The struct 'ism_client' is specialized for s390 platform firmware ISM.
So replace it with 'void' to make SMCD DMB registration helper generic
for both Emulated-ISM and existing ISM.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-and-tested-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Since [1], dma_alloc_coherent() does not accept requests for GFP_COMP
anymore, even on archs that may be able to fulfill this. Functionality that
relied on the receive buffer being a compound page broke at that point:
The SMC-D protocol, that utilizes the ism device driver, passes receive
buffers to the splice processor in a struct splice_pipe_desc with a
single entry list of struct pages. As the buffer is no longer a compound
page, the splice processor now rejects requests to handle more than a
page worth of data.
Replace dma_alloc_coherent() and allocate a buffer with folio_alloc and
create a DMA map for it with dma_map_page(). Since only receive buffers
on ISM devices use DMA, qualify the mapping as FROM_DEVICE.
Since ISM devices are available on arch s390, only, and on that arch all
DMA is coherent, there is no need to introduce and export some kind of
dma_sync_to_cpu() method to be called by the SMC-D protocol layer.
Analogously, replace dma_free_coherent by a two step dma_unmap_page,
then folio_put to free the receive buffer.
[1] https://lore.kernel.org/all/20221113163535.884299-1-hch@lst.de/
Fixes: c08004eede ("s390/ism: don't pass bogus GFP_ flags to dma_alloc_coherent")
Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The System EID (SEID) is an internal EID that is used by the SMCv2
software stack that has a predefined and constant value representing
the s390 physical machine that the OS is executing on. So it should
be managed by SMC stack instead of ISM driver and be consistent for
all ISMv2 device (including virtual ISM devices) on s390 architecture.
Suggested-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-and-tested-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
According to virtual ISM support feature defined by SMCv2.1, GIDs of
virtual ISM device are UUIDs defined by RFC4122, which are 128-bits
long. So some adaptation work is required. And note that the GIDs of
existing platform firmware ISM devices still remain 64-bits long.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit a72178cfe8 ("net/smc: Fix dependency of SMC on ISM")
you can build the ism code without selecting the SMC network protocol.
That leaves some ism functions be reported as unused. Move these
functions under the conditional compile with CONFIG_SMC.
Also codify the suggestion to also configure the SMC protocol in ism's
Kconfig - but with an "imply" rather than a "select" as SMC depends on
other config options and allow for a deliberate decision not to build
SMC. Also, mention that in ISM's help.
Fixes: a72178cfe8 ("net/smc: Fix dependency of SMC on ISM")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Closes: https://lore.kernel.org/netdev/afd142a2-1fa0-46b9-8b2d-7652d41d3ab8@infradead.org/
Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: David S. Miller <davem@davemloft.net>
When ism_unregister_client() is called but the client still has DMBs
registered it returns -EBUSY and prints an error. This only happens
after the client has already been unregistered however. This is
unexpected as the unregister claims to have failed. Furthermore as this
implies a client bug a WARN() is more appropriate. Thus move the
deregistration after the check and use WARN().
Fixes: 89e7d2ba61 ("net/ism: Add new API for client registration")
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Previously the clients_lock was protecting the clients array against
concurrent addition/removal of clients but was also accessed from IRQ
context. This meant that it had to be a spinlock and that the add() and
remove() callbacks in which clients need to do allocation and take
mutexes can't be called under the clients_lock. To work around this these
callbacks were moved to workqueues. This not only introduced significant
complexity but is also subtly broken in at least one way.
In ism_dev_init() and ism_dev_exit() clients[i]->tgt_ism is used to
communicate the added/removed ISM device to the work function. While
write access to client[i]->tgt_ism is protected by the clients_lock and
the code waits that there is no pending add/remove work before and after
setting clients[i]->tgt_ism this is not enough. The problem is that the
wait happens based on per ISM device counters. Thus a concurrent
ism_dev_init()/ism_dev_exit() for a different ISM device may overwrite
a clients[i]->tgt_ism between unlocking the clients_lock and the
subsequent wait for the work to finnish.
Thankfully with the clients_lock no longer held in IRQ context it can be
turned into a mutex which can be held during the calls to add()/remove()
completely removing the need for the workqueues and the associated
broken housekeeping including the per ISM device counters and the
clients[i]->tgt_ism.
Fixes: 89e7d2ba61 ("net/ism: Add new API for client registration")
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The clients array references all registered clients and is protected by
the clients_lock. Besides its use as general list of clients the clients
array is accessed in ism_handle_irq() to forward ISM device events to
clients.
While the clients_lock is taken in the IRQ handler when calling
handle_event() it is however incorrectly not held during the
client->handle_irq() call and for the preceding clients[] access leaving
it unprotected against concurrent client (un-)registration.
