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
init_svm(void)17 static 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 }
37 machine_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 */
svm_swiotlb_init(void)44 void __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
set_memory_encrypted(unsigned long addr,int numpages)64 int 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
set_memory_decrypted(unsigned long addr,int numpages)74 int 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
87 static struct page *dtl_page_store[NR_DTL_PAGE];
88 static long dtl_nr_pages;
89
is_dtl_page_shared(struct page * page)90 static 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
dtl_cache_ctor(void * addr)101 void 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
