[PATCH] x86/acpi: remove unused ACPI_FLUSH_CPU_CACHE macro

[PATCH] x86/acpi: remove unused ACPI_FLUSH_CPU_CACHE macro

[Ashwin Gundarapu]

From 97f29e8874ab462cd741a5d202d833e3ba9f1c26 Mon Sep 17 00:00:00 2001
From: Ashwin Gundarapu <linuxuser509@outlook.com>
Date: Sun, 14 Jun 2026 20:00:42 +0530
Subject: [PATCH] x86/acpi: remove unused ACPI_FLUSH_CPU_CACHE macro

The ACPI_FLUSH_CPU_CACHE macro is unused in arch/x86/. Remove it.

Signed-off-by: Ashwin Gundarapu <linuxuser509@zohomail.in>
---
 arch/x86/include/asm/acenv.h | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/arch/x86/include/asm/acenv.h b/arch/x86/include/asm/acenv.h
index d937c55e717e..db29f77352d3 100644
--- a/arch/x86/include/asm/acenv.h
+++ b/arch/x86/include/asm/acenv.h
@@ -21,11 +21,6 @@
  * Changing sleep state in a virtual machine doesn't affect the host system
  * sleep state and cannot lead to data loss.
  */
-#define ACPI_FLUSH_CPU_CACHE()					\
-do {								\
-	if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))	\
-		wbinvd();					\
-} while (0)
 
 int __acpi_acquire_global_lock(unsigned int *lock);
 int __acpi_release_global_lock(unsigned int *lock);
-- 
2.47.3

Re: [PATCH] x86/acpi: remove unused ACPI_FLUSH_CPU_CACHE macro

[kernel test robot]

Hi Ashwin,

kernel test robot noticed the following build warnings:

[auto build test WARNING on tip/master]
[also build test WARNING on tip/auto-latest tip/x86/core linus/master v7.1 next-20260612]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Ashwin-Gundarapu/x86-acpi-remove-unused-ACPI_FLUSH_CPU_CACHE-macro/20260614-224607
base:   tip/master
patch link:    https://lore.kernel.org/r/19ec69410f9.1df26e0036083.1465238188751484552%40zohomail.in
patch subject: [PATCH] x86/acpi: remove unused ACPI_FLUSH_CPU_CACHE macro
config: x86_64-randconfig-011-20260615 (https://download.01.org/0day-ci/archive/20260615/202606150752.I0Au8al5-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260615/202606150752.I0Au8al5-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202606150752.I0Au8al5-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/acpi/processor_idle.c: In function 'acpi_idle_enter':
>> drivers/acpi/processor_idle.c:699:39: warning: suggest braces around empty body in an 'if' statement [-Wempty-body]
     699 |                 ACPI_FLUSH_CPU_CACHE();
         |                                       ^


vim +/if +699 drivers/acpi/processor_idle.c

6491bc0c616969 Rafael J. Wysocki    2015-02-03  676  
409dfdcaffb266 Guilherme G. Piccoli 2022-06-07  677  static int __cpuidle acpi_idle_enter(struct cpuidle_device *dev,
6491bc0c616969 Rafael J. Wysocki    2015-02-03  678  			   struct cpuidle_driver *drv, int index)
6491bc0c616969 Rafael J. Wysocki    2015-02-03  679  {
6491bc0c616969 Rafael J. Wysocki    2015-02-03  680  	struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
6491bc0c616969 Rafael J. Wysocki    2015-02-03  681  	struct acpi_processor *pr;
6491bc0c616969 Rafael J. Wysocki    2015-02-03  682  
6491bc0c616969 Rafael J. Wysocki    2015-02-03  683  	pr = __this_cpu_read(processors);
6491bc0c616969 Rafael J. Wysocki    2015-02-03  684  	if (unlikely(!pr))
6491bc0c616969 Rafael J. Wysocki    2015-02-03  685  		return -EINVAL;
6491bc0c616969 Rafael J. Wysocki    2015-02-03  686  
6491bc0c616969 Rafael J. Wysocki    2015-02-03  687  	if (cx->type != ACPI_STATE_C1) {
1fecfdbb7acc66 Peter Zijlstra       2020-09-15  688  		if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check)
1fecfdbb7acc66 Peter Zijlstra       2020-09-15  689  			return acpi_idle_enter_bm(drv, pr, cx, index);
1fecfdbb7acc66 Peter Zijlstra       2020-09-15  690  
1fecfdbb7acc66 Peter Zijlstra       2020-09-15  691  		/* C2 to C1 demotion. */
5f5081852038d9 Rafael J. Wysocki    2015-02-11  692  		if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
dc2251bf98c66d Rafael J. Wysocki    2017-08-23  693  			index = ACPI_IDLE_STATE_START;
6491bc0c616969 Rafael J. Wysocki    2015-02-03  694  			cx = per_cpu(acpi_cstate[index], dev->cpu);
6491bc0c616969 Rafael J. Wysocki    2015-02-03  695  		}
6491bc0c616969 Rafael J. Wysocki    2015-02-03  696  	}
6491bc0c616969 Rafael J. Wysocki    2015-02-03  697  
6491bc0c616969 Rafael J. Wysocki    2015-02-03  698  	if (cx->type == ACPI_STATE_C3)
6491bc0c616969 Rafael J. Wysocki    2015-02-03 @699  		ACPI_FLUSH_CPU_CACHE();
6491bc0c616969 Rafael J. Wysocki    2015-02-03  700  
6491bc0c616969 Rafael J. Wysocki    2015-02-03  701  	acpi_idle_do_entry(cx);
6491bc0c616969 Rafael J. Wysocki    2015-02-03  702  
e978aa7d7d57d0 Deepthi Dharwar      2011-10-28  703  	return index;
4f86d3a8e29720 Len Brown            2007-10-03  704  }
4f86d3a8e29720 Len Brown            2007-10-03  705  

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