From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: Ben Widawsky <ben.widawsky@intel.com>
Cc: <linux-cxl@vger.kernel.org>,
Chet Douglas <chet.r.douglas@intel.com>,
Alison Schofield <alison.schofield@intel.com>,
Dan Williams <dan.j.williams@intel.com>,
Ira Weiny <ira.weiny@intel.com>,
Vishal Verma <vishal.l.verma@intel.com>
Subject: Re: [RFC PATCH v2 08/28] cxl/port: Introduce a port driver
Date: Wed, 3 Nov 2021 15:18:59 +0000 [thread overview]
Message-ID: <20211103151859.0000493a@Huawei.com> (raw)
In-Reply-To: <20211022183709.1199701-9-ben.widawsky@intel.com>
On Fri, 22 Oct 2021 11:36:49 -0700
Ben Widawsky <ben.widawsky@intel.com> wrote:
> The CXL port driver will be responsible for managing the decoder
> resources contained within the port. It will also provide APIs that
> other drivers will consume for managing these resources.
>
> Since the port driver is responsible for instantiating new decoders, and
> it does so during probe(), a new API is needed to add decoders for
> callers which already hold the device lock of the port.
>
> This patch has no functional change because no driver is registering new
> ports and the root ports that are already registered should be skipped.
>
> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Hi Ben, A few fairly generic comments on stuff noticed whilst
catching up with discussion around this series.
Jonathan
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index 91b8fd54bc93..ad22caf9135c 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> @@ -17,6 +17,9 @@
> * (port-driver, region-driver, nvdimm object-drivers... etc).
> */
>
> +/* CXL 2.0 8.2.4 CXL Component Register Layout and Definition */
> +#define CXL_COMPONENT_REG_BLOCK_SIZE SZ_64K
> +
> /* CXL 2.0 8.2.5 CXL.cache and CXL.mem Registers*/
> #define CXL_CM_OFFSET 0x1000
> #define CXL_CM_CAP_HDR_OFFSET 0x0
> @@ -36,11 +39,22 @@
> #define CXL_HDM_DECODER_CAP_OFFSET 0x0
> #define CXL_HDM_DECODER_COUNT_MASK GENMASK(3, 0)
> #define CXL_HDM_DECODER_TARGET_COUNT_MASK GENMASK(7, 4)
> -#define CXL_HDM_DECODER0_BASE_LOW_OFFSET 0x10
> -#define CXL_HDM_DECODER0_BASE_HIGH_OFFSET 0x14
> -#define CXL_HDM_DECODER0_SIZE_LOW_OFFSET 0x18
> -#define CXL_HDM_DECODER0_SIZE_HIGH_OFFSET 0x1c
> -#define CXL_HDM_DECODER0_CTRL_OFFSET 0x20
> +#define CXL_HDM_DECODER_INTERLEAVE_11_8 BIT(8)
> +#define CXL_HDM_DECODER_INTERLEAVE_14_12 BIT(9)
> +#define CXL_HDM_DECODER_CTRL_OFFSET 0x4
> +#define CXL_HDM_DECODER_ENABLE BIT(1)
> +#define CXL_HDM_DECODER0_BASE_LOW_OFFSET(i) (0x20 * (i) + 0x10)
> +#define CXL_HDM_DECODER0_BASE_HIGH_OFFSET(i) (0x20 * (i) + 0x14)
> +#define CXL_HDM_DECODER0_SIZE_LOW_OFFSET(i) (0x20 * (i) + 0x18)
> +#define CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(i) (0x20 * (i) + 0x1c)
> +#define CXL_HDM_DECODER0_CTRL_OFFSET(i) (0x20 * (i) + 0x20)
> +#define CXL_HDM_DECODER0_CTRL_IG_MASK GENMASK(3, 0)
> +#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_TYPE BIT(12)
> +#define CXL_HDM_DECODER0_TL_LOW(i) (0x20 * (i) + 0x24)
> +#define CXL_HDM_DECODER0_TL_HIGH(i) (0x20 * (i) + 0x28)
CXL_HDM_DECODERX_TL_HIGH etc perhaps as no longer just decoder 0?
> diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c
> new file mode 100644
> index 000000000000..ebbfb72ae995
> --- /dev/null
> +++ b/drivers/cxl/port.c
...
> +
> +static u64 get_decoder_size(void __iomem *hdm_decoder, int n)
> +{
> + u32 ctrl = readl(hdm_decoder + CXL_HDM_DECODER0_CTRL_OFFSET(n));
> +
> + if (!!FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl))
Drop the !! as doesn't do anything useful.
