ethernet: fix PTP_1588_CLOCK dependencies

The 'imply' keyword does not do what most people think it does, it only
politely asks Kconfig to turn on another symbol, but does not prevent
it from being disabled manually or built as a loadable module when the
user is built-in. In the ICE driver, the latter now causes a link failure:

aarch64-linux-ld: drivers/net/ethernet/intel/ice/ice_main.o: in function `ice_eth_ioctl':
ice_main.c:(.text+0x13b0): undefined reference to `ice_ptp_get_ts_config'
ice_main.c:(.text+0x13b0): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `ice_ptp_get_ts_config'
aarch64-linux-ld: ice_main.c:(.text+0x13bc): undefined reference to `ice_ptp_set_ts_config'
ice_main.c:(.text+0x13bc): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `ice_ptp_set_ts_config'
aarch64-linux-ld: drivers/net/ethernet/intel/ice/ice_main.o: in function `ice_prepare_for_reset':
ice_main.c:(.text+0x31fc): undefined reference to `ice_ptp_release'
ice_main.c:(.text+0x31fc): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `ice_ptp_release'
aarch64-linux-ld: drivers/net/ethernet/intel/ice/ice_main.o: in function `ice_rebuild':

This is a recurring problem in many drivers, and we have discussed
it several times befores, without reaching a consensus. I'm providing
a link to the previous email thread for reference, which discusses
some related problems.

To solve the dependency issue better than the 'imply' keyword, introduce a
separate Kconfig symbol "CONFIG_PTP_1588_CLOCK_OPTIONAL" that any driver
can depend on if it is able to use PTP support when available, but works
fine without it. Whenever CONFIG_PTP_1588_CLOCK=m, those drivers are
then prevented from being built-in, the same way as with a 'depends on
PTP_1588_CLOCK || !PTP_1588_CLOCK' dependency that does the same trick,
but that can be rather confusing when you first see it.

Since this should cover the dependencies correctly, the IS_REACHABLE()
hack in the header is no longer needed now, and can be turned back
into a normal IS_ENABLED() check. Any driver that gets the dependency
wrong will now cause a link time failure rather than being unable to use
PTP support when that is in a loadable module.

However, the two recently added ptp_get_vclocks_index() and
ptp_convert_timestamp() interfaces are only called from builtin code with
ethtool and socket timestamps, so keep the current behavior by stubbing
those out completely when PTP is in a loadable module. This should be
addressed properly in a follow-up.

As Richard suggested, we may want to actually turn PTP support into a
'bool' option later on, preventing it from being a loadable module
altogether, which would be one way to solve the problem with the ethtool
interface.

Fixes: 06c16d89d2cb ("ice: register 1588 PTP clock device object for E810 devices")
Link: https://lore.kernel.org/netdev/20210804121318.337276-1-arnd@kernel.org/
Link: https://lore.kernel.org/netdev/CAK8P3a06enZOf=XyZ+zcAwBczv41UuCTz+=0FMf2gBz1_cOnZQ@mail.gmail.com/
Link: https://lore.kernel.org/netdev/CAK8P3a3=eOxE-K25754+fB_-i_0BZzf9a9RfPTX3ppSwu9WZXw@mail.gmail.com/
Link: https://lore.kernel.org/netdev/20210726084540.3282344-1-arnd@kernel.org/
Acked-by: Shannon Nelson <snelson@pensando.io>
Acked-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20210812183509.1362782-1-arnd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

scsi: cxgb4i: Fix TLS dependency

SCSI_CXGB4_ISCSI selects CHELSIO_T4. The latter depends on TLS || TLS=n, so
since 'select' does not check dependencies of the selected symbol,
SCSI_CXGB4_ISCSI should also depend on TLS || TLS=n.

This prevents the following kconfig warning and restricts SCSI_CXGB4_ISCSI
to 'm' whenever TLS=m.

