kernel/git/stable/linux.git/drivers/s390/net/lcs.c, branch master

s390/net: Remove LCS driver

2025-02-06T02:19:01+00:00

The original Open Systems Adapter (OSA) was introduced by IBM in the mid-90s. These were then superseded by OSA-Express in 1999 which used Queued Direct IO to greatly improve throughput. The newer cards retained the older, slower non-QDIO (OSE) modes for compatibility with older systems. In Linux, the lcs driver was responsible for cards operating in the older OSE mode and the qeth driver was introduced to allow the OSA-Express cards to operate in the newer QDIO (OSD) mode. For an S390 machine from 1998 or later, there is no reason to use the OSE mode and lcs driver as all OSA cards since 1999 provide the faster OSD mode. As a result, it's been years since we have heard of a customer configuration involving the lcs driver. This patch removes the lcs driver. The technology it supports has been obsolete for past 25+ years and is irrelevant for current use cases. Reviewed-by: Alexandra Winter Acked-by: Heiko Carstens Acked-by: Peter Oberparleiter Signed-off-by: Aswin Karuvally Signed-off-by: Alexandra Winter Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250204103135.1619097-1-wintera@linux.ibm.com Signed-off-by: Jakub Kicinski

s390/lcs: add missing MODULE_DESCRIPTION() macro

2024-06-27T21:37:04+00:00

With ARCH=s390, make allmodconfig && make W=1 C=1 reports: WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/s390/net/lcs.o Add the missing invocation of the MODULE_DESCRIPTION() macro. Signed-off-by: Jeff Johnson Acked-by: Alexandra Winter Link: https://patch.msgid.link/20240625-md-s390-drivers-s390-net-v2-1-5a8a2b2f2ae3@quicinc.com Signed-off-by: Jakub Kicinski

s390/lcs: use new address translation helpers

2024-03-13T08:23:48+00:00

Use virt_to_dma32() and friends to properly convert virtual to physical and physical to virtual addresses so that "make C=1" does not generate any warnings anymore. Signed-off-by: Heiko Carstens

s390/lcs: Remove FDDI option

2023-07-26T03:06:56+00:00

The last s390 machine that supported FDDI was z900 ('7th generation', released in 2000). The oldest machine generation currently supported by the Linux kernel is MARCH_Z10 (released 2008). If there is still a usecase for connecting a Linux on s390 instance to a LAN Channel Station (LCS), it can only do so via Ethernet. Randy Dunlap[1] found that LCS over FDDI has never worked, when FDDI was compiled as module. Instead of fixing that, remove the FDDI option from the lcs driver. While at it, make the CONFIG_LCS description a bit more helpful. References: [1] https://lore.kernel.org/netdev/20230621213742.8245-1-rdunlap@infradead.org/ Signed-off-by: Alexandra Winter Acked-by: Christian Borntraeger Reviewed-by: Randy Dunlap Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230724131546.3597001-1-wintera@linux.ibm.com Signed-off-by: Jakub Kicinski

revert "s390/net: lcs: use IS_ENABLED() for kconfig detection"

2023-06-24T22:10:49+00:00

The referenced patch is causing build errors when ETHERNET=y and FDDI=m. While we work out the preferred patch(es), revert this patch to make the pain go away. Fixes: 128272336120 ("s390/net: lcs: use IS_ENABLED() for kconfig detection") Signed-off-by: Randy Dunlap Reported-by: kernel test robot Link: lore.kernel.org/r/202306202129.pl0AqK8G-lkp@intel.com Cc: Alexandra Winter Cc: Wenjia Zhang Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230622155409.27311-1-rdunlap@infradead.org Signed-off-by: Jakub Kicinski

s390/lcs: Convert sysfs sprintf to sysfs_emit

2023-06-23T09:55:54+00:00

Following the advice of the Documentation/filesystems/sysfs.rst. All sysfs related show()-functions should only use sysfs_emit() or sysfs_emit_at() when formatting the value to be returned to user space. While at it, follow Linux kernel coding style and unify indentation Reported-by: Jules Irenge Reported-by: Joe Perches Reviewed-by: Alexandra Winter Reviewed-by: Simon Horman Signed-off-by: Thorsten Winkler Signed-off-by: Alexandra Winter Signed-off-by: Paolo Abeni

s390/net: lcs: use IS_ENABLED() for kconfig detection

2023-06-16T08:07:10+00:00

When CONFIG_ETHERNET=m or CONFIG_FDDI=m, lcs.s has build errors or warnings: ../drivers/s390/net/lcs.c:40:2: error: #error Cannot compile lcs.c without some net devices switched on. 40 | #error Cannot compile lcs.c without some net devices switched on. ../drivers/s390/net/lcs.c: In function 'lcs_startlan_auto': ../drivers/s390/net/lcs.c:1601:13: warning: unused variable 'rc' [-Wunused-variable] 1601 | int rc; Solve this by using IS_ENABLED(CONFIG_symbol) instead of ifdef CONFIG_symbol. The latter only works for builtin (=y) values while IS_ENABLED() works for builtin or modular values. Signed-off-by: Randy Dunlap Cc: Alexandra Winter Cc: Wenjia Zhang Cc: linux-s390@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Signed-off-by: David S. Miller

s390/lcs: Fix return type of lcs_start_xmit()

2022-11-07T11:24:37+00:00

With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed. A proposed warning in clang aims to catch these at compile time, which reveals: drivers/s390/net/lcs.c:2090:21: error: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Werror,-Wincompatible-function-pointer-types-strict] .ndo_start_xmit = lcs_start_xmit, ^~~~~~~~~~~~~~ drivers/s390/net/lcs.c:2097:21: error: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Werror,-Wincompatible-function-pointer-types-strict] .ndo_start_xmit = lcs_start_xmit, ^~~~~~~~~~~~~~ ->ndo_start_xmit() in 'struct net_device_ops' expects a return type of 'netdev_tx_t', not 'int'. Adjust the return type of lcs_start_xmit() to match the prototype's to resolve the warning and potential CFI failure, should s390 select ARCH_SUPPORTS_CFI_CLANG in the future. Link: https://github.com/ClangBuiltLinux/linux/issues/1750 Reviewed-by: Alexandra Winter Reviewed-by: Kees Cook Signed-off-by: Nathan Chancellor Signed-off-by: David S. Miller

s390/lcs: fix variable dereferenced before check

2022-05-11T11:31:01+00:00

smatch complains about drivers/s390/net/lcs.c:1741 lcs_get_control() warn: variable dereferenced before check 'card->dev' (see line 1739) Fixes: 27eb5ac8f015 ("[PATCH] s390: lcs driver bug fixes and improvements [1/2]") Signed-off-by: Alexandra Winter Signed-off-by: David S. Miller

s390/net: sort out physical vs virtual pointers usage

2022-02-23T00:09:13+00:00

Fix virtual vs physical address confusion (which currently are the same). Reviewed-by: Alexandra Winter Reviewed-by: Wenjia Zhang Signed-off-by: Alexander Gordeev Signed-off-by: Alexandra Winter Signed-off-by: Jakub Kicinski