Messages in this thread | | | Date | Mon, 10 Sep 2018 17:50:11 +0100 | From | Catalin Marinas <> | Subject | Re: [RFC 1/3] arm: mm: reordering memory type table |
| |
On Thu, Sep 06, 2018 at 07:22:10PM +0900, Minchan Kim wrote: > diff --git a/arch/arm/include/asm/pgtable-2level.h b/arch/arm/include/asm/pgtable-2level.h > index 92fd2c8a9af0..91b99fadcba1 100644 > --- a/arch/arm/include/asm/pgtable-2level.h > +++ b/arch/arm/include/asm/pgtable-2level.h > @@ -164,14 +164,23 @@ > #define L_PTE_MT_BUFFERABLE (_AT(pteval_t, 0x01) << 2) /* 0001 */ > #define L_PTE_MT_WRITETHROUGH (_AT(pteval_t, 0x02) << 2) /* 0010 */ > #define L_PTE_MT_WRITEBACK (_AT(pteval_t, 0x03) << 2) /* 0011 */ > +#define L_PTE_MT_DEV_SHARED (_AT(pteval_t, 0x04) << 2) /* 0100 */ > #define L_PTE_MT_MINICACHE (_AT(pteval_t, 0x06) << 2) /* 0110 (sa1100, xscale) */ > #define L_PTE_MT_WRITEALLOC (_AT(pteval_t, 0x07) << 2) /* 0111 */ > -#define L_PTE_MT_DEV_SHARED (_AT(pteval_t, 0x04) << 2) /* 0100 */ > -#define L_PTE_MT_DEV_NONSHARED (_AT(pteval_t, 0x0c) << 2) /* 1100 */ > +#if defined(CONFIG_CPU_V7) || defined(CONFIG_CPU_V7M) || \ > + defined (CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K) > +#define L_PTE_MT_DEV_WC L_PTE_MT_BUFFERABLE > +#define L_PTE_MT_DEV_CACHED L_PTE_MT_WRITEBACK > +#define L_PTE_MT_DEV_NONSHARED L_PTE_MT_MINICACHE
I think you can just ignore v7M here, it doesn't have an MMU.
You are defining L_PTE_MT_DEV_NONSHARED to L_PTE_MT_MINICACHE but what I think you just meant is index 6 in the cpu_v6_mt_table which I would use explicitly to avoid confusion.
Anyway, on ARMv7 or ARMv6+LPAE, the non-shared device gets mapped to shared device in hardware. Looking through the arm32 code, it seems that MT_DEVICE_NONSHARED is used by arch/arm/mach-shmobile/setup-r8a7779.c and IIUC that's a v7 platform (R-Car H1, Cortex-A9). I think the above should be defined to L_PTE_MT_DEV_SHARED, unless I miss any place where DEV_NONSHARED is relevant on ARMv6 (adding Simon to confirm on shmobile).
> diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S > index 81d0efb055c6..f896a30653fa 100644 > --- a/arch/arm/mm/proc-macros.S > +++ b/arch/arm/mm/proc-macros.S > @@ -134,21 +134,21 @@ > .macro armv6_mt_table pfx > \pfx\()_mt_table:
Since you changed the MT index, you'd have to fix proc-v7-*levels.S as well. If you define DEV_NONSHARED to SHARED, I think you only need to update the index for L_PTE_MT_VECTORS.
-- Catalin
| |