linux-imx

/*

 * Copyright 2017 IBM Corp.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version

 * 2 of the License, or (at your option) any later version.

 */

​

#include <linux/hugetlb.h>

#include <linux/sched/mm.h>

#include <asm/pnv-pci.h>

#include <misc/cxllib.h>

​

#include "cxl.h"

​

#define CXL_INVALID_DRA                 ~0ull

#define CXL_DUMMY_READ_SIZE             128

#define CXL_DUMMY_READ_ALIGN            8

#define CXL_CAPI_WINDOW_START           0x2000000000000ull

#define CXL_CAPI_WINDOW_LOG_SIZE        48

#define CXL_XSL_CONFIG_CURRENT_VERSION  CXL_XSL_CONFIG_VERSION1

​

​

bool cxllib_slot_is_supported(struct pci_dev *dev, unsigned long flags)

{

    int rc;

    u32 phb_index;

    u64 chip_id, capp_unit_id;

​

    /* No flags currently supported */

    if (flags)

        return false;

​

    if (!cpu_has_feature(CPU_FTR_HVMODE))

        return false;

​

    if (!cxl_is_power9())

        return false;

​

    if (cxl_slot_is_switched(dev))

        return false;

​

    /* on p9, some pci slots are not connected to a CAPP unit */

    rc = cxl_calc_capp_routing(dev, &chip_id, &phb_index, &capp_unit_id);

    if (rc)

        return false;

​

    return true;

}

EXPORT_SYMBOL_GPL(cxllib_slot_is_supported);

​

static DEFINE_MUTEX(dra_mutex);

static u64 dummy_read_addr = CXL_INVALID_DRA;

​

static int allocate_dummy_read_buf(void)

{

    u64 buf, vaddr;

    size_t buf_size;

​

    /*

     * Dummy read buffer is 128-byte long, aligned on a

     * 256-byte boundary and we need the physical address.

     */

    buf_size = CXL_DUMMY_READ_SIZE + (1ull << CXL_DUMMY_READ_ALIGN);

    buf = (u64) kzalloc(buf_size, GFP_KERNEL);

    if (!buf)

        return -ENOMEM;

​

    vaddr = (buf + (1ull << CXL_DUMMY_READ_ALIGN) - 1) &

                    (~0ull << CXL_DUMMY_READ_ALIGN);

​

    WARN((vaddr + CXL_DUMMY_READ_SIZE) > (buf + buf_size),

        "Dummy read buffer alignment issue");

    dummy_read_addr = virt_to_phys((void *) vaddr);

    return 0;

}

​

int cxllib_get_xsl_config(struct pci_dev *dev, struct cxllib_xsl_config *cfg)

{

    int rc;

    u32 phb_index;

    u64 chip_id, capp_unit_id;

​

    if (!cpu_has_feature(CPU_FTR_HVMODE))

        return -EINVAL;

​

    mutex_lock(&dra_mutex);

    if (dummy_read_addr == CXL_INVALID_DRA) {

        rc = allocate_dummy_read_buf();

        if (rc) {

            mutex_unlock(&dra_mutex);