From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: <linux-cxl@vger.kernel.org>, kernel test robot <lkp@intel.com>,
<vishal.l.verma@intel.com>, <alison.schofield@intel.com>,
<nvdimm@lists.linux.dev>, <ira.weiny@intel.com>,
<ben.widawsky@intel.com>
Subject: Re: [PATCH v3 28/28] cxl/core: Split decoder setup into alloc + add
Date: Fri, 3 Sep 2021 14:33:45 +0100 [thread overview]
Message-ID: <20210903143345.00006c60@Huawei.com> (raw)
In-Reply-To: <162982127644.1124374.2704629829686138331.stgit@dwillia2-desk3.amr.corp.intel.com>
On Tue, 24 Aug 2021 09:07:56 -0700
Dan Williams <dan.j.williams@intel.com> wrote:
> The kbuild robot reports:
>
> drivers/cxl/core/bus.c:516:1: warning: stack frame size (1032) exceeds
> limit (1024) in function 'devm_cxl_add_decoder'
>
> It is also the case the devm_cxl_add_decoder() is unwieldy to use for
> all the different decoder types. Fix the stack usage by splitting the
> creation into alloc and add steps. This also allows for context
> specific construction before adding.
>
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Trivial comment inline - otherwise looks like a nice improvement.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> ---
> drivers/cxl/acpi.c | 74 ++++++++++++++++++++---------
> drivers/cxl/core/bus.c | 124 +++++++++++++++---------------------------------
> drivers/cxl/cxl.h | 15 ++----
> 3 files changed, 95 insertions(+), 118 deletions(-)
>
> @@ -268,6 +275,7 @@ static int add_host_bridge_uport(struct device *match, void *arg)
> struct cxl_port *port;
> struct cxl_dport *dport;
> struct cxl_decoder *cxld;
> + int single_port_map[1], rc;
> struct cxl_walk_context ctx;
> struct acpi_pci_root *pci_root;
> struct cxl_port *root_port = arg;
> @@ -301,22 +309,42 @@ static int add_host_bridge_uport(struct device *match, void *arg)
> return -ENODEV;
> if (ctx.error)
> return ctx.error;
> + if (ctx.count > 1)
> + return 0;
>
> /* TODO: Scan CHBCR for HDM Decoder resources */
>
> /*
> - * In the single-port host-bridge case there are no HDM decoders
> - * in the CHBCR and a 1:1 passthrough decode is implied.
> + * Per the CXL specification (8.2.5.12 CXL HDM Decoder Capability
> + * Structure) single ported host-bridges need not publish a decoder
> + * capability when a passthrough decode can be assumed, i.e. all
> + * transactions that the uport sees are claimed and passed to the single
> + * dport. Default the range a 0-base 0-length until the first CXL region
> + * is activated.
> */
Is comment in right place or should it be up with the ctx.count > 1
> - if (ctx.count == 1) {
> - cxld = devm_cxl_add_passthrough_decoder(host, port);
> - if (IS_ERR(cxld))
> - return PTR_ERR(cxld);
> + cxld = cxl_decoder_alloc(port, 1);
> + if (IS_ERR(cxld))
> + return PTR_ERR(cxld);
> +
> + cxld->interleave_ways = 1;
> + cxld->interleave_granularity = PAGE_SIZE;
> + cxld->target_type = CXL_DECODER_EXPANDER;
> + cxld->range = (struct range) {
> + .start = 0,
> + .end = -1,
> + };
>
> + device_lock(&port->dev);
> + dport = list_first_entry(&port->dports, typeof(*dport), list);
> + device_unlock(&port->dev);
> +
> + single_port_map[0] = dport->port_id;
> +
> + rc = devm_cxl_add_decoder(host, cxld, single_port_map);
> + if (rc == 0)
> dev_dbg(host, "add: %s\n", dev_name(&cxld->dev));
> - }
>
> - return 0;
> + return rc;
> }
>
> static int add_host_bridge_dport(struct device *match, void *arg)
> diff --git a/drivers/cxl/core/bus.c b/drivers/cxl/core/bus.c
> index 9a755a37eadf..1320a996220a 100644
> --- a/drivers/cxl/core/bus.c
> +++ b/drivers/cxl/core/bus.c
> @@ -453,27 +453,15 @@ int cxl_add_dport(struct cxl_port *port, struct device *dport_dev, int port_id,
> }
> EXPORT_SYMBOL_GPL(cxl_add_dport);
>
> -static struct cxl_decoder *
> -cxl_decoder_alloc(struct device *host, struct cxl_port *port, int nr_targets,
> - resource_size_t base, resource_size_t len,
> - int interleave_ways, int interleave_granularity,
