Fixed MTP to work with TWRP

arch/arm/mach-mvebu/coherency.c

@@ -0,0 +1,469 @@
+/*
+ * 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;
+
+	/*
+	 * We should switch the PL310 to I/O coherency mode only if
+	 * I/O coherency is actually enabled.
+	 */
+	if (!coherency_available())
+		return;
+
+	/*
+	 * 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;
+	int type;
+
+	/*
+	 * The coherency fabric is needed:
+	 * - For coherency between processors on Armada XP, so only
+	 *   when SMP is enabled.
+	 * - For coherency between the processor and I/O devices, but
+	 *   this coherency requires many pre-requisites (write
+	 *   allocate cache policy, shareable pages, SMP bit set) that
+	 *   are only meant in SMP situations.
+	 *
+	 * Note that this means that on Armada 370, there is currently
+	 * no way to use hardware I/O coherency, because even when
+	 * CONFIG_SMP is enabled, is_smp() returns false due to the
+	 * Armada 370 being a single-core processor. To lift this
+	 * limitation, we would have to find a way to make the cache
+	 * policy set to write-allocate (on all Armada SoCs), and to
+	 * set the shareable attribute in page tables (on all Armada
+	 * SoCs except the Armada 370). Unfortunately, such decisions
+	 * are taken very early in the kernel boot process, at a point
+	 * where we don't know yet on which SoC we are running.
+
+	 */
+	if (!is_smp())
+		return COHERENCY_FABRIC_TYPE_NONE;
+
+	np = of_find_matching_node_and_match(NULL, of_coherency_table, &match);
+	if (!np)
+		return COHERENCY_FABRIC_TYPE_NONE;
+
+	type = (int) match->data;
+
+	of_node_put(np);
+
+	return type;
+}
+
+/*
+ * As a precaution, we currently completely disable hardware I/O
+ * coherency, until enough testing is done with automatic I/O
+ * synchronization barriers to validate that it is a proper solution.
+ */
+int coherency_available(void)
+{
+	return false;
+}
+
+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);
+
+	of_node_put(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