From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752198AbcFUOlv (ORCPT ); Tue, 21 Jun 2016 10:41:51 -0400 Received: from mail-yw0-f169.google.com ([209.85.161.169]:32966 "EHLO mail-yw0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752166AbcFUOlt (ORCPT ); Tue, 21 Jun 2016 10:41:49 -0400 MIME-Version: 1.0 In-Reply-To: <1466475876-5937-1-git-send-email-zhang.chunyan@linaro.org> References: <1466475876-5937-1-git-send-email-zhang.chunyan@linaro.org> From: Mathieu Poirier Date: Tue, 21 Jun 2016 08:40:18 -0600 Message-ID: Subject: Re: [PATCH V2] coresight-stm: support mmapping channel regions with mmio_addr To: Chunyan Zhang Cc: "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Al Grant , Lyra Zhang Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 20 June 2016 at 20:24, Chunyan Zhang wrote: > CoreSight STM device allows direct mapping of the channel regions to > userspace for zero-copy writing. To support this ability, the STM > framework has provided a hook 'mmio_addr', this patch just implemented > this hook for CoreSight STM. > > This patch also added an item into 'channel_space' to save the physical > base address of channel region which mmap operation needs to know. > > Signed-off-by: Chunyan Zhang > --- > drivers/hwtracing/coresight/coresight-stm.c | 22 ++++++++++++++++++++++ > 1 file changed, 22 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c > index 73be58a..482c8bb 100644 > --- a/drivers/hwtracing/coresight/coresight-stm.c > +++ b/drivers/hwtracing/coresight/coresight-stm.c > @@ -105,10 +105,12 @@ module_param_named( > /** > * struct channel_space - central management entity for extended ports > * @base: memory mapped base address where channels start. > + * @phys: physical base address of channel region. > * @guaraneed: is the channel delivery guaranteed. > */ > struct channel_space { > void __iomem *base; > + phys_addr_t phys; > unsigned long *guaranteed; > }; > > @@ -356,6 +358,23 @@ static void stm_generic_unlink(struct stm_data *stm_data, > stm_disable(drvdata->csdev); > } > > +static phys_addr_t > +stm_mmio_addr(struct stm_data *stm_data, unsigned int master, > + unsigned int channel, unsigned int nr_chans) > +{ > + struct stm_drvdata *drvdata = container_of(stm_data, > + struct stm_drvdata, stm); > + phys_addr_t addr; > + > + addr = drvdata->chs.phys + channel * BYTES_PER_CHANNEL; > + > + if (offset_in_page(addr) || > + offset_in_page(nr_chans * BYTES_PER_CHANNEL)) > + return 0; > + > + return addr; > +} > + > static long stm_generic_set_options(struct stm_data *stm_data, > unsigned int master, > unsigned int channel, > @@ -761,7 +780,9 @@ static void stm_init_generic_data(struct stm_drvdata *drvdata) > drvdata->stm.sw_end = 1; > drvdata->stm.hw_override = true; > drvdata->stm.sw_nchannels = drvdata->numsp; > + drvdata->stm.sw_mmiosz = BYTES_PER_CHANNEL; > drvdata->stm.packet = stm_generic_packet; > + drvdata->stm.mmio_addr = stm_mmio_addr; > drvdata->stm.link = stm_generic_link; > drvdata->stm.unlink = stm_generic_unlink; > drvdata->stm.set_options = stm_generic_set_options; > @@ -808,6 +829,7 @@ static int stm_probe(struct amba_device *adev, const struct amba_id *id) > ret = stm_get_resource_byname(np, "stm-stimulus-base", &ch_res); > if (ret) > return ret; > + drvdata->chs.phys = ch_res.start; > > base = devm_ioremap_resource(dev, &ch_res); > if (IS_ERR(base)) > -- > 1.9.1 > Applied - thanks. Mathieu