arch/arm/mach-mvebu/coherency.c - kernel/msm-4.9 - Gitiles

 /*
  * Coherency fabric (Aurora) support for Armada 370 and XP platforms.
  *
  * Copyright (C) 2012 Marvell
  *
  * Yehuda Yitschak <yehuday@marvell.com>
  * Gregory Clement <gregory.clement@free-electrons.com>
  * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  *
  * This file is licensed under the terms of the GNU General Public
  * License version 2.  This program is licensed "as is" without any
  * warranty of any kind, whether express or implied.
  *
  * The Armada 370 and Armada XP SOCs have a coherency fabric which is
  * responsible for ensuring hardware coherency between all CPUs and between
  * CPUs and I/O masters. This file initializes the coherency fabric and
  * supplies basic routines for configuring and controlling hardware coherency
  */

 #define pr_fmt(fmt) "mvebu-coherency: " fmt

 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/of_address.h>
 #include <linux/io.h>
 #include <linux/smp.h>
 #include <linux/dma-mapping.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/mbus.h>
 #include <linux/clk.h>
 #include <linux/pci.h>
 #include <asm/smp_plat.h>
 #include <asm/cacheflush.h>
 #include <asm/mach/map.h>
 #include "armada-370-xp.h"
 #include "coherency.h"
 #include "mvebu-soc-id.h"

 unsigned long coherency_phys_base;
 void __iomem *coherency_base;
 static void __iomem *coherency_cpu_base;

 /* Coherency fabric registers */
 #define COHERENCY_FABRIC_CFG_OFFSET		   0x4

 #define IO_SYNC_BARRIER_CTL_OFFSET		   0x0

 enum {
 	COHERENCY_FABRIC_TYPE_NONE,
 	COHERENCY_FABRIC_TYPE_ARMADA_370_XP,
 	COHERENCY_FABRIC_TYPE_ARMADA_375,
 	COHERENCY_FABRIC_TYPE_ARMADA_380,
 };

 static struct of_device_id of_coherency_table[] = {
 	{.compatible = "marvell,coherency-fabric",
 	 .data = (void *) COHERENCY_FABRIC_TYPE_ARMADA_370_XP },
 	{.compatible = "marvell,armada-375-coherency-fabric",
 	 .data = (void *) COHERENCY_FABRIC_TYPE_ARMADA_375 },
 	{.compatible = "marvell,armada-380-coherency-fabric",
 	 .data = (void *) COHERENCY_FABRIC_TYPE_ARMADA_380 },
 	{ /* end of list */ },
 };

 /* Functions defined in coherency_ll.S */
 int ll_enable_coherency(void);
 void ll_add_cpu_to_smp_group(void);

 int set_cpu_coherent(void)
 {
 	if (!coherency_base) {
 		pr_warn("Can't make current CPU cache coherent.\n");
 		pr_warn("Coherency fabric is not initialized\n");
 		return 1;
 	}

 	ll_add_cpu_to_smp_group();
 	return ll_enable_coherency();
 }

 /*
  * The below code implements the I/O coherency workaround on Armada
  * 375. This workaround consists in using the two channels of the
  * first XOR engine to trigger a XOR transaction that serves as the
  * I/O coherency barrier.
  */

 static void __iomem *xor_base, *xor_high_base;
 static dma_addr_t coherency_wa_buf_phys[CONFIG_NR_CPUS];
 static void *coherency_wa_buf[CONFIG_NR_CPUS];
 static bool coherency_wa_enabled;

 #define XOR_CONFIG(chan)            (0x10 + (chan * 4))
 #define XOR_ACTIVATION(chan)        (0x20 + (chan * 4))
 #define WINDOW_BAR_ENABLE(chan)     (0x240 + ((chan) << 2))
 #define WINDOW_BASE(w)              (0x250 + ((w) << 2))
 #define WINDOW_SIZE(w)              (0x270 + ((w) << 2))
 #define WINDOW_REMAP_HIGH(w)        (0x290 + ((w) << 2))
 #define WINDOW_OVERRIDE_CTRL(chan)  (0x2A0 + ((chan) << 2))
 #define XOR_DEST_POINTER(chan)      (0x2B0 + (chan * 4))
 #define XOR_BLOCK_SIZE(chan)        (0x2C0 + (chan * 4))
 #define XOR_INIT_VALUE_LOW           0x2E0
 #define XOR_INIT_VALUE_HIGH          0x2E4

 static inline void mvebu_hwcc_armada375_sync_io_barrier_wa(void)
 {
 	int idx = smp_processor_id();

