Subject: [PATCH v2] ARM: mm: Fix stage-2 device memory attributes

From: [email-masked] (Catalin Marinas)
Date: Mon, 27 Jan 2014 16:57:31 +0000

On Mon, Jan 27, 2014 at 11:16:57AM +0000, Marc Zyngier wrote:
> On 24/01/14 23:37, Christoffer Dall wrote:
> > On Sat, Jan 04, 2014 at 08:27:23AM -0800, Christoffer Dall wrote:
> >> --- a/arch/arm/include/asm/pgtable-3level.h
> >> +++ b/arch/arm/include/asm/pgtable-3level.h
> >> @@ -120,13 +120,19 @@
> >>  /*
> >>   * 2nd stage PTE definitions for LPAE.
> >>   */
> >> -#define L_PTE_S2_MT_UNCACHED	 (_AT(pteval_t, 0x5) << 2) /* MemAttr[3:0] */
> >> -#define L_PTE_S2_MT_WRITETHROUGH (_AT(pteval_t, 0xa) << 2) /* MemAttr[3:0] */
> >> -#define L_PTE_S2_MT_WRITEBACK	 (_AT(pteval_t, 0xf) << 2) /* MemAttr[3:0] */
> >> -#define L_PTE_S2_RDONLY		 (_AT(pteval_t, 1) << 6)   /* HAP[1]   */
> >> -#define L_PTE_S2_RDWR		 (_AT(pteval_t, 3) << 6)   /* HAP[2:1] */
> >> -
> >> -#define L_PMD_S2_RDWR		 (_AT(pmdval_t, 3) << 6)   /* HAP[2:1] */
> >> +#define L_PTE_S2_MT_UNCACHED		(_AT(pteval_t, 0x0) << 2) /* strongly ordered */
> >> +#define L_PTE_S2_MT_WRITETHROUGH	(_AT(pteval_t, 0xa) << 2) /* normal inner write-through */
> >> +#define L_PTE_S2_MT_WRITEBACK		(_AT(pteval_t, 0xf) << 2) /* normal inner write-back */
> >> +#define L_PTE_S2_MT_DEV_SHARED		(_AT(pteval_t, 0x1) << 2) /* device */
> >> +#define L_PTE_S2_MT_DEV_NONSHARED	(_AT(pteval_t, 0x1) << 2) /* device */
> >> +#define L_PTE_S2_MT_DEV_WC		(_AT(pteval_t, 0x5) << 2) /* normal non-cacheable */
> >> +#define L_PTE_S2_MT_DEV_CACHED		(_AT(pteval_t, 0xf) << 2) /* normal inner write-back */
> >> +#define L_PTE_S2_MT_MASK		(_AT(pteval_t, 0xf) << 2)
> >> +
> >> +#define L_PTE_S2_RDONLY			(_AT(pteval_t, 1) << 6)   /* HAP[1]   */
> >> +#define L_PTE_S2_RDWR			(_AT(pteval_t, 3) << 6)   /* HAP[2:1] */
> >> +
> >> +#define L_PMD_S2_RDWR			(_AT(pmdval_t, 3) << 6)   /* HAP[2:1] */
> >>  
> >>  /*
> >>   * Hyp-mode PL2 PTE definitions for LPAE.
> 
> The change makes sense to me. arm64 uses a slightly different approach,
> by using a PTE_S2_MEMATTR macro, but I'm not sure that would work for ARM.
> 
> Russell, Catalin: could you please have a look at this?

Do we actually need more than Normal Cacheable and Device for stage 2?

-- 
Catalin