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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright 2017 IBM Corp.
*/
#ifndef _MISC_CXLLIB_H
#define _MISC_CXLLIB_H
#include <linux/pci.h>
#include <asm/reg.h>
/*
* cxl driver exports a in-kernel 'library' API which can be called by
* other drivers to help interacting with an IBM XSL.
*/
/*
* tells whether capi is supported on the PCIe slot where the
* device is seated
*
* Input:
* dev: device whose slot needs to be checked
* flags: 0 for the time being
*/
bool cxllib_slot_is_supported(struct pci_dev *dev, unsigned long flags);
/*
* Returns the configuration parameters to be used by the XSL or device
*
* Input:
* dev: device, used to find PHB
* Output:
* struct cxllib_xsl_config:
* version
* capi BAR address, i.e. 0x2000000000000-0x2FFFFFFFFFFFF
* capi BAR size
* data send control (XSL_DSNCTL)
* dummy read address (XSL_DRA)
*/
#define CXL_XSL_CONFIG_VERSION1 1
struct cxllib_xsl_config {
u32 version; /* format version for register encoding */
u32 log_bar_size;/* log size of the capi_window */
u64 bar_addr; /* address of the start of capi window */
u64 dsnctl; /* matches definition of XSL_DSNCTL */
u64 dra; /* real address that can be used for dummy read */
};
int cxllib_get_xsl_config(struct pci_dev *dev, struct cxllib_xsl_config *cfg);
/*
* Activate capi for the pci host bridge associated with the device.
* Can be extended to deactivate once we know how to do it.
* Device must be ready to accept messages from the CAPP unit and
* respond accordingly (TLB invalidates, ...)
*
* PHB is switched to capi mode through calls to skiboot.
* CAPP snooping is activated
*
* Input:
* dev: device whose PHB should switch mode
* mode: mode to switch to i.e. CAPI or PCI
* flags: options related to the mode
*/
enum cxllib_mode {
CXL_MODE_CXL,
CXL_MODE_PCI,
};
#define CXL_MODE_NO_DMA 0
#define CXL_MODE_DMA_TVT0 1
#define CXL_MODE_DMA_TVT1 2
int cxllib_switch_phb_mode(struct pci_dev *dev, enum cxllib_mode mode,
unsigned long flags);
/*
* Set the device for capi DMA.
* Define its dma_ops and dma offset so that allocations will be using TVT#1
*
* Input:
* dev: device to set
* flags: options. CXL_MODE_DMA_TVT1 should be used
*/
int cxllib_set_device_dma(struct pci_dev *dev, unsigned long flags);
/*
* Get the Process Element structure for the given thread
*
* Input:
* task: task_struct for the context of the translation
* translation_mode: whether addresses should be translated
* Output:
* attr: attributes to fill up the Process Element structure from CAIA
*/
struct cxllib_pe_attributes {
u64 sr;
u32 lpid;
u32 tid;
u32 pid;
};
#define CXL_TRANSLATED_MODE 0
#define CXL_REAL_MODE 1
int cxllib_get_PE_attributes(struct task_struct *task,
unsigned long translation_mode, struct cxllib_pe_attributes *attr);
/*
* Handle memory fault.
* Fault in all the pages of the specified buffer for the permissions
* provided in ‘flags’
*
* Shouldn't be called from interrupt context
*
* Input:
* mm: struct mm for the thread faulting the pages
* addr: base address of the buffer to page in
* size: size of the buffer to page in
* flags: permission requested (DSISR_ISSTORE...)
*/
int cxllib_handle_fault(struct mm_struct *mm, u64 addr, u64 size, u64 flags);
#endif /* _MISC_CXLLIB_H */