Loongson Security Engine chip supports RNG, SM2, SM3 and SM4 accelerator
engines. This is the base driver for other specific engine drivers.

Co-developed-by: Yinggang Gu <guyingg...@loongson.cn>
Signed-off-by: Yinggang Gu <guyingg...@loongson.cn>
Signed-off-by: Qunqin Zhao <zhaoqun...@loongson.cn>
Reviewed-by: Huacai Chen <chenhua...@loongson.cn>
---
v8: As explained in the cover letter, moved this driver form MFD to here.
    Cleanned up coding style. Added some comments. Divided DMA memory
    equally among all engines.

v7: Moved Kconfig entry between MFD_INTEL_M10_BMC_PMCI and MFD_QNAP_MCU.

    Renamed se_enable_int_locked() to se_enable_int(), then moved the
    lock out of se_disable_int().
    
    "se_send_genl_cmd" ---> "se_send_cmd".
    "struct lsse_ch" ---> "struct se_channel".

v6: Replace all "ls6000se" with "loongson"
v5: Registered "ls6000se-rng" device.
v3-v4: None

 drivers/crypto/Kconfig                |   1 +
 drivers/crypto/Makefile               |   1 +
 drivers/crypto/loongson/Kconfig       |  11 ++
 drivers/crypto/loongson/Makefile      |   2 +
 drivers/crypto/loongson/loongson-se.c | 239 ++++++++++++++++++++++++++
 drivers/crypto/loongson/loongson-se.h |  52 ++++++
 6 files changed, 306 insertions(+)
 create mode 100644 drivers/crypto/loongson/Kconfig
 create mode 100644 drivers/crypto/loongson/Makefile
 create mode 100644 drivers/crypto/loongson/loongson-se.c
 create mode 100644 drivers/crypto/loongson/loongson-se.h

diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
index 470827820..371a2bd58 100644
--- a/drivers/crypto/Kconfig
+++ b/drivers/crypto/Kconfig
@@ -833,6 +833,7 @@ config CRYPTO_DEV_CCREE
          If unsure say Y.
 
 source "drivers/crypto/hisilicon/Kconfig"
+source "drivers/crypto/loongson/Kconfig"
 
 source "drivers/crypto/amlogic/Kconfig"
 