> + return 0;
> +
> + return ioread64_hi_lo(hdm_decoder +
> + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(n));
> +}
> +
> +static bool is_endpoint_port(struct cxl_port *port)
> +{
> + if (!port->uport->driver)
> + return false;
> +
> + return to_cxl_drv(port->uport->driver)->id ==
> + CXL_DEVICE_MEMORY_EXPANDER;
> +}
> +
> +static int enumerate_hdm_decoders(struct cxl_port *port,
> + struct cxl_port_data *portdata)
> +{
> + int i = 0;
Don't init.
> +
> + for (i = 0; i < portdata->caps.count; i++) {
> + int iw = 1, ig = 0, rc, target_count = portdata->caps.tc;
Use some more lines for this - it'll be easier to read!
> + void __iomem *hdm_decoder = portdata->regs.hdm_decoder;
> + enum cxl_decoder_type type = CXL_DECODER_EXPANDER;
> + struct resource res = DEFINE_RES_MEM(0, 0);
> + struct cxl_decoder *cxld;
> + int *target_map = NULL;
> + u64 size;
> +
> + if (is_endpoint_port(port))
> + target_count = 0;
I'd rather just see a bool for this instead of using the value not allowed for
other cases. Slightly more code, but no need for the comment in the previous
patch.
> +
> + cxld = cxl_decoder_alloc(port, target_count);
> + if (IS_ERR(cxld)) {
> + dev_warn(&port->dev,
> + "Failed to allocate the decoder\n");
> + return PTR_ERR(cxld);
> + }
> +
> + size = get_decoder_size(hdm_decoder, i);
> + if (size != 0) {
> + int temp[CXL_DECODER_MAX_INTERLEAVE];
> + u64 target_list, base;
> + u32 ctrl;
> + int j;
> +
> + target_map = temp;
> + ctrl = readl(hdm_decoder + CXL_HDM_DECODER0_CTRL_OFFSET(i));
> + base = ioread64_hi_lo(hdm_decoder + CXL_HDM_DECODER0_BASE_LOW_OFFSET(i));
> + res = (struct resource)DEFINE_RES_MEM(base, size);
> +
> + cxld->flags = CXL_DECODER_F_EN;
> + iw = cxl_hdm_decoder_iw(ctrl);
> + ig = cxl_hdm_decoder_ig(ctrl);
> +
> + if (FIELD_GET(CXL_HDM_DECODER0_CTRL_TYPE, ctrl) == 0)
> + type = CXL_DECODER_ACCELERATOR;
> +
> + target_list = ioread64_hi_lo(hdm_decoder + CXL_HDM_DECODER0_TL_LOW(i));
> + for (j = 0; j < iw; j++)
> + target_map[j] = (target_list >> (j * 8)) & 0xff;
temp just went out of scope, and target_map is still in it...
> + }
> +
> + cxld->target_type = type;
> + cxld->res = res;
> + cxld->interleave_ways = iw;
> + cxld->interleave_granularity = ig;
> +
> + rc = cxl_decoder_add_locked(cxld, target_map);
> + if (rc)
> + put_device(&cxld->dev);
> + else
> + rc = cxl_decoder_autoremove(port->uport->parent, cxld);
> + if (rc)
> + dev_err(&port->dev, "Failed to add decoder\n");
why not return an error?
> + }
> +
> + return 0;
> +}
> +
> +static int cxl_port_probe(struct device *dev)
> +{
> + struct cxl_port *port = to_cxl_port(dev);
> + struct cxl_port_data *portdata;
> + void __iomem *crb;
> + u32 ctrl;
> + int rc;
> +
> + if (port->component_reg_phys == CXL_RESOURCE_NONE)
> + return 0;
> +
> + portdata = devm_kzalloc(dev, sizeof(*portdata), GFP_KERNEL);
> + if (!portdata)
> + return -ENOMEM;
> +
> + crb = devm_cxl_iomap_block(&port->dev, port->component_reg_phys,
> + CXL_COMPONENT_REG_BLOCK_SIZE);
> + if (IS_ERR_OR_NULL(crb)) {
> + dev_err(&port->dev, "No component registers mapped\n");
> + return -ENXIO;
> + }
> +
> + rc = map_regs(port, crb, portdata);
> + if (rc)
> + return rc;
> +
> + get_caps(port, portdata);
> + if (portdata->caps.count == 0) {
> + dev_err(&port->dev, "Spec violation. Caps invalid\n");
> + return -ENXIO;
> + }
> +
> + /*
> + * Enable HDM decoders for this port.
> + *
> + * FIXME: If the component was using DVSEC range registers for decode,
> + * this will destroy that.
