Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "There's a reasonable amount here and the juicy details are all below.

  It's worth noting that the MTE/KASAN changes strayed outside of our
  usual directories due to core mm changes and some associated changes
  to some other architectures; Andrew asked for us to carry these [1]
  rather that take them via the -mm tree.

  Summary:

   - Optimise SVE switching for CPUs with 128-bit implementations.

   - Fix output format from SVE selftest.

   - Add support for versions v1.2 and 1.3 of the SMC calling
     convention.

   - Allow Pointer Authentication to be configured independently for
     kernel and userspace.

   - PMU driver cleanups for managing IRQ affinity and exposing event
     attributes via sysfs.

   - KASAN optimisations for both hardware tagging (MTE) and out-of-line
     software tagging implementations.

   - Relax frame record alignment requirements to facilitate 8-byte
     alignment with KASAN and Clang.

   - Cleanup of page-table definitions and removal of unused memory
     types.

   - Reduction of ARCH_DMA_MINALIGN back to 64 bytes.

   - Refactoring of our instruction decoding routines and addition of
     some missing encodings.

   - Move entry code moved into C and hardened against harmful compiler
     instrumentation.

   - Update booting requirements for the FEAT_HCX feature, added to v8.7
     of the architecture.

   - Fix resume from idle when pNMI is being used.

   - Additional CPU sanity checks for MTE and preparatory changes for
     systems where not all of the CPUs support 32-bit EL0.

   - Update our kernel string routines to the latest Cortex Strings
     implementation.

   - Big cleanup of our cache maintenance routines, which were
     confusingly named and inconsistent in their implementations.

   - Tweak linker flags so that GDB can understand vmlinux when using
     RELR relocations.

   - Boot path cleanups to enable early initialisation of per-cpu
     operations needed by KCSAN.

   - Non-critical fixes and miscellaneous cleanup"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (150 commits)
  arm64: tlb: fix the TTL value of tlb_get_level
  arm64: Restrict undef hook for cpufeature registers
  arm64/mm: Rename ARM64_SWAPPER_USES_SECTION_MAPS
  arm64: insn: avoid circular include dependency
  arm64: smp: Bump debugging information print down to KERN_DEBUG
  drivers/perf: fix the missed ida_simple_remove() in ddr_perf_probe()
  perf/arm-cmn: Fix invalid pointer when access dtc object sharing the same IRQ number
  arm64: suspend: Use cpuidle context helpers in cpu_suspend()
  PSCI: Use cpuidle context helpers in psci_cpu_suspend_enter()
  arm64: Convert cpu_do_idle() to using cpuidle context helpers
  arm64: Add cpuidle context save/restore helpers
  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: Conditionally configure PTR_AUTH key of the kernel.
  ...

1 files changed, 17 insertions, 5 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);