On Fri, Mar 06, 2015 at 10:48:17AM +0000, yong.wu@xxxxxxxxxxxx wrote: > From: Yong Wu <yong.wu@xxxxxxxxxxxx> > > This patch adds support for mediatek m4u (MultiMedia Memory Management Unit). > Currently this only supports m4u gen 2 with 2 levels of page table on mt8173. [...] > diff --git a/drivers/iommu/mtk_iommu_pagetable.c b/drivers/iommu/mtk_iommu_pagetable.c > new file mode 100644 > index 0000000..5fe9640 > --- /dev/null > +++ b/drivers/iommu/mtk_iommu_pagetable.c > @@ -0,0 +1,439 @@ > +/* > + * Copyright (c) 2014-2015 MediaTek Inc. > + * Author: Yong Wu <yong.wu@xxxxxxxxxxxx> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > +#include <linux/err.h> > +#include <linux/mm.h> > +#include <linux/iommu.h> > +#include <linux/errno.h> > +#include "asm/cacheflush.h" > + > +#include "mtk_iommu.h" > +#include "mtk_iommu_pagetable.h" > + > +/* 2 level pagetable: pgd -> pte */ > +#define F_PTE_TYPE_GET(regval) (regval & 0x3) > +#define F_PTE_TYPE_LARGE BIT(0) > +#define F_PTE_TYPE_SMALL BIT(1) > +#define F_PTE_B_BIT BIT(2) > +#define F_PTE_C_BIT BIT(3) > +#define F_PTE_BIT32_BIT BIT(9) > +#define F_PTE_S_BIT BIT(10) > +#define F_PTE_NG_BIT BIT(11) > +#define F_PTE_PA_LARGE_MSK (~0UL << 16) > +#define F_PTE_PA_LARGE_GET(regval) ((regval >> 16) & 0xffff) > +#define F_PTE_PA_SMALL_MSK (~0UL << 12) > +#define F_PTE_PA_SMALL_GET(regval) ((regval >> 12) & (~0)) > +#define F_PTE_TYPE_IS_LARGE_PAGE(pte) ((imu_pte_val(pte) & 0x3) == \ > + F_PTE_TYPE_LARGE) > +#define F_PTE_TYPE_IS_SMALL_PAGE(pte) ((imu_pte_val(pte) & 0x3) == \ > + F_PTE_TYPE_SMALL) This looks like the ARM short-descriptor format to me. Could you please add a new page table format to the io-pgtable code, so that other IOMMU drivers can make use of this? I know there was some interest in using short descriptor for the ARM SMMU, for example. Cheers, Will -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
