[PATCH 02/14] omap: Map only available sram memory

[Grazvydas Ignotas]

On Fri, Sep 17, 2010 at 12:47 PM, Santosh Shilimkar
<santosh.shilimkar at ti.com> wrote:
> Currently we map 1 MB section while setting up SRAM on OMAPs.
> The actual physcal OCM RAM available on OMAP SOCs is in order
> of KBs. This patch maps only available sram and removes some
> non necessary cpu_is_xxx checks.
>
> On the newer ARMs with speculation, this is dangerous and can
> result in untraceable aborts.
>
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar at ti.com>

This hangs OMAP3 pandora:

[    0.000000] Linux version
2.6.36-rc6-next-20101001-00002-ge76bb53-dirty (notaz at pixelinis) (gcc
version 4.3.3 (Sourcery G++ Lite 2009q1-20
[    0.000000] CPU: ARMv7 Processor [411fc082] revision 2 (ARMv7), cr=10c53c7f
[    0.000000] CPU: VIPT nonaliasing data cache, VIPT nonaliasing
instruction cache
[    0.000000] Machine: Pandora Handheld Console
[    0.000000] Ignoring unrecognised tag 0x54410008
[    0.000000] bootconsole [earlycon0] enabled
[    0.000000] Reserving 6422528 bytes SDRAM for VRAM
[    0.000000] Memory policy: ECC disabled, Data cache writeback
[    0.000000] OMAP3430/3530 ES2.1 (l2cache iva sgx neon isp )
[    0.000000] SRAM: Mapped pa 0x40200000 to va 0xfe400000 size: 0x10000
(stuck here)

reverting this fixes the problem.

> ---
>  arch/arm/plat-omap/sram.c |   25 +++++--------------------
>  1 files changed, 5 insertions(+), 20 deletions(-)
>
> diff --git a/arch/arm/plat-omap/sram.c b/arch/arm/plat-omap/sram.c
> index 226b2e8..10b3b4c 100644
> --- a/arch/arm/plat-omap/sram.c
> +++ b/arch/arm/plat-omap/sram.c
> @@ -220,20 +220,7 @@ void __init omap_map_sram(void)
>        if (omap_sram_size == 0)
>                return;
>
> -       if (cpu_is_omap24xx()) {
> -               omap_sram_io_desc[0].virtual = OMAP2_SRAM_VA;
> -
> -               base = OMAP2_SRAM_PA;
> -               base = ROUND_DOWN(base, PAGE_SIZE);
> -               omap_sram_io_desc[0].pfn = __phys_to_pfn(base);
> -       }
> -
>        if (cpu_is_omap34xx()) {
> -               omap_sram_io_desc[0].virtual = OMAP3_SRAM_VA;
> -               base = OMAP3_SRAM_PA;
> -               base = ROUND_DOWN(base, PAGE_SIZE);
> -               omap_sram_io_desc[0].pfn = __phys_to_pfn(base);
> -
>                /*
>                 * SRAM must be marked as non-cached on OMAP3 since the
>                 * CORE DPLL M2 divider change code (in SRAM) runs with the
> @@ -244,13 +231,11 @@ void __init omap_map_sram(void)
>                omap_sram_io_desc[0].type = MT_MEMORY_NONCACHED;
>        }
>
> -       if (cpu_is_omap44xx()) {
> -               omap_sram_io_desc[0].virtual = OMAP4_SRAM_VA;
> -               base = OMAP4_SRAM_PA;
> -               base = ROUND_DOWN(base, PAGE_SIZE);
> -               omap_sram_io_desc[0].pfn = __phys_to_pfn(base);
> -       }
> -       omap_sram_io_desc[0].length = 1024 * 1024;      /* Use section desc */
> +       omap_sram_io_desc[0].virtual = omap_sram_base;
> +       base = omap_sram_start;
> +       base = ROUND_DOWN(base, PAGE_SIZE);
> +       omap_sram_io_desc[0].pfn = __phys_to_pfn(base);
> +       omap_sram_io_desc[0].length = ROUND_DOWN(omap_sram_size, PAGE_SIZE);
>        iotable_init(omap_sram_io_desc, ARRAY_SIZE(omap_sram_io_desc));
>
>        printk(KERN_INFO "SRAM: Mapped pa 0x%08lx to va 0x%08lx size: 0x%lx\n",
> --
> 1.6.0.4
>
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