refactor(cpufeat): move helpers into .c file, rename FEAT_STATE_

The FEATURE_DETECTION functionality had some definitions in a header
file, although they were only used internally in the .c file.
Move them over there, since there are of no interest to other users.

Also use the opportuntiy to rename the less telling FEAT_STATE_[12]
names, and let the "0" case join the game. We use DISABLED, ALWAYS, and
CHECK now, so that the casual reader has some idea what those numbers
are supposed to mean.

feature_panic() becomes "static inline", since disabling all features
makes it unused, so the compiler complains otherwise.

Finally add a new category "cpufeat" to cover CPU feature related
changes.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Change-Id: If0c8ba91ad22440260ccff383c33bdd055eefbdc

changelog.yaml

@@ -101,6 +101,9 @@ subsections:
       - title: Extended Cache Index (FEAT_CCIDX)
         scope: ccidx
 
+      - title: CPU feature / ID register handling in general
+        scope: cpufeat
+
       - title: Support for the `HCRX_EL2` register (FEAT_HCX)
         scope: hcx
 

common/feat_detect.c

@@ -4,24 +4,39 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
+#include <arch_features.h>
+#include <common/debug.h>
 #include <common/feat_detect.h>
 
 /*******************************************************************************
  * This section lists the wrapper modules for each feature to evaluate the
- * feature states (FEAT_STATE_1 and FEAT_STATE_2) and perform necessary action
- * as below:
+ * feature states (FEAT_STATE_ALWAYS and FEAT_STATE_CHECK) and perform
+ * necessary action as below:
  *
  * It verifies whether the FEAT_XXX (eg: FEAT_SB) is supported by the PE or not.
  * Without this check an exception would occur during context save/restore
  * routines, if the feature is enabled but not supported by PE.
  ******************************************************************************/
 
+#define feat_detect_panic(a, b)		((a) ? (void)0 : feature_panic(b))
+
+/*******************************************************************************
+ * Function : feature_panic
+ * Customised panic function with error logging mechanism to list the feature
+ * not supported by the PE.
+ ******************************************************************************/
+static inline void feature_panic(char *feat_name)
+{
+	ERROR("FEAT_%s not supported by the PE\n", feat_name);
+	panic();
+}
+
 /******************************************
  * Feature : FEAT_SB (Speculation Barrier)
  *****************************************/
 static void read_feat_sb(void)
 {
-#if (ENABLE_FEAT_SB == FEAT_STATE_1)
+#if (ENABLE_FEAT_SB == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_armv8_0_feat_sb_present(), "SB");
 #endif
 }
@@ -31,7 +46,7 @@ static void read_feat_sb(void)
  *****************************************************/
 static void read_feat_csv2_2(void)
 {
-#if (ENABLE_FEAT_CSV2_2 == FEAT_STATE_1)
+#if (ENABLE_FEAT_CSV2_2 == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_armv8_0_feat_csv2_2_present(), "CSV2_2");
 #endif
 }
@@ -41,7 +56,7 @@ static void read_feat_csv2_2(void)
  **********************************************/
 static void read_feat_pan(void)
 {
-#if (ENABLE_FEAT_PAN == FEAT_STATE_1)
+#if (ENABLE_FEAT_PAN == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_armv8_1_pan_present(), "PAN");
 #endif
 }
@@ -51,7 +66,7 @@ static void read_feat_pan(void)
  *****************************************************/
 static void read_feat_vhe(void)
 {
-#if (ENABLE_FEAT_VHE == FEAT_STATE_1)
+#if (ENABLE_FEAT_VHE == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_armv8_1_vhe_present(), "VHE");
 #endif
 }
@@ -61,7 +76,7 @@ static void read_feat_vhe(void)
  ******************************************************************************/
 static void read_feat_ras(void)
 {
-#if (RAS_EXTENSION == FEAT_STATE_1)
+#if (RAS_EXTENSION == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_armv8_2_feat_ras_present(), "RAS");
 #endif
 }
@@ -71,7 +86,7 @@ static void read_feat_ras(void)
  ***********************************************/
 static void read_feat_pauth(void)
 {
-#if (ENABLE_PAUTH == FEAT_STATE_1) || (CTX_INCLUDE_PAUTH_REGS == FEAT_STATE_1)
+#if (ENABLE_PAUTH == FEAT_STATE_ALWAYS) || (CTX_INCLUDE_PAUTH_REGS == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_armv8_3_pauth_present(), "PAUTH");
 #endif
 }
@@ -81,7 +96,7 @@ static void read_feat_pauth(void)
  ***********************************************************/
 static void read_feat_dit(void)
 {
-#if (ENABLE_FEAT_DIT == FEAT_STATE_1)
+#if (ENABLE_FEAT_DIT == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_armv8_4_feat_dit_present(), "DIT");
 #endif
 }
@@ -91,7 +106,7 @@ static void read_feat_dit(void)
  ********************************************************/
 static void read_feat_amuv1(void)
 {
-#if (ENABLE_FEAT_AMUv1 == FEAT_STATE_1)
+#if (ENABLE_FEAT_AMUv1 == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_armv8_4_feat_amuv1_present(), "AMUv1");
 #endif
 }
@@ -101,7 +116,7 @@ static void read_feat_amuv1(void)
  ***************************************************************************/
 static void read_feat_mpam(void)
 {
-#if (ENABLE_MPAM_FOR_LOWER_ELS == FEAT_STATE_1)
+#if (ENABLE_MPAM_FOR_LOWER_ELS == FEAT_STATE_ALWAYS)
 	feat_detect_panic(get_mpam_version() != 0U, "MPAM");
 #endif
 }
@@ -111,7 +126,7 @@ static void read_feat_mpam(void)
  *************************************************************/
 static void read_feat_nv2(void)
 {
-#if (CTX_INCLUDE_NEVE_REGS == FEAT_STATE_1)
+#if (CTX_INCLUDE_NEVE_REGS == FEAT_STATE_ALWAYS)
 	unsigned int nv = get_armv8_4_feat_nv_support();
 
