From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 298232C9C for ; Fri, 7 Jan 2022 17:22:27 +0000 (UTC) Received: from fraeml712-chm.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4JVqfJ4h6Fz67NKf; Sat, 8 Jan 2022 01:17:28 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml712-chm.china.huawei.com (10.206.15.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Fri, 7 Jan 2022 18:22:24 +0100 Received: from localhost (10.122.247.231) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2308.20; Fri, 7 Jan 2022 17:22:24 +0000 Date: Fri, 7 Jan 2022 17:22:22 +0000 From: Jonathan Cameron To: Ben Widawsky CC: , , , , Bjorn Helgaas , Alison Schofield , "Dan Williams" , Ira Weiny , "Vishal Verma" Subject: Re: [PATCH 13/13] cxl: Program decoders for regions Message-ID: <20220107172222.000068ac@huawei.com> In-Reply-To: <20220107163341.mb7pchctbfcaev7r@intel.com> References: <20220107003756.806582-1-ben.widawsky@intel.com> <20220107003756.806582-14-ben.widawsky@intel.com> <20220107161812.00007956@huawei.com> <20220107163341.mb7pchctbfcaev7r@intel.com> Organization: Huawei Technologies R&D (UK) Ltd. X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.29; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.122.247.231] X-ClientProxiedBy: lhreml701-chm.china.huawei.com (10.201.108.50) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected On Fri, 7 Jan 2022 08:33:41 -0800 Ben Widawsky wrote: > On 22-01-07 16:18:12, Jonathan Cameron wrote: > > On Thu, 6 Jan 2022 16:37:56 -0800 > > Ben Widawsky wrote: > > > > > Do the HDM decoder programming for all endpoints and host bridges in a > > > region. Switches are currently unimplemented. > > > > > > Signed-off-by: Ben Widawsky > > > --- > > > drivers/cxl/core/hdm.c | 198 +++++++++++++++++++++++++++++++++++++++++ > > > drivers/cxl/cxl.h | 3 + > > > drivers/cxl/region.c | 39 +++++++- > > > 3 files changed, 237 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c > > > index 44e48cea8cd4..c7293cbd8547 100644 > > > --- a/drivers/cxl/core/hdm.c > > > +++ b/drivers/cxl/core/hdm.c > > > @@ -242,3 +242,201 @@ int devm_cxl_enumerate_switch_decoders(struct cxl_port *port) > > > return 0; > > > } > > > EXPORT_SYMBOL_NS_GPL(devm_cxl_enumerate_switch_decoders, CXL); > > > + > > > +#define COMMIT_TIMEOUT_MS 10 > > > +static int wait_for_commit(struct cxl_decoder *cxld) > > > +{ > > > + struct cxl_port *port = to_cxl_port(cxld->dev.parent); > > > + const unsigned long start = jiffies; > > > + struct cxl_port_state *cxlps; > > > + void __iomem *hdm_decoder; > > > + unsigned long end = start; > > > + u32 ctrl; > > > + > > > + cxlps = dev_get_drvdata(&port->dev); > > > + hdm_decoder = cxlps->regs.hdm_decoder; > > > + > > > + do { > > > + end = jiffies; > > > + ctrl = readl(hdm_decoder + > > > + CXL_HDM_DECODER0_CTRL_OFFSET(cxld->id)); > > > + if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl)) > > > + break; > > > + > > > + if (time_after(end, start + COMMIT_TIMEOUT_MS)) { > > > + dev_err(&cxld->dev, "HDM decoder commit timeout %x\n", ctrl); > > > + return -ETIMEDOUT; > > > + } > > > + if ((ctrl & CXL_HDM_DECODER0_CTRL_COMMIT_ERROR) != 0) { > > > + dev_err(&cxld->dev, "HDM decoder commit error %x\n", ctrl); > > > + return -ENXIO; > > > + } > > > + } while (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl)); > > > > Hi Ben, > > > > Thanks for posting this btw - it's very helpful indeed for hammering out bugs > > in the qemu code and to identify what isn't there yet. > > > > Took me a while to work out how this seemed to succeed on QEMU with no > > implementation of the commit for the host