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

* for-next/mm:
  arm64: booting: Require placement within 48-bit addressable memory
  arm64: mm: kfence: only handle translation faults
  arm64/mm: Simplify and document pte_to_phys() for 52 bit addresses

Author: willdeacon

Documentation/arm64/booting.rst

@@ -121,8 +121,9 @@ Header notes:
 			  to the base of DRAM, since memory below it is not
 			  accessible via the linear mapping
 			1
-			  2MB aligned base may be anywhere in physical
-			  memory
+			  2MB aligned base such that all image_size bytes
+			  counted from the start of the image are within
+			  the 48-bit addressable range of physical memory
   Bits 4-63	Reserved.
   ============= ===============================================================
 

arch/arm64/include/asm/assembler.h

@@ -660,12 +660,10 @@ alternative_endif
 	.endm
 
 	.macro	pte_to_phys, phys, pte
-#ifdef CONFIG_ARM64_PA_BITS_52
-	ubfiz	\phys, \pte, #(48 - 16 - 12), #16
-	bfxil	\phys, \pte, #16, #32
-	lsl	\phys, \phys, #16
-#else
 	and	\phys, \pte, #PTE_ADDR_MASK
+#ifdef CONFIG_ARM64_PA_BITS_52
+	orr	\phys, \phys, \phys, lsl #PTE_ADDR_HIGH_SHIFT
+	and	\phys, \phys, GENMASK_ULL(PHYS_MASK_SHIFT - 1, PAGE_SHIFT)
 #endif
 	.endm
 

arch/arm64/include/asm/pgtable-hwdef.h

@@ -159,6 +159,7 @@
 #ifdef CONFIG_ARM64_PA_BITS_52
 #define PTE_ADDR_HIGH		(_AT(pteval_t, 0xf) << 12)
 #define PTE_ADDR_MASK		(PTE_ADDR_LOW | PTE_ADDR_HIGH)
+#define PTE_ADDR_HIGH_SHIFT	36
 #else
 #define PTE_ADDR_MASK		PTE_ADDR_LOW
 #endif

arch/arm64/include/asm/pgtable.h

@@ -77,11 +77,11 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
 static inline phys_addr_t __pte_to_phys(pte_t pte)
 {
 	return (pte_val(pte) & PTE_ADDR_LOW) |
-		((pte_val(pte) & PTE_ADDR_HIGH) << 36);
+		((pte_val(pte) & PTE_ADDR_HIGH) << PTE_ADDR_HIGH_SHIFT);
 }
 static inline pteval_t __phys_to_pte_val(phys_addr_t phys)
 {
-	return (phys | (phys >> 36)) & PTE_ADDR_MASK;
+	return (phys | (phys >> PTE_ADDR_HIGH_SHIFT)) & PTE_ADDR_MASK;
 }
 #else
 #define __pte_to_phys(pte)	(pte_val(pte) & PTE_ADDR_MASK)

arch/arm64/mm/fault.c

@@ -354,6 +354,11 @@ static bool is_el1_mte_sync_tag_check_fault(unsigned long esr)
 	return false;
 }
 
+static bool is_translation_fault(unsigned long esr)
+{
+	return (esr & ESR_ELx_FSC_TYPE) == ESR_ELx_FSC_FAULT;
+}
+
 static void __do_kernel_fault(unsigned long addr, unsigned long esr,
 			      struct pt_regs *regs)
 {
@@ -386,7 +391,8 @@ static void __do_kernel_fault(unsigned long addr, unsigned long esr,
 	} else if (addr < PAGE_SIZE) {
 		msg = "NULL pointer dereference";
 	} else {
-		if (kfence_handle_page_fault(addr, esr & ESR_ELx_WNR, regs))
+		if (is_translation_fault(esr) &&
+		    kfence_handle_page_fault(addr, esr & ESR_ELx_WNR, regs))
 			return;
 
 		msg = "paging request";