[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <20251004200204.GK3360665@nvidia.com>
Date: Sat, 4 Oct 2025 17:02:04 -0300
From: Jason Gunthorpe <jgg@...dia.com>
To: Christophe Leroy <christophe.leroy@...roup.eu>
Cc: Leon Romanovsky <leon@...nel.org>,
Marek Szyprowski <m.szyprowski@...sung.com>,
Leon Romanovsky <leonro@...dia.com>,
Andreas Larsson <andreas@...sler.com>,
Borislav Petkov <bp@...en8.de>,
Dave Hansen <dave.hansen@...ux.intel.com>,
"David S. Miller" <davem@...emloft.net>,
Geoff Levand <geoff@...radead.org>, Helge Deller <deller@....de>,
Ingo Molnar <mingo@...hat.com>, iommu@...ts.linux.dev,
"James E.J. Bottomley" <James.Bottomley@...senpartnership.com>,
Jason Wang <jasowang@...hat.com>, Juergen Gross <jgross@...e.com>,
linux-alpha@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-mips@...r.kernel.org, linux-parisc@...r.kernel.org,
linuxppc-dev@...ts.ozlabs.org,
Madhavan Srinivasan <maddy@...ux.ibm.com>,
Matt Turner <mattst88@...il.com>,
Michael Ellerman <mpe@...erman.id.au>,
"Michael S. Tsirkin" <mst@...hat.com>,
Richard Henderson <richard.henderson@...aro.org>,
sparclinux@...r.kernel.org,
Stefano Stabellini <sstabellini@...nel.org>,
Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
Thomas Gleixner <tglx@...utronix.de>,
virtualization@...ts.linux.dev, x86@...nel.org,
xen-devel@...ts.xenproject.org, Magnus Lindholm <linmag7@...il.com>
Subject: Re: [PATCH v1 4/9] powerpc: Convert to physical address DMA mapping
On Sat, Oct 04, 2025 at 08:19:40AM +0200, Christophe Leroy wrote:
>
>
> Le 03/10/2025 à 18:35, Jason Gunthorpe a écrit :
> > On Sun, Sep 28, 2025 at 06:02:24PM +0300, Leon Romanovsky wrote:
> > > From: Leon Romanovsky <leonro@...dia.com>
> > >
> > > Adapt PowerPC DMA to use physical addresses in order to prepare code
> > > to removal .map_page and .unmap_page.
> > >
> > > Signed-off-by: Leon Romanovsky <leonro@...dia.com>
> > > ---
> > > arch/powerpc/include/asm/iommu.h | 8 +++---
> > > arch/powerpc/kernel/dma-iommu.c | 22 +++++++---------
> > > arch/powerpc/kernel/iommu.c | 14 +++++-----
> > > arch/powerpc/platforms/ps3/system-bus.c | 33 ++++++++++++++----------
> > > arch/powerpc/platforms/pseries/ibmebus.c | 15 ++++++-----
> > > arch/powerpc/platforms/pseries/vio.c | 21 ++++++++-------
> > > 6 files changed, 60 insertions(+), 53 deletions(-)
> >
> > I think this is good enough for PPC anything more looks quite hard
>
> Can you tell what you have in mind ? What more would be interesting to do
> but looks hard ? Maybe it can be a follow-up change ?
The phys_addr_t should be pushed down through the ops function pointer
and only the implementations that need the vaddr should call
virt_to_phys()
Ie try to avoid doing phys -> virt -> phys as it is not efficient.
Jason
Powered by blists - more mailing lists