Merge branch 'for-next/kexec' into for-next/core

Significant steps along the road to leaving the MMU enabled during kexec
relocation.

* for-next/kexec:
  arm64: hibernate: add __force attribute to gfp_t casting
  arm64: kexec: arm64_relocate_new_kernel don't use x0 as temp
  arm64: kexec: arm64_relocate_new_kernel clean-ups and optimizations
  arm64: kexec: call kexec_image_info only once
  arm64: kexec: move relocation function setup
  arm64: trans_pgd: hibernate: idmap the single page that holds the copy page routines
  arm64: mm: Always update TCR_EL1 from __cpu_set_tcr_t0sz()
  arm64: trans_pgd: pass NULL instead of init_mm to *_populate functions
  arm64: trans_pgd: pass allocator trans_pgd_create_copy
  arm64: trans_pgd: make trans_pgd_map_page generic
  arm64: hibernate: move page handling function to new trans_pgd.c
  arm64: hibernate: variable pudp is used instead of pd4dp
  arm64: kexec: make dtb_mem always enabled

3 files changed, 45 insertions, 6 deletions

diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
index d24b527e8c00..9befcd87e9a8 100644
--- a/arch/arm64/include/asm/kexec.h
+++ b/arch/arm64/include/asm/kexec.h
@@ -90,18 +90,19 @@ static inline void crash_prepare_suspend(void) {}
 static inline void crash_post_resume(void) {}
 #endif
 
-#ifdef CONFIG_KEXEC_FILE
 #define ARCH_HAS_KIMAGE_ARCH
 
 struct kimage_arch {
 	void *dtb;
-	unsigned long dtb_mem;
+	phys_addr_t dtb_mem;
+	phys_addr_t kern_reloc;
 	/* Core ELF header buffer */
 	void *elf_headers;
 	unsigned long elf_headers_mem;
 	unsigned long elf_headers_sz;
 };
 
+#ifdef CONFIG_KEXEC_FILE
 extern const struct kexec_file_ops kexec_image_ops;
 
 struct kimage;
diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h
index 0b3079fd28eb..70ce8c1d2b07 100644
--- a/arch/arm64/include/asm/mmu_context.h
+++ b/arch/arm64/include/asm/mmu_context.h
@@ -81,16 +81,15 @@ static inline bool __cpu_uses_extended_idmap_level(void)
 }
 
 /*
- * Set TCR.T0SZ to its default value (based on VA_BITS)
+ * Ensure TCR.T0SZ is set to the provided value.
  */
 static inline void __cpu_set_tcr_t0sz(unsigned long t0sz)
 {
-	unsigned long tcr;
+	unsigned long tcr = read_sysreg(tcr_el1);
 
-	if (!__cpu_uses_extended_idmap())
+	if ((tcr & TCR_T0SZ_MASK) >> TCR_T0SZ_OFFSET == t0sz)
 		return;
 
-	tcr = read_sysreg(tcr_el1);
 	tcr &= ~TCR_T0SZ_MASK;
 	tcr |= t0sz << TCR_T0SZ_OFFSET;
 	write_sysreg(tcr, tcr_el1);
diff --git a/arch/arm64/include/asm/trans_pgd.h b/arch/arm64/include/asm/trans_pgd.h
new file mode 100644
index 000000000000..5d08e5adf3d5
--- /dev/null
+++ b/arch/arm64/include/asm/trans_pgd.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Copyright (c) 2020, Microsoft Corporation.
+ * Pavel Tatashin <pasha.tatashin@soleen.com>
+ */
+
+#ifndef _ASM_TRANS_TABLE_H
+#define _ASM_TRANS_TABLE_H
+
+#include <linux/bits.h>
+#include <linux/types.h>
+#include <asm/pgtable-types.h>
+
+/*
+ * trans_alloc_page
+ *	- Allocator that should return exactly one zeroed page, if this
+ *	  allocator fails, trans_pgd_create_copy() and trans_pgd_map_page()
+ *	  return -ENOMEM error.
+ *
+ * trans_alloc_arg
+ *	- Passed to trans_alloc_page as an argument
+ */
+
+struct trans_pgd_info {
+	void * (*trans_alloc_page)(void *arg);
+	void *trans_alloc_arg;
+};
+
+int trans_pgd_create_copy(struct trans_pgd_info *info, pgd_t **trans_pgd,
+			  unsigned long start, unsigned long end);
+
+int trans_pgd_map_page(struct trans_pgd_info *info, pgd_t *trans_pgd,
+		       void *page, unsigned long dst_addr, pgprot_t pgprot);
+
+int trans_pgd_idmap_page(struct trans_pgd_info *info, phys_addr_t *trans_ttbr0,
+			 unsigned long *t0sz, void *page);
+
+#endif /* _ASM_TRANS_TABLE_H */