[RFC,v2,28/28] cxl: Program decoders for regions

Message ID	20211022183709.1199701-29-ben.widawsky@intel.com
State	New, archived
Headers	show Return-Path: <linux-cxl-owner@kernel.org> From: Ben Widawsky <ben.widawsky@intel.com> To: linux-cxl@vger.kernel.org, Chet Douglas <chet.r.douglas@intel.com> Cc: Ben Widawsky <ben.widawsky@intel.com>, Alison Schofield <alison.schofield@intel.com>, Dan Williams <dan.j.williams@intel.com>, Ira Weiny <ira.weiny@intel.com>, Jonathan Cameron <Jonathan.Cameron@Huawei.com>, Vishal Verma <vishal.l.verma@intel.com> Subject: [RFC PATCH v2 28/28] cxl: Program decoders for regions Date: Fri, 22 Oct 2021 11:37:09 -0700 Message-Id: <20211022183709.1199701-29-ben.widawsky@intel.com> In-Reply-To: <20211022183709.1199701-1-ben.widawsky@intel.com> References: <20211022183709.1199701-1-ben.widawsky@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	CXL Region Creation / HDM decoder programming \| expand [RFC,v2,00/28] CXL Region Creation / HDM decoder programming [RFC,v2,01/28] cxl: Rename CXL_MEM to CXL_PCI [RFC,v2,02/28] cxl: Move register block enumeration to core [RFC,v2,03/28] cxl/acpi: Map component registers for Root Ports [RFC,v2,04/28] cxl: Add helper for new drivers [RFC,v2,05/28] cxl/core: Convert decoder range to resource [RFC,v2,06/28] cxl: Introduce endpoint decoders [RFC,v2,07/28] cxl/core: Move target population locking to caller [RFC,v2,08/28] cxl/port: Introduce a port driver [RFC,v2,09/28] cxl/acpi: Map single port host bridge component registers [RFC,v2,10/28] cxl/core: Store global list of root ports [RFC,v2,11/28] cxl/acpi: Rescan bus at probe completion [RFC,v2,12/28] cxl/core: Store component register base for memdevs [RFC,v2,13/28] cxl: Flesh out register names [RFC,v2,14/28] cxl: Hide devm host for ports [RFC,v2,15/28] cxl/core: Introduce API to scan switch ports [RFC,v2,16/28] cxl: Introduce cxl_mem driver [RFC,v2,17/28] cxl: Disable switch hierarchies for now [RFC,v2,18/28] cxl/region: Add region creation ABI [RFC,v2,19/28] cxl/region: Introduce concept of region configuration [RFC,v2,20/28] cxl/region: Introduce a cxl_region driver [RFC,v2,21/28] cxl/acpi: Handle address space allocation [RFC,v2,22/28] cxl/region: Address space allocation [RFC,v2,23/28] cxl/region: Implement XHB verification [RFC,v2,24/28] cxl/region: HB port config verification [RFC,v2,25/28] cxl/region: Record host bridge target list [RFC,v2,26/28] cxl/mem: Store the endpoint's uport [RFC,v2,27/28] cxl/region: Gather HDM decoder resources [RFC,v2,28/28] cxl: Program decoders for regions

diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 79d22992fddf..f2ee26ac2398 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -52,6 +52,7 @@ #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) @@ -337,6 +338,8 @@ struct cxl_dport *cxl_find_dport_by_dev(struct cxl_port *port, struct device *dev); struct cxl_decoder *cxl_pop_decoder(struct cxl_port *port); void cxl_push_decoder(struct cxl_decoder *cxld); +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_root_decoder(struct device *dev); diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c index 5d35ccf2407f..67143c7f59bb 100644 --- a/drivers/cxl/port.c +++ b/drivers/cxl/port.c @@ -99,6 +99,202 @@ struct cxl_port_data { } caps; }; +#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_data *cpd; + void __iomem *hdm_decoder; + unsigned long end = start; + u32 ctrl; + + cpd = dev_get_drvdata(&port->dev); + hdm_decoder = cpd->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)); + + 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_data *cpd; + 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_EN) == 0, + "Invalid %s enable state\n", dev_name(&cxld->dev))) + return -ENXIO; + + cpd = dev_get_drvdata(&port->dev); + hdm_decoder = cpd->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->res.start & 0xffffffff)); + base_hi = FIELD_PREP(~0, (u32)(cxld->res.start >> 32)); + + size_lo = (u32)(resource_size(&cxld->res)) & GENMASK(31, 28); + size_hi = (u32)((resource_size(&cxld->res) >> 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; + +#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->res.start, + resource_size(&cxld->res), 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_data *cpd; + void __iomem *hdm_decoder; + u32 ctrl; + + cpd = dev_get_drvdata(&port->dev); + hdm_decoder = cpd->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_EN) == 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); + static inline int cxl_hdm_decoder_ig(u32 ctrl) { int val = FIELD_GET(CXL_HDM_DECODER0_CTRL_IG_MASK, ctrl); diff --git a/drivers/cxl/region.c b/drivers/cxl/region.c index f4d190ede3ee..05e7ca3d0900 100644 --- a/drivers/cxl/region.c +++ b/drivers/cxl/region.c @@ -526,7 +526,38 @@ static int gather_hdm_decoders(const struct cxl_region *region, struct decoder_p static int bind_region(const struct cxl_region *region) { - /* TODO: */ + const struct decoder_programming *p = &region->state; + int i, rc; + + for (i = 0; i < p->hb_count; i++) { + struct cxl_decoder *cxld = p->hbs[i].cxld; + int j; + + cxld->res = (struct resource)DEFINE_RES_MEM(region->res->start, + region->size); + cxld->interleave_granularity = region->ig; + cxld->interleave_ways = p->hbs[i].rp_count; + for (j = 0; j < p->hbs[i].rp_count; j++) + cxld->target[j] = p->hbs[i].rp_target_list[j]; + + rc = cxl_commit_decoder(cxld); + if (rc) + return rc; + } + + for (i = 0; i < region_ways(region); i++) { + struct cxl_decoder *cxld = p->ep_cxld[i]; + + cxld->res = (struct resource)DEFINE_RES_MEM(region->res->start, + region->size); + cxld->interleave_granularity = region->ig; + cxld->interleave_ways = region_ways(region); + + rc = cxl_commit_decoder(cxld); + if (rc) + return rc; + } + return 0; }

[RFC,v2,28/28] cxl: Program decoders for regions

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