1 // SPDX-License-Identifier: GPL-2.0+
5 * Copyright 2018 IBM Corporation
6 * Author: Anshuman Khandual <khandual@linux.vnet.ibm.com>
10 #include <linux/memblock.h>
11 #include <asm/machdep.h>
13 #include <asm/swiotlb.h>
14 #include <asm/ultravisor.h>
17 static int __init init_svm(void)
19 if (!is_secure_guest())
22 /* Don't release the SWIOTLB buffer. */
23 ppc_swiotlb_enable = 1;
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
30 swiotlb_force = SWIOTLB_FORCE;
32 /* Share the SWIOTLB buffer with the host. */
33 swiotlb_update_mem_attributes();
37 machine_early_initcall(pseries, init_svm);
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.
44 void __init svm_swiotlb_init(void)
46 unsigned char *vstart;
47 unsigned long bytes, io_tlb_nslabs;
49 io_tlb_nslabs = (swiotlb_size_or_default() >> IO_TLB_SHIFT);
50 io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
52 bytes = io_tlb_nslabs << IO_TLB_SHIFT;
54 vstart = memblock_alloc(PAGE_ALIGN(bytes), PAGE_SIZE);
55 if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, false))
59 memblock_free_early(io_tlb_start,
60 PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
61 panic("SVM: Cannot allocate SWIOTLB buffer");
64 int set_memory_encrypted(unsigned long addr, int numpages)
66 if (!PAGE_ALIGNED(addr))
69 uv_unshare_page(PHYS_PFN(__pa(addr)), numpages);
74 int set_memory_decrypted(unsigned long addr, int numpages)
76 if (!PAGE_ALIGNED(addr))
79 uv_share_page(PHYS_PFN(__pa(addr)), numpages);
84 /* There's one dispatch log per CPU. */
85 #define NR_DTL_PAGE (DISPATCH_LOG_BYTES * CONFIG_NR_CPUS / PAGE_SIZE)
87 static struct page *dtl_page_store[NR_DTL_PAGE];
88 static long dtl_nr_pages;
90 static bool is_dtl_page_shared(struct page *page)
94 for (i = 0; i < dtl_nr_pages; i++)
95 if (dtl_page_store[i] == page)
101 void dtl_cache_ctor(void *addr)
103 unsigned long pfn = PHYS_PFN(__pa(addr));
104 struct page *page = pfn_to_page(pfn);
106 if (!is_dtl_page_shared(page)) {
107 dtl_page_store[dtl_nr_pages] = page;
109 WARN_ON(dtl_nr_pages >= NR_DTL_PAGE);
110 uv_share_page(pfn, 1);