 	feat_detect_panic((nv == ID_AA64MMFR2_EL1_NV2_SUPPORTED), "NV2");
@@ -123,7 +138,7 @@ static void read_feat_nv2(void)
  **********************************/
 static void read_feat_sel2(void)
 {
-#if (ENABLE_FEAT_SEL2 == FEAT_STATE_1)
+#if (ENABLE_FEAT_SEL2 == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_armv8_4_sel2_present(), "SEL2");
 #endif
 }
@@ -133,7 +148,7 @@ static void read_feat_sel2(void)
  ***************************************************/
 static void read_feat_trf(void)
 {
-#if (ENABLE_TRF_FOR_NS == FEAT_STATE_1)
+#if (ENABLE_TRF_FOR_NS == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_arm8_4_feat_trf_present(), "TRF");
 #endif
 }
@@ -143,7 +158,7 @@ static void read_feat_trf(void)
  ***********************************************/
 static void read_feat_mte(void)
 {
-#if (CTX_INCLUDE_MTE_REGS == FEAT_STATE_1)
+#if (CTX_INCLUDE_MTE_REGS == FEAT_STATE_ALWAYS)
 	unsigned int mte = get_armv8_5_mte_support();
 
 	feat_detect_panic((mte != MTE_UNIMPLEMENTED), "MTE");
@@ -155,7 +170,7 @@ static void read_feat_mte(void)
  **********************************************/
 static void read_feat_rng(void)
 {
-#if (ENABLE_FEAT_RNG == FEAT_STATE_1)
+#if (ENABLE_FEAT_RNG == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_armv8_5_rng_present(), "RNG");
 #endif
 }
@@ -165,7 +180,7 @@ static void read_feat_rng(void)
  ***************************************************/
 static void read_feat_bti(void)
 {
-#if (ENABLE_BTI == FEAT_STATE_1)
+#if (ENABLE_BTI == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_armv8_5_bti_present(), "BTI");
 #endif
 }
@@ -175,7 +190,7 @@ static void read_feat_bti(void)
  ***************************************/
 static void read_feat_fgt(void)
 {
-#if (ENABLE_FEAT_FGT == FEAT_STATE_1)
+#if (ENABLE_FEAT_FGT == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_armv8_6_fgt_present(), "FGT");
 #endif
 }
@@ -185,7 +200,7 @@ static void read_feat_fgt(void)
  **********************************************/
 static void read_feat_amuv1p1(void)
 {
-#if (ENABLE_FEAT_AMUv1p1 == FEAT_STATE_1)
+#if (ENABLE_FEAT_AMUv1p1 == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_armv8_6_feat_amuv1p1_present(), "AMUv1p1");
 #endif
 }
@@ -195,7 +210,7 @@ static void read_feat_amuv1p1(void)
  ******************************************************/
 static void read_feat_ecv(void)
 {
-#if (ENABLE_FEAT_ECV == FEAT_STATE_1)
+#if (ENABLE_FEAT_ECV == FEAT_STATE_ALWAYS)
 	unsigned int ecv = get_armv8_6_ecv_support();
 
