ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/arch/x86/boot/compressed/kaslr_64.c b/marvell/linux/arch/x86/boot/compressed/kaslr_64.c
new file mode 100644
index 0000000..9557c5a
--- /dev/null
+++ b/marvell/linux/arch/x86/boot/compressed/kaslr_64.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This code is used on x86_64 to create page table identity mappings on
+ * demand by building up a new set of page tables (or appending to the
+ * existing ones), and then switching over to them when ready.
+ *
+ * Copyright (C) 2015-2016 Yinghai Lu
+ * Copyright (C) 2016 Kees Cook
+ */
+
+/*
+ * Since we're dealing with identity mappings, physical and virtual
+ * addresses are the same, so override these defines which are ultimately
+ * used by the headers in misc.h.
+ */
+#define __pa(x) ((unsigned long)(x))
+#define __va(x) ((void *)((unsigned long)(x)))
+
+/* No PAGE_TABLE_ISOLATION support needed either: */
+#undef CONFIG_PAGE_TABLE_ISOLATION
+
+#include "misc.h"
+
+/* These actually do the work of building the kernel identity maps. */
+#include <asm/init.h>
+#include <asm/pgtable.h>
+/* Use the static base for this part of the boot process */
+#undef __PAGE_OFFSET
+#define __PAGE_OFFSET __PAGE_OFFSET_BASE
+#include "../../mm/ident_map.c"
+
+/* Used to track our page table allocation area. */
+struct alloc_pgt_data {
+ unsigned char *pgt_buf;
+ unsigned long pgt_buf_size;
+ unsigned long pgt_buf_offset;
+};
+
+/*
+ * Allocates space for a page table entry, using struct alloc_pgt_data
+ * above. Besides the local callers, this is used as the allocation
+ * callback in mapping_info below.
+ */
+static void *alloc_pgt_page(void *context)
+{
+ struct alloc_pgt_data *pages = (struct alloc_pgt_data *)context;
+ unsigned char *entry;
+
+ /* Validate there is space available for a new page. */
+ if (pages->pgt_buf_offset >= pages->pgt_buf_size) {
+ debug_putstr("out of pgt_buf in " __FILE__ "!?\n");
+ debug_putaddr(pages->pgt_buf_offset);
+ debug_putaddr(pages->pgt_buf_size);
+ return NULL;
+ }
+
+ entry = pages->pgt_buf + pages->pgt_buf_offset;
+ pages->pgt_buf_offset += PAGE_SIZE;
+
+ return entry;
+}
+
+/* Used to track our allocated page tables. */
+static struct alloc_pgt_data pgt_data;
+
+/* The top level page table entry pointer. */
+static unsigned long top_level_pgt;
+
+phys_addr_t physical_mask = (1ULL << __PHYSICAL_MASK_SHIFT) - 1;
+
+/*
+ * Mapping information structure passed to kernel_ident_mapping_init().
+ * Due to relocation, pointers must be assigned at run time not build time.
+ */
+static struct x86_mapping_info mapping_info;
+
+/* Locates and clears a region for a new top level page table. */
+void initialize_identity_maps(void)
+{
+ /* If running as an SEV guest, the encryption mask is required. */
+ set_sev_encryption_mask();
+
+ /* Exclude the encryption mask from __PHYSICAL_MASK */
+ physical_mask &= ~sme_me_mask;
+
+ /* Init mapping_info with run-time function/buffer pointers. */
+ mapping_info.alloc_pgt_page = alloc_pgt_page;
+ mapping_info.context = &pgt_data;
+ mapping_info.page_flag = __PAGE_KERNEL_LARGE_EXEC | sme_me_mask;
+ mapping_info.kernpg_flag = _KERNPG_TABLE;
+
+ /*
+ * It should be impossible for this not to already be true,
+ * but since calling this a second time would rewind the other
+ * counters, let's just make sure this is reset too.
+ */
+ pgt_data.pgt_buf_offset = 0;
+
+ /*
+ * If we came here via startup_32(), cr3 will be _pgtable already
+ * and we must append to the existing area instead of entirely
+ * overwriting it.
+ *
+ * With 5-level paging, we use '_pgtable' to allocate the p4d page table,
+ * the top-level page table is allocated separately.
+ *
+ * p4d_offset(top_level_pgt, 0) would cover both the 4- and 5-level
+ * cases. On 4-level paging it's equal to 'top_level_pgt'.
+ */
+ top_level_pgt = read_cr3_pa();
+ if (p4d_offset((pgd_t *)top_level_pgt, 0) == (p4d_t *)_pgtable) {
+ debug_putstr("booted via startup_32()\n");
+ pgt_data.pgt_buf = _pgtable + BOOT_INIT_PGT_SIZE;
+ pgt_data.pgt_buf_size = BOOT_PGT_SIZE - BOOT_INIT_PGT_SIZE;
+ memset(pgt_data.pgt_buf, 0, pgt_data.pgt_buf_size);
+ } else {
+ debug_putstr("booted via startup_64()\n");
+ pgt_data.pgt_buf = _pgtable;
+ pgt_data.pgt_buf_size = BOOT_PGT_SIZE;
+ memset(pgt_data.pgt_buf, 0, pgt_data.pgt_buf_size);
+ top_level_pgt = (unsigned long)alloc_pgt_page(&pgt_data);
+ }
+}
+
+/*
+ * Adds the specified range to what will become the new identity mappings.
+ * Once all ranges have been added, the new mapping is activated by calling
+ * finalize_identity_maps() below.
+ */
+void add_identity_map(unsigned long start, unsigned long size)
+{
+ unsigned long end = start + size;
+
+ /* Align boundary to 2M. */
+ start = round_down(start, PMD_SIZE);
+ end = round_up(end, PMD_SIZE);
+ if (start >= end)
+ return;
+
+ /* Build the mapping. */
+ kernel_ident_mapping_init(&mapping_info, (pgd_t *)top_level_pgt,
+ start, end);
+}
+
+/*
+ * This switches the page tables to the new level4 that has been built
+ * via calls to add_identity_map() above. If booted via startup_32(),
+ * this is effectively a no-op.
+ */
+void finalize_identity_maps(void)
+{
+ write_cr3(top_level_pgt);
+}