drivers: soc: Add LLCC driver

LLCC (Last Level Cache Controller) provides additional cache memory
in the system. LLCC is partitioned into multiple slices and each
slice gets its own priority, size, ID and other config parameters.
LLCC driver programs these parameters for each slice. Clients that
are assigned to use LLCC need to get information such size & ID of the
slice they get and activate or deactivate the slice as needed. LLCC driver
provides API for the clients to perform these operations.

Signed-off-by: Channagoud Kadabi <ckadabi@codeaurora.org>
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>

1 files changed, 335 insertions, 0 deletions

diff --git a/drivers/soc/qcom/llcc-slice.c b/drivers/soc/qcom/llcc-slice.c
new file mode 100644
index 000000000000..fcaad1a4b41d
--- /dev/null
+++ b/drivers/soc/qcom/llcc-slice.c
@@ -0,0 +1,335 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
+ *
+ */
+
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/soc/qcom/llcc-qcom.h>
+
+#define ACTIVATE                      BIT(0)
+#define DEACTIVATE                    BIT(1)
+#define ACT_CTRL_OPCODE_ACTIVATE      BIT(0)
+#define ACT_CTRL_OPCODE_DEACTIVATE    BIT(1)
+#define ACT_CTRL_ACT_TRIG             BIT(0)
+#define ACT_CTRL_OPCODE_SHIFT         0x01
+#define ATTR1_PROBE_TARGET_WAYS_SHIFT 0x02
+#define ATTR1_FIXED_SIZE_SHIFT        0x03
+#define ATTR1_PRIORITY_SHIFT          0x04
+#define ATTR1_MAX_CAP_SHIFT           0x10
+#define ATTR0_RES_WAYS_MASK           GENMASK(11, 0)
+#define ATTR0_BONUS_WAYS_MASK         GENMASK(27, 16)
+#define ATTR0_BONUS_WAYS_SHIFT        0x10
+#define LLCC_STATUS_READ_DELAY        100
+
+#define CACHE_LINE_SIZE_SHIFT         6
+
+#define LLCC_COMMON_STATUS0           0x0003000c
+#define LLCC_LB_CNT_MASK              GENMASK(31, 28)
+#define LLCC_LB_CNT_SHIFT             28
+
+#define MAX_CAP_TO_BYTES(n)           (n * SZ_1K)
+#define LLCC_TRP_ACT_CTRLn(n)         (n * SZ_4K)
+#define LLCC_TRP_STATUSn(n)           (4 + n * SZ_4K)
+#define LLCC_TRP_ATTR0_CFGn(n)        (0x21000 + SZ_8 * n)
+#define LLCC_TRP_ATTR1_CFGn(n)        (0x21004 + SZ_8 * n)
+
+#define BANK_OFFSET_STRIDE	      0x80000
+
+static struct llcc_drv_data *drv_data;
+
+static const struct regmap_config llcc_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.fast_io = true,
+};
+
+/**
+ * llcc_slice_getd - get llcc slice descriptor
+ * @uid: usecase_id for the client
+ *
+ * A pointer to llcc slice descriptor will be returned on success and
+ * and error pointer is returned on failure
+ */
+struct llcc_slice_desc *llcc_slice_getd(u32 uid)
+{
+	const struct llcc_slice_config *cfg;
+	struct llcc_slice_desc *desc;
+	u32 sz, count;
+
+	cfg = drv_data->cfg;
+	sz = drv_data->cfg_size;
+
+	for (count = 0; cfg && count < sz; count++, cfg++)
+		if (cfg->usecase_id == uid)
+			break;
+
+	if (count == sz || !cfg)
+		return ERR_PTR(-ENODEV);
+
+	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
+	if (!desc)
+		return ERR_PTR(-ENOMEM);
+
+	desc->slice_id = cfg->slice_id;
+	desc->slice_size = cfg->max_cap;
+
+	return desc;
+}
+EXPORT_SYMBOL_GPL(llcc_slice_getd);
+
+/**
+ * llcc_slice_putd - llcc slice descritpor
+ * @desc: Pointer to llcc slice descriptor
+ */
+void llcc_slice_putd(struct llcc_slice_desc *desc)
+{
+	kfree(desc);
+}
+EXPORT_SYMBOL_GPL(llcc_slice_putd);
+
+static int llcc_update_act_ctrl(u32 sid,
+				u32 act_ctrl_reg_val, u32 status)
+{
+	u32 act_ctrl_reg;
+	u32 status_reg;
+	u32 slice_status;
+	int ret;
+
+	act_ctrl_reg = drv_data->bcast_off + LLCC_TRP_ACT_CTRLn(sid);
