1 files changed, 364 insertions, 0 deletions
diff --git a/drivers/soc/bcm/brcmstb/biuctrl.c b/drivers/soc/bcm/brcmstb/biuctrl.c
new file mode 100644
index 000000000..364ddbe36
--- /dev/null
+++ b/drivers/soc/bcm/brcmstb/biuctrl.c
@@ -0,0 +1,364 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Broadcom STB SoCs Bus Unit Interface controls
+ *
+ * Copyright (C) 2015, Broadcom Corporation
+ */
+
+#define pr_fmt(fmt)	"brcmstb: " KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/syscore_ops.h>
+#include <linux/soc/brcmstb/brcmstb.h>
+
+#define RACENPREF_MASK			0x3
+#define RACPREFINST_SHIFT		0
+#define RACENINST_SHIFT			2
+#define RACPREFDATA_SHIFT		4
+#define RACENDATA_SHIFT			6
+#define RAC_CPU_SHIFT			8
+#define RACCFG_MASK			0xff
+#define DPREF_LINE_2_SHIFT		24
+#define DPREF_LINE_2_MASK		0xff
+
+/* Bitmask to enable instruction and data prefetching with a 256-bytes stride */
+#define RAC_DATA_INST_EN_MASK		(1 << RACPREFINST_SHIFT | \
+					 RACENPREF_MASK << RACENINST_SHIFT | \
+					 1 << RACPREFDATA_SHIFT | \
+					 RACENPREF_MASK << RACENDATA_SHIFT)
+
+#define  CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK	0x70000000
+#define CPU_CREDIT_REG_MCPx_READ_CRED_MASK	0xf
+#define CPU_CREDIT_REG_MCPx_WRITE_CRED_MASK	0xf
+#define CPU_CREDIT_REG_MCPx_READ_CRED_SHIFT(x)	((x) * 8)
+#define CPU_CREDIT_REG_MCPx_WRITE_CRED_SHIFT(x)	(((x) * 8) + 4)
+
+#define CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_SHIFT(x)	((x) * 8)
+#define CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_MASK		0xff
+
+#define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_THRESHOLD_MASK	0xf
+#define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_MASK		0xf
+#define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_SHIFT	4
+#define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_ENABLE		BIT(8)
+
+static void __iomem *cpubiuctrl_base;
+static bool mcp_wr_pairing_en;
+static const int *cpubiuctrl_regs;
+
+enum cpubiuctrl_regs {
+	CPU_CREDIT_REG = 0,
+	CPU_MCP_FLOW_REG,
+	CPU_WRITEBACK_CTRL_REG,
+	RAC_CONFIG0_REG,
+	RAC_CONFIG1_REG,
+	NUM_CPU_BIUCTRL_REGS,
+};
+
+static inline u32 cbc_readl(int reg)
+{
+	int offset = cpubiuctrl_regs[reg];
+
+	if (offset == -1 ||
+	    (IS_ENABLED(CONFIG_CACHE_B15_RAC) && reg >= RAC_CONFIG0_REG))
+		return (u32)-1;
+
+	return readl_relaxed(cpubiuctrl_base + offset);
+}
+
+static inline void cbc_writel(u32 val, int reg)
+{
+	int offset = cpubiuctrl_regs[reg];
+
+	if (offset == -1 ||
+	    (IS_ENABLED(CONFIG_CACHE_B15_RAC) && reg >= RAC_CONFIG0_REG))
+		return;
+
+	writel(val, cpubiuctrl_base + offset);
+}
+
+static const int b15_cpubiuctrl_regs[] = {
+	[CPU_CREDIT_REG] = 0x184,
+	[CPU_MCP_FLOW_REG] = -1,
+	[CPU_WRITEBACK_CTRL_REG] = -1,
+	[RAC_CONFIG0_REG] = -1,
+	[RAC_CONFIG1_REG] = -1,
+};
+
+/* Odd cases, e.g: 7260A0 */
+static const int b53_cpubiuctrl_no_wb_regs[] = {
+	[CPU_CREDIT_REG] = 0x0b0,
+	[CPU_MCP_FLOW_REG] = 0x0b4,
+	[CPU_WRITEBACK_CTRL_REG] = -1,
+	[RAC_CONFIG0_REG] = 0x78,
+	[RAC_CONFIG1_REG] = 0x7c,
+};
+
+static const int b53_cpubiuctrl_regs[] = {
+	[CPU_CREDIT_REG] = 0x0b0,
+	[CPU_MCP_FLOW_REG] = 0x0b4,
+	[CPU_WRITEBACK_CTRL_REG] = 0x22c,
+	[RAC_CONFIG0_REG] = 0x78,
+	[RAC_CONFIG1_REG] = 0x7c,
+};
+
+static const int a72_cpubiuctrl_regs[] = {
+	[CPU_CREDIT_REG] = 0x18,
