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path: root/drivers/misc/cxl/vphb.c
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* cxl: drop the dma_set_mask callback from vphbChristoph Hellwig2018-12-201-12/+0
| | | | | | | | | | The CXL code never even looks at the dma mask, so there is no good reason for this sanity check. Remove it because it gets in the way of the dma ops refactoring. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* Revert "cxl: Allow a default context to be associated with an external pci_dev"Frederic Barrat2018-07-021-3/+27
| | | | | | | | | | Remove abandonned capi support for the Mellanox CX4. This reverts commit a19bd79e31769626d288cc016e21a31b6f47bf6f. Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* Revert "cxl: Add support for using the kernel API with a real PHB"Alastair D'Silva2018-07-021-14/+2
| | | | | | | | | | Remove abandonned capi support for the Mellanox CX4. This reverts commit 317f5ef1b363417b6f1e93b90dfd2ffd6be6e867. Signed-off-by: Alastair D'Silva <alastair@d-silva.org> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc: rename dma_direct_ to dma_nommu_Christoph Hellwig2018-01-101-1/+1
| | | | | | | We want to use the dma_direct_ namespace for a generic implementation, so rename powerpc to the second best choice: dma_nommu_. Signed-off-by: Christoph Hellwig <hch@lst.de>
* cxl: fix nested locking hang during EEH hotplugAndrew Donnellan2017-02-211-4/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | Commit 14a3ae34bfd0 ("cxl: Prevent read/write to AFU config space while AFU not configured") introduced a rwsem to fix an invalid memory access that occurred when someone attempts to access the config space of an AFU on a vPHB whilst the AFU is deconfigured, such as during EEH recovery. It turns out that it's possible to run into a nested locking issue when EEH recovery fails and a full device hotplug is required. cxl_pci_error_detected() deconfigures the AFU, taking a writer lock on configured_rwsem. When EEH recovery fails, the EEH code calls pci_hp_remove_devices() to remove the device, which in turn calls cxl_remove() -> cxl_pci_remove_afu() -> pci_deconfigure_afu(), which tries to grab the writer lock that's already held. Standard rwsem semantics don't express what we really want to do here and don't allow for nested locking. Fix this by replacing the rwsem with an atomic_t which we can control more finely. Allow the AFU to be locked multiple times so long as there are no readers. Fixes: 14a3ae34bfd0 ("cxl: Prevent read/write to AFU config space while AFU not configured") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* cxl: Prevent read/write to AFU config space while AFU not configuredAndrew Donnellan2017-01-251-22/+29
| | | | | | | | | | | | | | | | | | | | | During EEH recovery, we deconfigure all AFUs whilst leaving the corresponding vPHB and virtual PCI device in place. If something attempts to interact with the AFU's PCI config space (e.g. running lspci) after the AFU has been deconfigured and before it's reconfigured, cxl_pcie_{read,write}_config() will read invalid values from the deconfigured struct cxl_afu and proceed to Oops when they try to dereference pointers that have been set to NULL during deconfiguration. Add a rwsem to struct cxl_afu so we can prevent interaction with config space while the AFU is deconfigured. Reported-by: Pradipta Ghosh <pradghos@in.ibm.com> Suggested-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* cxl: use pcibios_free_controller_deferred() when removing vPHBsAndrew Donnellan2016-08-221-1/+9
| | | | | | | | | | | | | | | | | | | | When cxl removes a vPHB, it's possible that the pci_controller may be freed before all references to the devices on the vPHB have been released. This in turn causes an invalid memory access when the devices are eventually released, as pcibios_release_device() attempts to call the phb's release_device hook. In cxl_pci_vphb_remove(), remove the existing call to pcibios_free_controller(). Instead, use pcibios_free_controller_deferred() to free the pci_controller after all devices have been released. Export pci_set_host_bridge_release() so we can do this. Cc: stable@vger.kernel.org Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* cxl: Fix sparse warningsAndrew Donnellan2016-08-091-1/+1
| | | | | | | | | | Make native_irq_wait() static and use NULL rather than 0 to initialise phb->cfg_data in cxl_pci_vphb_add() to remove sparse warnings. Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* cxl: Add support for using the kernel API with a real PHBIan Munsie2016-07-141-2/+14
| | | | | | | | | | | | | | | | | This hooks up support for using the kernel API with a real PHB. After the AFU initialisation has completed it calls into the PHB code to pass it the AFU that will be used by other peer physical functions on the adapter. The cxl_pci_to_afu API is extended to work with peer PCI devices, retrieving the peer AFU from the PHB. This API may also now return an error if it is called on a PCI device that is not associated with either a cxl vPHB or a peer PCI device to an AFU, and this error is propagated down. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* cxl: Do not create vPHB if there are no AFU configuration recordsIan Munsie2016-07-141-0/+11