+	status_reg = drv_data->bcast_off + LLCC_TRP_STATUSn(sid);
+
+	/* Set the ACTIVE trigger */
+	act_ctrl_reg_val |= ACT_CTRL_ACT_TRIG;
+	ret = regmap_write(drv_data->regmap, act_ctrl_reg, act_ctrl_reg_val);
+	if (ret)
+		return ret;
+
+	/* Clear the ACTIVE trigger */
+	act_ctrl_reg_val &= ~ACT_CTRL_ACT_TRIG;
+	ret = regmap_write(drv_data->regmap, act_ctrl_reg, act_ctrl_reg_val);
+	if (ret)
+		return ret;
+
+	ret = regmap_read_poll_timeout(drv_data->regmap, status_reg,
+				      slice_status, !(slice_status & status),
+				      0, LLCC_STATUS_READ_DELAY);
+	return ret;
+}
+
+/**
+ * llcc_slice_activate - Activate the llcc slice
+ * @desc: Pointer to llcc slice descriptor
+ *
+ * A value of zero will be returned on success and a negative errno will
+ * be returned in error cases
+ */
+int llcc_slice_activate(struct llcc_slice_desc *desc)
+{
+	int ret;
+	u32 act_ctrl_val;
+
+	mutex_lock(&drv_data->lock);
+	if (test_bit(desc->slice_id, drv_data->bitmap)) {
+		mutex_unlock(&drv_data->lock);
+		return 0;
+	}
+
+	act_ctrl_val = ACT_CTRL_OPCODE_ACTIVATE << ACT_CTRL_OPCODE_SHIFT;
+
+	ret = llcc_update_act_ctrl(desc->slice_id, act_ctrl_val,
+				  DEACTIVATE);
+	if (ret) {
+		mutex_unlock(&drv_data->lock);
+		return ret;
+	}
+
+	__set_bit(desc->slice_id, drv_data->bitmap);
+	mutex_unlock(&drv_data->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(llcc_slice_activate);
+
+/**
+ * llcc_slice_deactivate - Deactivate the llcc slice
+ * @desc: Pointer to llcc slice descriptor
+ *
+ * A value of zero will be returned on success and a negative errno will
+ * be returned in error cases
+ */
+int llcc_slice_deactivate(struct llcc_slice_desc *desc)
+{
+	u32 act_ctrl_val;
+	int ret;
+
+	mutex_lock(&drv_data->lock);
+	if (!test_bit(desc->slice_id, drv_data->bitmap)) {
+		mutex_unlock(&drv_data->lock);
+		return 0;
+	}
+	act_ctrl_val = ACT_CTRL_OPCODE_DEACTIVATE << ACT_CTRL_OPCODE_SHIFT;
+
+	ret = llcc_update_act_ctrl(desc->slice_id, act_ctrl_val,
+				  ACTIVATE);
+	if (ret) {
+		mutex_unlock(&drv_data->lock);
+		return ret;
+	}
+
+	__clear_bit(desc->slice_id, drv_data->bitmap);
+	mutex_unlock(&drv_data->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(llcc_slice_deactivate);
+
+/**
+ * llcc_get_slice_id - return the slice id
+ * @desc: Pointer to llcc slice descriptor
+ */
+int llcc_get_slice_id(struct llcc_slice_desc *desc)
+{
+	return desc->slice_id;
+}
+EXPORT_SYMBOL_GPL(llcc_get_slice_id);
+
+/**
+ * llcc_get_slice_size - return the slice id
+ * @desc: Pointer to llcc slice descriptor
+ */
+size_t llcc_get_slice_size(struct llcc_slice_desc *desc)
+{
+	return desc->slice_size;
+}
+EXPORT_SYMBOL_GPL(llcc_get_slice_size);
+
+static int qcom_llcc_cfg_program(struct platform_device *pdev)
+{
+	int i;
+	u32 attr1_cfg;
+	u32 attr0_cfg;
+	u32 attr1_val;
+	u32 attr0_val;
+	u32 max_cap_cacheline;
+	u32 sz;
+	int ret;
+	const struct llcc_slice_config *llcc_table;
+	struct llcc_slice_desc desc;
+	u32 bcast_off = drv_data->bcast_off;
+
+	sz = drv_data->cfg_size;
+	llcc_table = drv_data->cfg;
+
+	for (i = 0; i < sz; i++) {
+		attr1_cfg = bcast_off +
+				LLCC_TRP_ATTR1_CFGn(llcc_table[i].slice_id);
+		attr0_cfg = bcast_off +
+				LLCC_TRP_ATTR0_CFGn(llcc_table[i].slice_id);
+
+		attr1_val = llcc_table[i].cache_mode;
+		attr1_val |= llcc_table[i].probe_target_ways <<
+				ATTR1_PROBE_TARGET_WAYS_SHIFT;
+		attr1_val |= llcc_table[i].fixed_size <<
+				ATTR1_FIXED_SIZE_SHIFT;
+		attr1_val |= llcc_table[i].priority <<
+				ATTR1_PRIORITY_SHIFT;
+
+		max_cap_cacheline = MAX_CAP_TO_BYTES(llcc_table[i].max_cap);
+
+		/* LLCC instances can vary for each target.