 	/* Write '1' to the first word of the buffer */
 	writel(0x1, coherency_wa_buf[idx]);

 	/* Wait until the engine is idle */
 	while ((readl(xor_base + XOR_ACTIVATION(idx)) >> 4) & 0x3)
 		;

 	dmb();

 	/* Trigger channel */
 	writel(0x1, xor_base + XOR_ACTIVATION(idx));

 	/* Poll the data until it is cleared by the XOR transaction */
 	while (readl(coherency_wa_buf[idx]))
 		;
 }

 static void __init armada_375_coherency_init_wa(void)
 {
 	const struct mbus_dram_target_info *dram;
 	struct device_node *xor_node;
 	struct property *xor_status;
 	struct clk *xor_clk;
 	u32 win_enable = 0;
 	int i;

 	pr_warn("enabling coherency workaround for Armada 375 Z1, one XOR engine disabled\n");

 	/*
 	 * Since the workaround uses one XOR engine, we grab a
 	 * reference to its Device Tree node first.
 	 */
 	xor_node = of_find_compatible_node(NULL, NULL, "marvell,orion-xor");
 	BUG_ON(!xor_node);

 	/*
 	 * Then we mark it as disabled so that the real XOR driver
 	 * will not use it.
 	 */
 	xor_status = kzalloc(sizeof(struct property), GFP_KERNEL);
 	BUG_ON(!xor_status);

 	xor_status->value = kstrdup("disabled", GFP_KERNEL);
 	BUG_ON(!xor_status->value);

 	xor_status->length = 8;
 	xor_status->name = kstrdup("status", GFP_KERNEL);
 	BUG_ON(!xor_status->name);

 	of_update_property(xor_node, xor_status);

 	/*
 	 * And we remap the registers, get the clock, and do the
 	 * initial configuration of the XOR engine.
 	 */
 	xor_base = of_iomap(xor_node, 0);
 	xor_high_base = of_iomap(xor_node, 1);

 	xor_clk = of_clk_get_by_name(xor_node, NULL);
 	BUG_ON(!xor_clk);

 	clk_prepare_enable(xor_clk);

 	dram = mv_mbus_dram_info();

 	for (i = 0; i < 8; i++) {
 		writel(0, xor_base + WINDOW_BASE(i));
 		writel(0, xor_base + WINDOW_SIZE(i));
 		if (i < 4)
 			writel(0, xor_base + WINDOW_REMAP_HIGH(i));
 	}

 	for (i = 0; i < dram->num_cs; i++) {
 		const struct mbus_dram_window *cs = dram->cs + i;
 		writel((cs->base & 0xffff0000) |
 		       (cs->mbus_attr << 8) |
 		       dram->mbus_dram_target_id, xor_base + WINDOW_BASE(i));
 		writel((cs->size - 1) & 0xffff0000, xor_base + WINDOW_SIZE(i));

 		win_enable |= (1 << i);
 		win_enable |= 3 << (16 + (2 * i));
 	}

 	writel(win_enable, xor_base + WINDOW_BAR_ENABLE(0));
 	writel(win_enable, xor_base + WINDOW_BAR_ENABLE(1));
 	writel(0, xor_base + WINDOW_OVERRIDE_CTRL(0));
 	writel(0, xor_base + WINDOW_OVERRIDE_CTRL(1));

 	for (i = 0; i < CONFIG_NR_CPUS; i++) {
 		coherency_wa_buf[i] = kzalloc(PAGE_SIZE, GFP_KERNEL);
 		BUG_ON(!coherency_wa_buf[i]);

