Tegra: gpcdma: driver for general purpose DMA

This patch adds the driver for the general purpose DMA hardware
block on newer Tegra SoCs. The GPCDMA is a special purpose DMA
used to speed up memory copy operations to/from DRAM and TZSRAM.

This patch introduces a macro 'USE_GPC_DMA' to allow platforms
to override CPU based memory operations.

Change-Id: I3170d409c83b77e785437b1002a8d70188fabbeb
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

plat/nvidia/tegra/common/drivers/gpcdma/gpcdma.c

@@ -0,0 +1,188 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch_helpers.h>
+#include <common/debug.h>
+#include <delay_timer.h>
+#include <errno.h>
+#include <gpcdma.h>
+#include <mmio.h>
+#include <platform_def.h>
+#include <stdbool.h>
+#include <tegra_def.h>
+#include <utils_def.h>
+
+/* DMA channel registers */
+#define DMA_CH_CSR				U(0x0)
+#define DMA_CH_CSR_WEIGHT_SHIFT			U(10)
+#define DMA_CH_CSR_XFER_MODE_SHIFT		U(21)
+#define DMA_CH_CSR_DMA_MODE_MEM2MEM		U(4)
+#define DMA_CH_CSR_DMA_MODE_FIXEDPATTERN	U(6)
+#define DMA_CH_CSR_IRQ_MASK_ENABLE		(U(1) << 15)
+#define DMA_CH_CSR_RUN_ONCE			(U(1) << 27)
+#define DMA_CH_CSR_ENABLE			(U(1) << 31)
+
+#define DMA_CH_STAT				U(0x4)
+#define DMA_CH_STAT_BUSY			(U(1) << 31)
+
+#define DMA_CH_SRC_PTR				U(0xC)
+
+#define DMA_CH_DST_PTR				U(0x10)
+
+#define DMA_CH_HI_ADR_PTR			U(0x14)
+#define DMA_CH_HI_ADR_PTR_SRC_MASK		U(0xFF)
+#define DMA_CH_HI_ADR_PTR_DST_SHIFT		U(16)
+#define DMA_CH_HI_ADR_PTR_DST_MASK		U(0xFF)
+
+#define DMA_CH_MC_SEQ				U(0x18)
+#define DMA_CH_MC_SEQ_REQ_CNT_SHIFT		U(25)
+#define DMA_CH_MC_SEQ_REQ_CNT_VAL		U(0x10)
+#define DMA_CH_MC_SEQ_BURST_SHIFT		U(23)
+#define DMA_CH_MC_SEQ_BURST_16_WORDS		U(0x3)
+
+#define DMA_CH_WORD_COUNT			U(0x20)
+#define DMA_CH_FIXED_PATTERN			U(0x34)
+#define DMA_CH_TZ				U(0x38)
+#define DMA_CH_TZ_ACCESS_ENABLE			U(0)
+#define DMA_CH_TZ_ACCESS_DISABLE		U(3)
+
+#define MAX_TRANSFER_SIZE			(1U*1024U*1024U*1024U)	/* 1GB */
+#define GPCDMA_TIMEOUT_MS			U(100)
+#define GPCDMA_RESET_BIT			(U(1) << 1)
+
+static bool init_done;
+
+static void tegra_gpcdma_write32(uint32_t offset, uint32_t val)
+{
+	mmio_write_32(TEGRA_GPCDMA_BASE + offset, val);
+}
+
+static uint32_t tegra_gpcdma_read32(uint32_t offset)
+{
+	return mmio_read_32(TEGRA_GPCDMA_BASE + offset);
+}
+
+static void tegra_gpcdma_init(void)
+{
+	/* assert reset for DMA engine */
+	mmio_write_32(TEGRA_CAR_RESET_BASE + TEGRA_GPCDMA_RST_SET_REG_OFFSET,
+		      GPCDMA_RESET_BIT);
+
+	udelay(2);
+
+	/* de-assert reset for DMA engine */
+	mmio_write_32(TEGRA_CAR_RESET_BASE + TEGRA_GPCDMA_RST_CLR_REG_OFFSET,
+		      GPCDMA_RESET_BIT);
+}
+
+static void tegra_gpcdma_memcpy_priv(uint64_t dst_addr, uint64_t src_addr,
+				     uint32_t num_bytes, uint32_t mode)
+{
+	uint32_t val, timeout = 0;
+	int32_t ret = 0;
+
+	/* sanity check byte count */
+	if ((num_bytes > MAX_TRANSFER_SIZE) || ((num_bytes & 0x3U) != U(0))) {
+		ret = -EINVAL;
+	}
+
+	/* initialise GPCDMA block */
+	if (!init_done) {
+		tegra_gpcdma_init();
+		init_done = true;
+	}
+
+	/* make sure channel isn't busy */
+	val = tegra_gpcdma_read32(DMA_CH_STAT);
+	if ((val & DMA_CH_STAT_BUSY) == DMA_CH_STAT_BUSY) {
+		ERROR("DMA channel is busy\n");
+		ret = -EBUSY;
+	}
+
+	if (ret == 0) {
+
+		/* disable any DMA transfers */
+		tegra_gpcdma_write32(DMA_CH_CSR, 0);
+
+		/* enable DMA access to TZDRAM */
+		tegra_gpcdma_write32(DMA_CH_TZ, DMA_CH_TZ_ACCESS_ENABLE);
+
+		/* configure MC sequencer */
+		val = (DMA_CH_MC_SEQ_REQ_CNT_VAL << DMA_CH_MC_SEQ_REQ_CNT_SHIFT) |
+		      (DMA_CH_MC_SEQ_BURST_16_WORDS << DMA_CH_MC_SEQ_BURST_SHIFT);
+		tegra_gpcdma_write32(DMA_CH_MC_SEQ, val);
+
+		/* reset fixed pattern */
+		tegra_gpcdma_write32(DMA_CH_FIXED_PATTERN, 0);
+
+		/* populate src and dst address registers */
+		tegra_gpcdma_write32(DMA_CH_SRC_PTR, (uint32_t)src_addr);
+		tegra_gpcdma_write32(DMA_CH_DST_PTR, (uint32_t)dst_addr);
+
+		val = (uint32_t)((src_addr >> 32) & DMA_CH_HI_ADR_PTR_SRC_MASK);
+		val |= (uint32_t)(((dst_addr >> 32) & DMA_CH_HI_ADR_PTR_DST_MASK) <<
+			DMA_CH_HI_ADR_PTR_DST_SHIFT);
+		tegra_gpcdma_write32(DMA_CH_HI_ADR_PTR, val);
+
+		/* transfer size (in words) */
+		tegra_gpcdma_write32(DMA_CH_WORD_COUNT, ((num_bytes >> 2) - 1U));
+
+		/* populate value for CSR */
+		val = (mode << DMA_CH_CSR_XFER_MODE_SHIFT) |
+		      DMA_CH_CSR_RUN_ONCE | (U(1) << DMA_CH_CSR_WEIGHT_SHIFT) |
+		      DMA_CH_CSR_IRQ_MASK_ENABLE;
+		tegra_gpcdma_write32(DMA_CH_CSR, val);
+
+		/* enable transfer */
+		val = tegra_gpcdma_read32(DMA_CH_CSR);
+		val |= DMA_CH_CSR_ENABLE;
+		tegra_gpcdma_write32(DMA_CH_CSR, val);
+
+		/* wait till transfer completes */
+		do {
+
+			/* read the status */
+			val = tegra_gpcdma_read32(DMA_CH_STAT);
+			if ((val & DMA_CH_STAT_BUSY) != DMA_CH_STAT_BUSY) {
+				break;
+			}
+
+			mdelay(1);
+			timeout++;
+
+		} while (timeout < GPCDMA_TIMEOUT_MS);
+
+		/* flag timeout error */
+		if (timeout == GPCDMA_TIMEOUT_MS) {
+			ERROR("DMA transfer timed out\n");
+		}
+
+		dsbsy();
+
+		/* disable DMA access to TZDRAM */
+		tegra_gpcdma_write32(DMA_CH_TZ, DMA_CH_TZ_ACCESS_DISABLE);
+		isb();
+	}
+}
+
+/*******************************************************************************
+ * Memcpy using GPCDMA block (Mem2Mem copy)
+ ******************************************************************************/
+void tegra_gpcdma_memcpy(uint64_t dst_addr, uint64_t src_addr,
+			 uint32_t num_bytes)
+{
+	tegra_gpcdma_memcpy_priv(dst_addr, src_addr, num_bytes,
+				 DMA_CH_CSR_DMA_MODE_MEM2MEM);
+}
+
+/*******************************************************************************
+ * Memset using GPCDMA block (Fixed pattern write)
+ ******************************************************************************/
+void tegra_gpcdma_zeromem(uint64_t dst_addr, uint32_t num_bytes)
+{
+	tegra_gpcdma_memcpy_priv(dst_addr, 0, num_bytes,
+				 DMA_CH_CSR_DMA_MODE_FIXEDPATTERN);
+}

