Change in coreboot[master]: arch/x86: CAR setup CQOS

[Naresh Solanki (Code Review)]

Naresh Solanki has uploaded this change for review. ( https://review.coreboot.org/21701

Change subject: arch/x86: CAR setup CQOS
......................................................................

arch/x86: CAR setup CQOS

Enable CQOS on Geminilake.

In Appololake, CBM_LEN is 0x7. Whereas the same in Geminilake is 0xF.

Thus get CBM_LEN using cpuid instruction & generate CBM_LEN_MASK.

Later use the CBM_LEN_MASK when writing to IA32_L2_MASK_* to set right
bits.

BUG=None
TEST= Build for Geminilake platform i.e., glkrvp & check for successful
CAR setup. Even verified the same on APL platfrom i.e., on Reef

Change-Id: Ic736dba1a46629ff5bf3183082799c0c1468e6d9
Signed-off-by: Naresh G Solanki <[e-mail]
---
M src/soc/intel/common/block/cpu/car/cache_as_ram.S
1 file changed, 29 insertions(+), 3 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/01/21701/4

diff --git a/src/soc/intel/common/block/cpu/car/cache_as_ram.S b/src/soc/intel/common/block/cpu/car/cache_as_ram.S
index 94e2694..9475c8c 100644
--- a/src/soc/intel/common/block/cpu/car/cache_as_ram.S
+++ b/src/soc/intel/common/block/cpu/car/cache_as_ram.S
@@ -255,6 +255,25 @@
 .global car_cqos
 car_cqos:
    /*
+	 * Create CBM_LEN_MASK based on CBM_LEN
+	 * Get CPUID.(EAX=10H, ECX=2H):EAX.CBM_LEN[bits 4:0]
+	 */
+	mov $0x10, %eax
+	mov $0x2,  %ecx
+	cpuid
+	and $0xF, %eax
+	add $1, %al
+
+	mov $1, %ebx
+	xor %ecx, %ecx
+	mov %al, %cl
+	shl %cl, %ebx
+	sub $1, %ebx
+
+	/* Store the CBM_LEN_MASK in mm3 for later use. */
+	movd %ebx, %mm3
+
+	/*
     * Disable both L1 and L2 prefetcher. For yet-to-understood reason,
     * prefetchers slow down filling cache with rep stos in CQOS mode.
     */
@@ -284,7 +303,7 @@
    /* Set this mask for initial cache fill */
    mov	$MSR_L2_QOS_MASK(0), %ecx
    rdmsr
-	mov	%bl, %al
+	mov	%ebx, %eax
    wrmsr

/* Set CLOS selector to 0 */
@@ -297,8 +316,15 @@
    mov	$MSR_L2_QOS_MASK(1), %ecx
    rdmsr
    /* Invert bits that are to be used for cache */
-	mov	%bl, %al
-	xor	$~0, %al			/* invert 8 bits */
+	mov	%ebx, %eax
+	xor	$~0, %eax			/* invert 32 bits */
+
+	/*
+	 * Use CBM_LEN_MASK stored in mm3 to set bits based on Capacity Bit
+	 * Mask Length.
+	 */
+	movd	%mm3, %ebx
+	and	%ebx, %eax
    wrmsr

post_code(0x26)