 		/*
 		 * We can't use the DMA mapping API, since we don't
 		 * have a valid 'struct device' pointer
 		 */
 		coherency_wa_buf_phys[i] =
 			virt_to_phys(coherency_wa_buf[i]);
 		BUG_ON(!coherency_wa_buf_phys[i]);

 		/*
 		 * Configure the XOR engine for memset operation, with
 		 * a 128 bytes block size
 		 */
 		writel(0x444, xor_base + XOR_CONFIG(i));
 		writel(128, xor_base + XOR_BLOCK_SIZE(i));
 		writel(coherency_wa_buf_phys[i],
 		       xor_base + XOR_DEST_POINTER(i));
 	}

 	writel(0x0, xor_base + XOR_INIT_VALUE_LOW);
 	writel(0x0, xor_base + XOR_INIT_VALUE_HIGH);

 	coherency_wa_enabled = true;
 }

 static inline void mvebu_hwcc_sync_io_barrier(void)
 {
 	if (coherency_wa_enabled) {
 		mvebu_hwcc_armada375_sync_io_barrier_wa();
 		return;
 	}

 	writel(0x1, coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET);
 	while (readl(coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET) & 0x1);
 }

 static dma_addr_t mvebu_hwcc_dma_map_page(struct device *dev, struct page *page,
 				  unsigned long offset, size_t size,
 				  enum dma_data_direction dir,
 				  struct dma_attrs *attrs)
 {
 	if (dir != DMA_TO_DEVICE)
 		mvebu_hwcc_sync_io_barrier();
 	return pfn_to_dma(dev, page_to_pfn(page)) + offset;
 }


 static void mvebu_hwcc_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
 			      size_t size, enum dma_data_direction dir,
 			      struct dma_attrs *attrs)
 {
 	if (dir != DMA_TO_DEVICE)
 		mvebu_hwcc_sync_io_barrier();
 }

 static void mvebu_hwcc_dma_sync(struct device *dev, dma_addr_t dma_handle,
 			size_t size, enum dma_data_direction dir)
 {
 	if (dir != DMA_TO_DEVICE)
 		mvebu_hwcc_sync_io_barrier();
 }

 static struct dma_map_ops mvebu_hwcc_dma_ops = {
 	.alloc			= arm_dma_alloc,
 	.free			= arm_dma_free,
 	.mmap			= arm_dma_mmap,
 	.map_page		= mvebu_hwcc_dma_map_page,
 	.unmap_page		= mvebu_hwcc_dma_unmap_page,
 	.get_sgtable		= arm_dma_get_sgtable,
 	.map_sg			= arm_dma_map_sg,
 	.unmap_sg		= arm_dma_unmap_sg,
 	.sync_single_for_cpu	= mvebu_hwcc_dma_sync,
 	.sync_single_for_device	= mvebu_hwcc_dma_sync,
 	.sync_sg_for_cpu	= arm_dma_sync_sg_for_cpu,
 	.sync_sg_for_device	= arm_dma_sync_sg_for_device,
 	.set_dma_mask		= arm_dma_set_mask,
 };

 static int mvebu_hwcc_notifier(struct notifier_block *nb,
 			       unsigned long event, void *__dev)
 {
 	struct device *dev = __dev;

 	if (event != BUS_NOTIFY_ADD_DEVICE)
 		return NOTIFY_DONE;
 	set_dma_ops(dev, &mvebu_hwcc_dma_ops);

 	return NOTIFY_OK;
 }

 static struct notifier_block mvebu_hwcc_nb = {
 	.notifier_call = mvebu_hwcc_notifier,
 };

 static struct notifier_block mvebu_hwcc_pci_nb = {
 	.notifier_call = mvebu_hwcc_notifier,
 };

 static void __init armada_370_coherency_init(struct device_node *np)
 {
 	struct resource res;

 	of_address_to_resource(np, 0, &res);
 	coherency_phys_base = res.start;
 	/*
 	 * Ensure secondary CPUs will see the updated value,
 	 * which they read before they join the coherency
 	 * fabric, and therefore before they are coherent with
 	 * the boot CPU cache.
 	 */
 	sync_cache_w(&coherency_phys_base);
 	coherency_base = of_iomap(np, 0);
 	coherency_cpu_base = of_iomap(np, 1);
 	set_cpu_coherent();
 }

