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

Pull arm64 updates from Catalin Marinas:

 - struct thread_info moved off-stack (also touching
   include/linux/thread_info.h and include/linux/restart_block.h)

 - cpus_have_cap() reworked to avoid __builtin_constant_p() for static
   key use (also touching drivers/irqchip/irq-gic-v3.c)

 - uprobes support (currently only for native 64-bit tasks)

 - Emulation of kernel Privileged Access Never (PAN) using TTBR0_EL1
   switching to a reserved page table

 - CPU capacity information passing via DT or sysfs (used by the
   scheduler)

 - support for systems without FP/SIMD (IOW, kernel avoids touching
   these registers; there is no soft-float ABI, nor kernel emulation for
   AArch64 FP/SIMD)

 - handling of hardware watchpoint with unaligned addresses, varied
   lengths and offsets from base

 - use of the page table contiguous hint for kernel mappings

 - hugetlb fixes for sizes involving the contiguous hint

 - remove unnecessary I-cache invalidation in flush_cache_range()

 - CNTHCTL_EL2 access fix for CPUs with VHE support (ARMv8.1)

 - boot-time checks for writable+executable kernel mappings

 - simplify asm/opcodes.h and avoid including the 32-bit ARM counterpart
   and make the arm64 kernel headers self-consistent (Xen headers patch
   merged separately)

 - Workaround for broken .inst support in certain binutils versions

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (60 commits)
  arm64: Disable PAN on uaccess_enable()
  arm64: Work around broken .inst when defective gas is detected
  arm64: Add detection code for broken .inst support in binutils
  arm64: Remove reference to asm/opcodes.h
  arm64: Get rid of asm/opcodes.h
  arm64: smp: Prevent raw_smp_processor_id() recursion
  arm64: head.S: Fix CNTHCTL_EL2 access on VHE system
  arm64: Remove I-cache invalidation from flush_cache_range()
  arm64: Enable HIBERNATION in defconfig
  arm64: Enable CONFIG_ARM64_SW_TTBR0_PAN
  arm64: xen: Enable user access before a privcmd hvc call
  arm64: Handle faults caused by inadvertent user access with PAN enabled
  arm64: Disable TTBR0_EL1 during normal kernel execution
  arm64: Introduce uaccess_{disable,enable} functionality based on TTBR0_EL1
  arm64: Factor out TTBR0_EL1 post-update workaround into a specific asm macro
  arm64: Factor out PAN enabling/disabling into separate uaccess_* macros
  arm64: Update the synchronous external abort fault description
  selftests: arm64: add test for unaligned/inexact watchpoint handling
  arm64: Allow hw watchpoint of length 3,5,6 and 7
  arm64: hw_breakpoint: Handle inexact watchpoint addresses
  ...

arch/arm64/include/asm/cpufeature.h

@@ -9,8 +9,6 @@
 #ifndef __ASM_CPUFEATURE_H
 #define __ASM_CPUFEATURE_H
 
-#include <linux/jump_label.h>
-
 #include <asm/cpucaps.h>
 #include <asm/hwcap.h>
 #include <asm/sysreg.h>
@@ -27,6 +25,8 @@
 
 #ifndef __ASSEMBLY__
 
+#include <linux/bug.h>
+#include <linux/jump_label.h>
 #include <linux/kernel.h>
 
 /* CPU feature register tracking */
@@ -104,14 +104,19 @@ static inline bool cpu_have_feature(unsigned int num)
 	return elf_hwcap & (1UL << num);
 }
 
+/* System capability check for constant caps */
+static inline bool cpus_have_const_cap(int num)
+{
+	if (num >= ARM64_NCAPS)
+		return false;
+	return static_branch_unlikely(&cpu_hwcap_keys[num]);
+}
+
 static inline bool cpus_have_cap(unsigned int num)
 {
 	if (num >= ARM64_NCAPS)
 		return false;
-	if (__builtin_constant_p(num))
-		return static_branch_unlikely(&cpu_hwcap_keys[num]);
-	else
-		return test_bit(num, cpu_hwcaps);
+	return test_bit(num, cpu_hwcaps);
 }
 
 static inline void cpus_set_cap(unsigned int num)
@@ -200,7 +205,7 @@ static inline bool cpu_supports_mixed_endian_el0(void)
 
 static inline bool system_supports_32bit_el0(void)
 {
-	return cpus_have_cap(ARM64_HAS_32BIT_EL0);
+	return cpus_have_const_cap(ARM64_HAS_32BIT_EL0);
 }
 
 static inline bool system_supports_mixed_endian_el0(void)
@@ -208,6 +213,17 @@ static inline bool system_supports_mixed_endian_el0(void)
 	return id_aa64mmfr0_mixed_endian_el0(read_system_reg(SYS_ID_AA64MMFR0_EL1));
 }
 
+static inline bool system_supports_fpsimd(void)
+{
+	return !cpus_have_const_cap(ARM64_HAS_NO_FPSIMD);
+}
+
+static inline bool system_uses_ttbr0_pan(void)
+{
+	return IS_ENABLED(CONFIG_ARM64_SW_TTBR0_PAN) &&
+		!cpus_have_cap(ARM64_HAS_PAN);
+}
+
 #endif /* __ASSEMBLY__ */
 
 #endif