plat/nvidia/tegra/include/drivers/gpcdma.h

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __GPCDMA_H__
+#define __GPCDMA_H__
+
+#include <stdint.h>
+
+void tegra_gpcdma_memcpy(uint64_t dst_addr, uint64_t src_addr,
+			    uint32_t num_bytes);
+void tegra_gpcdma_zeromem(uint64_t dst_addr, uint32_t num_bytes);
+
+#endif /* __GPCDMA_H__ */

plat/nvidia/tegra/include/t186/tegra_def.h

@@ -115,6 +115,11 @@
 #define TSA_CONFIG_CSW_MEMTYPE_OVERRIDE_MASK		(U(0x3) << 11)
 #define TSA_CONFIG_CSW_MEMTYPE_OVERRIDE_PASTHRU		(U(0) << 11)
 
+/*******************************************************************************
+ * Tegra General Purpose Centralised DMA constants
+ ******************************************************************************/
+#define TEGRA_GPCDMA_BASE		U(0x2610000)
+
 /*******************************************************************************
  * Tegra Memory Controller constants
  ******************************************************************************/
@@ -198,6 +203,8 @@
 #define TEGRA_CAR_RESET_BASE		U(0x05000000)
 #define TEGRA_GPU_RESET_REG_OFFSET	U(0x30)
 #define  GPU_RESET_BIT			(U(1) << 0)
+#define TEGRA_GPCDMA_RST_SET_REG_OFFSET	U(0x6A0004)
+#define TEGRA_GPCDMA_RST_CLR_REG_OFFSET	U(0x6A0008)
 
 /*******************************************************************************
  * Tegra micro-seconds timer constants

plat/nvidia/tegra/soc/t186/platform_t186.mk

@@ -50,6 +50,7 @@ PLAT_INCLUDES		+=	-I${SOC_DIR}/drivers/include
 
 BL31_SOURCES		+=	lib/cpus/aarch64/denver.S		\
 				lib/cpus/aarch64/cortex_a57.S		\
+				${COMMON_DIR}/drivers/gpcdma/gpcdma.c	\
 				${COMMON_DIR}/drivers/memctrl/memctrl_v2.c \
 				${COMMON_DIR}/drivers/smmu/smmu.c	\
 				${SOC_DIR}/drivers/mce/mce.c		\