+		 * The SW writes to broadcast register which gets propagated
+		 * to each llcc instace (llcc0,.. llccN).
+		 * Since the size of the memory is divided equally amongst the
+		 * llcc instances, we need to configure the max cap accordingly.
+		 */
+		max_cap_cacheline = max_cap_cacheline / drv_data->num_banks;
+		max_cap_cacheline >>= CACHE_LINE_SIZE_SHIFT;
+		attr1_val |= max_cap_cacheline << ATTR1_MAX_CAP_SHIFT;
+
+		attr0_val = llcc_table[i].res_ways & ATTR0_RES_WAYS_MASK;
+		attr0_val |= llcc_table[i].bonus_ways << ATTR0_BONUS_WAYS_SHIFT;
+
+		ret = regmap_write(drv_data->regmap, attr1_cfg, attr1_val);
+		if (ret)
+			return ret;
+		ret = regmap_write(drv_data->regmap, attr0_cfg, attr0_val);
+		if (ret)
+			return ret;
+		if (llcc_table[i].activate_on_init) {
+			desc.slice_id = llcc_table[i].slice_id;
+			ret = llcc_slice_activate(&desc);
+		}
+	}
+	return ret;
+}
+
+int qcom_llcc_probe(struct platform_device *pdev,
+		      const struct llcc_slice_config *llcc_cfg, u32 sz)
+{
+	u32 num_banks;
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	void __iomem *base;
+	int ret, i;
+
+	drv_data = devm_kzalloc(dev, sizeof(*drv_data), GFP_KERNEL);
+	if (!drv_data)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	drv_data->regmap = devm_regmap_init_mmio(dev, base,
+					&llcc_regmap_config);
+	if (IS_ERR(drv_data->regmap))
+		return PTR_ERR(drv_data->regmap);
+
+	ret = regmap_read(drv_data->regmap, LLCC_COMMON_STATUS0,
+						&num_banks);
+	if (ret)
+		return ret;
+
+	num_banks &= LLCC_LB_CNT_MASK;
+	num_banks >>= LLCC_LB_CNT_SHIFT;
+	drv_data->num_banks = num_banks;
+
+	for (i = 0; i < sz; i++)
+		if (llcc_cfg[i].slice_id > drv_data->max_slices)
+			drv_data->max_slices = llcc_cfg[i].slice_id;
+
+	drv_data->offsets = devm_kcalloc(dev, num_banks, sizeof(u32),
+							GFP_KERNEL);
+	if (!drv_data->offsets)
+		return -ENOMEM;
+
+	for (i = 0; i < num_banks; i++)
+		drv_data->offsets[i] = i * BANK_OFFSET_STRIDE;
+
+	drv_data->bcast_off = num_banks * BANK_OFFSET_STRIDE;
+
+	drv_data->bitmap = devm_kcalloc(dev,
+	BITS_TO_LONGS(drv_data->max_slices), sizeof(unsigned long),
+						GFP_KERNEL);
+	if (!drv_data->bitmap)
+		return -ENOMEM;
+
+	drv_data->cfg = llcc_cfg;
+	drv_data->cfg_size = sz;
+	mutex_init(&drv_data->lock);
+	platform_set_drvdata(pdev, drv_data);
+
+	return qcom_llcc_cfg_program(pdev);
+}
+EXPORT_SYMBOL_GPL(qcom_llcc_probe);