early_alloc.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2020 Google LLC
 * Author: Quentin Perret <qperret@google.com>
 */
 
#include <asm/kvm_pgtable.h>
 
#include <nvhe/early_alloc.h>
#include <nvhe/memory.h>
 
struct kvm_pgtable_mm_ops hyp_early_alloc_mm_ops;
s64 __ro_after_init hyp_physvirt_offset;
 
static unsigned long base;
static unsigned long end;
static unsigned long cur;
 
unsigned long hyp_early_alloc_nr_used_pages(void)
{
    return (cur - base) >> PAGE_SHIFT;
}
 
void *hyp_early_alloc_contig(unsigned int nr_pages)
{
    unsigned long size = (nr_pages << PAGE_SHIFT);
    void *ret = (void *)cur;
 
    if (!nr_pages)
        return NULL;
 
    if (end - cur < size)
        return NULL;
 
    cur += size;
    memset(ret, 0, size);
 
    return ret;
}
 
void *hyp_early_alloc_page(void *arg)
{
    return hyp_early_alloc_contig(1);
}
 
static void hyp_early_alloc_get_page(void *addr) { }
static void hyp_early_alloc_put_page(void *addr) { }
 
void hyp_early_alloc_init(void *virt, unsigned long size)
{
    base = cur = (unsigned long)virt;
    end = base + size;
 
    hyp_early_alloc_mm_ops.zalloc_page = hyp_early_alloc_page;
    hyp_early_alloc_mm_ops.phys_to_virt = hyp_phys_to_virt;
    hyp_early_alloc_mm_ops.virt_to_phys = hyp_virt_to_phys;
    hyp_early_alloc_mm_ops.get_page = hyp_early_alloc_get_page;
    hyp_early_alloc_mm_ops.put_page = hyp_early_alloc_put_page;
}