WARNING: unmet direct dependencies detected for CHELSIO_T4
Depends on [m]: NETDEVICES [=y] && ETHERNET [=y] && NET_VENDOR_CHELSIO [=y] && PCI [=y] && (IPV6 [=y] || IPV6 [=y]=n) && (TLS [=m] || TLS [=m]=n)
Selected by [y]:
- SCSI_CXGB4_ISCSI [=y] && SCSI_LOWLEVEL [=y] && SCSI [=y] && PCI [=y] && INET [=y] && (IPV6 [=y] || IPV6 [=y]=n) && ETHERNET [=y]

Link: https://lore.kernel.org/r/20201208220505.24488-1-rdunlap@infradead.org
Fixes: 7b36b6e03b0d ("[SCSI] cxgb4i v5: iscsi driver")
Cc: Karen Xie <kxie@chelsio.com>
Cc: linux-scsi@vger.kernel.org
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

treewide: replace '---help---' in Kconfig files with 'help'

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: cxgb4i: fix thermal configuration dependencies

I fixed a bug by adding a dependency in the network driver, but that fix
caused a related bug in the SCSI driver:

WARNING: unmet direct dependencies detected for CHELSIO_T4
Depends on [m]: NETDEVICES [=y] && ETHERNET [=y] && NET_VENDOR_CHELSIO [=y] && PCI [=y] && (IPV6 [=y] || IPV6 [=y]=n) && (THERMAL [=m] || !THERMAL [=m])
Selected by [y]:
- SCSI_CXGB4_ISCSI [=y] && SCSI_LOWLEVEL [=y] && SCSI [=y] && PCI [=y] && INET [=y] && (IPV6 [=y] || IPV6 [=y]=n)
drivers/net/ethernet/chelsio/cxgb4/cxgb4_thermal.o: In function `cxgb4_thermal_init':
cxgb4_thermal.c:(.text+0x158): undefined reference to `thermal_zone_device_register'
drivers/net/ethernet/chelsio/cxgb4/cxgb4_thermal.o: In function `cxgb4_thermal_remove':
cxgb4_thermal.c:(.text+0x1d8): undefined reference to `thermal_zone_device_unregister'
/git/arm-soc/Makefile:1042: recipe for target 'vmlinux' failed

The same dependency needs to be propagated here to make it work correctly
with CONFIG_THERMAL=m and SCSI_CXGB4_ISCSI=y. That change by itself causes
another problem with a circular dependency, as we use 'select NETDEVICES'.
This is something we really should not do anyway, as a driver symbol should
never select another major subsystem, so let's turn that into a 'depends
on'. I don't see any downsides of that, as NETDEVICES is only disabled in
rather obscure cases that are not relevant to the users of cxgb4i.

Fixes: e70a57fa59bb ("cxgb4: fix thermal configuration dependencies")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

cxgb4i,libcxgbi: add iSCSI DDP support

Add iSCSI DDP support in cxgb4i driver
using common iSCSI DDP Page Pod Manager.

Signed-off-by: Varun Prakash <varun@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

libcxgbi/cxgb4i : Fix ipv6 build failure caught with randconfig

Previous guard of IS_ENABLED(CONFIG_IPV6) is not sufficient when cxgbi drivers
are built into kernel but ipv6 is not.

v2: Use Kconfig to disable compiling cxgbi built into kernel when ipv6 is
compiled as a module

Fixes: e81fbf6cd652 ("libcxgbi:cxgb4i Guard ipv6 code with a config check")
Fixes: fc8d0590d914 ("libcxgbi: Add ipv6 api to driver")
Signed-off-by: Anish Bhatt <anish@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

cxgbi: Fix scsi Kconfig dependencies.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

cxgb{3,4}*: improve Kconfig dependencies

- Remove the dependency of cxgb4 and cxgb4vf on INET. cxgb3 really
depends on INET, keep it but add it directly to the driver's Kconfig
entry.
- Make the iSCSI drivers cxgb3i and cxgb4i available in the SCSI menu
without requiring any options in the net driver menu to be enabled
first. Add needed selects so the iSCSI drivers can build their
corresponding net drivers.
- Remove CHELSIO_T*_DEPENDS.

Signed-off-by: Dimitris Michailidis <dm@chelsio.com>
Acked-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[SCSI] cxgb4i v5: iscsi driver

Added cxgb4i iSCSI driver.

This patch implements the cxgb4i iscsi connection acceleration for the
open-iscsi initiator.

The cxgb4i driver offers the iscsi PDU based offload:
- digest insertion and verification
- payload direct-placement into host memory buffer.

Signed-off-by: Karen Xie <kxie@chelsio.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>