[PATCH v10 03/12] x86/resctrl: Require 64-bit x86 for resctrl support

[Chen Yu]

From: Tony Luck <tony.luck@xxxxxxxxx>

Intel Application Energy Telemetry (AET) provides event counts in 64-bit
registers in MMIO space. For accurate results these should be read with a single
64-bit load operation from the CPU.

In preparation for the removal of the separate CONFIG_X86_CPU_RESCTRL_INTEL_AET
configuration option, move the X86_64 dependency to X86_CPU_RESCTRL.

This is in line with Dave Hansen's proposal[1] for an addition to Linux
documentation that details reduced 32-bit x86 support.

Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>
Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Link: https://lore.kernel.org/all/c6ab0c24-8931-4f0d-9be6-23498ab4c38b@xxxxxxxxx/ # [1]
---
Changes since v9:
- This patch is picked up from the AET series so that both series carry
  identical versions, which is why its changelog refers to AET rather
  than ERDT. (Reinette Chatre)
- Add Reinette's Reviewed-by.

 arch/x86/Kconfig | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 58dce0b66179..4aff3c6cda0c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -515,7 +515,7 @@ config X86_MPPARSE
 
 config X86_CPU_RESCTRL
 	bool "x86 CPU resource control support"
-	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
+	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
 	depends on MISC_FILESYSTEMS
 	select ARCH_HAS_CPU_RESCTRL
 	select RESCTRL_FS
@@ -538,7 +538,7 @@ config X86_CPU_RESCTRL
 
 config X86_CPU_RESCTRL_INTEL_AET
 	bool "Intel Application Energy Telemetry"
-	depends on X86_64 && X86_CPU_RESCTRL && CPU_SUP_INTEL && INTEL_PMT_TELEMETRY=y && INTEL_TPMI=y
+	depends on X86_CPU_RESCTRL && CPU_SUP_INTEL && INTEL_PMT_TELEMETRY=y && INTEL_TPMI=y
 	help
 	  Enable per-RMID telemetry events in resctrl.
 
-- 
2.25.1