 /*
  * This ioremap hook is used on Armada 375/38x to ensure that PCIe
  * memory areas are mapped as MT_UNCACHED instead of MT_DEVICE. This
  * is needed as a workaround for a deadlock issue between the PCIe
  * interface and the cache controller.
  */
 static void __iomem *
 armada_pcie_wa_ioremap_caller(phys_addr_t phys_addr, size_t size,
 			      unsigned int mtype, void *caller)
 {
 	struct resource pcie_mem;

 	mvebu_mbus_get_pcie_mem_aperture(&pcie_mem);

 	if (pcie_mem.start <= phys_addr && (phys_addr + size) <= pcie_mem.end)
 		mtype = MT_UNCACHED;

 	return __arm_ioremap_caller(phys_addr, size, mtype, caller);
 }

 static void __init armada_375_380_coherency_init(struct device_node *np)
 {
 	struct device_node *cache_dn;

 	coherency_cpu_base = of_iomap(np, 0);
 	arch_ioremap_caller = armada_pcie_wa_ioremap_caller;

 	/*
 	 * Add the PL310 property "arm,io-coherent". This makes sure the
 	 * outer sync operation is not used, which allows to
 	 * workaround the system erratum that causes deadlocks when
 	 * doing PCIe in an SMP situation on Armada 375 and Armada
 	 * 38x.
 	 */
 	for_each_compatible_node(cache_dn, NULL, "arm,pl310-cache") {
 		struct property *p;

 		p = kzalloc(sizeof(*p), GFP_KERNEL);
 		p->name = kstrdup("arm,io-coherent", GFP_KERNEL);
 		of_add_property(cache_dn, p);
 	}
 }

 static int coherency_type(void)
 {
 	struct device_node *np;
 	const struct of_device_id *match;

 	np = of_find_matching_node_and_match(NULL, of_coherency_table, &match);
 	if (np) {
 		int type = (int) match->data;

 		/* Armada 370/XP coherency works in both UP and SMP */
 		if (type == COHERENCY_FABRIC_TYPE_ARMADA_370_XP)
 			return type;

 		/* Armada 375 coherency works only on SMP */
 		else if (type == COHERENCY_FABRIC_TYPE_ARMADA_375 && is_smp())
 			return type;

 		/* Armada 380 coherency works only on SMP */
 		else if (type == COHERENCY_FABRIC_TYPE_ARMADA_380 && is_smp())
 			return type;
 	}

 	return COHERENCY_FABRIC_TYPE_NONE;
 }

 int coherency_available(void)
 {
 	return coherency_type() != COHERENCY_FABRIC_TYPE_NONE;
 }

 int __init coherency_init(void)
 {
 	int type = coherency_type();
 	struct device_node *np;

 	np = of_find_matching_node(NULL, of_coherency_table);

 	if (type == COHERENCY_FABRIC_TYPE_ARMADA_370_XP)
 		armada_370_coherency_init(np);
 	else if (type == COHERENCY_FABRIC_TYPE_ARMADA_375 ||
 		 type == COHERENCY_FABRIC_TYPE_ARMADA_380)
 		armada_375_380_coherency_init(np);

 	return 0;
 }

 static int __init coherency_late_init(void)
 {
 	int type = coherency_type();

 	if (type == COHERENCY_FABRIC_TYPE_NONE)
 		return 0;

 	if (type == COHERENCY_FABRIC_TYPE_ARMADA_375) {
 		u32 dev, rev;

 		if (mvebu_get_soc_id(&dev, &rev) == 0 &&
 		    rev == ARMADA_375_Z1_REV)
 			armada_375_coherency_init_wa();
 	}

 	bus_register_notifier(&platform_bus_type,
 			      &mvebu_hwcc_nb);

 	return 0;
 }

 postcore_initcall(coherency_late_init);