> - enum cxl_decoder_type type, unsigned long flags,
> - int *target_map)
> +struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port, int nr_targets)
> {
> struct cxl_decoder *cxld;
> struct device *dev;
> - int rc = 0, i;
> + int rc = 0;
>
> - if (interleave_ways < 1)
> + if (nr_targets > CXL_DECODER_MAX_INTERLEAVE || nr_targets < 1)
> return ERR_PTR(-EINVAL);
>
> - device_lock(&port->dev);
> - if (list_empty(&port->dports))
> - rc = -EINVAL;
> - device_unlock(&port->dev);
> - if (rc)
> - return ERR_PTR(rc);
> -
> cxld = kzalloc(struct_size(cxld, target, nr_targets), GFP_KERNEL);
> if (!cxld)
> return ERR_PTR(-ENOMEM);
> @@ -482,31 +470,8 @@ cxl_decoder_alloc(struct device *host, struct cxl_port *port, int nr_targets,
> if (rc < 0)
> goto err;
>
> - *cxld = (struct cxl_decoder) {
> - .id = rc,
> - .range = {
> - .start = base,
> - .end = base + len - 1,
> - },
> - .flags = flags,
> - .interleave_ways = interleave_ways,
> - .interleave_granularity = interleave_granularity,
> - .target_type = type,
> - };
> -
> - device_lock(&port->dev);
> - for (i = 0; target_map && i < nr_targets; i++) {
> - struct cxl_dport *dport = find_dport(port, target_map[i]);
> -
> - if (!dport) {
> - rc = -ENXIO;
> - goto err;
> - }
> - dev_dbg(host, "%s: target: %d\n", dev_name(dport->dport), i);
> - cxld->target[i] = dport;
> - }
> - device_unlock(&port->dev);
> -
> + cxld->id = rc;
> + cxld->nr_targets = nr_targets;
> dev = &cxld->dev;
> device_initialize(dev);
> device_set_pm_not_required(dev);
> @@ -524,26 +489,43 @@ cxl_decoder_alloc(struct device *host, struct cxl_port *port, int nr_targets,
> kfree(cxld);
> return ERR_PTR(rc);
> }
> +EXPORT_SYMBOL_GPL(cxl_decoder_alloc);
>
> -struct cxl_decoder *
> -devm_cxl_add_decoder(struct device *host, struct cxl_port *port, int nr_targets,
> - resource_size_t base, resource_size_t len,
> - int interleave_ways, int interleave_granularity,
> - enum cxl_decoder_type type, unsigned long flags,
> - int *target_map)
> +int devm_cxl_add_decoder(struct device *host, struct cxl_decoder *cxld,
> + int *target_map)
> {
> - struct cxl_decoder *cxld;
> + struct cxl_port *port = to_cxl_port(cxld->dev.parent);
> struct device *dev;
> - int rc;
> + int rc = 0, i;
>
> - if (nr_targets > CXL_DECODER_MAX_INTERLEAVE)
> - return ERR_PTR(-EINVAL);
> + if (!cxld)
> + return -EINVAL;
>
> - cxld = cxl_decoder_alloc(host, port, nr_targets, base, len,
> - interleave_ways, interleave_granularity, type,
> - flags, target_map);
> if (IS_ERR(cxld))
> - return cxld;
> + return PTR_ERR(cxld);
> +
> + if (cxld->interleave_ways < 1) {
> + rc = -EINVAL;
> + goto err;
> + }
> +
> + device_lock(&port->dev);
> + if (list_empty(&port->dports))
> + rc = -EINVAL;
> +
> + for (i = 0; rc == 0 && target_map && i < cxld->nr_targets; i++) {
> + struct cxl_dport *dport = find_dport(port, target_map[i]);
> +
> + if (!dport) {
> + rc = -ENXIO;
> + break;
> + }
> + dev_dbg(host, "%s: target: %d\n", dev_name(dport->dport), i);
> + cxld->target[i] = dport;
> + }
> + device_unlock(&port->dev);
> + if (rc)
> + goto err;
>
> dev = &cxld->dev;
> rc = dev_set_name(dev, "decoder%d.%d", port->id, cxld->id);
> @@ -554,43 +536,13 @@ devm_cxl_add_decoder(struct device *host, struct cxl_port *port, int nr_targets,
> if (rc)
> goto err;
>
> - rc = devm_add_action_or_reset(host, unregister_cxl_dev, dev);
> - if (rc)
> - return ERR_PTR(rc);
> - return cxld;
> -
> + return devm_add_action_or_reset(host, unregister_cxl_dev, dev);
> err:
> put_device(dev);
> - return ERR_PTR(rc);
> + return rc;
> }
> EXPORT_SYMBOL_GPL(devm_cxl_add_decoder);
>
> -/*
> - * Per the CXL specification (8.2.5.12 CXL HDM Decoder Capability Structure)
> - * single ported host-bridges need not publish a decoder capability when a
> - * passthrough decode can be assumed, i.e. all transactions that the uport sees
> - * are claimed and passed to the single dport. Default the range a 0-base
> - * 0-length until the first CXL region is activated.
