diff options
author | Frederic Barrat <fbarrat@linux.vnet.ibm.com> | 2018-01-23 12:31:43 +0100 |
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committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-01-24 11:42:59 +1100 |
commit | 280b983ce2b8759722d911ea4b5af66e95d84e09 (patch) | |
tree | d3f3ffe5ee5acd780749b690921e97c09aa76845 /include | |
parent | aeddad1760aeb206d912b27b230269407efd5b06 (diff) | |
download | linux-280b983ce2b8759722d911ea4b5af66e95d84e09.tar.bz2 |
ocxl: Add a kernel API for other opencapi drivers
Some of the functions done by the generic driver should also be needed
by other opencapi drivers: attaching a context to an adapter,
translation fault handling, AFU interrupt allocation...
So to avoid code duplication, the driver provides a kernel API that
other drivers can use, similar to calling a in-kernel library.
It is still a bit theoretical, for lack of real hardware, and will
likely need adjustements down the road. But we used the cxlflash
driver as a guinea pig.
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'include')
-rw-r--r-- | include/misc/ocxl.h | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/include/misc/ocxl.h b/include/misc/ocxl.h new file mode 100644 index 000000000000..51ccf76db293 --- /dev/null +++ b/include/misc/ocxl.h @@ -0,0 +1,214 @@ +// SPDX-License-Identifier: GPL-2.0+ +// Copyright 2017 IBM Corp. +#ifndef _MISC_OCXL_H_ +#define _MISC_OCXL_H_ + +#include <linux/pci.h> + +/* + * Opencapi drivers all need some common facilities, like parsing the + * device configuration space, adding a Process Element to the Shared + * Process Area, etc... + * + * The ocxl module provides a kernel API, to allow other drivers to + * reuse common code. A bit like a in-kernel library. + */ + +#define OCXL_AFU_NAME_SZ (24+1) /* add 1 for NULL termination */ + +/* + * The following 2 structures are a fairly generic way of representing + * the configuration data for a function and AFU, as read from the + * configuration space. + */ +struct ocxl_afu_config { + u8 idx; + int dvsec_afu_control_pos; /* offset of AFU control DVSEC */ + char name[OCXL_AFU_NAME_SZ]; + u8 version_major; + u8 version_minor; + u8 afuc_type; + u8 afum_type; + u8 profile; + u8 global_mmio_bar; /* global MMIO area */ + u64 global_mmio_offset; + u32 global_mmio_size; + u8 pp_mmio_bar; /* per-process MMIO area */ + u64 pp_mmio_offset; + u32 pp_mmio_stride; + u8 log_mem_size; + u8 pasid_supported_log; + u16 actag_supported; +}; + +struct ocxl_fn_config { + int dvsec_tl_pos; /* offset of the Transaction Layer DVSEC */ + int dvsec_function_pos; /* offset of the Function DVSEC */ + int dvsec_afu_info_pos; /* offset of the AFU information DVSEC */ + s8 max_pasid_log; + s8 max_afu_index; +}; + +/* + * Read the configuration space of a function and fill in a + * ocxl_fn_config structure with all the function details + */ +extern int ocxl_config_read_function(struct pci_dev *dev, + struct ocxl_fn_config *fn); + +/* + * Check if an AFU index is valid for the given function. + * + * AFU indexes can be sparse, so a driver should check all indexes up + * to the maximum found in the function description + */ +extern int ocxl_config_check_afu_index(struct pci_dev *dev, + struct ocxl_fn_config *fn, int afu_idx); + +/* + * Read the configuration space of a function for the AFU specified by + * the index 'afu_idx'. Fills in a ocxl_afu_config structure + */ +extern int ocxl_config_read_afu(struct pci_dev *dev, + struct ocxl_fn_config *fn, + struct ocxl_afu_config *afu, + u8 afu_idx); + +/* + * Get the max PASID value that can be used by the function + */ +extern int ocxl_config_get_pasid_info(struct pci_dev *dev, int *count); + +/* + * Tell an AFU, by writing in the configuration space, the PASIDs that + * it can use. Range starts at 'pasid_base' and its size is a multiple + * of 2 + * + * 'afu_control_offset' is the offset of the AFU control DVSEC which + * can be found in the function configuration + */ +extern void ocxl_config_set_afu_pasid(struct pci_dev *dev, + int afu_control_offset, + int