x86: Add support for newer CAR schemes

Newer Intel SoCs have different ways of setting up cache-as-ram (CAR).
Add support for these along with suitable configuration options.

To make the code cleaner, adjust a few definitions in processor.h so that
they can be used from assembler.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/cpu/intel_common/car2_uninit.S b/arch/x86/cpu/intel_common/car2_uninit.S
new file mode 100644
index 0000000..aba3a53
--- /dev/null
+++ b/arch/x86/cpu/intel_common/car2_uninit.S
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2017 Intel Corp.
+ * Copyright 2019 Google LLC
+ * Taken from coreboot file exit_car.S
+ */
+
+#include <config.h>
+#include <asm/msr-index.h>
+#include <asm/mtrr.h>
+
+.text
+.global car_uninit
+car_uninit:
+
+	/*
+	 * Retrieve return address from stack as it will get trashed below if
+	 * execution is utilizing the cache-as-ram stack.
+	 */
+	pop	%ebx
+
+	/* Disable MTRRs */
+	mov	$(MTRR_DEF_TYPE_MSR), %ecx
+	rdmsr
+	and	$(~(MTRR_DEF_TYPE_EN | MTRR_DEF_TYPE_FIX_EN)), %eax
+	wrmsr
+
+#ifdef CONFIG_INTEL_CAR_NEM
+.global car_nem_teardown
+car_nem_teardown:
+
+	/* invalidate cache contents */
+	invd
+
+	/* Knock down bit 1 then bit 0 of NEM control not combining steps */
+	mov	$(MSR_EVICT_CTL), %ecx
+	rdmsr
+	and	$(~(1 << 1)), %eax
+	wrmsr
+	and	$(~(1 << 0)), %eax
+	wrmsr
+
+#elif IS_ENABLED(CONFIG_INTEL_CAR_CQOS)
+.global car_cqos_teardown
+car_cqos_teardown:
+
+	/* Go back to all-evicting mode, set both masks to all-1s */
+	mov	$MSR_L2_QOS_MASK(0), %ecx
+	rdmsr
+	mov	$~0, %al
+	wrmsr
+
+	mov	$MSR_L2_QOS_MASK(1), %ecx
+	rdmsr
+	mov	$~0, %al
+	wrmsr
+
+	/* Reset CLOS selector to 0 */
+	mov	$MSR_IA32_PQR_ASSOC, %ecx
+	rdmsr
+	and	$~MSR_IA32_PQR_ASSOC_MASK, %edx
+	wrmsr
+
+#elif IS_ENABLED(CONFIG_INTEL_CAR_NEM_ENHANCED)
+.global car_nem_enhanced_teardown
+car_nem_enhanced_teardown:
+
+	/* invalidate cache contents */
+	invd
+
+	/* Knock down bit 1 then bit 0 of NEM control not combining steps */
+	mov	$(MSR_EVICT_CTL), %ecx
+	rdmsr
+	and	$(~(1 << 1)), %eax
+	wrmsr
+	and	$(~(1 << 0)), %eax
+	wrmsr
+
+	/* Reset CLOS selector to 0 */
+	mov	$IA32_PQR_ASSOC, %ecx
+	rdmsr
+	and	$~IA32_PQR_ASSOC_MASK, %edx
+	wrmsr
+#endif
+
+	/* Return to caller */
+	jmp	*%ebx