On Mon, Mar 7, 2011 at 9:25 PM, Guzman Lugo, Fernando <fernando.lugo@xxxxxx> wrote: > On Mon, Mar 7, 2011 at 1:19 PM, David Cohen <dacohen@xxxxxxxxx> wrote: >> On Mon, Mar 7, 2011 at 9:17 PM, Guzman Lugo, Fernando >> <fernando.lugo@xxxxxx> wrote: >>> On Mon, Mar 7, 2011 at 7:10 AM, Michael Jones >>> <michael.jones@xxxxxxxxxxxxxxxx> wrote: >>>> From e7dbe4c4b64eb114f9b0804d6af3a3ca0e78acc8 Mon Sep 17 00:00:00 2001 >>>> From: Michael Jones <michael.jones@xxxxxxxxxxxxxxxx> >>>> Date: Mon, 7 Mar 2011 13:36:15 +0100 >>>> Subject: [PATCH] omap: iommu: disallow mapping NULL address >>>> >>>> commit c7f4ab26e3bcdaeb3e19ec658e3ad9092f1a6ceb allowed mapping >>>> the NULL address if da_start==0. ÂForce da_start to exclude the >>>> first page. >>> >>> what about devices that uses page 0? ipu after reset always starts >>> from 0x00000000 how could we map that address?? >> >> from 0x0? The driver sees da == 0 as error. May I ask you why do you want it? > > unlike DSP that you can load a register with the addres the DSP will > boot, IPU core always starts from address 0x00000000, so if you take > IPU out of reset it will try to access address 0x0 if not map it, > there will be a mmu fault. Hm. Looks like the iommu should not restrict any da. The valid da range should rely only on pdata. Michael, what about just update ISP's da_start on omap-iommu.c file? Set it to 0x1000. Hiroshi, any opinion? Br, David > > Regards, > Fernando. > >> >> Br, >> >> David >> >>> >>> Regards, >>> Fernando. >>> >>>> >>>> Signed-off-by: Michael Jones <michael.jones@xxxxxxxxxxxxxxxx> >>>> --- >>>> Âarch/arm/plat-omap/iommu.c | Â Â6 ++++-- >>>> Â1 files changed, 4 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/arch/arm/plat-omap/iommu.c b/arch/arm/plat-omap/iommu.c >>>> index 5990ea6..dcb5513 100644 >>>> --- a/arch/arm/plat-omap/iommu.c >>>> +++ b/arch/arm/plat-omap/iommu.c >>>> @@ -850,7 +850,7 @@ int iommu_set_da_range(struct iommu *obj, u32 start, u32 end) >>>> Â Â Â Âif (end < start || !PAGE_ALIGN(start | end)) >>>> Â Â Â Â Â Â Â Âreturn -EINVAL; >>>> >>>> - Â Â Â obj->da_start = start; >>>> + Â Â Â obj->da_start = max(start, (u32)PAGE_SIZE); >>>> Â Â Â Âobj->da_end = end; >>>> >>>> Â Â Â Âreturn 0; >>>> @@ -950,7 +950,9 @@ static int __devinit omap_iommu_probe(struct platform_device *pdev) >>>> Â Â Â Âobj->name = pdata->name; >>>> Â Â Â Âobj->dev = &pdev->dev; >>>> Â Â Â Âobj->ctx = (void *)obj + sizeof(*obj); >>>> - Â Â Â obj->da_start = pdata->da_start; >>>> + >>>> + Â Â Â /* reserve the first page for NULL */ >>>> + Â Â Â obj->da_start = max(pdata->da_start, (u32)PAGE_SIZE); >>>> Â Â Â Âobj->da_end = pdata->da_end; >>>> >>>> Â Â Â Âmutex_init(&obj->iommu_lock); >>>> -- >>>> 1.7.4.1 >>>> >>>> >>>> MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler >>>> Registergericht: Amtsgericht Stuttgart, HRB 271090 >>>> Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner >>>> >>> >> > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