 #if IS_ENABLED(CONFIG_PCI)
 static int __init coherency_pci_init(void)
 {
 	if (coherency_available())
 		bus_register_notifier(&pci_bus_type,
 				       &mvebu_hwcc_pci_nb);
 	return 0;
 }

 arch_initcall(coherency_pci_init);
 #endif
	/*
	* Coherency fabric (Aurora) support for Armada 370 and XP platforms.
	*
	* Copyright (C) 2012 Marvell
	*
	* Yehuda Yitschak <yehuday@marvell.com>
	* Gregory Clement <gregory.clement@free-electrons.com>
	* Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
	*
	* This file is licensed under the terms of the GNU General Public
	* License version 2. This program is licensed "as is" without any
	* warranty of any kind, whether express or implied.
	*
	* The Armada 370 and Armada XP SOCs have a coherency fabric which is
	* responsible for ensuring hardware coherency between all CPUs and between
	* CPUs and I/O masters. This file initializes the coherency fabric and
	* supplies basic routines for configuring and controlling hardware coherency
	*/

	#define pr_fmt(fmt) "mvebu-coherency: " fmt

	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/of_address.h>
	#include <linux/io.h>
	#include <linux/smp.h>
	#include <linux/dma-mapping.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/mbus.h>
	#include <linux/clk.h>
	#include <linux/pci.h>
	#include <asm/smp_plat.h>
	#include <asm/cacheflush.h>
	#include <asm/mach/map.h>
	#include "armada-370-xp.h"
	#include "coherency.h"
	#include "mvebu-soc-id.h"

	unsigned long coherency_phys_base;
	void __iomem *coherency_base;
	static void __iomem *coherency_cpu_base;

	/* Coherency fabric registers */
	#define COHERENCY_FABRIC_CFG_OFFSET 0x4

	#define IO_SYNC_BARRIER_CTL_OFFSET 0x0

	enum {
	COHERENCY_FABRIC_TYPE_NONE,
	COHERENCY_FABRIC_TYPE_ARMADA_370_XP,
	COHERENCY_FABRIC_TYPE_ARMADA_375,
	COHERENCY_FABRIC_TYPE_ARMADA_380,
	};

	static struct of_device_id of_coherency_table[] = {
	{.compatible = "marvell,coherency-fabric",
	.data = (void *) COHERENCY_FABRIC_TYPE_ARMADA_370_XP },
	{.compatible = "marvell,armada-375-coherency-fabric",
	.data = (void *) COHERENCY_FABRIC_TYPE_ARMADA_375 },
	{.compatible = "marvell,armada-380-coherency-fabric",
	.data = (void *) COHERENCY_FABRIC_TYPE_ARMADA_380 },
	{ /* end of list */ },
	};

	/* Functions defined in coherency_ll.S */
	int ll_enable_coherency(void);
	void ll_add_cpu_to_smp_group(void);

	int set_cpu_coherent(void)
	{
	if (!coherency_base) {
	pr_warn("Can't make current CPU cache coherent.\n");
	pr_warn("Coherency fabric is not initialized\n");
	return 1;
	}

	ll_add_cpu_to_smp_group();
	return ll_enable_coherency();
	}

	/*
	* The below code implements the I/O coherency workaround on Armada
	* 375. This workaround consists in using the two channels of the
	* first XOR engine to trigger a XOR transaction that serves as the
	* I/O coherency barrier.
	*/

	static void __iomem xor_base, xor_high_base;
	static dma_addr_t coherency_wa_buf_phys[CONFIG_NR_CPUS];
	static void *coherency_wa_buf[CONFIG_NR_CPUS];
	static bool coherency_wa_enabled;

