LXR linux/include/misc/cxllib.h

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3 * Copyright 2017 IBM Corp.
   4 */
   5
   6#ifndef _MISC_CXLLIB_H
   7#define _MISC_CXLLIB_H
   8
   9#include <linux/pci.h>
  10#include <asm/reg.h>
  11
  12/*
  13 * cxl driver exports a in-kernel 'library' API which can be called by
  14 * other drivers to help interacting with an IBM XSL.
  15 */
  16
  17/*
  18 * tells whether capi is supported on the PCIe slot where the
  19 * device is seated
  20 *
  21 * Input:
  22 *      dev: device whose slot needs to be checked
  23 *      flags: 0 for the time being
  24 */
  25bool cxllib_slot_is_supported(struct pci_dev *dev, unsigned long flags);
  26
  27
  28/*
  29 * Returns the configuration parameters to be used by the XSL or device
  30 *
  31 * Input:
  32 *      dev: device, used to find PHB
  33 * Output:
  34 *      struct cxllib_xsl_config:
  35 *              version
  36 *              capi BAR address, i.e. 0x2000000000000-0x2FFFFFFFFFFFF
  37 *              capi BAR size
  38 *              data send control (XSL_DSNCTL)
  39 *              dummy read address (XSL_DRA)
  40 */
  41#define CXL_XSL_CONFIG_VERSION1         1
  42struct cxllib_xsl_config {
  43        u32     version;     /* format version for register encoding */
  44        u32     log_bar_size;/* log size of the capi_window */
  45        u64     bar_addr;    /* address of the start of capi window */
  46        u64     dsnctl;      /* matches definition of XSL_DSNCTL */
  47        u64     dra;         /* real address that can be used for dummy read */
  48};
  49
  50int cxllib_get_xsl_config(struct pci_dev *dev, struct cxllib_xsl_config *cfg);
  51
  52
  53/*
  54 * Activate capi for the pci host bridge associated with the device.
  55 * Can be extended to deactivate once we know how to do it.
  56 * Device must be ready to accept messages from the CAPP unit and
  57 * respond accordingly (TLB invalidates, ...)
  58 *
  59 * PHB is switched to capi mode through calls to skiboot.
  60 * CAPP snooping is activated
  61 *
  62 * Input:
  63 *      dev: device whose PHB should switch mode
  64 *      mode: mode to switch to i.e. CAPI or PCI
  65 *      flags: options related to the mode
  66 */
  67enum cxllib_mode {
  68        CXL_MODE_CXL,
  69        CXL_MODE_PCI,
  70};
  71
  72#define CXL_MODE_NO_DMA       0
  73#define CXL_MODE_DMA_TVT0     1
  74#define CXL_MODE_DMA_TVT1     2
  75
  76int cxllib_switch_phb_mode(struct pci_dev *dev, enum cxllib_mode mode,
  77                        unsigned long flags);
  78
  79
  80/*
  81 * Set the device for capi DMA.
  82 * Define its dma_ops and dma offset so that allocations will be using TVT#1
  83 *
  84 * Input:
  85 *      dev: device to set
  86 *      flags: options. CXL_MODE_DMA_TVT1 should be used
  87 */
  88int cxllib_set_device_dma(struct pci_dev *dev, unsigned long flags);
  89
  90
  91/*
  92 * Get the Process Element structure for the given thread
  93 *
  94 * Input:
  95 *    task: task_struct for the context of the translation
  96 *    translation_mode: whether addresses should be translated
  97 * Output:
  98 *    attr: attributes to fill up the Process Element structure from CAIA
  99 */
 100struct cxllib_pe_attributes {
 101        u64 sr;
 102        u32 lpid;
 103        u32 tid;
 104        u32 pid;
 105};
 106#define CXL_TRANSLATED_MODE 0
 107#define CXL_REAL_MODE 1
 108
 109int cxllib_get_PE_attributes(struct task_struct *task,
 110             unsigned long translation_mode, struct cxllib_pe_attributes *attr);
 111
 112
 113/*
 114 * Handle memory fault.
 115 * Fault in all the pages of the specified buffer for the permissions
 116 * provided in ‘flags’
 117 *
 118 * Shouldn't be called from interrupt context
 119 *
 120 * Input:
 121 *      mm: struct mm for the thread faulting the pages
 122 *      addr: base address of the buffer to page in
 123 *      size: size of the buffer to page in
 124 *      flags: permission requested (DSISR_ISSTORE...)
 125 */
 126int cxllib_handle_fault(struct mm_struct *mm, u64 addr, u64 size, u64 flags);
 127
 128
 129#endif /* _MISC_CXLLIB_H */
 130