RE: [PATCH] cxl/mbox: Fix CEL logic for poison and security commands

From: Ira Weiny
Date: Wed Sep 13 2023 - 14:18:35 EST


Dan Williams wrote:
> Ira Weiny wrote:
> > The following debug output was observed while testing CXL
> >
> > cxl_core:cxl_walk_cel:721: cxl_mock_mem cxl_mem.0: Opcode 0x4300 unsupported by driver
> >
> > opcode 0x4300 (Get Poison) is supported by the driver and the mock
> > device supports it. The logic should be checking that the opcode is
> > both not poison and not security.
> >
> > Fix the logic to allow poison and security commands.
> >
> > Fixes: ad64f5952ce3 ("cxl/memdev: Only show sanitize sysfs files when supported")
> > Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
> > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
> > ---
> > drivers/cxl/core/mbox.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> > index ca60bb8114f2..b315bdab9197 100644
> > --- a/drivers/cxl/core/mbox.c
> > +++ b/drivers/cxl/core/mbox.c
> > @@ -716,8 +716,8 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel)
> > u16 opcode = le16_to_cpu(cel_entry[i].opcode);
> > struct cxl_mem_command *cmd = cxl_mem_find_command(opcode);
> >
> > - if (!cmd && (!cxl_is_poison_command(opcode) ||
> > - !cxl_is_security_command(opcode))) {
> > + if (!cmd && !cxl_is_poison_command(opcode) &&
> > + !cxl_is_security_command(opcode)) {
>
> Given that this is going to be a recurring pattern to add optional
> command support, I am not a fan of continuing to expand this boolean
> algebra eye exam.
>
> How about the following to only do the validation check and enabling in
> one place:

I like it.

Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>

>
>
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index ca60bb8114f2..4df4f614f490 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -715,24 +715,25 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel)
> for (i = 0; i < cel_entries; i++) {
> u16 opcode = le16_to_cpu(cel_entry[i].opcode);
> struct cxl_mem_command *cmd = cxl_mem_find_command(opcode);
> + int enabled = 0;
>
> - if (!cmd && (!cxl_is_poison_command(opcode) ||
> - !cxl_is_security_command(opcode))) {
> - dev_dbg(dev,
> - "Opcode 0x%04x unsupported by driver\n", opcode);
> - continue;
> - }
> -
> - if (cmd)
> + if (cmd) {
> set_bit(cmd->info.id, mds->enabled_cmds);
> + enabled++;
> + }
>
> - if (cxl_is_poison_command(opcode))
> + if (cxl_is_poison_command(opcode)) {
> cxl_set_poison_cmd_enabled(&mds->poison, opcode);
> + enabled++;
> + }
>
> - if (cxl_is_security_command(opcode))
> + if (cxl_is_security_command(opcode)) {
> cxl_set_security_cmd_enabled(&mds->security, opcode);
> + enabled++;
> + }
>
> - dev_dbg(dev, "Opcode 0x%04x enabled\n", opcode);
> + dev_dbg(dev, "Opcode 0x%04x %s\n", opcode,
> + enabled ? "enabled" : "unsupported by driver");
> }
> }
>