pasid_base, u32 pasid_count_log); + +/* + * Get the actag configuration for the function: + * 'base' is the first actag value that can be used. + * 'enabled' it the number of actags available, starting from base. + * 'supported' is the total number of actags desired by all the AFUs + * of the function. + */ +extern int ocxl_config_get_actag_info(struct pci_dev *dev, + u16 *base, u16 *enabled, u16 *supported); + +/* + * Tell a function, by writing in the configuration space, the actags + * it can use. + * + * 'func_offset' is the offset of the Function DVSEC that can found in + * the function configuration + */ +extern void ocxl_config_set_actag(struct pci_dev *dev, int func_offset, + u32 actag_base, u32 actag_count); + +/* + * Tell an AFU, by writing in the configuration space, the actags it + * can use. + * + * 'afu_control_offset' is the offset of the AFU control DVSEC for the + * desired AFU. It can be found in the AFU configuration + */ +extern void ocxl_config_set_afu_actag(struct pci_dev *dev, + int afu_control_offset, + int actag_base, int actag_count); + +/* + * Enable/disable an AFU, by writing in the configuration space. + * + * 'afu_control_offset' is the offset of the AFU control DVSEC for the + * desired AFU. It can be found in the AFU configuration + */ +extern void ocxl_config_set_afu_state(struct pci_dev *dev, + int afu_control_offset, int enable); + +/* + * Set the Transaction Layer configuration in the configuration space. + * Only needed for function 0. + * + * It queries the host TL capabilities, find some common ground + * between the host and device, and set the Transaction Layer on both + * accordingly. + */ +extern int ocxl_config_set_TL(struct pci_dev *dev, int tl_dvsec); + +/* + * Request an AFU to terminate a PASID. + * Will return once the AFU has acked the request, or an error in case + * of timeout. + * + * The hardware can only terminate one PASID at a time, so caller must + * guarantee some kind of serialization. + * + * 'afu_control_offset' is the offset of the AFU control DVSEC for the + * desired AFU. It can be found in the AFU configuration + */ +extern int ocxl_config_terminate_pasid(struct pci_dev *dev, + int afu_control_offset, int pasid); + +/* + * Set up the opencapi link for the function. + * + * When called for the first time for a link, it sets up the Shared + * Process Area for the link and the interrupt handler to process + * translation faults. + * + * Returns a 'link handle' that should be used for further calls for + * the link + */ +extern int ocxl_link_setup(struct pci_dev *dev, int PE_mask, + void **link_handle); + +/* + * Remove the association between the function and its link. + */ +extern void ocxl_link_release(struct pci_dev *dev, void *link_handle); + +/* + * Add a Process Element to the Shared Process Area for a link. + * The process is defined by its PASID, pid, tid and its mm_struct. + * + * 'xsl_err_cb' is an optional callback if the driver wants to be + * notified when the translation fault interrupt handler detects an + * address error. + * 'xsl_err_data' is an argument passed to the above callback, if + * defined + */ +extern int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr, + u64 amr, struct mm_struct *mm, + void (*xsl_err_cb)(void *data, u64 addr, u64 dsisr), + void *xsl_err_data); + +/* + * Remove a Process Element from the Shared Process Area for a link + */ +extern int ocxl_link_remove_pe(void *link_handle, int pasid); + +/* + * Allocate an AFU interrupt associated to the link. + * + * 'hw_irq' is the hardware interrupt number + * 'obj_handle' is the 64-bit object handle to be passed to the AFU to + * trigger the interrupt. + * On P9, 'obj_handle' is an address, which, if written, triggers the + * interrupt. It is an MMIO address which needs to be remapped (one + * page). + */ +extern int ocxl_link_irq_alloc(void *link_handle, int *hw_irq, + u64 *obj_handle); + +/* + * Free a previously allocated AFU interrupt + */ +extern void ocxl_link_free_irq(void *link_handle, int hw_irq); + +#endif /* _MISC_OCXL_H_ */ |