> -----Original Message----- > From: Arnd Bergmann <a...@arndb.de> > Sent: vendredi 30 novembre 2018 15:33 > To: Loic PALLARDY <loic.palla...@st.com> > Cc: Bjorn Andersson <bjorn.anders...@linaro.org>; Ohad Ben-Cohen > <o...@wizery.com>; linux-remotep...@vger.kernel.org; Linux Kernel > Mailing List <linux-kernel@vger.kernel.org>; Arnaud POULIQUEN > <arnaud.pouliq...@st.com>; Benjamin Gaignard > <benjamin.gaign...@linaro.org>; Suman Anna <s-a...@ti.com> > Subject: Re: [PATCH 4/7] remoteproc: add warning on resource table cast > > On Thu, Nov 29, 2018 at 10:31 PM Loic Pallardy <loic.palla...@st.com> wrote: > > > > Today resource table supports only 32bit address fields. > > This is not compliant with 64bit platform for which addresses > > are cast in 32bit. > > This patch adds warn messages when address cast is done. > > > > Signed-off-by: Loic Pallardy <loic.palla...@st.com> > > --- > > drivers/remoteproc/remoteproc_core.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/drivers/remoteproc/remoteproc_core.c > b/drivers/remoteproc/remoteproc_core.c > > index 18a1bbf820c9..61c954bd695e 100644 > > --- a/drivers/remoteproc/remoteproc_core.c > > +++ b/drivers/remoteproc/remoteproc_core.c > > @@ -772,6 +772,10 @@ static int rproc_alloc_carveout(struct rproc *rproc, > > dev_dbg(dev, "carveout mapped 0x%x to %pad\n", > > mem->da, &dma); > > } else { > > + /* Update device address as undefined by requester */ > > + if (sizeof(dma_addr_t) > sizeof(u32)) > > + dev_warn(dev, "DMA address cast in 32bit to fit > > resource table > format\n"); > > + > > mem->da = (u32)dma; > > } > > I think this patch is wrong: sizeof(dma_addr_t) is defined to be large enough > to support any machine that the kernel can run on. If you build a kernel that > happens to work on an ARM32 platform with LPAE enabled, then this will > warn every time, even if you are running on a machine that only has a 32-bit > address space.
I suppose if LPAE is enabled, address space is larger than 32bit. But I agree it is possible to display a warn only when some information will be lost due to cast. I'll propose a new version testing dma address itself and displaying warn only if above 4GB. Regards, Loic > > Arnd