+	[CPU_MCP_FLOW_REG] = 0x1c,
+	[CPU_WRITEBACK_CTRL_REG] = 0x20,
+	[RAC_CONFIG0_REG] = 0x08,
+	[RAC_CONFIG1_REG] = 0x0c,
+};
+
+static int __init mcp_write_pairing_set(void)
+{
+	u32 creds = 0;
+
+	if (!cpubiuctrl_base)
+		return -1;
+
+	creds = cbc_readl(CPU_CREDIT_REG);
+	if (mcp_wr_pairing_en) {
+		pr_info("MCP: Enabling write pairing\n");
+		cbc_writel(creds | CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK,
+			   CPU_CREDIT_REG);
+	} else if (creds & CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK) {
+		pr_info("MCP: Disabling write pairing\n");
+		cbc_writel(creds & ~CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK,
+			   CPU_CREDIT_REG);
+	} else {
+		pr_info("MCP: Write pairing already disabled\n");
+	}
+
+	return 0;
+}
+
+static const u32 a72_b53_mach_compat[] = {
+	0x7211,
+	0x72113,
+	0x72116,
+	0x7216,
+	0x72164,
+	0x72165,
+	0x7255,
+	0x7260,
+	0x7268,
+	0x7271,
+	0x7278,
+};
+
+/* The read-ahead cache present in the Brahma-B53 CPU is a special piece of
+ * hardware after the integrated L2 cache of the B53 CPU complex whose purpose
+ * is to prefetch instruction and/or data with a line size of either 64 bytes
+ * or 256 bytes. The rationale is that the data-bus of the CPU interface is
+ * optimized for 256-byte transactions, and enabling the read-ahead cache
+ * provides a significant performance boost (typically twice the performance
+ * for a memcpy benchmark application).
+ *
+ * The read-ahead cache is transparent for Virtual Address cache maintenance
+ * operations: IC IVAU, DC IVAC, DC CVAC, DC CVAU and DC CIVAC.  So no special
+ * handling is needed for the DMA API above and beyond what is included in the
+ * arm64 implementation.
+ *
+ * In addition, since the Point of Unification is typically between L1 and L2
+ * for the Brahma-B53 processor no special read-ahead cache handling is needed
+ * for the IC IALLU and IC IALLUIS cache maintenance operations.
+ *
+ * However, it is not possible to specify the cache level (L3) for the cache
+ * maintenance instructions operating by set/way to operate on the read-ahead
+ * cache.  The read-ahead cache will maintain coherency when inner cache lines
+ * are cleaned by set/way, but if it is necessary to invalidate inner cache
+ * lines by set/way to maintain coherency with system masters operating on
+ * shared memory that does not have hardware support for coherency, then it
+ * will also be necessary to explicitly invalidate the read-ahead cache.
+ */
+static void __init a72_b53_rac_enable_all(struct device_node *np)
+{
+	unsigned int cpu;
+	u32 enable = 0, pref_dist, shift;
+
+	if (IS_ENABLED(CONFIG_CACHE_B15_RAC))
+		return;
+
+	if (WARN(num_possible_cpus() > 4, "RAC only supports 4 CPUs\n"))
+		return;
+
+	pref_dist = cbc_readl(RAC_CONFIG1_REG);
+	for_each_possible_cpu(cpu) {
+		shift = cpu * RAC_CPU_SHIFT + RACPREFDATA_SHIFT;
+		enable |= RAC_DATA_INST_EN_MASK << (cpu * RAC_CPU_SHIFT);
+		if (cpubiuctrl_regs == a72_cpubiuctrl_regs) {
+			enable &= ~(RACENPREF_MASK << shift);
+			enable |= 3 << shift;
+			pref_dist |= 1 << (cpu + DPREF_LINE_2_SHIFT);
+		}
+	}
+
+	cbc_writel(enable, RAC_CONFIG0_REG);
+	cbc_writel(pref_dist, RAC_CONFIG1_REG);
+
+	pr_info("%pOF: Broadcom %s read-ahead cache\n",
+		np, cpubiuctrl_regs == a72_cpubiuctrl_regs ?