	#define XOR_CONFIG(chan) (0x10 + (chan * 4))
	#define XOR_ACTIVATION(chan) (0x20 + (chan * 4))
	#define WINDOW_BAR_ENABLE(chan) (0x240 + ((chan) << 2))
	#define WINDOW_BASE(w) (0x250 + ((w) << 2))
	#define WINDOW_SIZE(w) (0x270 + ((w) << 2))
	#define WINDOW_REMAP_HIGH(w) (0x290 + ((w) << 2))
	#define WINDOW_OVERRIDE_CTRL(chan) (0x2A0 + ((chan) << 2))
	#define XOR_DEST_POINTER(chan) (0x2B0 + (chan * 4))
	#define XOR_BLOCK_SIZE(chan) (0x2C0 + (chan * 4))
	#define XOR_INIT_VALUE_LOW 0x2E0
	#define XOR_INIT_VALUE_HIGH 0x2E4

	static inline void mvebu_hwcc_armada375_sync_io_barrier_wa(void)
	{
	int idx = smp_processor_id();

	/* Write '1' to the first word of the buffer */
	writel(0x1, coherency_wa_buf[idx]);

	/* Wait until the engine is idle */
	while ((readl(xor_base + XOR_ACTIVATION(idx)) >> 4) & 0x3)
	;

	dmb();

	/* Trigger channel */
	writel(0x1, xor_base + XOR_ACTIVATION(idx));

	/* Poll the data until it is cleared by the XOR transaction */
	while (readl(coherency_wa_buf[idx]))
	;
	}

	static void __init armada_375_coherency_init_wa(void)
	{
	const struct mbus_dram_target_info *dram;
	struct device_node *xor_node;
	struct property *xor_status;
	struct clk *xor_clk;
	u32 win_enable = 0;
	int i;

	pr_warn("enabling coherency workaround for Armada 375 Z1, one XOR engine disabled\n");

	/*
	* Since the workaround uses one XOR engine, we grab a
	* reference to its Device Tree node first.
	*/
	xor_node = of_find_compatible_node(NULL, NULL, "marvell,orion-xor");
	BUG_ON(!xor_node);

	/*
	* Then we mark it as disabled so that the real XOR driver
	* will not use it.
	*/
	xor_status = kzalloc(sizeof(struct property), GFP_KERNEL);
	BUG_ON(!xor_status);

	xor_status->value = kstrdup("disabled", GFP_KERNEL);
	BUG_ON(!xor_status->value);

	xor_status->length = 8;
	xor_status->name = kstrdup("status", GFP_KERNEL);
	BUG_ON(!xor_status->name);

	of_update_property(xor_node, xor_status);

	/*
	* And we remap the registers, get the clock, and do the
	* initial configuration of the XOR engine.
	*/
	xor_base = of_iomap(xor_node, 0);
	xor_high_base = of_iomap(xor_node, 1);

	xor_clk = of_clk_get_by_name(xor_node, NULL);
	BUG_ON(!xor_clk);

	clk_prepare_enable(xor_clk);

	dram = mv_mbus_dram_info();

	for (i = 0; i < 8; i++) {
	writel(0, xor_base + WINDOW_BASE(i));
	writel(0, xor_base + WINDOW_SIZE(i));
	if (i < 4)
	writel(0, xor_base + WINDOW_REMAP_HIGH(i));
	}

	for (i = 0; i < dram->num_cs; i++) {
	const struct mbus_dram_window *cs = dram->cs + i;
	writel((cs->base & 0xffff0000) \|
	(cs->mbus_attr << 8) \|
	dram->mbus_dram_target_id, xor_base + WINDOW_BASE(i));
	writel((cs->size - 1) & 0xffff0000, xor_base + WINDOW_SIZE(i));

	win_enable \|= (1 << i);
	win_enable \|= 3 << (16 + (2 * i));
	}

	writel(win_enable, xor_base + WINDOW_BAR_ENABLE(0));
	writel(win_enable, xor_base + WINDOW_BAR_ENABLE(1));
	writel(0, xor_base + WINDOW_OVERRIDE_CTRL(0));
	writel(0, xor_base + WINDOW_OVERRIDE_CTRL(1));

	for (i = 0; i < CONFIG_NR_CPUS; i++) {
	coherency_wa_buf[i] = kzalloc(PAGE_SIZE, GFP_KERNEL);
	BUG_ON(!coherency_wa_buf[i]);

