Merge tag 'cpuidle_psci-v5.5-rc4' of git://git.linaro.org/people/ulf.hansson/linux-pm into arm/drivers

Initial support for hierarchical CPU arrangement, managed by PSCI and its
corresponding cpuidle driver. This support is based upon using the generic
PM domain, which already supports devices belonging to CPUs.

Finally, these is a DTS patch that enables the hierarchical topology to be
used for the Qcom 410c Dragonboard, which supports the PSCI OS-initiated
mode.

* tag 'cpuidle_psci-v5.5-rc4' of git://git.linaro.org/people/ulf.hansson/linux-pm: (611 commits)
  arm64: dts: Convert to the hierarchical CPU topology layout for MSM8916
  cpuidle: psci: Add support for PM domains by using genpd
  PM / Domains: Introduce a genpd OF helper that removes a subdomain
  cpuidle: psci: Support CPU hotplug for the hierarchical model
  cpuidle: psci: Manage runtime PM in the idle path
  cpuidle: psci: Prepare to use OS initiated suspend mode via PM domains
  cpuidle: psci: Attach CPU devices to their PM domains
  cpuidle: psci: Add a helper to attach a CPU to its PM domain
  cpuidle: psci: Support hierarchical CPU idle states
  cpuidle: psci: Simplify OF parsing of CPU idle state nodes
  cpuidle: dt: Support hierarchical CPU idle states
  of: base: Add of_get_cpu_state_node() to get idle states for a CPU node
  firmware: psci: Export functions to manage the OSI mode
  dt: psci: Update DT bindings to support hierarchical PSCI states
  cpuidle: psci: Align psci_power_state count with idle state count
  Linux 5.5-rc4
  locks: print unsigned ino in /proc/locks
  riscv: export flush_icache_all to modules
  riscv: reject invalid syscalls below -1
  riscv: fix compile failure with EXPORT_SYMBOL() & !MMU
  ...

Link: https://lore.kernel.org/r/20200102160820.3572-1-ulf.hansson@linaro.org
Signed-off-by: Olof Johansson <olof@lixom.net>

1 files changed, 11 insertions, 4 deletions

diff --git a/arch/s390/kernel/unwind_bc.c b/arch/s390/kernel/unwind_bc.c
index da2d4d4c5b0e..707fd99f6734 100644
--- a/arch/s390/kernel/unwind_bc.c
+++ b/arch/s390/kernel/unwind_bc.c
@@ -36,10 +36,17 @@ static bool update_stack_info(struct unwind_state *state, unsigned long sp)
 	return true;
 }
 
-static inline bool is_task_pt_regs(struct unwind_state *state,
-				   struct pt_regs *regs)
+static inline bool is_final_pt_regs(struct unwind_state *state,
+				    struct pt_regs *regs)
 {
-	return task_pt_regs(state->task) == regs;
+	/* user mode or kernel thread pt_regs at the bottom of task stack */
+	if (task_pt_regs(state->task) == regs)
+		return true;
+
+	/* user mode pt_regs at the bottom of irq stack */
+	return state->stack_info.type == STACK_TYPE_IRQ &&
+	       state->stack_info.end - sizeof(struct pt_regs) == (unsigned long)regs &&
+	       READ_ONCE_NOCHECK(regs->psw.mask) & PSW_MASK_PSTATE;
 }
 
 bool unwind_next_frame(struct unwind_state *state)
@@ -80,7 +87,7 @@ bool unwind_next_frame(struct unwind_state *state)
 			if (!on_stack(info, sp, sizeof(struct pt_regs)))
 				goto out_err;
 			regs = (struct pt_regs *) sp;
-			if (is_task_pt_regs(state, regs))
+			if (is_final_pt_regs(state, regs))
 				goto out_stop;
 			ip = READ_ONCE_NOCHECK(regs->psw.addr);
 			sp = READ_ONCE_NOCHECK(regs->gprs[15]);