On Fri, Jul 26, 2013 at 4:28 AM, Cho KyongHo <pullip.cho@xxxxxxxxxxx> wrote:
> Prefetch buffer must be handled accurately, exact range of a buffer,
> frame by frame manually. Otherwise, it may causes page fault or
> deadlock in System MMU.
> Thus this patch removes prefetch buffer setting when System MMU is
> initialized(enabled).
>
> Signed-off-by: Cho KyongHo <pullip.cho@xxxxxxxxxxx>
Reviewed-by: Grant Grundler <grundler@xxxxxxxxxxxx>
BTW, cscope doesn't find any callers of exynos_sysmmu_enable().
Want to submit another patch to remove it?
(Note I'm talking about exynos_sysmmu_enable() without "__" prefix).
cheers,
grant
> ---
> drivers/iommu/exynos-iommu.c | 32 +++++++++++++++++++++++++++-----
> 1 files changed, 27 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> index cfc02ed..87f6bb7 100644
> --- a/drivers/iommu/exynos-iommu.c
> +++ b/drivers/iommu/exynos-iommu.c
> @@ -80,6 +80,8 @@
> #define CTRL_BLOCK 0x7
> #define CTRL_DISABLE 0x0
>
> +#define CFG_FLPDCACHE (1 << 20) /* System MMU 3.2+ only */
> +
> #define REG_MMU_CTRL 0x000
> #define REG_MMU_CFG 0x004
> #define REG_MMU_STATUS 0x008
> @@ -96,6 +98,9 @@
>
> #define REG_MMU_VERSION 0x034
>
> +#define MMU_MAJ_VER(reg) (reg >> 28)
> +#define MMU_MIN_VER(reg) ((reg >> 21) & 0x7F)
> +
> #define REG_PB0_SADDR 0x04C
> #define REG_PB0_EADDR 0x050
> #define REG_PB1_SADDR 0x054
> @@ -200,6 +205,22 @@ static bool is_sysmmu_active(struct sysmmu_drvdata *data)
> return data->activations > 0;
> }
>
> +static unsigned int __sysmmu_version(struct sysmmu_drvdata *data,
> + int idx, unsigned int *minor)
> +{
> + unsigned long major;
> +
> + major = readl(data->sfrbases[idx] + REG_MMU_VERSION);
> +
> + if (minor)
> + *minor = MMU_MIN_VER(major);
> +
> + if (MMU_MAJ_VER(major) > 3)
> + return 1;
> +
> + return MMU_MAJ_VER(major);
> +}
> +
> static void sysmmu_unblock(void __iomem *sfrbase)
> {
> __raw_writel(CTRL_ENABLE, sfrbase + REG_MMU_CTRL);
> @@ -460,14 +481,15 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
> data->pgtable = pgtable;
>
> for (i = 0; i < data->nsfrs; i++) {
> + unsigned int min;
> +
> __sysmmu_set_ptbase(data->sfrbases[i], pgtable);
>
> - if ((readl(data->sfrbases[i] + REG_MMU_VERSION) >> 28) == 3) {
> - /* System MMU version is 3.x */
> - __raw_writel((1 << 12) | (2 << 28),
> + if ((__sysmmu_version(data, i, &min) == 3) && (min > 1)) {
> + unsigned long cfg;
> + cfg = __raw_readl(data->sfrbases[i] + REG_MMU_CFG);
> + __raw_writel(cfg | CFG_FLPDCACHE,
> data->sfrbases[i] + REG_MMU_CFG);
> - __sysmmu_set_prefbuf(data->sfrbases[i], 0, -1, 0);
> - __sysmmu_set_prefbuf(data->sfrbases[i], 0, -1, 1);
> }
>
> __raw_writel(CTRL_ENABLE, data->sfrbases[i] + REG_MMU_CTRL);
> --
> 1.7.2.5
>
>
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