This driver supports Loongson Security Module, which provides the control
for it's hardware encryption acceleration child devices.

Co-developed-by: Yinggang Gu <guyingg...@loongson.cn>
Signed-off-by: Yinggang Gu <guyingg...@loongson.cn>
Signed-off-by: Qunqin Zhao <zhaoqun...@loongson.cn>
---
v3-v4: None

v2: Removed "ls6000se-sdf" device, added "ls6000se-tpm" device.
    Passed dmamem size to SE firmware in se_init_hw() function.

 drivers/mfd/Kconfig          |  10 +
 drivers/mfd/Makefile         |   2 +
 drivers/mfd/ls6000se.c       | 374 +++++++++++++++++++++++++++++++++++
 include/linux/mfd/ls6000se.h |  75 +++++++
 4 files changed, 461 insertions(+)
 create mode 100644 drivers/mfd/ls6000se.c
 create mode 100644 include/linux/mfd/ls6000se.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index d44c69bb3d..318fb113c1 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -2439,5 +2439,15 @@ config MFD_UPBOARD_FPGA
          To compile this driver as a module, choose M here: the module will be
          called upboard-fpga.
 
+config MFD_LS6000SE
+       tristate "Loongson Security Module Interface"
+       depends on LOONGARCH && ACPI
+       select MFD_CORE
+       help
+         The Loongson security module provides the control for hardware
+         encryption acceleration devices. Each device uses at least one
+         channel to interact with security module, and each channel may
+         have its own buffer provided by security module.
+
 endmenu
 endif
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 9220eaf7cf..9556de7715 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -294,3 +294,5 @@ obj-$(CONFIG_MFD_RSMU_I2C)  += rsmu_i2c.o rsmu_core.o
 obj-$(CONFIG_MFD_RSMU_SPI)     += rsmu_spi.o rsmu_core.o
 
