ARM: l2c: implement L2C-310 erratum 588369 as a method override

Implement L2C-310 erratum 588369 by overriding the invalidate range
and flush range methods in the outer_cache operations structure.
This allows us to sensibly contain the erratum code in one place
without affecting other locations/implemetations.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/cache-l2x0.c

@@ -522,6 +522,65 @@ static void l2c310_set_debug(unsigned long val)
 	writel_relaxed(val, l2x0_base + L2X0_DEBUG_CTRL);
 }
 
+static void l2c310_inv_range_erratum(unsigned long start, unsigned long end)
+{
+	void __iomem *base = l2x0_base;
+
+	if ((start | end) & (CACHE_LINE_SIZE - 1)) {
+		unsigned long flags;
+
+		/* Erratum 588369 for both clean+invalidate operations */
+		raw_spin_lock_irqsave(&l2x0_lock, flags);
+		l2c_set_debug(base, 0x03);
+
+		if (start & (CACHE_LINE_SIZE - 1)) {
+			start &= ~(CACHE_LINE_SIZE - 1);
+			writel_relaxed(start, base + L2X0_CLEAN_LINE_PA);
+			writel_relaxed(start, base + L2X0_INV_LINE_PA);
+			start += CACHE_LINE_SIZE;
+		}
+
+		if (end & (CACHE_LINE_SIZE - 1)) {
+			end &= ~(CACHE_LINE_SIZE - 1);
+			writel_relaxed(end, base + L2X0_CLEAN_LINE_PA);
+			writel_relaxed(end, base + L2X0_INV_LINE_PA);
+		}
+
+		l2c_set_debug(base, 0x00);
+		raw_spin_unlock_irqrestore(&l2x0_lock, flags);
+	}
+
+	__l2c210_op_pa_range(base + L2X0_INV_LINE_PA, start, end);
+	__l2c210_cache_sync(base);
+}
+
+static void l2c310_flush_range_erratum(unsigned long start, unsigned long end)
+{
+	raw_spinlock_t *lock = &l2x0_lock;
+	unsigned long flags;
+	void __iomem *base = l2x0_base;
+
+	raw_spin_lock_irqsave(lock, flags);
+	while (start < end) {
+		unsigned long blk_end = start + min(end - start, 4096UL);
+
+		l2c_set_debug(base, 0x03);
+		while (start < blk_end) {
+			writel_relaxed(start, base + L2X0_CLEAN_LINE_PA);
+			writel_relaxed(start, base + L2X0_INV_LINE_PA);
+			start += CACHE_LINE_SIZE;
+		}
+		l2c_set_debug(base, 0x00);
+
+		if (blk_end < end) {
+			raw_spin_unlock_irqrestore(lock, flags);
+			raw_spin_lock_irqsave(lock, flags);
+		}
+	}
+	raw_spin_unlock_irqrestore(lock, flags);
+	__l2c210_cache_sync(base);
+}
+
 static void l2c310_flush_all_erratum(void)
 {
 	void __iomem *base = l2x0_base;
@@ -600,9 +659,19 @@ static void __init l2c310_fixup(void __iomem *base, u32 cache_id,
 	const char *errata[4];
 	unsigned n = 0;
 
+	/* For compatibility */
 	if (revision <= L310_CACHE_ID_RTL_R3P0)
 		fns->set_debug = l2c310_set_debug;
 
+	if (IS_ENABLED(CONFIG_PL310_ERRATA_588369) &&
+	    revision < L310_CACHE_ID_RTL_R2P0 &&
+	    /* For bcm compatibility */
+	    fns->inv_range == l2x0_inv_range) {
+		fns->inv_range = l2c310_inv_range_erratum;
+		fns->flush_range = l2c310_flush_range_erratum;
+		errata[n++] = "588369";
+	}
+
 	if (IS_ENABLED(CONFIG_PL310_ERRATA_727915) &&
 	    revision >= L310_CACHE_ID_RTL_R2P0 &&
 	    revision < L310_CACHE_ID_RTL_R3P1) {