| | | | | | | | | | | | | | | | | | | | | | The vPHB model of the cxl kernel API is a hierarchy where the AFU is represented by the vPHB, and it's AFU configuration records are exposed as functions under that vPHB. If there are no AFU configuration records we will create a vPHB with nothing under it, which is a waste of resources and will opt us into EEH handling despite not having anything special to handle. This also does not make sense for cards using the peer model of the cxl kernel API, where the other functions of the device are exposed via additional peer physical functions rather than AFU configuration records. This model will also not work with the existing EEH handling in the cxl driver, as that is designed around the vPHB model. Skip creating the vPHB for AFUs without any AFU configuration records, and opt out of EEH handling for them. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* cxl: Allow a default context to be associated with an external pci_devIan Munsie2016-07-141-27/+3
| | | | | | | | | | | | | | | | | The cxl kernel API has a concept of a default context associated with each PCI device under the virtual PHB. The Mellanox CX4 will also use the cxl kernel API, but it does not use a virtual PHB - rather, the AFU appears as a physical function as a peer to the networking functions. In order to allow the kernel API to work with those networking functions, we will need to associate a default context with them as well. To this end, refactor the corresponding code to do this in vphb.c and export it so that it can be called from the PHB code. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* cxl: Make vPHB device node match adapter'sFrederic Barrat2016-06-161-11/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | On bare-metal, when a device is attached to the cxl card, lsvpd shows a location code such as (with cxlflash): # lsvpd -l sg22 ... *YL U78CB.001.WZS0073-P1-C33-B0-T0-L0 which makes it hard to easily identify the cxl adapter owning the flash device, since in this example C33 refers to a P8 processor. lsvpd looks in the parent devices until it finds a location code, so the device node for the vPHB ends up being used. By reusing the device node of the adapter for the vPHB, lsvpd shows: # lsvpd -l sg16 ... *YL U78C9.001.WZS09XA-P1-C7-B1-T0-L3 where C7 is the PCI slot of the cxl adapter. On powerVM, the vPHB was already using the adapter device node, so there's no change there. Tested by cxlflash on bare-metal and powerVM. Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* cxl: Ignore probes for virtual afu pci devicesVaibhav Jain2016-03-091-0/+9
| | | | | | | | | | | | | | | | | | | 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>
* cxl: Adapter failure handlingChristophe Lombard2016-03-091-1/+1
| | | | | | | | | | | | | | | | | | | 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>
* cxl: Support the cxl kernel API from a guestFrederic Barrat2016-03-091-89/+65
| | | | | | | | | | | | | | | | | | | | | | 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>
* cxl: Separate bare-metal fields in adapter and AFU data structuresChristophe Lombard2016-03-091-2/+2
| | | | | | | | | | | | | | 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>
* cxl: Introduce implementation-specific APIFrederic Barrat2016-03-091-3/+3
| | | | | | | | | | | | | | 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>
* cxl: use correct operator when writing pcie config space valuesAndrew Donnellan2015-11-241-1/+1
| | | | | | | | | | | | | | | | | | | 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>
* cxl: Free virtual PHB when removingAndrew Donnellan2015-10-151-0/+2
| | | | | | | | | | | | | 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: abort cxl_pci_enable_device_hook() if PCI channel is offlineAndrew Donnellan2015-09-071-0/+6
| | | | | | | | | | | | | | | | 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>
* cxl: EEH supportDaniel Axtens2015-08-141-0/+8
| | | | | | | | | 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>
* cxl: Drop commands if the PCI channel is not in normal stateDaniel Axtens2015-08-141-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* cxl/vphb.c: Use phb pointer after NULL checkManinder Singh2015-07-061-1/+2
| | | | | | | | | | | 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>
* cxl: Reset default context for vPHB on releaseMichael Neuling2015-06-071-0/+1
| | | | | | | | 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>
* cxl: Add AFU virtual PHB and kernel APIMichael Neuling2015-06-031-0/+269
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>
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