ARM: 7080/1: l2x0: make sure I&D are not locked down on init
Linus Walleij [Tue, 6 Sep 2011 06:45:46 +0000 (07:45 +0100)]
Fighting unfixed U-Boots and other beasts that may the cache in
a locked-down state when starting the kernel, we make sure to
disable all cache lock-down when initializing the l2x0 so we
are in a known state.

Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Rabin Vincent <rabin.vincent@stericsson.com>
Cc: Adrian Bunk <adrian.bunk@movial.com>
Cc: Rob Herring <robherring2@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reported-by: Jan Rinze <janrinze@gmail.com>
Tested-by: Robert Marklund <robert.marklund@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/hardware/cache-l2x0.h
arch/arm/mm/cache-l2x0.c

index bfa706f..99a6ed7 100644 (file)
 #define L2X0_CLEAN_INV_LINE_PA         0x7F0
 #define L2X0_CLEAN_INV_LINE_IDX                0x7F8
 #define L2X0_CLEAN_INV_WAY             0x7FC
-#define L2X0_LOCKDOWN_WAY_D            0x900
-#define L2X0_LOCKDOWN_WAY_I            0x904
+/*
+ * The lockdown registers repeat 8 times for L310, the L210 has only one
+ * D and one I lockdown register at 0x0900 and 0x0904.
+ */
+#define L2X0_LOCKDOWN_WAY_D_BASE       0x900
+#define L2X0_LOCKDOWN_WAY_I_BASE       0x904
+#define L2X0_LOCKDOWN_STRIDE           0x08
 #define L2X0_TEST_OPERATION            0xF00
 #define L2X0_LINE_DATA                 0xF10
 #define L2X0_LINE_TAG                  0xF30
index 44c0867..9ecfdb5 100644 (file)
@@ -277,6 +277,25 @@ static void l2x0_disable(void)
        spin_unlock_irqrestore(&l2x0_lock, flags);
 }
 
+static void __init l2x0_unlock(__u32 cache_id)
+{
+       int lockregs;
+       int i;
+
+       if (cache_id == L2X0_CACHE_ID_PART_L310)
+               lockregs = 8;
+       else
+               /* L210 and unknown types */
+               lockregs = 1;
+
+       for (i = 0; i < lockregs; i++) {
+               writel_relaxed(0x0, l2x0_base + L2X0_LOCKDOWN_WAY_D_BASE +
+                              i * L2X0_LOCKDOWN_STRIDE);
+               writel_relaxed(0x0, l2x0_base + L2X0_LOCKDOWN_WAY_I_BASE +
+                              i * L2X0_LOCKDOWN_STRIDE);
+       }
+}
+
 void __init l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask)
 {
        __u32 aux;
@@ -328,6 +347,8 @@ void __init l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask)
         * accessing the below registers will fault.
         */
        if (!(readl_relaxed(l2x0_base + L2X0_CTRL) & 1)) {
+               /* Make sure that I&D is not locked down when starting */
+               l2x0_unlock(cache_id);
 
                /* l2x0 controller is disabled */
                writel_relaxed(aux, l2x0_base + L2X0_AUX_CTRL);