From 86e756715db22cd79a9726c22644415c46b6b149 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 30 Jan 2026 16:03:58 -0800 Subject: [PATCH] cxl/port: Move decoder setup before dport creation There are port setup actions that run on first dport arrival, and there are setup actions that run per dport. RAS register setup is a future additional setup action to run per-port (once the first dport arrives), and each dport also has RAS registers to map. Before adding that, flip the order of "first dport" and "per-dport" actions. This makes allocation symmetric with teardown, "first dport" actions unwind after last dport removed. It also allows for using a devres group to collect the unrelated decoder, RAS, and dport setup actions into one group release action. The new cxl_port_open_group() collects "first dport" and "per-dport" into one group that can be released on any failure. This group's lifetime only needs to span the short duration of cxl_port_add_dport() to cleanup all potential damage from failing to add a dport. Contrast that to the "dport" devres group that is called upon to destruct fully formed dport objects. Reviewed-by: Dave Jiang Reviewed-by: Jonathan Cameron Tested-by: Terry Bowman Signed-off-by: Dan Williams Link: https://patch.msgid.link/20260131000403.2135324-5-dan.j.williams@intel.com Signed-off-by: Dave Jiang --- drivers/cxl/core/port.c | 33 +++++++++++++++++++++------------ 1 file changed, 21 insertions(+), 12 deletions(-) diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index 99bbcf9cf2366..6a554d0466a18 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -1651,10 +1651,14 @@ static bool dport_exists(struct cxl_port *port, struct device *dport_dev) return false; } -DEFINE_FREE(del_cxl_dport, struct cxl_dport *, if (!IS_ERR_OR_NULL(_T)) del_dport(_T)) +/* note this implicitly casts the group back to its @port */ +DEFINE_FREE(cxl_port_release_dr_group, struct cxl_port *, + if (_T) devres_release_group(&_T->dev, _T)) + static struct cxl_dport *cxl_port_add_dport(struct cxl_port *port, struct device *dport_dev) { + struct cxl_dport *dport; int rc; device_lock_assert(&port->dev); @@ -1664,14 +1668,13 @@ static struct cxl_dport *cxl_port_add_dport(struct cxl_port *port, if (dport_exists(port, dport_dev)) return ERR_PTR(-EBUSY); - struct cxl_dport *dport __free(del_cxl_dport) = - devm_cxl_add_dport_by_dev(port, dport_dev); - if (IS_ERR(dport)) - return dport; - - cxl_switch_parse_cdat(dport); + /* Temp group for all "first dport" and "per dport" setup actions */ + void *port_dr_group __free(cxl_port_release_dr_group) = + devres_open_group(&port->dev, port, GFP_KERNEL); + if (!port_dr_group) + return ERR_PTR(-ENOMEM); - if (port->nr_dports == 1) { + if (port->nr_dports == 0) { /* * Some host bridges are known to not have component regsisters * available until a root port has trained CXL. Perform that @@ -1684,18 +1687,24 @@ static struct cxl_dport *cxl_port_add_dport(struct cxl_port *port, rc = devm_cxl_switch_port_decoders_setup(port); if (rc) return ERR_PTR(rc); - dev_dbg(&port->dev, "first dport%d:%s added with decoders\n", - dport->port_id, dev_name(dport_dev)); - return no_free_ptr(dport); } + dport = devm_cxl_add_dport_by_dev(port, dport_dev); + if (IS_ERR(dport)) + return dport; + + /* This group was only needed for early exit above */ + devres_remove_group(&port->dev, no_free_ptr(port_dr_group)); + + cxl_switch_parse_cdat(dport); + /* New dport added, update the decoder targets */ device_for_each_child(&port->dev, dport, update_decoder_targets); dev_dbg(&port->dev, "dport%d:%s added\n", dport->port_id, dev_name(dport_dev)); - return no_free_ptr(dport); + return dport; } static struct cxl_dport *devm_cxl_create_port(struct device *ep_dev, -- 2.47.3