	/*
	* We can't use the DMA mapping API, since we don't
	* have a valid 'struct device' pointer
	*/
	coherency_wa_buf_phys[i] =
	virt_to_phys(coherency_wa_buf[i]);
	BUG_ON(!coherency_wa_buf_phys[i]);

	/*
	* Configure the XOR engine for memset operation, with
	* a 128 bytes block size
	*/
	writel(0x444, xor_base + XOR_CONFIG(i));
	writel(128, xor_base + XOR_BLOCK_SIZE(i));
	writel(coherency_wa_buf_phys[i],
	xor_base + XOR_DEST_POINTER(i));
	}

	writel(0x0, xor_base + XOR_INIT_VALUE_LOW);
	writel(0x0, xor_base + XOR_INIT_VALUE_HIGH);

	coherency_wa_enabled = true;
	}

	static inline void mvebu_hwcc_sync_io_barrier(void)
	{
	if (coherency_wa_enabled) {
	mvebu_hwcc_armada375_sync_io_barrier_wa();
	return;
	}

	writel(0x1, coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET);
	while (readl(coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET) & 0x1);
	}

	static dma_addr_t mvebu_hwcc_dma_map_page(struct device dev, struct page page,
	unsigned long offset, size_t size,
	enum dma_data_direction dir,
	struct dma_attrs *attrs)
	{
	if (dir != DMA_TO_DEVICE)
	mvebu_hwcc_sync_io_barrier();
	return pfn_to_dma(dev, page_to_pfn(page)) + offset;
	}


	static void mvebu_hwcc_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
	size_t size, enum dma_data_direction dir,
	struct dma_attrs *attrs)
	{
	if (dir != DMA_TO_DEVICE)
	mvebu_hwcc_sync_io_barrier();
	}

	static void mvebu_hwcc_dma_sync(struct device *dev, dma_addr_t dma_handle,
	size_t size, enum dma_data_direction dir)
	{
	if (dir != DMA_TO_DEVICE)
	mvebu_hwcc_sync_io_barrier();
	}

	static struct dma_map_ops mvebu_hwcc_dma_ops = {
	.alloc = arm_dma_alloc,
	.free = arm_dma_free,
	.mmap = arm_dma_mmap,
	.map_page = mvebu_hwcc_dma_map_page,
	.unmap_page = mvebu_hwcc_dma_unmap_page,
	.get_sgtable = arm_dma_get_sgtable,
	.map_sg = arm_dma_map_sg,
	.unmap_sg = arm_dma_unmap_sg,
	.sync_single_for_cpu = mvebu_hwcc_dma_sync,
	.sync_single_for_device = mvebu_hwcc_dma_sync,
	.sync_sg_for_cpu = arm_dma_sync_sg_for_cpu,
	.sync_sg_for_device = arm_dma_sync_sg_for_device,
	.set_dma_mask = arm_dma_set_mask,
	};

	static int mvebu_hwcc_notifier(struct notifier_block *nb,
	unsigned long event, void *__dev)
	{
	struct device *dev = __dev;

	if (event != BUS_NOTIFY_ADD_DEVICE)
	return NOTIFY_DONE;
	set_dma_ops(dev, &mvebu_hwcc_dma_ops);

	return NOTIFY_OK;
	}

	static struct notifier_block mvebu_hwcc_nb = {
	.notifier_call = mvebu_hwcc_notifier,
	};

	static struct notifier_block mvebu_hwcc_pci_nb = {
	.notifier_call = mvebu_hwcc_notifier,
	};

	static void __init armada_370_coherency_init(struct device_node *np)
	{
	struct resource res;

	of_address_to_resource(np, 0, &res);
	coherency_phys_base = res.start;
	/*
	* Ensure secondary CPUs will see the updated value,
	* which they read before they join the coherency
	* fabric, and therefore before they are coherent with
	* the boot CPU cache.
	*/
	sync_cache_w(&coherency_phys_base);
	coherency_base = of_iomap(np, 0);
	coherency_cpu_base = of_iomap(np, 1);
	set_cpu_coherent();
	}

