[S] Change in coreboot[main]: arch/x86/Kconfig: introduce RESERVED_PHYSICAL_ADDRESS_BITS_SUPPORT

[Felix Held (Code Review)]

Felix Held has submitted this change. ( https://review.coreboot.org/c/coreboot/+/78073?usp=email )

Change subject: arch/x86/Kconfig: introduce RESERVED_PHYSICAL_ADDRESS_BITS_SUPPORT
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arch/x86/Kconfig: introduce RESERVED_PHYSICAL_ADDRESS_BITS_SUPPORT

Since also some AMD CPUs have reserved physical address bits that can't
be used as normal address bits, introduce the
RESERVED_PHYSICAL_ADDRESS_BITS_SUPPORT Kconfig option which gets
selected by CPU_INTEL_COMMON, and use the new common option to configure
if the specific SoC/CPU code implements get_reserved_phys_addr_bits or
if the default of this returning 0 is used instead.

Signed-off-by: Felix Held 
Change-Id: I0059e63a160e60ddee280635bba72d363deca7f7
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78073
Tested-by: build bot (Jenkins) 
Reviewed-by: Marshall Dawson 
Reviewed-by: Jérémy Compostella 
Reviewed-by: Matt DeVillier 
---
M src/arch/x86/Kconfig
M src/arch/x86/include/arch/cpu.h
M src/cpu/intel/common/Kconfig
3 files changed, 12 insertions(+), 1 deletion(-)

Approvals:
  build bot (Jenkins): Verified
  Jérémy Compostella: Looks good to me, but someone else must approve
  Marshall Dawson: Looks good to me, but someone else must approve
  Matt DeVillier: Looks good to me, approved

diff --git a/src/arch/x86/Kconfig b/src/arch/x86/Kconfig
index 8676fad..c97fecb 100644
--- a/src/arch/x86/Kconfig
+++ b/src/arch/x86/Kconfig
@@ -92,6 +92,16 @@
      The position where to place pagetables. Needs to be known at
      compile time. Must not overlap other files in CBFS.

+config RESERVED_PHYSICAL_ADDRESS_BITS_SUPPORT
+	bool
+	help
+	  On some systems, the upper physical address bits are reserved and
+	  used as a tag which is typically related to a memory encryption
+	  feature. When selecting this option, the SoC code needs to implement
+	  get_reserved_phys_addr_bits so that the common code knows how many of
+	  the most significant physical address bits are reserved and can't be
+	  used as address bits.
+
 # This is an SMP option. It relates to starting up APs.
 # It is usually set in mainboard/*/Kconfig.
 # TODO: Improve description.
diff --git a/src/arch/x86/include/arch/cpu.h b/src/arch/x86/include/arch/cpu.h
index b24cd23..2c98d1e 100644
--- a/src/arch/x86/include/arch/cpu.h
+++ b/src/arch/x86/include/arch/cpu.h
@@ -316,7 +316,7 @@
  */
 bool fill_cpu_cache_info(uint8_t level, struct cpu_cache_info *info);

-#if CONFIG(CPU_INTEL_COMMON)
+#if CONFIG(RESERVED_PHYSICAL_ADDRESS_BITS_SUPPORT)
 unsigned int get_reserved_phys_addr_bits(void);
 #else
 /* Default implementation */
diff --git a/src/cpu/intel/common/Kconfig b/src/cpu/intel/common/Kconfig
index 7f9033c..51b8ccb 100644
--- a/src/cpu/intel/common/Kconfig
+++ b/src/cpu/intel/common/Kconfig
@@ -1,5 +1,6 @@
 config CPU_INTEL_COMMON
    bool
+	select RESERVED_PHYSICAL_ADDRESS_BITS_SUPPORT

if CPU_INTEL_COMMON