memory: Add NVIDIA Tegra memory controller support
The memory controller on NVIDIA Tegra exposes various knobs that can be
used to tune the behaviour of the clients attached to it.
Currently this driver sets up the latency allowance registers to the HW
defaults. Eventually an API should be exported by this driver (via a
custom API or a generic subsystem) to allow clients to register latency
requirements.
This driver also registers an IOMMU (SMMU) that's implemented by the
memory controller. It is supported on Tegra30, Tegra114 and Tegra124
currently. Tegra20 has a GART instead.
The Tegra SMMU operates on memory clients and SWGROUPs. A memory client
is a unidirectional, special-purpose DMA master. A SWGROUP represents a
set of memory clients that form a logical functional unit corresponding
to a single device. Typically a device has two clients: one client for
read transactions and one client for write transactions, but there are
also devices that have only read clients, but many of them (such as the
display controllers).
Because there is no 1:1 relationship between memory clients and devices
the driver keeps a table of memory clients and the SWGROUPs that they
belong to per SoC. Note that this is an exception and due to the fact
that the SMMU is tightly integrated with the rest of the Tegra SoC. The
use of these tables is discouraged in drivers for generic IOMMU devices
such as the ARM SMMU because the same IOMMU could be used in any number
of SoCs and keeping such tables for each SoC would not scale.
Acked-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
new file mode 100644
index 0000000..fe3c44e
--- /dev/null
+++ b/drivers/memory/tegra/mc.c
@@ -0,0 +1,301 @@
+/*
+ * Copyright (C) 2014 NVIDIA CORPORATION. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "mc.h"
+
+#define MC_INTSTATUS 0x000
+#define MC_INT_DECERR_MTS (1 << 16)
+#define MC_INT_SECERR_SEC (1 << 13)
+#define MC_INT_DECERR_VPR (1 << 12)
+#define MC_INT_INVALID_APB_ASID_UPDATE (1 << 11)
+#define MC_INT_INVALID_SMMU_PAGE (1 << 10)
+#define MC_INT_ARBITRATION_EMEM (1 << 9)
+#define MC_INT_SECURITY_VIOLATION (1 << 8)
+#define MC_INT_DECERR_EMEM (1 << 6)
+
+#define MC_INTMASK 0x004
+
+#define MC_ERR_STATUS 0x08
+#define MC_ERR_STATUS_TYPE_SHIFT 28
+#define MC_ERR_STATUS_TYPE_INVALID_SMMU_PAGE (6 << MC_ERR_STATUS_TYPE_SHIFT)
+#define MC_ERR_STATUS_TYPE_MASK (0x7 << MC_ERR_STATUS_TYPE_SHIFT)
+#define MC_ERR_STATUS_READABLE (1 << 27)
+#define MC_ERR_STATUS_WRITABLE (1 << 26)
+#define MC_ERR_STATUS_NONSECURE (1 << 25)
+#define MC_ERR_STATUS_ADR_HI_SHIFT 20
+#define MC_ERR_STATUS_ADR_HI_MASK 0x3
+#define MC_ERR_STATUS_SECURITY (1 << 17)
+#define MC_ERR_STATUS_RW (1 << 16)
+#define MC_ERR_STATUS_CLIENT_MASK 0x7f
+
+#define MC_ERR_ADR 0x0c
+
+#define MC_EMEM_ARB_CFG 0x90
+#define MC_EMEM_ARB_CFG_CYCLES_PER_UPDATE(x) (((x) & 0x1ff) << 0)
+#define MC_EMEM_ARB_CFG_CYCLES_PER_UPDATE_MASK 0x1ff
+#define MC_EMEM_ARB_MISC0 0xd8
+
+static const struct of_device_id tegra_mc_of_match[] = {
