Subject: [PATCH v2 3/3] ARM: OMAP2+: AM43x: L2 cache support

From: [email-masked] (Sekhar Nori)
Date: Fri, 11 Apr 2014 11:03:57 +0530

On Thursday 10 April 2014 07:10 PM, Russell King - ARM Linux wrote:
> On Thu, Apr 10, 2014 at 06:57:05PM +0530, Sekhar Nori wrote:
>> On Thursday 10 April 2014 05:46 PM, Sekhar Nori wrote:
>>> This will work. NS_LOCKDOWN is required for L2C-220 as well and so I was
>>> thinking about adding a new l2c220_enable() which will set the
>>> NS_LOCKDOWN and then call l2c_enable()
>>
>> Here is a patch for what I was saying above.
>>
>> diff --git a/arch/arm/include/asm/hardware/cache-l2x0.h b/arch/arm/include/asm/hardware/cache-l2x0.h
>> index c47ac8f..dc9e03b 100644
>> --- a/arch/arm/include/asm/hardware/cache-l2x0.h
>> +++ b/arch/arm/include/asm/hardware/cache-l2x0.h
>> @@ -105,6 +105,8 @@
>>  #define L2X0_AUX_CTRL_DIRTY_LATENCY_MASK	(7 << 9)
>>  #define L2X0_AUX_CTRL_ASSOC_SHIFT		13
>>  #define L2X0_AUX_CTRL_ASSOC_MASK		(15 << 13)
>> +/* L2C-220/310 common bits */
>> +#define L2C_AUX_CTRL_NS_LOCKDOWN		BIT(26)
>>  /* L2C-210 specific bits */
>>  #define L210_AUX_CTRL_WRAP_DISABLE		BIT(12)
>>  #define L210_AUX_CTRL_WA_OVERRIDE		BIT(23)
>> @@ -113,7 +115,6 @@
>>  #define L220_AUX_CTRL_EXCLUSIVE_CACHE		BIT(12)
>>  #define L220_AUX_CTRL_FWA_SHIFT			23
>>  #define L220_AUX_CTRL_FWA_MASK			(3 << 23)
>> -#define L220_AUX_CTRL_NS_LOCKDOWN		BIT(26)
>>  #define L220_AUX_CTRL_NS_INT_CTRL		BIT(27)
>>  /* L2C-310 specific bits */
>>  #define L310_AUX_CTRL_FULL_LINE_ZERO		BIT(0)	/* R2P0+ */
>> @@ -122,7 +123,6 @@
>>  #define L310_AUX_CTRL_EXCLUSIVE_CACHE		BIT(12)
>>  #define L310_AUX_CTRL_ASSOCIATIVITY_16		BIT(16)
>>  #define L310_AUX_CTRL_CACHE_REPLACE_RR		BIT(25)	/* R2P0+ */
>> -#define L310_AUX_CTRL_NS_LOCKDOWN		BIT(26)
> 
> NAK.  The reason for this split is because the NS lockdown bit is *not*
> on L2C-210, and so it does not deserve to be a "common" bit - because it
> isn't common to all variants.

Okay.

> 
>> @@ -764,7 +776,7 @@ static void __init l2c310_enable(void __iomem *base, u32 aux, unsigned num_lock)
>>  			power_ctrl & L310_STNDBY_MODE_EN ? "en" : "dis");
>>  	}
>>  
>> -	l2c_enable(base, aux, num_lock);
>> +	l2c220_enable(base, aux, num_lock);
> 
> My first reaction to this is to say NAK again - I don't want to create
> a multi-layered maze of X calls Y calls Z.  Who's to say that The 220
> won't need to do something different from 310 in the future?

Here is a revised patch which is just an extension of your patch 
with L2C-220 case handled. I dont really have L2C-220 hardware so even 
if you want to handle that at a later time, it would be perfectly okay 
with me.

Thanks,
Sekhar

diff --git a/arch/arm/mach-omap2/omap4-common.c b/arch/arm/mach-omap2/omap4-common.c
index 6b2a056..34cafe0 100644
--- a/arch/arm/mach-omap2/omap4-common.c
+++ b/arch/arm/mach-omap2/omap4-common.c
@@ -216,8 +216,6 @@ int __init omap4_l2_cache_init(void)
 {
 	/* 16-way associativity, parity disabled, way size - 64KB (es2.0 +) */
 	u32 aux_ctrl = L310_AUX_CTRL_CACHE_REPLACE_RR |
-		       L310_AUX_CTRL_NS_LOCKDOWN |
-		       L310_AUX_CTRL_NS_INT_CTRL |
 		       L2C_AUX_CTRL_SHARED_OVERRIDE |
 		       L310_AUX_CTRL_DATA_PREFETCH |
 		       L310_AUX_CTRL_INSTR_PREFETCH;
diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index b1f103d..72f41fa 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -498,11 +498,23 @@ static void l2c220_sync(void)
 	raw_spin_unlock_irqrestore(&l2x0_lock, flags);
 }
 
+static void __init l2c220_enable(void __iomem *base, u32 aux, unsigned num_lock)
+{
+	/*
+	 * Always enable non-secure access to the lockdown registers -
+	 * we write to them as part of the L2C enable sequence so they
+	 * need to be accessible.
+	 */
+	aux |= L220_AUX_CTRL_NS_LOCKDOWN;
+
+	l2c_enable(base, aux, num_lock);
+}
+
 static const struct l2c_init_data l2c220_data = {
 	.type = "L2C-220",
 	.way_size_0 = SZ_8K,
 	.num_lock = 1,
-	.enable = l2c_enable,
+	.enable = l2c220_enable,
 	.outer_cache = {
 		.inv_range = l2c220_inv_range,
 		.clean_range = l2c220_clean_range,
@@ -764,6 +776,13 @@ static void __init l2c310_enable(void __iomem *base, u32 aux, unsigned num_lock)
 			power_ctrl & L310_STNDBY_MODE_EN ? "en" : "dis");
 	}
 
+	/*
+	 * Always enable non-secure access to the lockdown registers -
+	 * we write to them as part of the L2C enable sequence so they
+	 * need to be accessible.
+	 */
+	aux |= L310_AUX_CTRL_NS_LOCKDOWN;
+
 	l2c_enable(base, aux, num_lock);
 
 	if (aux & L310_AUX_CTRL_FULL_LINE_ZERO) {
@@ -1027,7 +1046,7 @@ static const struct l2c_init_data of_l2c220_data __initconst = {
 	.way_size_0 = SZ_8K,
 	.num_lock = 1,
 	.of_parse = l2x0_of_parse,
-	.enable = l2c_enable,
+	.enable = l2c220_enable,
 	.outer_cache = {
 		.inv_range   = l2c220_inv_range,
 		.clean_range = l2c220_clean_range,