> + */
> + ctrl = readl(portdata->regs.hdm_decoder + CXL_HDM_DECODER_CTRL_OFFSET);
> + ctrl |= CXL_HDM_DECODER_ENABLE;
> + writel(ctrl, portdata->regs.hdm_decoder + CXL_HDM_DECODER_CTRL_OFFSET);
> +
> + rc = enumerate_hdm_decoders(port, portdata);
> + if (rc) {
> + dev_err(&port->dev, "Couldn't enumerate decoders (%d)\n", rc);
> + return rc;
> + }
> +
> + dev_set_drvdata(dev, portdata);
> + return 0;
> +}
> +
> +static struct cxl_driver cxl_port_driver = {
> + .name = "cxl_port",
> + .probe = cxl_port_probe,
> + .id = CXL_DEVICE_PORT,
> +};
> +module_cxl_driver(cxl_port_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_IMPORT_NS(CXL);
> +MODULE_ALIAS_CXL(CXL_DEVICE_PORT);
next prev parent reply other threads:[~2021-11-03 15:19 UTC|newest]
Thread overview: 112+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-22 18:36 [RFC PATCH v2 00/28] CXL Region Creation / HDM decoder programming Ben Widawsky
2021-10-22 18:36 ` [RFC PATCH v2 01/28] cxl: Rename CXL_MEM to CXL_PCI Ben Widawsky
2021-10-29 20:15 ` Dan Williams
2021-10-29 21:20 ` Ben Widawsky
2021-10-29 21:39 ` Dan Williams
2021-10-22 18:36 ` [RFC PATCH v2 02/28] cxl: Move register block enumeration to core Ben Widawsky
2021-10-29 20:23 ` Dan Williams
2021-10-29 21:23 ` Ben Widawsky
2021-10-22 18:36 ` [RFC PATCH v2 03/28] cxl/acpi: Map component registers for Root Ports Ben Widawsky
2021-10-29 20:28 ` Dan Williams
2021-10-22 18:36 ` [RFC PATCH v2 04/28] cxl: Add helper for new drivers Ben Widawsky
2021-10-29 20:30 ` Dan Williams
2021-10-22 18:36 ` [RFC PATCH v2 05/28] cxl/core: Convert decoder range to resource Ben Widawsky
2021-10-29 20:50 ` Dan Williams
2021-10-29 21:26 ` Ben Widawsky
2021-10-29 22:22 ` Dan Williams
2021-10-29 22:37 ` Ben Widawsky
2021-11-01 14:33 ` Ben Widawsky
2021-10-22 18:36 ` [RFC PATCH v2 06/28] cxl: Introduce endpoint decoders Ben Widawsky
2021-10-29 21:00 ` Dan Williams
2021-10-29 22:02 ` Ben Widawsky
2021-10-29 22:25 ` Dan Williams
2021-10-22 18:36 ` [RFC PATCH v2 07/28] cxl/core: Move target population locking to caller Ben Widawsky
2021-10-29 23:03 ` Dan Williams
2021-10-22 18:36 ` [RFC PATCH v2 08/28] cxl/port: Introduce a port driver Ben Widawsky
2021-10-30 1:37 ` Dan Williams
2021-10-31 17:53 ` Dan Williams
2021-10-31 18:10 ` Dan Williams
2021-11-01 17:36 ` Ben Widawsky
2021-11-01 17:53 ` Ben Widawsky
2021-11-01 17:54 ` Ben Widawsky
2021-11-02 3:31 ` Dan Williams
2021-11-02 16:27 ` Ben Widawsky
2021-11-02 17:21 ` Dan Williams
2021-11-02 16:58 ` Ben Widawsky
2021-11-04 19:10 ` Dan Williams
2021-11-04 19:49 ` Ben Widawsky
2021-11-04 20:04 ` Dan Williams
2021-11-04 21:25 ` Ben Widawsky
2021-11-04 16:37 ` Ben Widawsky
2021-11-04 19:17 ` Dan Williams
2021-11-04 19:46 ` Ben Widawsky
2021-11-04 20:00 ` Dan Williams
2021-11-04 21:26 ` Ben Widawsky
2021-11-03 15:18 ` Jonathan Cameron [this message]
2021-10-22 18:36 ` [RFC PATCH v2 09/28] cxl/acpi: Map single port host bridge component registers Ben Widawsky
2021-10-31 18:03 ` Dan Williams
2021-11-01 17:07 ` Ben Widawsky
2021-11-02 2:15 ` Dan Williams
2021-11-02 16:31 ` Ben Widawsky
2021-11-02 17:46 ` Dan Williams
2021-11-02 17:57 ` Ben Widawsky