> - */
> -struct cxl_decoder *devm_cxl_add_passthrough_decoder(struct device *host,
> - struct cxl_port *port)
> -{
> - struct cxl_dport *dport;
> - int target_map[1];
> -
> - device_lock(&port->dev);
> - dport = list_first_entry_or_null(&port->dports, typeof(*dport), list);
> - device_unlock(&port->dev);
> -
> - if (!dport)
> - return ERR_PTR(-ENXIO);
> -
> - target_map[0] = dport->port_id;
> - return devm_cxl_add_decoder(host, port, 1, 0, 0, 1, PAGE_SIZE,
> - CXL_DECODER_EXPANDER, 0, target_map);
> -}
> -EXPORT_SYMBOL_GPL(devm_cxl_add_passthrough_decoder);
> -
> /**
> * __cxl_driver_register - register a driver for the cxl bus
> * @cxl_drv: cxl driver structure to attach
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index 13e02528ddd3..3705b2454b66 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> @@ -195,6 +195,7 @@ enum cxl_decoder_type {
> * @interleave_granularity: data stride per dport
> * @target_type: accelerator vs expander (type2 vs type3) selector
> * @flags: memory type capabilities and locking
> + * @nr_targets: number of elements in @target
> * @target: active ordered target list in current decoder configuration
> */
> struct cxl_decoder {
> @@ -205,6 +206,7 @@ struct cxl_decoder {
> int interleave_granularity;
> enum cxl_decoder_type target_type;
> unsigned long flags;
> + int nr_targets;
> struct cxl_dport *target[];
> };
>
> @@ -286,15 +288,10 @@ int cxl_add_dport(struct cxl_port *port, struct device *dport, int port_id,
>
> struct cxl_decoder *to_cxl_decoder(struct device *dev);
> bool is_root_decoder(struct device *dev);
> -struct cxl_decoder *
> -devm_cxl_add_decoder(struct device *host, struct cxl_port *port, int nr_targets,
> - resource_size_t base, resource_size_t len,
> - int interleave_ways, int interleave_granularity,
> - enum cxl_decoder_type type, unsigned long flags,
> - int *target_map);
> -
> -struct cxl_decoder *devm_cxl_add_passthrough_decoder(struct device *host,
> - struct cxl_port *port);
> +struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port, int nr_targets);
> +int devm_cxl_add_decoder(struct device *host, struct cxl_decoder *cxld,
> + int *target_map);
> +
> extern struct bus_type cxl_bus_type;
>
> struct cxl_driver {
>
next prev parent reply other threads:[~2021-09-03 13:33 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-24 16:05 [PATCH v3 00/28] cxl_test: Enable CXL Topology and UAPI regression tests Dan Williams
2021-08-24 16:05 ` [PATCH v3 01/28] libnvdimm/labels: Introduce getters for namespace label fields Dan Williams
2021-08-24 16:05 ` [PATCH v3 02/28] libnvdimm/labels: Add isetcookie validation helper Dan Williams
2021-08-24 16:05 ` [PATCH v3 03/28] libnvdimm/labels: Introduce label setter helpers Dan Williams
2021-08-24 16:05 ` [PATCH v3 04/28] libnvdimm/labels: Add a checksum calculation helper Dan Williams
2021-08-24 16:05 ` [PATCH v3 05/28] libnvdimm/labels: Add blk isetcookie set / validation helpers Dan Williams
2021-08-24 16:05 ` [PATCH v3 06/28] libnvdimm/labels: Add blk special cases for nlabel and position helpers Dan Williams
2021-08-24 16:06 ` [PATCH v3 07/28] libnvdimm/labels: Add type-guid helpers Dan Williams
2021-08-24 16:06 ` [PATCH v3 08/28] libnvdimm/labels: Add claim class helpers Dan Williams
