Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/arch/riscv/kernel/efi.c b/arch/riscv/kernel/efi.c
new file mode 100644
index 0000000..0241592
--- /dev/null
+++ b/arch/riscv/kernel/efi.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ * Adapted from arch/arm64/kernel/efi.c
+ */
+
+#include <linux/efi.h>
+#include <linux/init.h>
+
+#include <asm/efi.h>
+#include <asm/pgtable.h>
+#include <asm/pgtable-bits.h>
+
+/*
+ * Only regions of type EFI_RUNTIME_SERVICES_CODE need to be
+ * executable, everything else can be mapped with the XN bits
+ * set. Also take the new (optional) RO/XP bits into account.
+ */
+static __init pgprot_t efimem_to_pgprot_map(efi_memory_desc_t *md)
+{
+ u64 attr = md->attribute;
+ u32 type = md->type;
+
+ if (type == EFI_MEMORY_MAPPED_IO)
+ return PAGE_KERNEL;
+
+ /* R-- */
+ if ((attr & (EFI_MEMORY_XP | EFI_MEMORY_RO)) ==
+ (EFI_MEMORY_XP | EFI_MEMORY_RO))
+ return PAGE_KERNEL_READ;
+
+ /* R-X */
+ if (attr & EFI_MEMORY_RO)
+ return PAGE_KERNEL_READ_EXEC;
+
+ /* RW- */
+ if (((attr & (EFI_MEMORY_RP | EFI_MEMORY_WP | EFI_MEMORY_XP)) ==
+ EFI_MEMORY_XP) ||
+ type != EFI_RUNTIME_SERVICES_CODE)
+ return PAGE_KERNEL;
+
+ /* RWX */
+ return PAGE_KERNEL_EXEC;
+}
+
+int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
+{
+ pgprot_t prot = __pgprot(pgprot_val(efimem_to_pgprot_map(md)) &
+ ~(_PAGE_GLOBAL));
+ int i;
+
+ /* RISC-V maps one page at a time */
+ for (i = 0; i < md->num_pages; i++)
+ create_pgd_mapping(mm->pgd, md->virt_addr + i * PAGE_SIZE,
+ md->phys_addr + i * PAGE_SIZE,
+ PAGE_SIZE, prot);
+ return 0;
+}
+
+static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data)
+{
+ efi_memory_desc_t *md = data;
+ pte_t pte = READ_ONCE(*ptep);
+ unsigned long val;
+
+ if (md->attribute & EFI_MEMORY_RO) {
+ val = pte_val(pte) & ~_PAGE_WRITE;
+ val = pte_val(pte) | _PAGE_READ;
+ pte = __pte(val);
+ }
+ if (md->attribute & EFI_MEMORY_XP) {
+ val = pte_val(pte) & ~_PAGE_EXEC;
+ pte = __pte(val);
+ }
+ set_pte(ptep, pte);
+
+ return 0;
+}
+
+int __init efi_set_mapping_permissions(struct mm_struct *mm,
+ efi_memory_desc_t *md)
+{
+ BUG_ON(md->type != EFI_RUNTIME_SERVICES_CODE &&
+ md->type != EFI_RUNTIME_SERVICES_DATA);
+
+ /*
+ * Calling apply_to_page_range() is only safe on regions that are
+ * guaranteed to be mapped down to pages. Since we are only called
+ * for regions that have been mapped using efi_create_mapping() above
+ * (and this is checked by the generic Memory Attributes table parsing
+ * routines), there is no need to check that again here.
+ */
+ return apply_to_page_range(mm, md->virt_addr,
+ md->num_pages << EFI_PAGE_SHIFT,
+ set_permissions, md);
+}