On 01.06.23 08:46, Sascha Hauer wrote: > On Wed, May 31, 2023 at 02:40:13PM +0200, Ahmad Fatoum wrote: >> On 31.05.23 14:38, Sascha Hauer wrote: >>> On Wed, May 31, 2023 at 01:58:33PM +0200, Ahmad Fatoum wrote: >>>>> From b6e5c92682467496bd9c57918996f1feffda2dd6 Mon Sep 17 00:00:00 2001 >>>>> From: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> >>>>> Date: Wed, 31 May 2023 11:58:51 +0200 >>>>> Subject: [PATCH] ARM: mmu_32: fix setting up zero page when it is in SDRAM >>>>> >>>>> We used to skip setting the zero page to faulting when SDRAM starts at >>>>> 0x0. As bootm code now explicitly sets the zero page accessible before >>>>> copying ATAGs there this should no longer be necessary, so >>>>> unconditionally set the zero page to faulting during MMU startup. This >>>>> also moves the zero page and vector table setup after the point the >>>>> SDRAM has been mapped cachable, because otherwise the zero page and >>>>> possibly the vector table mapping would be overwritten. >>>>> >>>>> Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> >>>>> --- >>>>> arch/arm/cpu/mmu_32.c | 23 +++++++++-------------- >>>>> 1 file changed, 9 insertions(+), 14 deletions(-) >>>>> >>>>> diff --git a/arch/arm/cpu/mmu_32.c b/arch/arm/cpu/mmu_32.c >>>>> index c4e5a3bb0a..14775768a3 100644 >>>>> --- a/arch/arm/cpu/mmu_32.c >>>>> +++ b/arch/arm/cpu/mmu_32.c >>>>> @@ -461,19 +461,14 @@ static int set_vector_table(unsigned long adr) >>>>> >>>>> static void create_zero_page(void) >>>> >>>> Is this commit incomplete? Vectors should be set up unconditionally and >>>> create_zero_page should be called after it. >>> >>> Vectors are set up unconditionally and create_zero_page() is called the >>> same way as before. >> >> So zero page is requested first and then on platforms with vector at >> address 0 requesting fails and we are left without configured IVT? > > I think you are misreading the patch. Please look at it again. > create_zero_page() is called only when the vector table is not at 0x0. > It has been like that without this patch, the patch doesn't change > anything here. No I get it. Reviewed-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> Thanks for bearing with me, Ahmad > > Sascha > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