2021-08-24 16:06 ` [PATCH v3 09/28] libnvdimm/labels: Add address-abstraction uuid definitions Dan Williams
2021-08-24 16:06 ` [PATCH v3 10/28] libnvdimm/labels: Add uuid helpers Dan Williams
2021-08-24 16:06 ` [PATCH v3 11/28] libnvdimm/label: Add a helper for nlabel validation Dan Williams
2021-09-02 16:37 ` Jonathan Cameron
2021-08-24 16:06 ` [PATCH v3 12/28] libnvdimm/labels: Introduce the concept of multi-range namespace labels Dan Williams
2021-09-02 16:43 ` Jonathan Cameron
2021-08-24 16:06 ` [PATCH v3 13/28] libnvdimm/label: Define CXL region labels Dan Williams
2021-09-02 16:36 ` Jonathan Cameron
2021-09-02 16:41 ` Jonathan Cameron
2021-09-03 3:58 ` Dan Williams
2021-08-24 16:06 ` [PATCH v3 14/28] libnvdimm/labels: Introduce CXL labels Dan Williams
2021-09-03 17:00 ` Dan Williams
2021-08-24 16:06 ` [PATCH v3 15/28] cxl/pci: Make 'struct cxl_mem' device type generic Dan Williams
2021-09-02 16:55 ` Jonathan Cameron
2021-09-02 17:34 ` Dan Williams
2021-08-24 16:06 ` [PATCH v3 16/28] cxl/mbox: Introduce the mbox_send operation Dan Williams
2021-09-02 17:07 ` Jonathan Cameron
2021-08-24 16:06 ` [PATCH v3 17/28] cxl/mbox: Move mailbox and other non-PCI specific infrastructure to the core Dan Williams
2021-09-02 17:56 ` Jonathan Cameron
2021-09-02 18:56 ` Dan Williams
2021-08-24 16:07 ` [PATCH v3 18/28] cxl/pci: Use module_pci_driver Dan Williams
2021-09-02 17:58 ` Jonathan Cameron
2021-08-24 16:07 ` [PATCH v3 19/28] cxl/mbox: Convert 'enabled_cmds' to DECLARE_BITMAP Dan Williams
2021-09-02 17:59 ` Jonathan Cameron
2021-08-24 16:07 ` [PATCH v3 20/28] cxl/mbox: Add exclusive kernel command support Dan Williams
2021-09-02 18:09 ` Jonathan Cameron
2021-09-03 20:47 ` Dan Williams
2021-08-24 16:07 ` [PATCH v3 21/28] cxl/pmem: Translate NVDIMM label commands to CXL label commands Dan Williams
2021-09-02 18:22 ` Jonathan Cameron
2021-09-03 21:09 ` Dan Williams
2021-08-24 16:07 ` [PATCH v3 22/28] cxl/pmem: Add support for multiple nvdimm-bridge objects Dan Williams
2021-09-03 11:15 ` Jonathan Cameron
2021-08-24 16:07 ` [PATCH v3 23/28] cxl/acpi: Do not add DSDT disabled ACPI0016 host bridge ports Dan Williams
2021-09-02 18:30 ` Jonathan Cameron
2021-09-03 17:51 ` Dan Williams
2021-08-24 16:07 ` [PATCH v3 24/28] tools/testing/cxl: Introduce a mocked-up CXL port hierarchy Dan Williams
2021-09-03 12:52 ` Jonathan Cameron
2021-09-03 21:49 ` Dan Williams
2021-09-06 8:32 ` Jonathan Cameron
2021-09-07 15:57 ` Dan Williams
2021-08-24 16:07 ` [PATCH v3 25/28] cxl/bus: Populate the target list at decoder create Dan Williams
2021-09-03 12:59 ` Jonathan Cameron
2021-09-03 22:43 ` Dan Williams
2021-09-06 8:52 ` Jonathan Cameron
2021-08-24 16:07 ` [PATCH v3 26/28] cxl/mbox: Move command definitions to common location Dan Williams
2021-09-03 13:04 ` Jonathan Cameron
2021-08-24 16:07 ` [PATCH v3 27/28] tools/testing/cxl: Introduce a mock memory device + driver Dan Williams
2021-09-03 13:21 ` Jonathan Cameron
2021-09-03 23:33 ` Dan Williams
2021-09-06 8:57 ` Jonathan Cameron
2021-08-24 16:07 ` [PATCH v3 28/28] cxl/core: Split decoder setup into alloc + add Dan Williams
2021-09-03 13:33 ` Jonathan Cameron [this message]
2021-09-03 16:26 ` Dan Williams
2021-09-03 18:01 ` Jonathan Cameron
2021-09-04 0:27 ` Dan Williams
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