[ANNOUNCE] v4.13.7-rt1v4.13.7-rt1-patches

Dear RT folks!

I'm pleased to announce the v4.13.7-rt1 patch set.

Changes since v4.11.12-rt16:

  - Rebase to v4.13.7

  - We have now only the reader bias version of RWLOCK. In v4.11 it was
    possible to choose between both implementations but since the reader
    bias version makes no problems it is now the only implementation.

  - The lockdep self test is now disabled. While it produced some false
    positives on v4.11 it now completly locks up the system and needs
    investigation before re-enabling.

Known issues
	None

You can get this release via the git tree at:

    git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git v4.13.7-rt1

The RT patch against v4.13.7 can be found here:

    https://cdn.kernel.org/pub/linux/kernel/projects/rt/4.13/older/patch-4.13.7-rt1.patch.xz

The split quilt queue is available at:

    https://cdn.kernel.org/pub/linux/kernel/projects/rt/4.13/older/patches-4.13.7-rt1.tar.xz

Sebastian

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

1 files changed, 0 insertions, 169 deletions

diff --git a/patches/arm64-cpufeature-don-t-use-mutex-in-bringup-path.patch b/patches/arm64-cpufeature-don-t-use-mutex-in-bringup-path.patch
deleted file mode 100644
index ce4f85545922..000000000000
--- a/patches/arm64-cpufeature-don-t-use-mutex-in-bringup-path.patch
+++ /dev/null
@@ -1,169 +0,0 @@
-From: Mark Rutland <mark.rutland@arm.com>
-Date: Tue, 16 May 2017 15:18:05 +0100
-Subject: [PATCH] arm64/cpufeature: don't use mutex in bringup path
-
-Commit b2bb439ad99a1497daa392a527c0e52c69915ce9 upstream
-
-Currently, cpus_set_cap() calls static_branch_enable_cpuslocked(), which
-must take the jump_label mutex.
-
-We call cpus_set_cap() in the secondary bringup path, from the idle
-thread where interrupts are disabled. Taking a mutex in this path "is a
-NONO" regardless of whether it's contended, and something we must avoid.
-We didn't spot this until recently, as ___might_sleep() won't warn for
-this case until all CPUs have been brought up.
-
-This patch avoids taking the mutex in the secondary bringup path. The
-poking of static keys is deferred until enable_cpu_capabilities(), which
-runs in a suitable context on the boot CPU. To account for the static
-keys being set later, cpus_have_const_cap() is updated to use another
-static key to check whether the const cap keys have been initialised,
-falling back to the caps bitmap until this is the case.
-
-This means that users of cpus_have_const_cap() gain should only gain a
-single additional NOP in the fast path once the const caps are
-initialised, but should always see the current cap value.
-
-The hyp code should never dereference the caps array, since the caps are
-initialized before we run the module initcall to initialise hyp. A check
-is added to the hyp init code to document this requirement.
-
-This change will sidestep a number of issues when the upcoming hotplug
-locking rework is merged.
-
-Signed-off-by: Mark Rutland <mark.rutland@arm.com>
-Reviewed-by: Marc Zyniger <marc.zyngier@arm.com>
-Reviewed-by: Suzuki Poulose <suzuki.poulose@arm.com>
-Acked-by: Will Deacon <will.deacon@arm.com>
-Cc: Christoffer Dall <christoffer.dall@linaro.org>
-Cc: Peter Zijlstra <peterz@infradead.org>
-Cc: Sebastian Sewior <bigeasy@linutronix.de>
-Cc: Thomas Gleixner <tglx@linutronix.de>
-Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
----
- arch/arm64/include/asm/cpufeature.h |   12 ++++++++++--
- arch/arm64/include/asm/kvm_host.h   |    8 ++++++--
- arch/arm64/kernel/cpufeature.c      |   23 +++++++++++++++++++++--
- 3 files changed, 37 insertions(+), 6 deletions(-)
