On Thu, 23 Jun 2022 21:19:42 -0700
Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> The region provisioning process involves allocating DPA to a set of
> endpoint decoders, and HPA plus the region geometry to a region device.
> Then the decoder is assigned to the region. At this point several
> validation steps can be performed to validate that the decoder is
> suitable to participate in the region.
>
> Co-developed-by: Ben Widawsky <bwidawsk@xxxxxxxxxx>
> Signed-off-by: Ben Widawsky <bwidawsk@xxxxxxxxxx>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> ---
> Documentation/ABI/testing/sysfs-bus-cxl | 19 ++
> drivers/cxl/core/core.h | 6 +
> drivers/cxl/core/hdm.c | 13 +-
> drivers/cxl/core/port.c | 12 +-
> drivers/cxl/core/region.c | 286 +++++++++++++++++++++++-
> drivers/cxl/cxl.h | 11 +
> 6 files changed, 342 insertions(+), 5 deletions(-)
>
A few fixes seems to have ended up in wrong patch.
Other trivial typos etc inline plus what looks to be an
item left from a todo list...
...
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index a604c24ff918..4830365f3857 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -24,6 +24,7 @@
> * but is only visible for persistent regions.
> * 1. Interleave granularity
> * 2. Interleave size
> + * 3. Decoder targets
> */
>
> /*
> @@ -138,6 +139,8 @@ static ssize_t interleave_ways_show(struct device *dev,
> return rc;
> }
>
> +static const struct attribute_group *get_cxl_region_target_group(void);
> +
> static ssize_t interleave_ways_store(struct device *dev,
> struct device_attribute *attr,
> const char *buf, size_t len)
> @@ -146,7 +149,7 @@ static ssize_t interleave_ways_store(struct device *dev,
> struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
> struct cxl_region *cxlr = to_cxl_region(dev);
> struct cxl_region_params *p = &cxlr->params;
> - int rc, val;
> + int rc, val, save;
> u8 iw;
>
> rc = kstrtoint(buf, 0, &val);
> @@ -175,9 +178,13 @@ static ssize_t interleave_ways_store(struct device *dev,
> goto out;
> }
>
> + save = p->interleave_ways;
> p->interleave_ways = val;
> + rc = sysfs_update_group(&cxlr->dev.kobj, get_cxl_region_target_group());
> + if (rc)
> + p->interleave_ways = save;
> out:
> - up_read(&cxl_region_rwsem);
> + up_write(&cxl_region_rwsem);
Bug in earlier patch?
> if (rc)
> return rc;
> return len;
> @@ -234,7 +241,7 @@ static ssize_t interleave_granularity_store(struct device *dev,
>
> p->interleave_granularity = val;
> out:
> - up_read(&cxl_region_rwsem);
> + up_write(&cxl_region_rwsem);
Bug in earlier patch?
> if (rc)
> return rc;
> return len;
> @@ -393,9 +400,262 @@ static const struct attribute_group cxl_region_group = {
> .is_visible = cxl_region_visible,
> };
...
> +/*
> + * - Check that the given endpoint is attached to a host-bridge identified
> + * in the root interleave.
Comment on something to fix? Or stale comment that can be dropped?
> + */
> +static int cxl_region_attach(struct cxl_region *cxlr,
> + struct cxl_endpoint_decoder *cxled, int pos)
> +{
> + struct cxl_region_params *p = &cxlr->params;
> +
> + if (cxled->mode == CXL_DECODER_DEAD) {
> + dev_dbg(&cxlr->dev, "%s dead\n", dev_name(&cxled->cxld.dev));
> + return -ENODEV;
> + }
> +
> + if (pos >= p->interleave_ways) {
> + dev_dbg(&cxlr->dev, "position %d out of range %d\n", pos,
> + p->interleave_ways);
> + return -ENXIO;
> + }
> +
> + if (p->targets[pos] == cxled)
> + return 0;
> +
> + if (p->targets[pos]) {
> + struct cxl_endpoint_decoder *cxled_target = p->targets[pos];
> + struct cxl_memdev *cxlmd_target = cxled_to_memdev(cxled_target);
> +
> + dev_dbg(&cxlr->dev, "position %d already assigned to %s:%s\n",
> + pos, dev_name(&cxlmd_target->dev),
> + dev_name(&cxled_target->cxld.dev));
> + return -EBUSY;
> + }
> +
> + p->targets[pos] = cxled;
> + cxled->pos = pos;
> + p->nr_targets++;
> +
> + return 0;
> +}
> +
> +static void cxl_region_detach(struct cxl_endpoint_decoder *cxled)
> +{
> + struct cxl_region *cxlr = cxled->cxld.region;
> + struct cxl_region_params *p;
> +
> + lockdep_assert_held_write(&cxl_region_rwsem);
> +
> + if (!cxlr)
> + return;
> +
> + p = &cxlr->params;
> + get_device(&cxlr->dev);
> +
> + if (cxled->pos < 0 || cxled->pos >= p->interleave_ways ||
> + p->targets[cxled->pos] != cxled) {
> + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
> +
> + dev_WARN_ONCE(&cxlr->dev, 1, "expected %s:%s at position %d\n",
> + dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev),
> + cxled->pos);
> + goto out;
> + }
> +
> + p->targets[cxled->pos] = NULL;
> + p->nr_targets--;
> +
> + /* notify the region driver that one of its targets has deparated */
departed?
> + up_write(&cxl_region_rwsem);
> + device_release_driver(&cxlr->dev);
> + down_write(&cxl_region_rwsem);
> +out:
> + put_device(&cxlr->dev);
> +}
> +