+		"Cortex-A72" : "Brahma-B53");
+}
+
+static void __init mcp_a72_b53_set(void)
+{
+	unsigned int i;
+	u32 reg;
+
+	reg = brcmstb_get_family_id();
+
+	for (i = 0; i < ARRAY_SIZE(a72_b53_mach_compat); i++) {
+		if (BRCM_ID(reg) == a72_b53_mach_compat[i])
+			break;
+	}
+
+	if (i == ARRAY_SIZE(a72_b53_mach_compat))
+		return;
+
+	/* Set all 3 MCP interfaces to 8 credits */
+	reg = cbc_readl(CPU_CREDIT_REG);
+	for (i = 0; i < 3; i++) {
+		reg &= ~(CPU_CREDIT_REG_MCPx_WRITE_CRED_MASK <<
+			 CPU_CREDIT_REG_MCPx_WRITE_CRED_SHIFT(i));
+		reg &= ~(CPU_CREDIT_REG_MCPx_READ_CRED_MASK <<
+			 CPU_CREDIT_REG_MCPx_READ_CRED_SHIFT(i));
+		reg |= 8 << CPU_CREDIT_REG_MCPx_WRITE_CRED_SHIFT(i);
+		reg |= 8 << CPU_CREDIT_REG_MCPx_READ_CRED_SHIFT(i);
+	}
+	cbc_writel(reg, CPU_CREDIT_REG);
+
+	/* Max out the number of in-flight Jwords reads on the MCP interface */
+	reg = cbc_readl(CPU_MCP_FLOW_REG);
+	for (i = 0; i < 3; i++)
+		reg |= CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_MASK <<
+			CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_SHIFT(i);
+	cbc_writel(reg, CPU_MCP_FLOW_REG);
+
+	/* Enable writeback throttling, set timeout to 128 cycles, 256 cycles
+	 * threshold
+	 */
+	reg = cbc_readl(CPU_WRITEBACK_CTRL_REG);
+	reg |= CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_ENABLE;
+	reg &= ~CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_THRESHOLD_MASK;
+	reg &= ~(CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_MASK <<
+		 CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_SHIFT);
+	reg |= 8;
+	reg |= 7 << CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_SHIFT;
+	cbc_writel(reg, CPU_WRITEBACK_CTRL_REG);
+}
+
+static int __init setup_hifcpubiuctrl_regs(struct device_node *np)
+{
+	struct device_node *cpu_dn;
+	u32 family_id;
+	int ret = 0;
+
+	cpubiuctrl_base = of_iomap(np, 0);
+	if (!cpubiuctrl_base) {
+		pr_err("failed to remap BIU control base\n");
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	mcp_wr_pairing_en = of_property_read_bool(np, "brcm,write-pairing");
+
+	cpu_dn = of_get_cpu_node(0, NULL);
+	if (!cpu_dn) {
+		pr_err("failed to obtain CPU device node\n");
+		ret = -ENODEV;
+		goto out;
+	}
+
+	if (of_device_is_compatible(cpu_dn, "brcm,brahma-b15"))
+		cpubiuctrl_regs = b15_cpubiuctrl_regs;
+	else if (of_device_is_compatible(cpu_dn, "brcm,brahma-b53"))
+		cpubiuctrl_regs = b53_cpubiuctrl_regs;
+	else if (of_device_is_compatible(cpu_dn, "arm,cortex-a72"))
+		cpubiuctrl_regs = a72_cpubiuctrl_regs;
+	else {
+		pr_err("unsupported CPU\n");
+		ret = -EINVAL;
+	}
+	of_node_put(cpu_dn);
+
+	family_id = brcmstb_get_family_id();
+	if (BRCM_ID(family_id) == 0x7260 && BRCM_REV(family_id) == 0)
+		cpubiuctrl_regs = b53_cpubiuctrl_no_wb_regs;
+out:
+	if (ret && cpubiuctrl_base) {
+		iounmap(cpubiuctrl_base);
+		cpubiuctrl_base = NULL;
+	}
+	return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static u32 cpubiuctrl_reg_save[NUM_CPU_BIUCTRL_REGS];
+
+static int brcmstb_cpu_credit_reg_suspend(void)
+{
+	unsigned int i;
+
+	if (!cpubiuctrl_base)
+		return 0;
+
+	for (i = 0; i < NUM_CPU_BIUCTRL_REGS; i++)
+		cpubiuctrl_reg_save[i] = cbc_readl(i);
+
+	return 0;
+}
+
+static void brcmstb_cpu_credit_reg_resume(void)
+{
+	unsigned int i;
+
+	if (!cpubiuctrl_base)
+		return;
+
+	for (i = 0; i < NUM_CPU_BIUCTRL_REGS; i++)
+		cbc_writel(cpubiuctrl_reg_save[i], i);
+}
+
+static struct syscore_ops brcmstb_cpu_credit_syscore_ops = {
+	.suspend = brcmstb_cpu_credit_reg_suspend,
+	.resume = brcmstb_cpu_credit_reg_resume,
+};
+#endif
+
+
+static int __init brcmstb_biuctrl_init(void)
+{
+	struct device_node *np;
+	int ret;
+
+	/* We might be running on a multi-platform kernel, don't make this a
+	 * fatal error, just bail out early
+	 */
+	np = of_find_compatible_node(NULL, NULL, "brcm,brcmstb-cpu-biu-ctrl");
+	if (!np)
+		return 0;
+
+	ret = setup_hifcpubiuctrl_regs(np);
+	if (ret)
+		goto out_put;
+
+	ret = mcp_write_pairing_set();
+	if (ret) {
+		pr_err("MCP: Unable to disable write pairing!\n");
+		goto out_put;
+	}
+
+	a72_b53_rac_enable_all(np);
+	mcp_a72_b53_set();
+#ifdef CONFIG_PM_SLEEP
+	register_syscore_ops(&brcmstb_cpu_credit_syscore_ops);
+#endif
+	ret = 0;
+out_put:
+	of_node_put(np);
+	return ret;
+}
+early_initcall(brcmstb_biuctrl_init);