	/*
	* This ioremap hook is used on Armada 375/38x to ensure that PCIe
	* memory areas are mapped as MT_UNCACHED instead of MT_DEVICE. This
	* is needed as a workaround for a deadlock issue between the PCIe
	* interface and the cache controller.
	*/
	static void __iomem *
	armada_pcie_wa_ioremap_caller(phys_addr_t phys_addr, size_t size,
	unsigned int mtype, void *caller)
	{
	struct resource pcie_mem;

	mvebu_mbus_get_pcie_mem_aperture(&pcie_mem);

	if (pcie_mem.start <= phys_addr && (phys_addr + size) <= pcie_mem.end)
	mtype = MT_UNCACHED;

	return __arm_ioremap_caller(phys_addr, size, mtype, caller);
	}

	static void __init armada_375_380_coherency_init(struct device_node *np)
	{
	struct device_node *cache_dn;

	coherency_cpu_base = of_iomap(np, 0);
	arch_ioremap_caller = armada_pcie_wa_ioremap_caller;

	/*
	* Add the PL310 property "arm,io-coherent". This makes sure the
	* outer sync operation is not used, which allows to
	* workaround the system erratum that causes deadlocks when
	* doing PCIe in an SMP situation on Armada 375 and Armada
	* 38x.
	*/
	for_each_compatible_node(cache_dn, NULL, "arm,pl310-cache") {
	struct property *p;

	p = kzalloc(sizeof(*p), GFP_KERNEL);
	p->name = kstrdup("arm,io-coherent", GFP_KERNEL);
	of_add_property(cache_dn, p);
	}
	}

	static int coherency_type(void)
	{
	struct device_node *np;
	const struct of_device_id *match;

	np = of_find_matching_node_and_match(NULL, of_coherency_table, &match);
	if (np) {
	int type = (int) match->data;

	/* Armada 370/XP coherency works in both UP and SMP */
	if (type == COHERENCY_FABRIC_TYPE_ARMADA_370_XP)
	return type;

	/* Armada 375 coherency works only on SMP */
	else if (type == COHERENCY_FABRIC_TYPE_ARMADA_375 && is_smp())
	return type;

	/* Armada 380 coherency works only on SMP */
	else if (type == COHERENCY_FABRIC_TYPE_ARMADA_380 && is_smp())
	return type;
	}

	return COHERENCY_FABRIC_TYPE_NONE;
	}

	int coherency_available(void)
	{
	return coherency_type() != COHERENCY_FABRIC_TYPE_NONE;
	}

	int __init coherency_init(void)
	{
	int type = coherency_type();
	struct device_node *np;

	np = of_find_matching_node(NULL, of_coherency_table);

	if (type == COHERENCY_FABRIC_TYPE_ARMADA_370_XP)
	armada_370_coherency_init(np);
	else if (type == COHERENCY_FABRIC_TYPE_ARMADA_375 \|\|
	type == COHERENCY_FABRIC_TYPE_ARMADA_380)
	armada_375_380_coherency_init(np);

	return 0;
	}

	static int __init coherency_late_init(void)
	{
	int type = coherency_type();

	if (type == COHERENCY_FABRIC_TYPE_NONE)
	return 0;

	if (type == COHERENCY_FABRIC_TYPE_ARMADA_375) {
	u32 dev, rev;

	if (mvebu_get_soc_id(&dev, &rev) == 0 &&
	rev == ARMADA_375_Z1_REV)
	armada_375_coherency_init_wa();
	}

	bus_register_notifier(&platform_bus_type,
	&mvebu_hwcc_nb);

	return 0;
	}

	postcore_initcall(coherency_late_init);

	#if IS_ENABLED(CONFIG_PCI)
	static int __init coherency_pci_init(void)
	{
	if (coherency_available())
	bus_register_notifier(&pci_bus_type,
	&mvebu_hwcc_pci_nb);
	return 0;
	}

	arch_initcall(coherency_pci_init);
	#endif