cpu/x86/lapic: Add lapic_update32() helper

Change-Id: I57c5d85d3098f9d59f26f427fe16829e4e769194
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55187
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Wonkyu Kim <wonkyu.kim@intel.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/src/include/cpu/x86/lapic.h b/src/include/cpu/x86/lapic.h
index e19458f06c..cf048a883e 100644
--- a/src/include/cpu/x86/lapic.h
+++ b/src/include/cpu/x86/lapic.h
@@ -92,6 +92,25 @@ static __always_inline void lapic_write(unsigned int reg, uint32_t v)
 		xapic_write(reg, v);
 }
 
+static __always_inline void lapic_update32(unsigned int reg, uint32_t mask, uint32_t or)
+{
+	if (is_x2apic_mode()) {
+		uint32_t index;
+		msr_t msr;
+		index = X2APIC_MSR_BASE_ADDRESS + (uint32_t)(reg >> 4);
+		msr = rdmsr(index);
+		msr.lo &= mask;
+		msr.lo |= or;
+		wrmsr(index, msr);
+	} else {
+		uint32_t value;
+		value = xapic_read(reg);
+		value &= mask;
+		value |= or;
+		xapic_write_atomic(reg, value);
+	}
+}
+
 static __always_inline void lapic_wait_icr_idle(void)
 {
 	do { } while (lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY);