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  */
  25 bool 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
  42 struct 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
  50 int 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  */
  67 enum 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
  76 int 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  */
  88 int 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  */
 100 struct 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
 109 int 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  */
 126 int cxllib_handle_fault(struct mm_struct *mm, u64 addr, u64 size, u64 flags);
 127
 128
 129 #endif /* _MISC_CXLLIB_H */