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Diffstat (limited to 'kernel/dma/swiotlb.c')
-rw-r--r--kernel/dma/swiotlb.c50
1 files changed, 48 insertions, 2 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 8e840fbbed7c..f1e7ea160b43 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -50,6 +50,7 @@
#include <asm/io.h>
#include <asm/dma.h>
+#include <linux/io.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/iommu-helper.h>
@@ -72,6 +73,8 @@ enum swiotlb_force swiotlb_force;
struct io_tlb_mem io_tlb_default_mem;
+phys_addr_t swiotlb_unencrypted_base;
+
/*
* Max segment that we can provide which (if pages are contingous) will
* not be bounced (unless SWIOTLB_FORCE is set).
@@ -156,6 +159,34 @@ static inline unsigned long nr_slots(u64 val)
}
/*
+ * Remap swioltb memory in the unencrypted physical address space
+ * when swiotlb_unencrypted_base is set. (e.g. for Hyper-V AMD SEV-SNP
+ * Isolation VMs).
+ */
+#ifdef CONFIG_HAS_IOMEM
+static void *swiotlb_mem_remap(struct io_tlb_mem *mem, unsigned long bytes)
+{
+ void *vaddr = NULL;
+
+ if (swiotlb_unencrypted_base) {
+ phys_addr_t paddr = mem->start + swiotlb_unencrypted_base;
+
+ vaddr = memremap(paddr, bytes, MEMREMAP_WB);
+ if (!vaddr)
+ pr_err("Failed to map the unencrypted memory %pa size %lx.\n",
+ &paddr, bytes);
+ }
+
+ return vaddr;
+}
+#else
+static void *swiotlb_mem_remap(struct io_tlb_mem *mem, unsigned long bytes)
+{
+ return NULL;
+}
+#endif
+
+/*
* Early SWIOTLB allocation may be too early to allow an architecture to
* perform the desired operations. This function allows the architecture to
* call SWIOTLB when the operations are possible. It needs to be called
@@ -172,7 +203,12 @@ void __init swiotlb_update_mem_attributes(void)
vaddr = phys_to_virt(mem->start);
bytes = PAGE_ALIGN(mem->nslabs << IO_TLB_SHIFT);
set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
- memset(vaddr, 0, bytes);
+
+ mem->vaddr = swiotlb_mem_remap(mem, bytes);
+ if (!mem->vaddr)
+ mem->vaddr = vaddr;
+
+ memset(mem->vaddr, 0, bytes);
}
static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start,
@@ -196,7 +232,17 @@ static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start,
mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
mem->slots[i].alloc_size = 0;
}
+
+ /*
+ * If swiotlb_unencrypted_base is set, the bounce buffer memory will
+ * be remapped and cleared in swiotlb_update_mem_attributes.
+ */
+ if (swiotlb_unencrypted_base)
+ return;
+
memset(vaddr, 0, bytes);
+ mem->vaddr = vaddr;
+ return;
}
int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
@@ -371,7 +417,7 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size
phys_addr_t orig_addr = mem->slots[index].orig_addr;
size_t alloc_size = mem->slots[index].alloc_size;
unsigned long pfn = PFN_DOWN(orig_addr);
- unsigned char *vaddr = phys_to_virt(tlb_addr);
+ unsigned char *vaddr = mem->vaddr + tlb_addr - mem->start;
unsigned int tlb_offset, orig_addr_offset;
if (orig_addr == INVALID_PHYS_ADDR)