raw)
In-Reply-To: <1572454800-17976-1-git-send-email-arbab@linux.ibm.com>
On Wed, Oct 30, 2019 at 11:59:49AM -0500, Reza Arbab wrote:
> With recent kernels, TCE tables for NPU devices are no longer being
> configured. That task was performed by pnv_npu_try_dma_set_bypass(), a
> function that got swept away in recent overhauling of dma code.
>
> Patches 1-4 here bring the lost function back and reintegrate it with
> the updated generic iommu bypass infrastructure.
>
> Patch 5 fixes a regression in behavior when a requested dma mask can not
> be fulfilled.
>
> Patches 6-8 are cleanup. I put these later in the set because they
> aren't bisectable until after the restored code is wired back in.
>
> Patches 9-11 refactor pnv_pci_ioda_iommu_bypass_supported(). It seems
> wrong for a boolean *_supported() function to have side effects. They
> reintroduce a pci controller based dma_set_mask() hook. If that's
> undesirable, these last three patches can be dropped.
How do you even use this code? Nothing in the kernel even calls
dma_set_mask for NPU devices, as we only suport vfio pass through.
next prev parent reply other threads:[~2019-10-30 17:55 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-30 16:59 [PATCH 00/11] powerpv/powernv: Restore pnv_npu_try_dma_set_bypass() Reza Arbab
2019-10-30 16:59 ` [PATCH 01/11] Revert "powerpc/powernv: Remove unused pnv_npu_try_dma_set_bypass() function" Reza Arbab
2019-10-30 16:59 ` [PATCH 02/11] powerpc/powernv: Add pnv_ioda_pe_iommu_bypass_supported() Reza Arbab
2019-10-30 16:59 ` [PATCH 03/11] powerpc/powernv/npu: Change pnv_npu_try_dma_set_bypass() argument Reza Arbab
2019-10-30 16:59 ` [PATCH 04/11] powerpc/powernv/npu: Wire up pnv_npu_try_dma_set_bypass() Reza Arbab
2019-10-30 16:59 ` [PATCH 05/11] powerpc/powernv: Return failure for some uses of dma_set_mask() Reza Arbab
2019-10-30 16:59 ` [PATCH 06/11] powerpc/powernv: Remove intermediate variable Reza Arbab
2019-10-30 16:59 ` [PATCH 07/11] powerpc/powernv/npu: Simplify pnv_npu_try_dma_set_bypass() loop Reza Arbab
2019-10-30 16:59 ` [PATCH 08/11] powerpc/powernv: Replace open coded pnv_ioda_get_pe()s Reza Arbab
2019-10-30 16:59 ` [PATCH 09/11] Revert "powerpc/pci: remove the dma_set_mask pci_controller ops methods" Reza Arbab
2019-10-30 16:59 ` [PATCH 10/11] powerpc/powernv: Add pnv_phb3_iommu_bypass_supported() Reza Arbab
2019-10-30 17:00 ` [PATCH 11/11] powerpc/powernv: Add pnv_pci_ioda_dma_set_mask() Reza Arbab
2019-10-30 17:55 ` Christoph Hellwig
2019-10-30 18:10 ` Reza Arbab
2019-10-30 17:53 ` Christoph Hellwig [this message]
2019-10-30 18:08 ` [PATCH 00/11] powerpv/powernv: Restore pnv_npu_try_dma_set_bypass() Reza Arbab
2019-10-30 18:13 ` Christoph Hellwig
2019-10-30 18:32 ` Reza Arbab
2019-10-30 18:33 ` Christoph Hellwig
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