 	feat_detect_panic(((ecv == ID_AA64MMFR0_EL1_ECV_SUPPORTED) ||
@@ -208,7 +223,7 @@ static void read_feat_ecv(void)
  **********************************************************/
 static void read_feat_twed(void)
 {
-#if (ENABLE_FEAT_TWED == FEAT_STATE_1)
+#if (ENABLE_FEAT_TWED == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_armv8_6_twed_present(), "TWED");
 #endif
 }
@@ -218,7 +233,7 @@ static void read_feat_twed(void)
  *****************************************************************/
 static void read_feat_hcx(void)
 {
-#if (ENABLE_FEAT_HCX == FEAT_STATE_1)
+#if (ENABLE_FEAT_HCX == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_feat_hcx_present(), "HCX");
 #endif
 }
@@ -228,7 +243,7 @@ static void read_feat_hcx(void)
  *************************************************/
 static void read_feat_rme(void)
 {
-#if (ENABLE_RME == FEAT_STATE_1)
+#if (ENABLE_RME == FEAT_STATE_ALWAYS)
 	feat_detect_panic((get_armv9_2_feat_rme_support() !=
 			ID_AA64PFR0_FEAT_RME_NOT_SUPPORTED), "RME");
 #endif
@@ -239,7 +254,7 @@ static void read_feat_rme(void)
  *****************************************************/
 static void read_feat_brbe(void)
 {
-#if (ENABLE_BRBE_FOR_NS == FEAT_STATE_1)
+#if (ENABLE_BRBE_FOR_NS == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_feat_brbe_present(), "BRBE");
 #endif
 }
@@ -249,7 +264,7 @@ static void read_feat_brbe(void)
  *****************************************************/
 static void read_feat_trbe(void)
 {
-#if (ENABLE_TRBE_FOR_NS == FEAT_STATE_1)
+#if (ENABLE_TRBE_FOR_NS == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_feat_trbe_present(), "TRBE");
 #endif
 }
@@ -259,7 +274,7 @@ static void read_feat_trbe(void)
  *****************************************************************/
 static void read_feat_rng_trap(void)
 {
-#if (ENABLE_FEAT_RNG_TRAP == FEAT_STATE_1)
+#if (ENABLE_FEAT_RNG_TRAP == FEAT_STATE_ALWAYS)
 	feat_detect_panic(is_feat_rng_trap_present(), "RNG_TRAP");
 #endif
 }
@@ -283,8 +298,9 @@ static void read_feat_rng_trap(void)
  * ENABLE_FEAT_xxx = 2 : The feature is enabled but dynamically enabled at runtime
  *                       depending on hardware capability.
  *
- * For better readability, state values are defined with macros namely:
- * { FEAT_STATE_0, FEAT_STATE_1, FEAT_STATE_2 } taking values as their naming.
+ * For better readability, state values are defined with macros, namely:
+ * { FEAT_STATE_DISABLED, FEAT_STATE_ALWAYS, FEAT_STATE_CHECK }, taking values
+ * { 0, 1, 2 }, respectively, as their naming.
  **********************************************************************************/
 void detect_arch_features(void)
 {

include/common/feat_detect.h

@@ -7,26 +7,12 @@
 #ifndef FEAT_DETECT_H
 #define FEAT_DETECT_H
 
-#include <arch_features.h>
-#include <common/debug.h>
-
 /* Function Prototypes */
 void detect_arch_features(void);
 
 /* Macro Definitions */
-#define FEAT_STATE_1	1
-#define FEAT_STATE_2	2
-#define feat_detect_panic(a, b)		((a) ? (void)0 : feature_panic(b))
-
-/*******************************************************************************
- * Function : feature_panic
- * Customised panic module with error logging mechanism to list the feature
- * not supported by the PE.
- ******************************************************************************/
-static inline void feature_panic(char *feat_name)
-{
-	ERROR("FEAT_%s not supported by the PE\n", feat_name);
-	panic();
-}
+#define FEAT_STATE_DISABLED	0
+#define FEAT_STATE_ALWAYS	1
+#define FEAT_STATE_CHECK	2
 
 #endif /* FEAT_DETECT_H */