When writing a value to config space, cxl_pcie_write_config() calls
cxl_pcie_config_info() to obtain a mask and shift value, shifts the new
value accordingly, then uses the mask to combine the shifted value with the
existing value at the address as part of a read-modify-write pattern.
Currently, we use a logical OR operator rather than a bitwise OR operator,
which means any use of this function results in an incorrect value being
written. Replace the logical OR operator with a bitwise OR operator so the
value is written correctly.
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: stable@vger.kernel.org
Fixes: 6f7f0b3df6 ("cxl: Add AFU virtual PHB and kernel API")
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When adding a vPHB in cxl_pci_vphb_add(), we allocate a pci_controller
struct using pcibios_alloc_controller(). However, we don't free it in
cxl_pci_vphb_remove(), causing a leak.
Call pcibios_free_controller() in cxl_pci_vphb_remove() to free the vPHB
data structure correctly.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
cxl_pci_enable_device_hook() is called when attempting to enable an AFU
sitting on a vPHB. At present, the state of the underlying CXL card's PCI
channel is only checked when it calls cxl_afu_check_and_enable() at the
very end, after it has already set DMA options and initialised a default
context.
Check the CXL card's link status before setting DMA options or initialising
a default context. If the link is down, print a warning and return
immediately.
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
EEH (Enhanced Error Handling) allows a driver to recover from the
temporary failure of an attached PCI card. Enable basic CXL support
for EEH.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If the PCI channel has gone down, don't attempt to poke the hardware.
We need to guard every time cxl_whatever_(read|write) is called. This
is because a call to those functions will dereference an offset into an
mmio register, and the mmio mappings get invalidated in the EEH
teardown.
Check in the read/write functions in the header.
We give them the same semantics as usual PCI operations:
- a write to a channel that is down is ignored.
- a read from a channel that is down returns all fs.
Also, we try to access the MMIO space of a vPHB device as part of the
PCI disable path. Because that's a read that bypasses most of our usual
checks, we handle it explicitly.
As far as user visible warnings go:
- Check link state in file ops, return -EIO if down.
- Be reasonably quiet if there's an error in a teardown path,
or when we already know the hardware is going down.
- Throw a big WARN if someone tries to start a CXL operation
while the card is down. This gives a useful stacktrace for
debugging whatever is doing that.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
static Anlaysis detected below error:-
(error) Possible null pointer dereference: phb
So, Use phb after NULL check.
Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we release the device, we should also invalidate the default context.
With this cxl_get_context() will return null after removal.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch does two things.
Firstly it presents the Accelerator Function Unit (AFUs) behind the POWER
Service Layer (PSL) as PCI devices on a virtual PCI Host Bridge (vPHB). This
in in addition to the PSL being a PCI device itself.
As part of the Coherent Accelerator Interface Architecture (CAIA) AFUs can
provide an AFU configuration. This AFU configuration recored is architected to
be the same as a PCI config space.
This patch sets discovers the AFU configuration records, provides AFU config
space read/write functions to these configuration records. It then enumerates
the PCI bus. It also hooks in PCI ops where appropriate. It also destroys the
vPHB when the physical card is removed.
Secondly, it add an in kernel API for AFU to use CXL. AFUs must present a
driver that firstly binds as a PCI device. This PCI device can then be using
to do CXL specific operations (that can't sit in the PCI ops) using this API.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Andrew Donnellan