2021-11-02 18:10 ` Dan Williams
2021-11-02 18:27 ` Ben Widawsky
2021-11-02 18:49 ` Dan Williams
2021-11-02 21:15 ` Ben Widawsky
2021-11-02 21:34 ` Dan Williams
2021-11-02 21:47 ` Ben Widawsky
2021-10-22 18:36 ` [RFC PATCH v2 10/28] cxl/core: Store global list of root ports Ben Widawsky
2021-10-31 18:32 ` Dan Williams
2021-11-01 18:43 ` Ben Widawsky
2021-11-02 2:04 ` Dan Williams
2021-10-22 18:36 ` [RFC PATCH v2 11/28] cxl/acpi: Rescan bus at probe completion Ben Widawsky
2021-10-31 19:25 ` Dan Williams
2021-11-01 18:56 ` Ben Widawsky
2021-11-01 21:45 ` Ben Widawsky
2021-11-02 1:56 ` Dan Williams
2021-10-22 18:36 ` [RFC PATCH v2 12/28] cxl/core: Store component register base for memdevs Ben Widawsky
2021-10-31 20:13 ` Dan Williams
2021-11-01 21:50 ` Ben Widawsky
2021-10-22 18:36 ` [RFC PATCH v2 13/28] cxl: Flesh out register names Ben Widawsky
2021-10-31 20:18 ` Dan Williams
2021-11-01 22:00 ` Ben Widawsky
2021-11-02 1:53 ` Dan Williams
2021-11-03 15:53 ` Jonathan Cameron
2021-11-03 16:03 ` Ben Widawsky
2021-11-03 16:42 ` Jonathan Cameron
2021-11-03 17:05 ` Ben Widawsky
2021-10-22 18:36 ` [RFC PATCH v2 14/28] cxl: Hide devm host for ports Ben Widawsky
2021-10-31 21:14 ` Dan Williams
2021-10-22 18:36 ` [RFC PATCH v2 15/28] cxl/core: Introduce API to scan switch ports Ben Widawsky
2021-11-01 5:39 ` Dan Williams
2021-11-01 22:56 ` Ben Widawsky
2021-11-02 1:45 ` Dan Williams
2021-11-02 16:39 ` Ben Widawsky
2021-11-02 20:00 ` Dan Williams
2021-11-16 16:50 ` Ben Widawsky
2021-11-16 17:51 ` Dan Williams
2021-11-16 18:02 ` Ben Widawsky
2021-11-03 16:08 ` Jonathan Cameron
2021-11-10 17:49 ` Ben Widawsky
2021-11-10 18:10 ` Jonathan Cameron
2021-11-10 21:03 ` Dan Williams
2021-10-22 18:36 ` [RFC PATCH v2 16/28] cxl: Introduce cxl_mem driver Ben Widawsky
2021-10-22 18:36 ` [RFC PATCH v2 17/28] cxl: Disable switch hierarchies for now Ben Widawsky
2021-10-22 18:36 ` [RFC PATCH v2 18/28] cxl/region: Add region creation ABI Ben Widawsky
2021-10-22 18:37 ` [RFC PATCH v2 19/28] cxl/region: Introduce concept of region configuration Ben Widawsky
2021-12-15 17:47 ` Jonathan Cameron
2021-10-22 18:37 ` [RFC PATCH v2 20/28] cxl/region: Introduce a cxl_region driver Ben Widawsky
2021-10-22 18:37 ` [RFC PATCH v2 21/28] cxl/acpi: Handle address space allocation Ben Widawsky
2021-10-22 18:37 ` [RFC PATCH v2 22/28] cxl/region: Address " Ben Widawsky
2021-10-22 18:37 ` [RFC PATCH v2 23/28] cxl/region: Implement XHB verification Ben Widawsky
2022-01-06 16:55 ` Jonathan Cameron
2022-01-06 16:58 ` Ben Widawsky
2022-01-06 17:33 ` Jonathan Cameron
2022-01-06 18:10 ` Jonathan Cameron
2022-01-06 18:34 ` Ben Widawsky
2021-10-22 18:37 ` [RFC PATCH v2 24/28] cxl/region: HB port config verification Ben Widawsky
2021-10-22 18:37 ` [RFC PATCH v2 25/28] cxl/region: Record host bridge target list Ben Widawsky
2021-10-22 18:37 ` [RFC PATCH v2 26/28] cxl/mem: Store the endpoint's uport Ben Widawsky
2021-10-22 18:37 ` [RFC PATCH v2 27/28] cxl/region: Gather HDM decoder resources Ben Widawsky
2021-10-22 18:37 ` [RFC PATCH v2 28/28] cxl: Program decoders for regions Ben Widawsky
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