cpu/x86/tsc: Flip and rename TSC_CONSTANT_RATE to UNKNOWN_TSC_RATE

The x86 timers are a bit of a mess. Cases where different stages use
different counters and timestamps use different counters from udelays.

The original intention was to only flip TSC_CONSTANT_RATE Kconfig
to NOT_CONSTANT_TSC_RATE. The name would be incorrect though, those
counters do run with a constant rate but we just lack tsc_freq_mhz()
implementation for three platforms.

Note that for boards with UNKNOWN_TSC_RATE=y, each stage will have a
slow run of calibrate_tsc_with_pit(). This is easy enough to fix with
followup implementation of tsc_freq_mhz() for the platforms.

Implementations with LAPIC_MONOTONIC_TIMER typically will not have
tsc_freq_mhz() implemented and default to UNKNOWN_TSC_RATE. However,
as they don't use TSC for udelay() the slow calibrate_tsc_with_pit()
is avoided.

Because x86/tsc_delay.tsc was using two different guards and nb/via/vx900
claimed UDELAY_TSC, but pulled UDELAY_IO implementation, we also switch
that romstage to use UDELAY_TSC.

Change-Id: I1690cb80295d6b006b75ed69edea28899b674b68
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33928
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

11 files changed, 0 insertions, 11 deletions

diff --git a/src/soc/intel/apollolake/Kconfig b/src/soc/intel/apollolake/Kconfig
index b54528f579..026f6da669 100644
--- a/src/soc/intel/apollolake/Kconfig
+++ b/src/soc/intel/apollolake/Kconfig
@@ -95,7 +95,6 @@ config CPU_SPECIFIC_OPTIONS
 	select SOC_INTEL_COMMON_BLOCK_SPI
 	select SOC_INTEL_COMMON_BLOCK_CSE
 	select UDELAY_TSC
-	select TSC_CONSTANT_RATE
 	select TSC_MONOTONIC_TIMER
 	select PLATFORM_USES_FSP2_0
 	select UDK_2015_BINDING if !SOC_INTEL_GLK
diff --git a/src/soc/intel/baytrail/Kconfig b/src/soc/intel/baytrail/Kconfig
index c833c5360f..397e86768c 100644
--- a/src/soc/intel/baytrail/Kconfig
+++ b/src/soc/intel/baytrail/Kconfig
@@ -27,7 +27,6 @@ config CPU_SPECIFIC_OPTIONS
 	select SMP
 	select SPI_FLASH
 	select SSE2
-	select TSC_CONSTANT_RATE
 	select TSC_MONOTONIC_TIMER
 	select TSC_SYNC_MFENCE
 	select UDELAY_TSC
diff --git a/src/soc/intel/braswell/Kconfig b/src/soc/intel/braswell/Kconfig
index 5053790c75..7ea01863ae 100644
--- a/src/soc/intel/braswell/Kconfig
+++ b/src/soc/intel/braswell/Kconfig
@@ -34,7 +34,6 @@ config CPU_SPECIFIC_OPTIONS
 	select SMP
 	select SPI_FLASH
 	select SSE2
-	select TSC_CONSTANT_RATE
 	select TSC_MONOTONIC_TIMER
 	select TSC_SYNC_MFENCE
 	select UDELAY_TSC
diff --git a/src/soc/intel/broadwell/Kconfig b/src/soc/intel/broadwell/Kconfig
index 5856ef1e50..fadbb417ae 100644
--- a/src/soc/intel/broadwell/Kconfig
+++ b/src/soc/intel/broadwell/Kconfig
@@ -27,7 +27,6 @@ config CPU_SPECIFIC_OPTIONS
 	select SMP
 	select SPI_FLASH
 	select SSE2
-	select TSC_CONSTANT_RATE
 	select TSC_SYNC_MFENCE
 	select UDELAY_TSC
 	select SOC_INTEL_COMMON
diff --git a/src/soc/intel/cannonlake/Kconfig b/src/soc/intel/cannonlake/Kconfig
