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Diffstat (limited to 'arch/arm/mach-mvebu/coherency.c')
| -rw-r--r-- | arch/arm/mach-mvebu/coherency.c | 439 |
1 files changed, 439 insertions, 0 deletions
diff --git a/arch/arm/mach-mvebu/coherency.c b/arch/arm/mach-mvebu/coherency.c new file mode 100644 index 00000000000..2bdc3233abe --- /dev/null +++ b/arch/arm/mach-mvebu/coherency.c @@ -0,0 +1,439 @@ +/* + * 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 |