Furthermore the accesses to ism->sba_client_arr[] in ism_register_dmb()
and ism_unregister_dmb() are not protected by any lock. This is
especially problematic as the client ID from the ism->sba_client_arr[]
is not checked against NO_CLIENT and neither is the client pointer
checked.
Instead of expanding the use of the clients_lock further add a separate
array in struct ism_dev which references clients subscribed to the
device's events and IRQs. This array is protected by ism->lock which is
already taken in ism_handle_irq() and can be taken outside the IRQ
handler when adding/removing subscribers or the accessing
ism->sba_client_arr[]. This also means that the clients_lock is no
longer taken in IRQ context.
Fixes: 89e7d2ba61 ("net/ism: Add new API for client registration")
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch prevents the system from crashing when unloading the ISM module.
How to reproduce: Attach an ISM device and execute 'rmmod ism'.
Error-Log:
- Trying to free already-free IRQ 0
- WARNING: CPU: 1 PID: 966 at kernel/irq/manage.c:1890 free_irq+0x140/0x540
After calling ism_dev_exit() for each ISM device in the exit routine,
pci_unregister_driver() will execute ism_remove() for each ISM device.
Because ism_remove() also calls ism_dev_exit(),
free_irq(pci_irq_vector(pdev, 0), ism) is called twice for each ISM
device. This results in a crash with the error
'Trying to free already-free IRQ'.
In the exit routine, it is enough to call pci_unregister_driver()
because it ensures that ism_dev_exit() is called once per
ISM device.
Cc: <stable@vger.kernel.org> # 6.3+
Fixes: 89e7d2ba61 ("net/ism: Add new API for client registration")
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Julian Ruess <julianr@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A future change will convert the DMA API implementation from the
architecture specific arch/s390/pci/pci_dma.c to using the common code
drivers/iommu/dma-iommu.c which the utilizes the same IOMMU hardware
through the s390-iommu driver. Unlike the s390 specific DMA API this
requires devices to correctly set the coherent mask to be allowed to use
IOVAs >2^32 in dma_alloc_coherent(). This was however not done for ISM
devices. ISM requires such addresses since currently the DMA aperture
for PCI devices starts at 2^32 and all calls to dma_alloc_coherent()
would thus fail.
Link: https://lore.kernel.org/all/20230310-dma_iommu-v9-1-65bb8edd2beb@linux.ibm.com/
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20230524075411.3734141-1-schnelle@linux.ibm.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Remove pci_clear_master to simplify the code,
the bus-mastering is also cleared in do_pci_disable_device,
like this:
./drivers/pci/pci.c:2197
static void do_pci_disable_device(struct pci_dev *dev)
{
u16 pci_command;
pci_read_config_word(dev, PCI_COMMAND, &pci_command);
if (pci_command & PCI_COMMAND_MASTER) {
pci_command &= ~PCI_COMMAND_MASTER;
pci_write_config_word(dev, PCI_COMMAND, pci_command);
}
pcibios_disable_device(dev);
}.
And dev->is_busmaster is set to 0 in pci_disable_device.
Signed-off-by: Cai Huoqing <cai.huoqing@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Previously, v2 support was derived from a very specific format of the SEID
as part of the SMC-D codebase. Make this part of the SMC-D device API, so
implementers do not need to adhere to a specific SEID format.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Reviewed-and-tested-by: Jan Karcher <jaka@linux.ibm.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The struct device for ISM devices was part of struct smcd_dev. Move to
struct ism_dev, provide a new API call in struct smcd_ops, and convert
existing SMCD code accordingly.
Furthermore, remove struct smcd_dev from struct ism_dev.
This is the final part of a bigger overhaul of the interfaces between SMC
and ISM.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The ism module had SMC-D-specific code sprinkled across the entire module.
We are now consolidating the SMC-D-specific parts into the latter parts
of the module, so it becomes more clear what code is intended for use with
ISM, and which parts are glue code for usage in the context of SMC-D.
This is the fourth part of a bigger overhaul of the interfaces between SMC
and ISM.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We separate the code implementing the struct smcd_ops API in the ISM
device driver from the functions that may be used by other exploiters of
ISM devices.
Note: We start out small, and don't offer the whole breadth of the ISM
device for public use, as many functions are specific to or likely only
ever used in the context of SMC-D.
This is the third part of a bigger overhaul of the interfaces between SMC
and ISM.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Register the smc module with the new ism device driver API.
This is the second part of a bigger overhaul of the interfaces between SMC
and ISM.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new API that allows other drivers to concurrently access ISM devices.
To do so, we introduce a new API that allows other modules to register for
ISM device usage. Furthermore, we move the GID to struct ism, where it
belongs conceptually, and rename and relocate struct smcd_event to struct
ism_event.
