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

Lots of cleanup to our various page-table definitions, but also some
non-critical fixes and removal of some unnecessary memory types. The
most interesting change here is the reduction of ARCH_DMA_MINALIGN back
to 64 bytes, since we're not aware of any machines that need a higher
value with the way the code is structured (only needed for non-coherent
DMA).

* for-next/mm:
  arm64: tlb: fix the TTL value of tlb_get_level
  arm64/mm: Rename ARM64_SWAPPER_USES_SECTION_MAPS
  arm64: head: fix code comments in set_cpu_boot_mode_flag
  arm64: mm: drop unused __pa(__idmap_text_start)
  arm64: mm: fix the count comments in compute_indices
  arm64/mm: Fix ttbr0 values stored in struct thread_info for software-pan
  arm64: mm: Pass original fault address to handle_mm_fault()
  arm64/mm: Drop SECTION_[SHIFT|SIZE|MASK]
  arm64/mm: Use CONT_PMD_SHIFT for ARM64_MEMSTART_SHIFT
  arm64/mm: Drop SWAPPER_INIT_MAP_SIZE
  arm64: mm: decode xFSC in mem_abort_decode()
  arm64: mm: Add is_el1_data_abort() helper
  arm64: cache: Lower ARCH_DMA_MINALIGN to 64 (L1_CACHE_BYTES)
  arm64: mm: Remove unused support for Normal-WT memory type
  arm64: acpi: Map EFI_MEMORY_WT memory as Normal-NC
  arm64: mm: Remove unused support for Device-GRE memory type
  arm64: mm: Use better bitmap_zalloc()
  arm64/mm: Make vmemmap_free() available only with CONFIG_MEMORY_HOTPLUG
  arm64/mm: Remove [PUD|PMD]_TABLE_BIT from [pud|pmd]_bad()
  arm64/mm: Validate CONFIG_PGTABLE_LEVELS

3 files changed, 20 insertions, 9 deletions

diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index cada0b816c8a..f3851724fe35 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -239,6 +239,18 @@ done:
 	}
 }
 
+static pgprot_t __acpi_get_writethrough_mem_attribute(void)
+{
+	/*
+	 * Although UEFI specifies the use of Normal Write-through for
+	 * EFI_MEMORY_WT, it is seldom used in practice and not implemented
+	 * by most (all?) CPUs. Rather than allocate a MAIR just for this
+	 * purpose, emit a warning and use Normal Non-cacheable instead.
+	 */
+	pr_warn_once("No MAIR allocation for EFI_MEMORY_WT; treating as Normal Non-cacheable\n");
+	return __pgprot(PROT_NORMAL_NC);
+}
+
 pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
 {
 	/*
@@ -246,7 +258,7 @@ pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
 	 * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is
 	 * mapped to a corresponding MAIR attribute encoding.
 	 * The EFI memory attribute advises all possible capabilities
-	 * of a memory region. We use the most efficient capability.
+	 * of a memory region.
 	 */
 
 	u64 attr;
@@ -254,10 +266,10 @@ pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
 	attr = efi_mem_attributes(addr);
 	if (attr & EFI_MEMORY_WB)
 		return PAGE_KERNEL;
-	if (attr & EFI_MEMORY_WT)
-		return __pgprot(PROT_NORMAL_WT);
 	if (attr & EFI_MEMORY_WC)
 		return __pgprot(PROT_NORMAL_NC);
+	if (attr & EFI_MEMORY_WT)
+		return __acpi_get_writethrough_mem_attribute();
 	return __pgprot(PROT_DEVICE_nGnRnE);
 }
 
@@ -340,10 +352,10 @@ void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
 		default:
 			if (region->attribute & EFI_MEMORY_WB)
 				prot = PAGE_KERNEL;
-			else if (region->attribute & EFI_MEMORY_WT)
-				prot = __pgprot(PROT_NORMAL_WT);
 			else if (region->attribute & EFI_MEMORY_WC)
 				prot = __pgprot(PROT_NORMAL_NC);
+			else if (region->attribute & EFI_MEMORY_WT)
+				prot = __acpi_get_writethrough_mem_attribute();
 		}
 	}
 	return __ioremap(phys, size, prot);
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index a6ccd6557d19..c5c994a73a64 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -196,7 +196,7 @@ SYM_CODE_END(preserve_boot_args)
 	and	\iend, \iend, \istart	// iend = (vend >> shift) & (ptrs - 1)
 	mov	\istart, \ptrs
 	mul	\istart, \istart, \count
-	add	\iend, \iend, \istart	// iend += (count - 1) * ptrs
+	add	\iend, \iend, \istart	// iend += count * ptrs
 					// our entries span multiple tables
 
 	lsr	\istart, \vstart, \shift
@@ -354,7 +354,6 @@ SYM_FUNC_START_LOCAL(__create_page_tables)
 #endif
 1:
 	ldr_l	x4, idmap_ptrs_per_pgd
-	mov	x5, x3				// __pa(__idmap_text_start)
 	adr_l	x6, __idmap_text_end		// __pa(__idmap_text_end)
 
 	map_memory x0, x1, x3, x6, x7, x3, x4, x10, x11, x12, x13, x14
@@ -568,7 +567,7 @@ SYM_FUNC_START_LOCAL(set_cpu_boot_mode_flag)
 	cmp	w0, #BOOT_CPU_MODE_EL2
 	b.ne	1f
 	add	x1, x1, #4
-1:	str	w0, [x1]			// This CPU has booted in EL1
+1:	str	w0, [x1]			// Save CPU boot mode
 	dmb	sy
 	dc	ivac, x1			// Invalidate potentially stale cache line
 	ret
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index b7a35a03e9b9..8ed66142b088 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -375,7 +375,7 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p)
 	 * faults in case uaccess_enable() is inadvertently called by the init
 	 * thread.
 	 */
-	init_task.thread_info.ttbr0 = __pa_symbol(reserved_pg_dir);
+	init_task.thread_info.ttbr0 = phys_to_ttbr(__pa_symbol(reserved_pg_dir));
 #endif
 
 	if (boot_args[1] || boot_args[2] || boot_args[3]) {