commit 5f0a5507eb6c9ed3745b89a1246bb7a7b6141857
Author: Petter Lundanes <petter.lundanes@arm.com>
Date:   Mon Feb 9 14:37:06 2015 +0100

    Adds a service to enable/disable GPU cache snooping
    
    Adds a service to enable/disable cache snooping over
    CCI for GPU on request from SMC (mali kernel driver).

diff --git a/bl31/bl31.mk b/bl31/bl31.mk
index 4c25a60..cd0b530 100644
--- a/bl31/bl31.mk
+++ b/bl31/bl31.mk
@@ -50,7 +50,8 @@ BL31_SOURCES		+=	bl31/bl31_main.c				\
 				services/std_svc/psci/psci_helpers.S		\
 				services/std_svc/psci/psci_main.c		\
 				services/std_svc/psci/psci_setup.c		\
-				services/std_svc/psci/psci_system_off.c
+				services/std_svc/psci/psci_system_off.c \
+				services/sips/arm/css/svc.c
 
 ifeq (${USE_COHERENT_MEM}, 1)
 BL31_SOURCES		+=	lib/locks/bakery/bakery_lock_coherent.c
diff --git a/services/sips/arm/css/svc.c b/services/sips/arm/css/svc.c
new file mode 100644
index 0000000..bbc63a4
--- /dev/null
+++ b/services/sips/arm/css/svc.c
@@ -0,0 +1,88 @@
+#include <debug.h>
+#include <runtime_svc.h>
+#include <stdint.h>
+#include <cci400.h>
+#include <uuid.h>
+#include <mmio.h>
+
+
+/* This should be updated to the CCI port the GPU is connect to on your platform.*/
+#define GPU_CCI_PORT 3U
+
+/*
+ * See SMC calling convention for details.
+ * Bit 31 - 1 = Fast call.
+ * Bits 29:24 - 0x2 = SIP service call.
+ * Bits 15:00 - Function number.
+ *
+ * These must correspond to the IDs given in device tree for the device driver.
+ */
+#define SMC_FID_ENABLE_COHERENCY (0x8200ff04)
+#define SMC_FID_DISABLE_COHERENCY (0x8200ff05)
+
+/* Setup CSS Services */
+static int32_t css_svc_setup(void)
+{
+	return 0;
+}
+
+static void cci_enable_gpu_coherency(unsigned int cciport)
+{
+	/* Enable Snoops */
+	mmio_write_32(CCI400_BASE + SLAVE_IFACE_OFFSET(cciport) + SNOOP_CTRL_REG,
+		      (SNOOP_EN_BIT));
+
+	/* Wait for the dust to settle down */
+	while (mmio_read_32(CCI400_BASE + STATUS_REG) & CHANGE_PENDING_BIT)
+		;
+}
+static void cci_disable_gpu_coherency(unsigned int cciport)
+{
+	/* Disable Snoops */
+	mmio_write_32(CCI400_BASE + SLAVE_IFACE_OFFSET(cciport) + SNOOP_CTRL_REG,
+		      0U);
+
+	/* Wait for the dust to settle down */
+	while (mmio_read_32(CCI400_BASE + STATUS_REG) & CHANGE_PENDING_BIT)
+		;
+}
+
+/*
+ * Top-level CSS Service SMC handler.
+ */
+uint64_t css_svc_smc_handler(uint32_t smc_fid,
+			     uint64_t x1,
+			     uint64_t x2,
+			     uint64_t x3,
+			     uint64_t x4,
+			     void *cookie,
+			     void *handle,
+			     uint64_t flags)
+{
+	switch (smc_fid) {
+	case SMC_FID_ENABLE_COHERENCY:
+	{
+		cci_enable_gpu_coherency(GPU_CCI_PORT);
+		SMC_RET1(handle, 0x0);
+	}
+	case SMC_FID_DISABLE_COHERENCY:
+	{
+		cci_disable_gpu_coherency(GPU_CCI_PORT);
+		SMC_RET1(handle, 0x0);
+	}
+	default:
+		WARN("Unimplemented CSS Service Call: 0x%x \n", smc_fid);
+		SMC_RET1(handle, SMC_UNK);
+	}
+}
+
+/* Register as runtime service */
+DECLARE_RT_SVC(
+		css_svc,
+
+		OEN_SIP_START,
+		OEN_SIP_END,
+		SMC_TYPE_FAST,
+		css_svc_setup,
+		css_svc_smc_handler
+);