Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759222Ab0GBQ1Q (ORCPT ); Fri, 2 Jul 2010 12:27:16 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:59329 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759089Ab0GBQ1O convert rfc822-to-8bit (ORCPT ); Fri, 2 Jul 2010 12:27:14 -0400 From: "Guzman Lugo, Fernando" To: "Kanigeri, Hari" , "linux-omap@vger.kernel.org" , "linux-kernel@vger.kernel.org" CC: "ohad@wizery.com" , "hiroshi.doyu@nokia.com" , "ameya.palande@nokia.com" , "felipe.contreras@nokia.com" Date: Fri, 2 Jul 2010 11:27:09 -0500 Subject: RE: [PATCH 8/9] dspbridge: add map support for big buffers Thread-Topic: [PATCH 8/9] dspbridge: add map support for big buffers Thread-Index: AcsYsiGs9TjFYcgfQgej6lNQk7fClgAw2joAACMEqqA= Message-ID: <496565EC904933469F292DDA3F1663E602CBDD3ADE@dlee06.ent.ti.com> References: <1277943660-4112-1-git-send-email-x0095840@ti.com> <1277943660-4112-2-git-send-email-x0095840@ti.com> <1277943660-4112-3-git-send-email-x0095840@ti.com> <1277943660-4112-4-git-send-email-x0095840@ti.com> <1277943660-4112-5-git-send-email-x0095840@ti.com> <1277943660-4112-6-git-send-email-x0095840@ti.com> <1277943660-4112-7-git-send-email-x0095840@ti.com> <1277943660-4112-8-git-send-email-x0095840@ti.com> <1277943660-4112-9-git-send-email-x0095840@ti.com> <8F7AF80515AF0D4D93307E594F3CB40E4CAD34D5@dlee03.ent.ti.com> In-Reply-To: <8F7AF80515AF0D4D93307E594F3CB40E4CAD34D5@dlee03.ent.ti.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1781 Lines: 41 Hi Hari, > -----Original Message----- > From: Kanigeri, Hari > Sent: Thursday, July 01, 2010 6:36 PM > To: Guzman Lugo, Fernando; linux-omap@vger.kernel.org; linux- > kernel@vger.kernel.org > Cc: ohad@wizery.com; hiroshi.doyu@nokia.com; ameya.palande@nokia.com; > felipe.contreras@nokia.com; Guzman Lugo, Fernando > Subject: RE: [PATCH 8/9] dspbridge: add map support for big buffers > > Fernando, > > > - for_each_sg(sgt->sgl, sg, sgt->nents, i) > > - sg_set_page(sg, usr_pgs[i], PAGE_SIZE, 0); > > + da = iommu_vmap(mmu, da, sgt, IOVMF_ENDIAN_LITTLE | > > + IOVMF_ELSZ_32); > > -- iommu_vmap does the Kernel mapping to the buffers you are mapping to > DSP MMU. Why do you need Kernel mappings ? > > If there is no benefit in maintaining Kernel mapping I would rather call > iopgtable_store_entry directly to map the entries. Where inside iommu_vmap is the mapping done? I thought the kernel can access to that buffer after get_user_pages() where the user pages are pin and we can get a kernel address. The intention using iommu_vmap was to use api's proved by the iovmmu module. iommu_vmap() it is also tracking the mapped areas, so maybe the next step could be: remove dmm.c/h files and also proc_reserve/unreserved functions. If you think the function is unneeded steps and could affect the performance I can do the change to use only iopgtable_store_entry(). I think a kernel mapping is needed for flush/invalidate api's, please correct me if I am wrong. Regards, Fernando. > > Thank you, > Best regards, Hari -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/