-
---- a/arch/arm64/include/asm/cpufeature.h
-+++ b/arch/arm64/include/asm/cpufeature.h
-@@ -115,6 +115,7 @@ struct arm64_cpu_capabilities {
- 
- extern DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
- extern struct static_key_false cpu_hwcap_keys[ARM64_NCAPS];
-+extern struct static_key_false arm64_const_caps_ready;
- 
- bool this_cpu_has_cap(unsigned int cap);
- 
-@@ -124,7 +125,7 @@ static inline bool cpu_have_feature(unsi
- }
- 
- /* System capability check for constant caps */
--static inline bool cpus_have_const_cap(int num)
-+static inline bool __cpus_have_const_cap(int num)
- {
- 	if (num >= ARM64_NCAPS)
- 		return false;
-@@ -138,6 +139,14 @@ static inline bool cpus_have_cap(unsigne
- 	return test_bit(num, cpu_hwcaps);
- }
- 
-+static inline bool cpus_have_const_cap(int num)
-+{
-+	if (static_branch_likely(&arm64_const_caps_ready))
-+		return __cpus_have_const_cap(num);
-+	else
-+		return cpus_have_cap(num);
-+}
-+
- static inline void cpus_set_cap(unsigned int num)
- {
- 	if (num >= ARM64_NCAPS) {
-@@ -145,7 +154,6 @@ static inline void cpus_set_cap(unsigned
- 			num, ARM64_NCAPS);
- 	} else {
- 		__set_bit(num, cpu_hwcaps);
--		static_branch_enable(&cpu_hwcap_keys[num]);
- 	}
- }
- 
---- a/arch/arm64/include/asm/kvm_host.h
-+++ b/arch/arm64/include/asm/kvm_host.h
-@@ -24,6 +24,7 @@
- 
- #include <linux/types.h>
- #include <linux/kvm_types.h>
-+#include <asm/cpufeature.h>
- #include <asm/kvm.h>
- #include <asm/kvm_asm.h>
- #include <asm/kvm_mmio.h>
-@@ -356,9 +357,12 @@ static inline void __cpu_init_hyp_mode(p
- 				       unsigned long vector_ptr)
- {
- 	/*
--	 * Call initialization code, and switch to the full blown
--	 * HYP code.
-+	 * Call initialization code, and switch to the full blown HYP code.
-+	 * If the cpucaps haven't been finalized yet, something has gone very
-+	 * wrong, and hyp will crash and burn when it uses any
-+	 * cpus_have_const_cap() wrapper.
- 	 */
-+	BUG_ON(!static_branch_likely(&arm64_const_caps_ready));
- 	__kvm_call_hyp((void *)pgd_ptr, hyp_stack_ptr, vector_ptr);
- }
- 
---- a/arch/arm64/kernel/cpufeature.c
-+++ b/arch/arm64/kernel/cpufeature.c
-@@ -975,8 +975,16 @@ void update_cpu_capabilities(const struc
-  */
- void __init enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps)
- {
--	for (; caps->matches; caps++)
--		if (caps->enable && cpus_have_cap(caps->capability))
-+	for (; caps->matches; caps++) {
-+		unsigned int num = caps->capability;
-+
-+		if (!cpus_have_cap(num))
-+			continue;
-+
-+		/* Ensure cpus_have_const_cap(num) works */
-+		static_branch_enable(&cpu_hwcap_keys[num]);
-+
-+		if (caps->enable) {
- 			/*
- 			 * Use stop_machine() as it schedules the work allowing
- 			 * us to modify PSTATE, instead of on_each_cpu() which
-@@ -984,6 +992,8 @@ void __init enable_cpu_capabilities(cons
- 			 * we return.
- 			 */
- 			stop_machine(caps->enable, NULL, cpu_online_mask);
-+		}
-+	}
- }
- 
- /*
-@@ -1086,6 +1096,14 @@ static void __init setup_feature_capabil
- 	enable_cpu_capabilities(arm64_features);
- }
- 
-+DEFINE_STATIC_KEY_FALSE(arm64_const_caps_ready);
-+EXPORT_SYMBOL(arm64_const_caps_ready);
-+
-+static void __init mark_const_caps_ready(void)
-+{
-+	static_branch_enable(&arm64_const_caps_ready);
-+}
-+
- /*
-  * Check if the current CPU has a given feature capability.
-  * Should be called from non-preemptible context.
-@@ -1112,6 +1130,7 @@ void __init setup_cpu_features(void)
- 	/* Set the CPU feature capabilies */
- 	setup_feature_capabilities();
- 	enable_errata_workarounds();
-+	mark_const_caps_ready();
- 	setup_elf_hwcaps(arm64_elf_hwcaps);
- 
- 	if (system_supports_32bit_el0())