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From: alison.schofield@intel.com
To: Ben Widawsky <ben.widawsky@intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Ira Weiny <ira.weiny@intel.com>,
	Vishal Verma <vishal.l.verma@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>, linux-cxl@vger.kernel.org
Subject: [PATCH v4 9/9] cxl/pmem: Remove CXL SET_PARTITION_INFO from exclusive_cmds list
Date: Tue, 29 Mar 2022 18:30:24 -0700	[thread overview]
Message-ID: <56e8479832ef95bee0aa9099148ecd3e5539c372.1648601710.git.alison.schofield@intel.com> (raw)
In-Reply-To: <cover.1648601710.git.alison.schofield@intel.com>

From: Alison Schofield <alison.schofield@intel.com>

With SET_PARTITION_INFO on the exclusive_cmds list for the CXL_PMEM
driver, userspace cannot execute a set-partition command without
first unbinding the pmem driver from the device.

When userspace requests a partition change to take effect on the
next reboot this unbind requirement is unnecessarily restrictive.
The driver does not need to enforce an unbind because partitions
will not change until the next reboot. Of course, userspace still
needs to be aware that changing the size of persistent capacity
on the next reboot will result in the loss of data stored. That
can happen regardless of whether it is presently bound at the time
of issuing the set-partition command.

When userspace requests a partition change to take effect immediately,
restrictions are needed. The CXL_MEM driver currently blocks the usage
of immediate mode, making the presence of SET_PARTITION_INFO, in this
exclusive commands list, redundant.

In the future, when the CXL_MEM driver adds support for immediate
changes to device partitions it will ensure that the partition change
will not affect any active decode. That means the work will not fall
right back here, onto the CXL_PMEM driver.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 drivers/cxl/pmem.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c
index 564d125d25ef..35c6f3af18f2 100644
--- a/drivers/cxl/pmem.c
+++ b/drivers/cxl/pmem.c
@@ -344,7 +344,6 @@ static __init int cxl_pmem_init(void)
 {
 	int rc;
 
-	set_bit(CXL_MEM_COMMAND_ID_SET_PARTITION_INFO, exclusive_cmds);
 	set_bit(CXL_MEM_COMMAND_ID_SET_SHUTDOWN_STATE, exclusive_cmds);
 	set_bit(CXL_MEM_COMMAND_ID_SET_LSA, exclusive_cmds);
 
-- 
2.31.1


      parent reply	other threads:[~2022-03-30  1:28 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-30  1:30 [PATCH v4 0/9] Do not allow set-partition immediate mode alison.schofield
2022-03-30  1:30 ` [PATCH v4 1/9] cxl/mbox: Move cxl_mem_command construction to helper funcs alison.schofield
2022-03-30  3:23   ` Dan Williams
2022-03-30  1:30 ` [PATCH v4 2/9] cxl/mbox: Move raw command warning to raw command validation alison.schofield
2022-03-30  3:24   ` Dan Williams
2022-03-30  1:30 ` [PATCH v4 3/9] cxl/mbox: Move build of user mailbox cmd to a helper function alison.schofield
2022-03-30  3:29   ` Dan Williams
2022-03-30  1:30 ` [PATCH v4 4/9] cxl/mbox: Construct a users cxl_mbox_cmd in the validation path alison.schofield
2022-03-30  4:39   ` Dan Williams
2022-03-30  1:30 ` [PATCH v4 5/9] cxl/mbox: Remove dependency on cxl_mem_command for a debug msg alison.schofield
2022-03-30  4:50   ` Dan Williams
2022-03-30 19:14     ` Alison Schofield
2022-03-30  1:30 ` [PATCH v4 6/9] cxl/mbox: Make handle_mailbox_cmd_from_user() use a mbox param alison.schofield
2022-03-30  5:00   ` Dan Williams
2022-03-30  1:30 ` [PATCH v4 7/9] cxl/mbox: Move cxl_mem_command param to a local variable alison.schofield
2022-03-30  1:30 ` [PATCH v4 8/9] cxl/mbox: Block immediate mode in SET_PARTITION_INFO command alison.schofield
2022-03-30  1:30 ` alison.schofield [this message]

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