diff --git a/drivers/crypto/Makefile b/drivers/crypto/Makefile
index c97f0ebc5..479875e6c 100644
--- a/drivers/crypto/Makefile
+++ b/drivers/crypto/Makefile
@@ -50,3 +50,4 @@ obj-y += hisilicon/
 obj-$(CONFIG_CRYPTO_DEV_AMLOGIC_GXL) += amlogic/
 obj-y += intel/
 obj-y += starfive/
+obj-y += loongson/
diff --git a/drivers/crypto/loongson/Kconfig b/drivers/crypto/loongson/Kconfig
new file mode 100644
index 000000000..9fdcc73bc
--- /dev/null
+++ b/drivers/crypto/loongson/Kconfig
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0
+config CRYPTO_DEV_LOONGSON_SE
+       tristate "Loongson Security Engine chip controller driver"
+       depends on LOONGARCH && ACPI
+       select MFD_CORE
+       help
+         The Loongson Security Engine chip supports RNG, SM2, SM3 and
+         SM4 accelerator engines. Each engine have its own DMA buffer
+         provided by the controller. The kernel cannot directly send
+         commands to the engine and must first send them to the controller,
+         which will forward them to the corresponding engine.
diff --git a/drivers/crypto/loongson/Makefile b/drivers/crypto/loongson/Makefile
new file mode 100644
index 000000000..5ebcd9ff8
--- /dev/null
+++ b/drivers/crypto/loongson/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_CRYPTO_DEV_LOONGSON_SE)   += loongson-se.o
diff --git a/drivers/crypto/loongson/loongson-se.c 
b/drivers/crypto/loongson/loongson-se.c
new file mode 100644
index 000000000..aad0f2d79
--- /dev/null
+++ b/drivers/crypto/loongson/loongson-se.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Copyright (C) 2025 Loongson Technology Corporation Limited */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include "loongson-se.h"
+
+struct loongson_se {
+       void __iomem *base;
+       spinlock_t dev_lock;
+       struct completion cmd_completion;
+
+       void *dmam_base;
+       int dmam_size;
+
+       struct mutex engine_init_lock;
+       struct loongson_se_engine engines[SE_ENGINE_MAX];
+};
+
+struct loongson_se_controller_cmd {
+       u32 command_id;
+       u32 info[7];
+};
+
+static int loongson_se_poll(struct loongson_se *se, u32 int_bit)
+{
+       u32 status;
+       int err;
+
+       spin_lock_irq(&se->dev_lock);
+
+       /* Notify the controller that the engine needs to be started */
+       writel(int_bit, se->base + SE_L2SINT_SET);
+       /* Polling until the controller has forwarded the engine command */
+       err = readl_relaxed_poll_timeout_atomic(se->base + SE_L2SINT_STAT, 
status,
+                                               !(status & int_bit), 1, 10000);
+
+       spin_unlock_irq(&se->dev_lock);
+
+       return err;
+}
+
+static int loongson_se_send_controller_cmd(struct loongson_se *se,
+                                          struct loongson_se_controller_cmd 
*cmd)
+{
+       u32 *send_cmd = (u32 *)cmd;
+       int err, i;
+
+       for (i = 0; i < SE_SEND_CMD_REG_LEN; i++)
+               writel(send_cmd[i], se->base + SE_SEND_CMD_REG + i * 4);
+
+       err = loongson_se_poll(se, SE_INT_CONTROLLER);
+       if (err)
+               return err;
+
+       return wait_for_completion_interruptible(&se->cmd_completion);
+}
+
+int loongson_se_send_engine_cmd(struct loongson_se_engine *engine)
+{
+       /* After engine initialization, the controller already knows
+        * where to obtain engine commands from. Now all we need to
+        * do is notify the controller that the engine needs to be started.
+        */
+       int err = loongson_se_poll(engine->se, BIT(engine->id));
+
+       if (err)
+               return err;
+
+       return wait_for_completion_interruptible(&engine->completion);
+}
+EXPORT_SYMBOL_GPL(loongson_se_send_engine_cmd);
+
+struct loongson_se_engine *loongson_se_init_engine(struct device *dev, int id)
+{
+       struct loongson_se *se = dev_get_drvdata(dev);
+       struct loongson_se_engine *engine = &se->engines[id];
+       struct loongson_se_controller_cmd cmd;
+
+       engine->se = se;
+       engine->id = id;
+       init_completion(&engine->completion);
+
+       /* Divide DMA memory equally among all engines */
+       engine->buffer_size = se->dmam_size / SE_ENGINE_MAX;
+       engine->buffer_off = (se->dmam_size / SE_ENGINE_MAX) * id;
+       engine->data_buffer = se->dmam_base + engine->buffer_off;
+
+       /*
+        * There has no engine0, use its data buffer as command buffer for other
+        * engines. The DMA memory size is obtained from the ACPI table, which
+        * ensures that the data buffer size of engine0 is larger than the
+        * command buffer size of all engines.
+        */
+       engine->command = se->dmam_base + id * (2 * SE_ENGINE_CMD_SIZE);
+       engine->command_ret = engine->command + SE_ENGINE_CMD_SIZE;
+
+       mutex_lock(&se->engine_init_lock);
+       /* Tell the controller where to find engine command */
+       cmd.command_id = SE_CMD_SET_ENGINE_CMDBUF;
+       cmd.info[0] = id;
+       cmd.info[1] = engine->command - se->dmam_base;
+       cmd.info[2] = 2 * SE_ENGINE_CMD_SIZE;
+       if (loongson_se_send_controller_cmd(se, &cmd))
+               engine = NULL;
+       mutex_unlock(&se->engine_init_lock);
+
+       return engine;
+}
+EXPORT_SYMBOL_GPL(loongson_se_init_engine);
+
+static irqreturn_t se_irq_handler(int irq, void *dev_id)
+{
+       struct loongson_se_engine *engine;
