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path: root/drivers/misc/cxl/vphb.c
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2016-03-09cxl: Ignore probes for virtual afu pci devicesVaibhav Jain
Add a check at the beginning of cxl_probe function to ignore virtual pci devices created for each afu registered. This fixes the the errors messages logged about missing CXL vsec, when cxl probe is unable to find necessary vsec entries in device pci config space. The error message logged are of the form : cxl-pci 0004:00:00.0: ABORTING: CXL VSEC not found! cxl-pci 0004:00:00.0: cxl_init_adapter failed: -19 Cc: Ian Munsie <imunsie@au1.ibm.com> Cc: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Reviewed-by: fbarrat@linux.vnet.ibm.com Reviewed-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>
2016-03-09cxl: Adapter failure handlingChristophe Lombard
Check the AFU state whenever an API is called. The hypervisor may issue a reset of the adapter when it detects a fault. When it happens, it launches an error recovery which will either move the AFU to a permanent failure state, or in the disabled state. If the AFU is found to be disabled, detach all existing contexts from it before issuing a AFU reset to re-enable it. Before detaching contexts, notify any kernel driver through the EEH callbacks of the AFU pci device. Co-authored-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-09cxl: Support the cxl kernel API from a guestFrederic Barrat
Like on bare-metal, the cxl driver creates a virtual PHB and a pci device for the AFU. The configuration space of the device is mapped to the configuration record of the AFU. Reuse the code defined in afu_cr_read8|16|32() when reading the configuration space of the AFU device. Even though the (virtual) AFU device is a pci device, the adapter is not. So a driver using the cxl kernel API cannot read the VPD of the adapter through the usual PCI interface. Therefore, we add a call to the cxl kernel API: ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count); Co-authored-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-09cxl: Separate bare-metal fields in adapter and AFU data structuresChristophe Lombard
Introduce sub-structures containing the bare-metal specific fields in the structures describing the adapter (struct cxl) and AFU (struct cxl_afu). Update all their references. Co-authored-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-09cxl: Introduce implementation-specific APIFrederic Barrat
The backend API (in cxl.h) lists some low-level functions whose implementation is different on bare-metal and in a guest. Each environment implements its own functions, and the common code uses them through function pointers, defined in cxl_backend_ops Co-authored-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-11-24cxl: use correct operator when writing pcie config space valuesAndrew Donnellan
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: 6f7f0b3df6d4 ("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>
2015-10-15cxl: Free virtual PHB when removingAndrew Donnellan
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>
2015-09-07cxl: abort cxl_pci_enable_device_hook() if PCI channel is offlineAndrew Donnellan
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>
2015-08-14cxl: EEH supportDaniel Axtens
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>
2015-08-14cxl: Drop commands if the PCI channel is not in normal stateDaniel Axtens
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>
2015-07-06cxl/vphb.c: Use phb pointer after NULL checkManinder Singh
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>
2015-06-07cxl: Reset default context for vPHB on releaseMichael Neuling
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>
2015-06-03cxl: Add AFU virtual PHB and kernel APIMichael Neuling
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>