This is the first part of a bigger overhaul of the interfaces between SMC
and ISM.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conceptually, a DMB is a structure that belongs to ISM devices. However,
SMC currently 'owns' this structure. So future exploiters of ISM devices
would be forced to include SMC headers to work - which is just weird.
Therefore, we switch ISM to struct ism_dmb, introduce a new public header
with the definition (will be populated with further API calls later on),
and, add a thin wrapper to please SMC. Since structs smcd_dmb and ism_dmb
are identical, we can simply convert between the two for now.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
dma_alloc_coherent is an opaque allocator that only uses the GFP_ flags
for allocation context control. Don't pass __GFP_COMP which makes no
sense for an allocation that can't in any way be converted to a page
pointer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Wenjia Zhang <wenjia@linux.ibm.com>
Make the DMBE bits, which are passed on individually in ism_move() as
parameter idx, available to the receiver.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Wenjia Zhang < wenjia@linux.ibm.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reworked signature of the function to retrieve the system EID: No plausible
reason to use a double pointer. And neither to pass in the device as an
argument, as this identifier is by definition per system, not per device.
Plus some minor consistency edits.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Wenjia Zhang < wenjia@linux.ibm.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The wrappers in include/linux/pci-dma-compat.h should go away.
The patch has been generated with the coccinelle script below.
@@
expression e1, e2;
@@
- pci_set_dma_mask(e1, e2)
+ dma_set_mask(&e1->dev, e2)
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The system EID that is defined by the ISM driver is not correct. Using
an incorrect system EID allows to communicate with remote Linux systems
that use the same incorrect system EID, but when it comes to
interoperability with other operating systems then the system EIDs do
never match which prevents SMC-Dv2 communication.
Using the correct system EID fixes this problem.
Fixes: 201091ebb2 ("net/smc: introduce System Enterprise ID (SEID)")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
With SMCD version 2 the CHIDs of ISM devices are needed for the
CLC handshake.
This patch provides the new callback to retrieve the CHID of an
ISM device.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
SMCD version 2 defines a System Enterprise ID (short SEID).
This patch contains the SEID creation and adds the callback to
retrieve the created SEID.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the ism driver allocates a new dmb in ism_alloc_dmb() it must
first check for and reserve a slot in the sba bitmap. When
find_next_zero_bit() finds no free slot then the return code is -ENOMEM.
This code conflicts with the error when the alloc() fails later in the
code. As a result of that the caller can not differentiate
between out-of-memory conditions and sba-bitmap-full conditions.
Fix that by using the return code -ENOSPC when the sba slot
reservation failed.
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix to return negative error code -ENOMEM from the smcd_alloc_dev()
error handling case instead of 0, as done elsewhere in this function.
Fixes: 684b89bc39 ("s390/ism: add device driver for internal shared memory")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As s390 no longer supports ARCH_HIBERNATION_POSSIBLE, drop the unused
pm ops from the ism driver.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
ISM devices are special in how they access PCI memory space. Provide
wrappers for handling commands to the device. No functional change.
Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Prior to dma unmap/free operations the ism driver tries to ensure
that the memory is no longer accessed by the HW. When errors
during deregistration of memory regions from the HW occur the ism
driver will not unmap/free this memory.
When we receive notification from the hypervisor that a PCI function
has been detached we can no longer access the device and would never
unmap/free these memory regions which led to complaints by the DMA
debug API.
Treat this kind of errors during the deregistration of memory regions
from the HW as success since it is already ensured that the memory
is no longer accessed by HW.
Reported-by: Karsten Graul <kgraul@linux.ibm.com>
Reported-by: Hans Wippel <hwippel@linux.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
We already need to zero out memory for dma_alloc_coherent(), as such
using dma_zalloc_coherent() is superflous. Phase it out.
This change was generated with the following Coccinelle SmPL patch:
@ replace_dma_zalloc_coherent @
expression dev, size, data, handle, flags;
@@
-dma_zalloc_coherent(dev, size, handle, flags)
+dma_alloc_coherent(dev, size, handle, flags)
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
[hch: re-ran the script on the latest tree]
Signed-off-by: Christoph Hellwig <hch@lst.de>
SMC-D stress workload showed connection stalls. Since the firmware
decides to skip raising an interrupt if the SBA DMBE mask bit is
still set, this SBA DMBE mask bit should be cleared before the
IRQ handling in the SMC code runs. Otherwise there are small windows
possible with missing interrupts for incoming data.
SMC-D currently does not care about the old value of the SBA DMBE
mask.
Acked-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The few callers can just use dma_set_max_seg_size ()directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The two callers can just use dma_set_seg_boundary() directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Add support for the Internal Shared Memory vPCI Adapter.
This driver implements the interfaces of the SMC-D protocol.
Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