index 941c150892..3330a69081 100644
--- a/src/soc/intel/cannonlake/Kconfig
+++ b/src/soc/intel/cannonlake/Kconfig
@@ -102,7 +102,6 @@ config CPU_SPECIFIC_OPTIONS
 	select SOC_INTEL_COMMON_RESET
 	select SSE2
 	select SUPPORT_CPU_UCODE_IN_CBFS
-	select TSC_CONSTANT_RATE
 	select TSC_MONOTONIC_TIMER
 	select UDELAY_TSC
 	select UDK_2017_BINDING
diff --git a/src/soc/intel/denverton_ns/Kconfig b/src/soc/intel/denverton_ns/Kconfig
index 2aadcae584..cb3713d3b0 100644
--- a/src/soc/intel/denverton_ns/Kconfig
+++ b/src/soc/intel/denverton_ns/Kconfig
@@ -50,7 +50,6 @@ config CPU_SPECIFIC_OPTIONS
 	select SOC_INTEL_COMMON_BLOCK_FAST_SPI
 	select SOC_INTEL_COMMON_BLOCK_GPIO
 	select SOC_INTEL_COMMON_BLOCK_PCR
-	select TSC_CONSTANT_RATE
 	select TSC_MONOTONIC_TIMER
 	select TSC_SYNC_MFENCE
 	select UDELAY_TSC
diff --git a/src/soc/intel/fsp_baytrail/Kconfig b/src/soc/intel/fsp_baytrail/Kconfig
index efe12da480..5a8bec995b 100644
--- a/src/soc/intel/fsp_baytrail/Kconfig
+++ b/src/soc/intel/fsp_baytrail/Kconfig
@@ -36,7 +36,6 @@ config CPU_SPECIFIC_OPTIONS
 	select SMP
 	select SPI_FLASH
 	select SSE2
-	select TSC_CONSTANT_RATE
 	select TSC_SYNC_MFENCE
 	select UDELAY_TSC
 	select TSC_MONOTONIC_TIMER
diff --git a/src/soc/intel/fsp_broadwell_de/Kconfig b/src/soc/intel/fsp_broadwell_de/Kconfig
index 6c74a749a4..4c50828e0d 100644
--- a/src/soc/intel/fsp_broadwell_de/Kconfig
+++ b/src/soc/intel/fsp_broadwell_de/Kconfig
@@ -24,7 +24,6 @@ config CPU_SPECIFIC_OPTIONS
 	select INTEL_DESCRIPTOR_MODE_CAPABLE
 	select HAVE_SMI_HANDLER
 	select TSC_MONOTONIC_TIMER
-	select TSC_CONSTANT_RATE
 	select HAVE_FSP_BIN
 	select CPU_INTEL_FIRMWARE_INTERFACE_TABLE
 	select SOC_INTEL_COMMON
diff --git a/src/soc/intel/icelake/Kconfig b/src/soc/intel/icelake/Kconfig
index 993e9b2d3b..86f1ff53e0 100644
--- a/src/soc/intel/icelake/Kconfig
+++ b/src/soc/intel/icelake/Kconfig
@@ -53,7 +53,6 @@ config CPU_SPECIFIC_OPTIONS
 	select SOC_INTEL_COMMON_RESET
 	select SSE2
 	select SUPPORT_CPU_UCODE_IN_CBFS
-	select TSC_CONSTANT_RATE
 	select TSC_MONOTONIC_TIMER
 	select UDELAY_TSC
 	select UDK_2017_BINDING
diff --git a/src/soc/intel/quark/Kconfig b/src/soc/intel/quark/Kconfig
index b752784d15..75f13543ca 100644
--- a/src/soc/intel/quark/Kconfig
+++ b/src/soc/intel/quark/Kconfig
@@ -34,7 +34,6 @@ config CPU_SPECIFIC_OPTIONS
 	select SOC_INTEL_COMMON_RESET
 	select SOC_SETS_MSRS
 	select SPI_FLASH
-	select TSC_CONSTANT_RATE
 	select UART_OVERRIDE_REFCLK
 	select UDELAY_TSC
 	select UNCOMPRESSED_RAMSTAGE
diff --git a/src/soc/intel/skylake/Kconfig b/src/soc/intel/skylake/Kconfig
index f9f6f9302b..d4720a21be 100644
--- a/src/soc/intel/skylake/Kconfig
+++ b/src/soc/intel/skylake/Kconfig
@@ -76,7 +76,6 @@ config CPU_SPECIFIC_OPTIONS
 	select SOC_INTEL_COMMON_RESET
 	select SSE2
 	select SUPPORT_CPU_UCODE_IN_CBFS
-	select TSC_CONSTANT_RATE
 	select TSC_MONOTONIC_TIMER
 	select TSC_SYNC_MFENCE
 	select UDELAY_TSC