+       struct loongson_se *se = dev_id;
+       u32 int_status;
+       int id;
+
+       spin_lock(&se->dev_lock);
+
+       int_status = readl(se->base + SE_S2LINT_STAT);
+       /* For controller */
+       if (int_status & SE_INT_CONTROLLER) {
+               complete(&se->cmd_completion);
+               int_status &= ~SE_INT_CONTROLLER;
+               writel(SE_INT_CONTROLLER, se->base + SE_S2LINT_CL);
+       }
+       /* For engines */
+       while (int_status) {
+               id = __ffs(int_status);
+
+               engine = &se->engines[id];
+               complete(&engine->completion);
+               int_status &= ~BIT(id);
+               writel(BIT(id), se->base + SE_S2LINT_CL);
+       }
+
+       spin_unlock(&se->dev_lock);
+
+       return IRQ_HANDLED;
+}
+
+static int loongson_se_init(struct loongson_se *se, dma_addr_t addr, int size)
+{
+       struct loongson_se_controller_cmd cmd;
+       int err;
+
+       cmd.command_id = SE_CMD_START;
+       err = loongson_se_send_controller_cmd(se, &cmd);
+       if (err)
+               return err;
+
+       cmd.command_id = SE_CMD_SET_DMA;
+       cmd.info[0] = lower_32_bits(addr);
+       cmd.info[1] = upper_32_bits(addr);
+       cmd.info[2] = size;
+
+       return loongson_se_send_controller_cmd(se, &cmd);
+}
+
+static const struct mfd_cell engines[] = {
+       { .name = "loongson-rng" },
+       { .name = "loongson-tpm" },
+};
+
+static int loongson_se_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct loongson_se *se;
+       int nr_irq, irq, err;
+       dma_addr_t paddr;
+
+       se = devm_kmalloc(dev, sizeof(*se), GFP_KERNEL);
+       if (!se)
+               return -ENOMEM;
+       dev_set_drvdata(dev, se);
+       init_completion(&se->cmd_completion);
+       spin_lock_init(&se->dev_lock);
+       mutex_init(&se->engine_init_lock);
+
+       dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
+       if (device_property_read_u32(dev, "dmam_size", &se->dmam_size))
+               return -ENODEV;
+       se->dmam_base = dmam_alloc_coherent(dev, se->dmam_size, &paddr, 
GFP_KERNEL);
+       if (!se->dmam_base)
+               return -ENOMEM;
+
+       se->base = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(se->base))
+               return PTR_ERR(se->base);
+       writel(SE_INT_ALL, se->base + SE_S2LINT_EN);
+
+       nr_irq = platform_irq_count(pdev);
+       if (nr_irq <= 0)
+               return -ENODEV;
+       while (nr_irq) {
+               irq = platform_get_irq(pdev, --nr_irq);
+               err = devm_request_irq(dev, irq, se_irq_handler, 0, 
"loongson-se", se);
+               if (err)
+                       dev_err(dev, "failed to request irq: %d\n", irq);
+       }
+
+       err = loongson_se_init(se, paddr, se->dmam_size);
+       if (err)
+               return err;
+
+       return devm_mfd_add_devices(dev, 0, engines, ARRAY_SIZE(engines), NULL, 
0, NULL);
+}
+
+static const struct acpi_device_id loongson_se_acpi_match[] = {
+       {"LOON0011", 0},
+       {}
+};
+MODULE_DEVICE_TABLE(acpi, loongson_se_acpi_match);
+
+static struct platform_driver loongson_se_driver = {
+       .probe   = loongson_se_probe,
+       .driver  = {
+               .name  = "loongson-se",
+               .acpi_match_table = loongson_se_acpi_match,
+       },
+};
+module_platform_driver(loongson_se_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Yinggang Gu <guyingg...@loongson.cn>");
+MODULE_AUTHOR("Qunqin Zhao <zhaoqun...@loongson.cn>");
+MODULE_DESCRIPTION("Loongson Security Module driver");
diff --git a/drivers/crypto/loongson/loongson-se.h 
b/drivers/crypto/loongson/loongson-se.h
new file mode 100644
index 000000000..f962d6143
--- /dev/null
+++ b/drivers/crypto/loongson/loongson-se.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/* Copyright (C) 2025 Loongson Technology Corporation Limited */
+
+#ifndef __LOONGSON_SE_H__
+#define __LOONGSON_SE_H__
+
+#define SE_SEND_CMD_REG                        0x0
+#define SE_SEND_CMD_REG_LEN            0x8
+/* controller command id */
+#define SE_CMD_START                   0x0
+#define SE_CMD_SET_DMA                 0x3
+#define SE_CMD_SET_ENGINE_CMDBUF       0x4
+
+#define SE_S2LINT_STAT                 0x88
+#define SE_S2LINT_EN                   0x8c
+#define SE_S2LINT_CL                   0x94
+#define SE_L2SINT_STAT                 0x98
+#define SE_L2SINT_SET                  0xa0
+
+#define SE_INT_ALL                     0xffffffff
+#define SE_INT_CONTROLLER              BIT(0)
+
+#define SE_ENGINE_MAX                  16
+#define SE_ENGINE_RNG                  1
+#define SE_CMD_RNG                     0x100
+
+#define SE_ENGINE_TPM                  5
+#define SE_CMD_TPM                     0x500
+
+#define SE_ENGINE_CMD_SIZE             32
+
+struct loongson_se_engine {
+       struct loongson_se *se;
+       int id;
+
+       /* Command buffer */
+       void *command;
+       void *command_ret;
+
+       void *data_buffer;
+       uint buffer_size;
+       /* Data buffer offset to DMA base */
+       uint buffer_off;
+
+       struct completion completion;
+
+};
+
+struct loongson_se_engine *loongson_se_init_engine(struct device *dev, int id);
+int loongson_se_send_engine_cmd(struct loongson_se_engine *engine);
+
+#endif
-- 
2.45.2


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