linux/include/misc/ocxl.h
Frederic Barrat 280b983ce2 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>
2018-01-24 11:42:59 +11:00

215 lines
6.5 KiB
C

// 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_ */