+#ifdef CONFIG_ARCH_TEGRA_3x_SOC
+ { .compatible = "nvidia,tegra30-mc", .data = &tegra30_mc_soc },
+#endif
+#ifdef CONFIG_ARCH_TEGRA_114_SOC
+ { .compatible = "nvidia,tegra114-mc", .data = &tegra114_mc_soc },
+#endif
+#ifdef CONFIG_ARCH_TEGRA_124_SOC
+ { .compatible = "nvidia,tegra124-mc", .data = &tegra124_mc_soc },
+#endif
+ { }
+};
+MODULE_DEVICE_TABLE(of, tegra_mc_of_match);
+
+static int tegra_mc_setup_latency_allowance(struct tegra_mc *mc)
+{
+ unsigned long long tick;
+ unsigned int i;
+ u32 value;
+
+ /* compute the number of MC clock cycles per tick */
+ tick = mc->tick * clk_get_rate(mc->clk);
+ do_div(tick, NSEC_PER_SEC);
+
+ value = readl(mc->regs + MC_EMEM_ARB_CFG);
+ value &= ~MC_EMEM_ARB_CFG_CYCLES_PER_UPDATE_MASK;
+ value |= MC_EMEM_ARB_CFG_CYCLES_PER_UPDATE(tick);
+ writel(value, mc->regs + MC_EMEM_ARB_CFG);
+
+ /* write latency allowance defaults */
+ for (i = 0; i < mc->soc->num_clients; i++) {
+ const struct tegra_mc_la *la = &mc->soc->clients[i].la;
+ u32 value;
+
+ value = readl(mc->regs + la->reg);
+ value &= ~(la->mask << la->shift);
+ value |= (la->def & la->mask) << la->shift;
+ writel(value, mc->regs + la->reg);
+ }
+
+ return 0;
+}
+
+static const char *const status_names[32] = {
+ [ 1] = "External interrupt",
+ [ 6] = "EMEM address decode error",
+ [ 8] = "Security violation",
+ [ 9] = "EMEM arbitration error",
+ [10] = "Page fault",
+ [11] = "Invalid APB ASID update",
+ [12] = "VPR violation",
+ [13] = "Secure carveout violation",
+ [16] = "MTS carveout violation",
+};
+
+static const char *const error_names[8] = {
+ [2] = "EMEM decode error",
+ [3] = "TrustZone violation",
+ [4] = "Carveout violation",
+ [6] = "SMMU translation error",
+};
+
+static irqreturn_t tegra_mc_irq(int irq, void *data)
+{
+ struct tegra_mc *mc = data;
+ unsigned long status, mask;
+ unsigned int bit;
+
+ /* mask all interrupts to avoid flooding */
+ status = mc_readl(mc, MC_INTSTATUS);
+ mask = mc_readl(mc, MC_INTMASK);
+
+ for_each_set_bit(bit, &status, 32) {
+ const char *error = status_names[bit] ?: "unknown";
+ const char *client = "unknown", *desc;
+ const char *direction, *secure;
+ phys_addr_t addr = 0;
+ unsigned int i;
+ char perm[7];
+ u8 id, type;
+ u32 value;
+
+ value = mc_readl(mc, MC_ERR_STATUS);
+
+#ifdef CONFIG_PHYS_ADDR_T_64BIT
+ if (mc->soc->num_address_bits > 32) {
+ addr = ((value >> MC_ERR_STATUS_ADR_HI_SHIFT) &
+ MC_ERR_STATUS_ADR_HI_MASK);
+ addr <<= 32;
+ }
+#endif
+
+ if (value & MC_ERR_STATUS_RW)
+ direction = "write";
+ else
+ direction = "read";
+
+ if (value & MC_ERR_STATUS_SECURITY)
+ secure = "secure ";
+ else
+ secure = "";
+
+ id = value & MC_ERR_STATUS_CLIENT_MASK;
+
+ for (i = 0; i < mc->soc->num_clients; i++) {
+ if (mc->soc->clients[i].id == id) {
+ client = mc->soc->clients[i].name;
+ break;
+ }
+ }
+
+ type = (value & MC_ERR_STATUS_TYPE_MASK) >>
+ MC_ERR_STATUS_TYPE_SHIFT;
+ desc = error_names[type];
+
+ switch (value & MC_ERR_STATUS_TYPE_MASK) {
+ case MC_ERR_STATUS_TYPE_INVALID_SMMU_PAGE:
+ perm[0] = ' ';
+ perm[1] = '[';
+
+ if (value & MC_ERR_STATUS_READABLE)
+ perm[2] = 'R';
+ else
+ perm[2] = '-';
+
+ if (value & MC_ERR_STATUS_WRITABLE)
+ perm[3] = 'W';
+ else
+ perm[3] = '-';
+
+ if (value & MC_ERR_STATUS_NONSECURE)
+ perm[4] = '-';
+ else
+ perm[4] = 'S';
+
+ perm[5] = ']';
+ perm[6] = '\0';
+ break;
+
+ default:
+ perm[0] = '\0';
+ break;
+ }
+
+ value = mc_readl(mc, MC_ERR_ADR);
+ addr |= value;
+
+ dev_err_ratelimited(mc->dev, "%s: %s%s @%pa: %s (%s%s)\n",
+ client, secure, direction, &addr, error,
+ desc, perm);
+ }
+
+ /* clear interrupts */
+ mc_writel(mc, status, MC_INTSTATUS);
+
+ return IRQ_HANDLED;
+}
+
+static int tegra_mc_probe(struct platform_device *pdev)
+{
+ const struct of_device_id *match;
+ struct resource *res;
+ struct tegra_mc *mc;
+ u32 value;
+ int err;
+
+ match = of_match_node(tegra_mc_of_match, pdev->dev.of_node);
+ if (!match)
+ return -ENODEV;
+
+ mc = devm_kzalloc(&pdev->dev, sizeof(*mc), GFP_KERNEL);
+ if (!mc)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, mc);
+ mc->soc = match->data;
+ mc->dev = &pdev->dev;
+
+ /* length of MC tick in nanoseconds */
+ mc->tick = 30;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ mc->regs = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(mc->regs))
+ return PTR_ERR(mc->regs);
+
+ mc->clk = devm_clk_get(&pdev->dev, "mc");
+ if (IS_ERR(mc->clk)) {
+ dev_err(&pdev->dev, "failed to get MC clock: %ld\n",
+ PTR_ERR(mc->clk));
+ return PTR_ERR(mc->clk);
+ }
+
+ err = tegra_mc_setup_latency_allowance(mc);
+ if (err < 0) {
+ dev_err(&pdev->dev, "failed to setup latency allowance: %d\n",
+ err);
+ return err;
+ }
+
+ if (IS_ENABLED(CONFIG_TEGRA_IOMMU_SMMU)) {
+ mc->smmu = tegra_smmu_probe(&pdev->dev, mc->soc->smmu, mc);
+ if (IS_ERR(mc->smmu)) {
+ dev_err(&pdev->dev, "failed to probe SMMU: %ld\n",
+ PTR_ERR(mc->smmu));
+ return PTR_ERR(mc->smmu);
+ }
+ }
+
+ mc->irq = platform_get_irq(pdev, 0);
+ if (mc->irq < 0) {
+ dev_err(&pdev->dev, "interrupt not specified\n");
+ return mc->irq;
+ }
+
+ err = devm_request_irq(&pdev->dev, mc->irq, tegra_mc_irq, IRQF_SHARED,
+ dev_name(&pdev->dev), mc);
+ if (err < 0) {
+ dev_err(&pdev->dev, "failed to request IRQ#%u: %d\n", mc->irq,
+ err);
+ return err;
+ }
+
+ value = MC_INT_DECERR_MTS | MC_INT_SECERR_SEC | MC_INT_DECERR_VPR |
+ MC_INT_INVALID_APB_ASID_UPDATE | MC_INT_INVALID_SMMU_PAGE |
+ MC_INT_ARBITRATION_EMEM | MC_INT_SECURITY_VIOLATION |
+ MC_INT_DECERR_EMEM;
+ mc_writel(mc, value, MC_INTMASK);
+
+ return 0;
+}
+
+static struct platform_driver tegra_mc_driver = {
+ .driver = {
+ .name = "tegra-mc",
+ .of_match_table = tegra_mc_of_match,
+ .suppress_bind_attrs = true,
+ },
+ .prevent_deferred_probe = true,
+ .probe = tegra_mc_probe,
+};
+
+static int tegra_mc_init(void)
+{
+ return platform_driver_register(&tegra_mc_driver);
+}
+arch_initcall(tegra_mc_init);
+
+MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
+MODULE_DESCRIPTION("NVIDIA Tegra Memory Controller driver");
+MODULE_LICENSE("GPL v2");