LXR linux/arch/powerpc/platforms/powernv/ultravisor.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Ultravisor high level interfaces
   4 *
   5 * Copyright 2019, IBM Corporation.
   6 *
   7 */
   8#include <linux/init.h>
   9#include <linux/printk.h>
  10#include <linux/of_fdt.h>
  11#include <linux/of.h>
  12
  13#include <asm/ultravisor.h>
  14#include <asm/firmware.h>
  15#include <asm/machdep.h>
  16
  17#include "powernv.h"
  18
  19static struct kobject *ultravisor_kobj;
  20
  21int __init early_init_dt_scan_ultravisor(unsigned long node, const char *uname,
  22                                         int depth, void *data)
  23{
  24        if (!of_flat_dt_is_compatible(node, "ibm,ultravisor"))
  25                return 0;
  26
  27        powerpc_firmware_features |= FW_FEATURE_ULTRAVISOR;
  28        pr_debug("Ultravisor detected!\n");
  29        return 1;
  30}
  31
  32static struct memcons *uv_memcons;
  33
  34static ssize_t uv_msglog_read(struct file *file, struct kobject *kobj,
  35                              struct bin_attribute *bin_attr, char *to,
  36                              loff_t pos, size_t count)
  37{
  38        return memcons_copy(uv_memcons, to, pos, count);
  39}
  40
  41static struct bin_attribute uv_msglog_attr = {
  42        .attr = {.name = "msglog", .mode = 0400},
  43        .read = uv_msglog_read
  44};
  45
  46static int __init uv_init(void)
  47{
  48        struct device_node *node;
  49
  50        if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR))
  51                return 0;
  52
  53        node = of_find_compatible_node(NULL, NULL, "ibm,uv-firmware");
  54        if (!node)
  55                return -ENODEV;
  56
  57        uv_memcons = memcons_init(node, "memcons");
  58        if (!uv_memcons)
  59                return -ENOENT;
  60
  61        uv_msglog_attr.size = memcons_get_size(uv_memcons);
  62
  63        ultravisor_kobj = kobject_create_and_add("ultravisor", firmware_kobj);
  64        if (!ultravisor_kobj)
  65                return -ENOMEM;
  66
  67        return sysfs_create_bin_file(ultravisor_kobj, &uv_msglog_attr);
  68}
  69machine_subsys_initcall(powernv, uv_init);
  70