bridges (just adding that now ;) > > Reason is this condition is inverse of what I think you intend. > > > > Given you have an exit condition above this could probably just be a while (1) > > loop. > > > > Jonathan > > Quick response without looking at code. I thought I did implement this in QEMU, > but you're correct that the logic is inverted. If you have a QEMU branch for me > to use when I fix this, please let me know. The branch I got from your gitlab has it specifically for the type3 device, but not more generally. Qemu wise will see if I can hammer something into a shape to share but might take a little while to hammer out remaining bugs. I've made a few fiddly changes to try and simplify the setup + avoid fixed PA address ranges anywhere. Jonathan > > > > > > + > > > + return 0; > > > +} > > > + > > > +/** > > > + * cxl_commit_decoder() - Program a configured cxl_decoder > > > + * @cxld: The preconfigured cxl decoder. > > > + * > > > + * A cxl decoder that is to be committed should have been earmarked as enabled. > > > + * This mechanism acts as a soft reservation on the decoder. > > > + * > > > + * Returns 0 if commit was successful, negative error code otherwise. > > > + */ > > > +int cxl_commit_decoder(struct cxl_decoder *cxld) > > > +{ > > > + u32 ctrl, tl_lo, tl_hi, base_lo, base_hi, size_lo, size_hi; > > > + struct cxl_port *port = to_cxl_port(cxld->dev.parent); > > > + struct cxl_port_state *cxlps; > > > + void __iomem *hdm_decoder; > > > + int rc; > > > + > > > + /* > > > + * Decoder flags are entirely software controlled and therefore this > > > + * case is purely a driver bug. > > > + */ > > > + if (dev_WARN_ONCE(&port->dev, (cxld->flags & CXL_DECODER_F_ENABLE) != 0, > > > + "Invalid %s enable state\n", dev_name(&cxld->dev))) > > > + return -ENXIO; > > > + > > > + cxlps = dev_get_drvdata(&port->dev); > > > + hdm_decoder = cxlps->regs.hdm_decoder; > > > + ctrl = readl(hdm_decoder + CXL_HDM_DECODER0_CTRL_OFFSET(cxld->id)); > > > + > > > + /* > > > + * A decoder that's currently active cannot be changed without the > > > + * system being quiesced. While the driver should prevent against this, > > > + * for a variety of reasons the hardware might not be in sync with the > > > + * hardware and so, do not splat on error. > > > + */ > > > + size_hi = readl(hdm_decoder + > > > + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(cxld->id)); > > > + size_lo = > > > + readl(hdm_decoder + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(cxld->id)); > > > + if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl) && > > > + (size_lo + size_hi)) { > > > + dev_err(&port->dev, "Tried to change an active decoder (%s)\n", > > > + dev_name(&cxld->dev)); > > > + return -EBUSY; > > > + } > > > + > > > + u32p_replace_bits(&ctrl, 8 - ilog2(cxld->interleave_granularity), > > > + CXL_HDM_DECODER0_CTRL_IG_MASK); > > > + u32p_replace_bits(&ctrl, ilog2(cxld->interleave_ways), > > > + CXL_HDM_DECODER0_CTRL_IW_MASK); > > > + u32p_replace_bits(&ctrl, 1, CXL_HDM_DECODER0_CTRL_COMMIT); > > > + > > > + /* TODO: set based on type */ > > > + u32p_replace_bits(&ctrl, 1, CXL_HDM_DECODER0_CTRL_TYPE); > > > + > > > + base_lo = FIELD_PREP(GENMASK(31, 28), > > > + (u32)(cxld->decoder_range.start & 0xffffffff)); > > > + base_hi = FIELD_PREP(~0, (u32)(cxld->decoder_range.start >> 32)); > > > + > > > + size_lo = (u32)(range_len(&cxld->decoder_range)) & GENMASK(31, 28); > > > + size_hi = (u32)((range_len(&cxld->decoder_range) >> 32)); > > > + > > > + if (cxld->nr_targets > 0) { > > > + tl_lo |= FIELD_PREP(GENMASK(7, 0), cxld->target[0]->port_id); > > > + if (cxld->interleave_ways > 1) > > > + tl_lo |= FIELD_PREP(GENMASK(15, 8), > > > + cxld->target[1]->port_id); > > > + if (cxld->interleave_ways > 2) > > > + tl_lo |= FIELD_PREP(GENMASK(23, 16), > > > + cxld->target[2]->port_id); > > > + if (cxld->interleave_ways > 3) > > > + tl_lo |= FIELD_PREP(GENMASK(31, 24), > > > + cxld->target[3]->port_id); > > > + if (cxld->interleave_ways > 4) > > > + tl_hi |= FIELD_PREP(GENMASK(7, 0), > > > + cxld->target[4]->port_id); > > > + if (cxld->interleave_ways > 5) > > > + tl_hi |= FIELD_PREP(GENMASK(15, 8), > > > + cxld->target[5]->port_id); > > > + if (cxld->interleave_ways > 6) > > > + tl_hi |= FIELD_PREP(GENMASK(23, 16), > > > + cxld->target[6]->port_id); > > > + if (cxld->interleave_ways > 7) > > > + tl_hi |= FIELD_PREP(GENMASK(31, 24), > > > + cxld->target[7]->port_id); > > > + > > > + writel(tl_hi, hdm_decoder + CXL_HDM_DECODER0_TL_HIGH(cxld->id)); > > > + writel(tl_lo, hdm_decoder + CXL_HDM_DECODER0_TL_LOW(cxld->id)); > > > + } > > > + > > > + writel(size_hi, > > > + hdm_decoder + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(cxld->id)); > > > + writel(size_lo, > > > + hdm_decoder + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(cxld->id)); > > > + writel(base_hi, > > > + hdm_decoder + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(cxld->id)); > > > + writel(base_lo, > > > + hdm_decoder + CXL_HDM_DECODER0_BASE_LOW_OFFSET(cxld->id)); > > > + writel(ctrl, hdm_decoder + CXL_HDM_DECODER0_CTRL_OFFSET(cxld->id)); > > > + > > > + rc = wait_for_commit(cxld); > > > + if (rc) > > > + return rc; > > > + > > > + cxld->flags |= CXL_DECODER_F_ENABLE; > > > + > > > +#define DPORT_TL_STR "%d %d %d %d %d %d %d %d" > > > +#define DPORT(i) \ > > > + (cxld->nr_targets && cxld->interleave_ways > (i)) ? \ > > > + cxld->target[(i)]->port_id : \ > > > + -1 > > > +#define DPORT_TL \ > > > + DPORT(0), DPORT(1), DPORT(2), DPORT(3), DPORT(4), DPORT(5), DPORT(6), \ > > > + DPORT(7) > > > + > > > + dev_dbg(&port->dev, > > > + "%s\n\tBase %pa\n\tSize %llu\n\tIG %u\n\tIW %u\n\tTargetList: " DPORT_TL_STR, > > > + dev_name(&cxld->dev), &cxld->decoder_range.start, > > > + range_len(&cxld->decoder_range), cxld->interleave_granularity, > > > + cxld->interleave_ways, DPORT_TL); > > > +#undef DPORT_TL > > > +#undef DPORT > > > +#undef DPORT_TL_STR > > > + return 0; > > > +} > > > +EXPORT_SYMBOL_GPL(cxl_commit_decoder); > > > + > > > +/** > > > + * cxl_disable_decoder() - Disables a decoder > > > + * @cxld: The active cxl decoder. > > > + * > > > + * CXL decoders (as of 2.0 spec) have no way to deactivate them other than to > > > + * set the size of the HDM to 0. This function will clear all registers, and if > > > + * the decoder is active, commit the 0'd out registers. > > > + */ > > > +void cxl_disable_decoder(struct cxl_decoder *cxld) > > > +{ > > > + struct cxl_port *port = to_cxl_port(cxld->dev.parent); > > > + struct cxl_port_state *cxlps; > > > + void __iomem *hdm_decoder; > > > + u32 ctrl; > > > + > > > + cxlps = dev_get_drvdata(&port->dev); > > > + hdm_decoder = cxlps->regs.hdm_decoder; > > > + ctrl = readl(hdm_decoder + CXL_HDM_DECODER0_CTRL_OFFSET(cxld->id)); > > > + > > > + if (dev_WARN_ONCE(&port->dev, (cxld->flags & CXL_DECODER_F_ENABLE) == 0, > > > + "Invalid decoder enable state\n")) > > > + return; > > > + > > > + /* There's no way to "uncommit" a committed decoder, only 0 size it */ > > > + writel(0, hdm_decoder + CXL_HDM_DECODER0_TL_HIGH(cxld->id)); > > > + writel(0, hdm_decoder + CXL_HDM_DECODER0_TL_LOW(cxld->id)); > > > + writel(0, hdm_decoder + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(cxld->id)); > > > + writel(0, hdm_decoder + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(cxld->id)); > > > + writel(0, hdm_decoder + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(cxld->id)); > > > + writel(0, hdm_decoder + CXL_HDM_DECODER0_BASE_LOW_OFFSET(cxld->id)); > > > + > > > + /* If the device isn't actually active, just zero out all the fields */ > > > + if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl)) > > > + writel(CXL_HDM_DECODER0_CTRL_COMMIT, > > > + hdm_decoder + CXL_HDM_DECODER0_CTRL_OFFSET(cxld->id)); > > > +} > > > +EXPORT_SYMBOL_GPL(cxl_disable_decoder); > > > diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h > > > index 79bca9a8246c..587b75f7fa53 100644 > > > --- a/drivers/cxl/cxl.h > > > +++ b/drivers/cxl/cxl.h > > > @@ -54,6 +54,7 @@ > > > #define CXL_HDM_DECODER0_CTRL_IW_MASK GENMASK(7, 4) > > > #define CXL_HDM_DECODER0_CTRL_COMMIT BIT(9) > > > #define CXL_HDM_DECODER0_CTRL_COMMITTED BIT(10) > > > +#define CXL_HDM_DECODER0_CTRL_COMMIT_ERROR BIT(11) > > > #define CXL_HDM_DECODER0_CTRL_TYPE BIT(12) > > > #define CXL_HDM_DECODER0_TL_LOW(i) (0x20 * (i) + 0x24) > > > #define CXL_HDM_DECODER0_TL_HIGH(i) (0x20 * (i) + 0x28) > > > @@ -364,6 +365,8 @@ int devm_cxl_add_dport(struct cxl_port *port, struct device *dport, int port_id, > > > struct cxl_dport *cxl_find_dport_by_dev(struct cxl_port *port, > > > const struct device *dev); > > > struct cxl_port *ep_find_cxl_port(struct cxl_memdev *cxlmd, unsigned int depth); > > > +int cxl_commit_decoder(struct cxl_decoder *cxld); > > > +void cxl_disable_decoder(struct cxl_decoder *cxld); > > > > > > struct cxl_decoder *to_cxl_decoder(struct device *dev); > > > bool is_cxl_decoder(struct device *dev); > > > diff --git a/drivers/cxl/region.c b/drivers/cxl/region.c > > > index 3120b65b0bc5..fd82d37ba573 100644 > > > --- a/drivers/cxl/region.c > > > +++ b/drivers/cxl/region.c > > > @@ -580,10 +580,30 @@ static void cleanup_staged_decoders(struct cxl_region *region) > > > } > > > } > > > > > > -static int bind_region(const struct cxl_region *region) > > > +static int bind_region(struct cxl_region *region) > > > { > > > - /* TODO: */ > > > - return 0; > > > + struct cxl_decoder *cxld, *d; > > > + int rc; > > > + > > > + list_for_each_entry_safe(cxld, d, ®ion->staged_list, region_link) { > > > + rc = cxl_commit_decoder(cxld); > > > + if (!rc) > > > + list_move_tail(&cxld->region_link, ®ion->commit_list); > > > + else > > > + break; > > > + } > > > + > > > + list_for_each_entry_safe(cxld, d, ®ion->commit_list, region_link) { > > > + if (rc) > > > + cxl_disable_decoder(cxld); > > > + list_del(&cxld->region_link); > > > + } > > > + > > > + if (rc) > > > + cleanup_staged_decoders((struct cxl_region *)region); > > > + > > > + BUG_ON(!list_empty(®ion->staged_list)); > > > + return rc; > > > } > > > > > > static int cxl_region_probe(struct device *dev) > > > @@ -650,9 +670,22 @@ static int cxl_region_probe(struct device *dev) > > > return ret; > > > } > > > > > > +static void cxl_region_remove(struct device *dev) > > > +{ > > > + struct cxl_region *region = to_cxl_region(dev); > > > + struct cxl_decoder *cxld, *d; > > > + > > > + list_for_each_entry_safe(cxld, d, ®ion->commit_list, region_link) { > > > + cxl_disable_decoder(cxld); > > > + list_del(&cxld->region_link); > > > + cxl_put_decoder(cxld); > > > + } > > > +} > > > + > > > static struct cxl_driver cxl_region_driver = { > > > .name = "cxl_region", > > > .probe = cxl_region_probe, > > > + .remove = cxl_region_remove, > > > .id = CXL_DEVICE_REGION, > > > }; > > > module_cxl_driver(cxl_region_driver); > >