From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH 2/5] iommu/mediatek: Add mt8173 IOMMU driver Date: Fri, 6 Mar 2015 10:58:21 +0000 Message-ID: <20150306105821.GE22377@arm.com> References: <1425638900-24989-1-git-send-email-yong.wu@mediatek.com> <1425638900-24989-3-git-send-email-yong.wu@mediatek.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1425638900-24989-3-git-send-email-yong.wu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: "yong.wu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org" Cc: Mark Rutland , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "srv_heupstream-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org" , Catalin Marinas , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Tomasz Figa , "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , Rob Herring , Daniel Kurtz , Sasha Hauer , Matthias Brugger , "linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , Lucas Stach List-Id: devicetree@vger.kernel.org On Fri, Mar 06, 2015 at 10:48:17AM +0000, yong.wu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org wrote: > From: Yong Wu > > 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 > + * > + * 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 > +#include > +#include > +#include > +#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