1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Secure VM platform
4 *
5 * Copyright 2018 IBM Corporation
6 * Author: Anshuman Khandual <khandual@linux.vnet.ibm.com>
7 */
8
9#include <linux/mm.h>
10#include <linux/memblock.h>
11#include <asm/machdep.h>
12#include <asm/svm.h>
13#include <asm/swiotlb.h>
14#include <asm/ultravisor.h>
15#include <asm/dtl.h>
16
17static int __init init_svm(void)
18{
19	if (!is_secure_guest())
20		return 0;
21
22	/* Don't release the SWIOTLB buffer. */
23	ppc_swiotlb_enable = 1;
24
25	/*
26	 * Since the guest memory is inaccessible to the host, devices always
27	 * need to use the SWIOTLB buffer for DMA even if dma_capable() says
28	 * otherwise.
29	 */
30	swiotlb_force = SWIOTLB_FORCE;
31
32	/* Share the SWIOTLB buffer with the host. */
33	swiotlb_update_mem_attributes();
34
35	return 0;
36}
37machine_early_initcall(pseries, init_svm);
38
39/*
40 * Initialize SWIOTLB. Essentially the same as swiotlb_init(), except that it
41 * can allocate the buffer anywhere in memory. Since the hypervisor doesn't have
42 * any addressing limitation, we don't need to allocate it in low addresses.
43 */
44void __init svm_swiotlb_init(void)
45{
46	unsigned char *vstart;
47	unsigned long bytes, io_tlb_nslabs;
48
49	io_tlb_nslabs = (swiotlb_size_or_default() >> IO_TLB_SHIFT);
50	io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
51
52	bytes = io_tlb_nslabs << IO_TLB_SHIFT;
53
54	vstart = memblock_alloc(PAGE_ALIGN(bytes), PAGE_SIZE);
55	if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, false))
56		return;
57
58	if (io_tlb_start)
59		memblock_free_early(io_tlb_start,
60				    PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
61	panic("SVM: Cannot allocate SWIOTLB buffer");
62}
63
64int set_memory_encrypted(unsigned long addr, int numpages)
65{
66	if (!PAGE_ALIGNED(addr))
67		return -EINVAL;
68
69	uv_unshare_page(PHYS_PFN(__pa(addr)), numpages);
70
71	return 0;
72}
73
74int set_memory_decrypted(unsigned long addr, int numpages)
75{
76	if (!PAGE_ALIGNED(addr))
77		return -EINVAL;
78
79	uv_share_page(PHYS_PFN(__pa(addr)), numpages);
80
81	return 0;
82}
83
84/* There's one dispatch log per CPU. */
85#define NR_DTL_PAGE (DISPATCH_LOG_BYTES * CONFIG_NR_CPUS / PAGE_SIZE)
86
87static struct page *dtl_page_store[NR_DTL_PAGE];
88static long dtl_nr_pages;
89
90static bool is_dtl_page_shared(struct page *page)
91{
92	long i;
93
94	for (i = 0; i < dtl_nr_pages; i++)
95		if (dtl_page_store[i] == page)
96			return true;
97
98	return false;
99}
100
101void dtl_cache_ctor(void *addr)
102{
103	unsigned long pfn = PHYS_PFN(__pa(addr));
104	struct page *page = pfn_to_page(pfn);
105
106	if (!is_dtl_page_shared(page)) {
107		dtl_page_store[dtl_nr_pages] = page;
108		dtl_nr_pages++;
109		WARN_ON(dtl_nr_pages >= NR_DTL_PAGE);
110		uv_share_page(pfn, 1);
111	}
112}
113