 obj-$(CONFIG_MFD_UPBOARD_FPGA) += upboard-fpga.o
+
+obj-$(CONFIG_MFD_LS6000SE)     += ls6000se.o
diff --git a/drivers/mfd/ls6000se.c b/drivers/mfd/ls6000se.c
new file mode 100644
index 0000000000..24d76c2ffc
--- /dev/null
+++ b/drivers/mfd/ls6000se.c
@@ -0,0 +1,374 @@
+// 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/mfd/ls6000se.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+/*
+ * The Loongson Security Module provides the control for hardware
+ * encryption acceleration child devices. The SE framework is
+ * shown as follows:
+ *
+ *                   +------------+
+ *                   |    CPU     |
+ *                   +------------+
+ *                     ^       ^
+ *                 DMA |       | IRQ
+ *                     v       v
+ *        +-----------------------------------+
+ *        |     Loongson Security Module      |
+ *        +-----------------------------------+
+ *             ^                ^
+ *    channel1 |       channel2 |
+ *             v                v
+ *        +-----------+    +----------+
+ *        | sub-dev1  |    | sub-dev2 |  ..... Max sub-dev31
+ *        +-----------+    +----------+
+ *
+ * The CPU cannot directly communicate with SE's sub devices,
+ * but sends commands to SE, which processes the commands and
+ * sends them to the corresponding sub devices.
+ */
+
+struct loongson_se {
+       void __iomem *base;
+       u32 version;
+       spinlock_t dev_lock;
+       struct completion cmd_completion;
+
+       /* dma memory */
+       void *mem_base;
+       int mem_map_pages;
+       unsigned long *mem_map;
+
+       /* channel */
+       struct mutex ch_init_lock;
+       struct lsse_ch chs[SE_CH_MAX];
+};
+
+union se_request {
+       u32 info[8];
+       struct se_cmd {
+               u32 cmd;
+               u32 info[7];
+       } req;
+       struct se_res {
+               u32 cmd;
+               u32 cmd_ret;
+               u32 info[6];
+       } res;
+};
+
+static inline u32 se_readl(struct loongson_se *se, u32 off)
+{
+       return readl(se->base + off);
+}
+
+static inline void se_writel(struct loongson_se *se, u32 val, u32 off)
+{
+       writel(val, se->base + off);
+}
+
+static void se_enable_int_locked(struct loongson_se *se, u32 int_bit)
+{
+       u32 tmp;
+
+       tmp = se_readl(se, SE_S2LINT_EN);
+       tmp |= int_bit;
+       se_writel(se, tmp, SE_S2LINT_EN);
+}
+
+static void se_disable_int(struct loongson_se *se, u32 int_bit)
+{
+       unsigned long flag;
+       u32 tmp;
+
+       spin_lock_irqsave(&se->dev_lock, flag);
+
+       tmp = se_readl(se, SE_S2LINT_EN);
+       tmp &= ~(int_bit);
+       se_writel(se, tmp, SE_S2LINT_EN);
+
+       spin_unlock_irqrestore(&se->dev_lock, flag);
+}
+
+static int se_poll(struct loongson_se *se, u32 int_bit)
+{
+       u32 status;
+       int err;
+
+       spin_lock_irq(&se->dev_lock);
+
+       se_enable_int_locked(se, int_bit);
+       se_writel(se, int_bit, SE_L2SINT_SET);
+       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 se_send_requeset(struct loongson_se *se, union se_request *req)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(req->info); i++)
+               se_writel(se, req->info[i], SE_DATA_S + i * 4);
+
+       return se_poll(se, SE_INT_SETUP);
+}
+
+/*
+ * Called by SE's child device driver.
+ * Send a request to the corresponding device.
+ */
+int se_send_ch_requeset(struct lsse_ch *ch)
+{
+       return se_poll(ch->se, ch->int_bit);
+}
+EXPORT_SYMBOL_GPL(se_send_ch_requeset);
+
+static int se_get_res(struct loongson_se *se, u32 cmd, union se_request *res)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(res->info); i++)
+               res->info[i] = se_readl(se, SE_DATA_L + i * 4);
+
+       if (res->res.cmd != cmd)
+               return -EFAULT;
+
+       return 0;
+}
+
+static int se_send_genl_cmd(struct loongson_se *se, union se_request *req)
+{
+       int err;
+
+       err = se_send_requeset(se, req);
+       if (err)
+               return err;
+
+       if (!wait_for_completion_timeout(&se->cmd_completion, HZ))
+               return -ETIME;
+
+       return se_get_res(se, req->req.cmd, req);
+}
+
+static int se_set_msg(struct lsse_ch *ch)
+{
+       struct loongson_se *se = ch->se;
+       union se_request req;
+
+       req.req.cmd = SE_CMD_SETMSG;
+       req.req.info[0] = ch->id;
+       req.req.info[1] = ch->smsg - se->mem_base;
+       req.req.info[2] = ch->msg_size;
+
+       return se_send_genl_cmd(se, &req);
+}
+
+static irqreturn_t se_irq(int irq, void *dev_id)
+{
+       struct loongson_se *se = (struct loongson_se *)dev_id;
+       struct lsse_ch *ch;
+       u32 int_status;
+       int id;
+
+       int_status = se_readl(se, SE_S2LINT_STAT);
+       se_disable_int(se, int_status);
+       if (int_status & SE_INT_SETUP) {
+               complete(&se->cmd_completion);
+               int_status &= ~SE_INT_SETUP;
+               se_writel(se, SE_INT_SETUP, SE_S2LINT_CL);
+       }
+
+       while (int_status) {
+               id = __ffs(int_status);
+
+               ch = &se->chs[id];
+               if (ch->complete)
+                       ch->complete(ch);
+               int_status &= ~BIT(id);
+               se_writel(se, BIT(id), SE_S2LINT_CL);
+       }
+
+       return IRQ_HANDLED;
+}
+
+static int se_init_hw(struct loongson_se *se, dma_addr_t addr, int size)
+{
+       union se_request req;
+       int err;
+
+       /* Start engine */
+       req.req.cmd = SE_CMD_START;
+       err = se_send_genl_cmd(se, &req);
+       if (err)
+               return err;
+
+       /* Get Version */
+       req.req.cmd = SE_CMD_GETVER;
+       err = se_send_genl_cmd(se, &req);
+       if (err)
+               return err;
+       se->version = req.res.info[0];
+
+       /* Setup dma memory */
+       req.req.cmd = SE_CMD_SETBUF;
+       req.req.info[0] = addr & 0xffffffff;
+       req.req.info[1] = addr >> 32;
+       req.req.info[2] = size;
+
+       return se_send_genl_cmd(se, &req);
+}
+
+/*
+ * se_init_ch() - Init the channel used by child device.
+ *
+ * Allocate dma memory as agreed upon with SE on SE probe,
+ * and register the callback function when the data processing
+ * in this channel is completed.
+ */
+struct lsse_ch *se_init_ch(struct device *dev, int id, int data_size, int 
msg_size,
+                          void *priv, void (*complete)(struct lsse_ch *se_ch))
+{
+       struct loongson_se *se = dev_get_drvdata(dev);
+       struct lsse_ch *ch;
+       int data_first, data_nr;
+       int msg_first, msg_nr;
+
+       mutex_lock(&se->ch_init_lock);
+
+       ch = &se->chs[id];
+       ch->se = se;
+       ch->id = id;
+       ch->int_bit = BIT(id);
+
+       data_nr = round_up(data_size, PAGE_SIZE) / PAGE_SIZE;
+       data_first = bitmap_find_next_zero_area(se->mem_map, se->mem_map_pages,
+                                               0, data_nr, 0);
+       if (data_first >= se->mem_map_pages) {
+               ch = NULL;
+               goto out_unlock;
+       }
+
+       bitmap_set(se->mem_map, data_first, data_nr);
+       ch->off = data_first * PAGE_SIZE;
+       ch->data_buffer = se->mem_base + ch->off;
+       ch->data_size = data_size;
+
+       msg_nr = round_up(msg_size, PAGE_SIZE) / PAGE_SIZE;
+       msg_first = bitmap_find_next_zero_area(se->mem_map, se->mem_map_pages,
+                                              0, msg_nr, 0);
+       if (msg_first >= se->mem_map_pages) {
+               ch = NULL;
+               goto out_unlock;
+       }
+
+       bitmap_set(se->mem_map, msg_first, msg_nr);
+       ch->smsg = se->mem_base + msg_first * PAGE_SIZE;
+       ch->rmsg = ch->smsg + msg_size / 2;
+       ch->msg_size = msg_size;
+       ch->complete = complete;
+       ch->priv = priv;
+       ch->version = se->version;
+
+       if (se_set_msg(ch))
+               ch = NULL;
+
+out_unlock:
+       mutex_unlock(&se->ch_init_lock);
+
+       return ch;
+}
+EXPORT_SYMBOL_GPL(se_init_ch);
+
+static const struct mfd_cell se_devs[] = {
+       { .name = "ls6000se-sdf" },
+       { .name = "ls6000se-tpm" },
+};
+
+static int loongson_se_probe(struct platform_device *pdev)
+{
+       struct loongson_se *se;
+       struct device *dev = &pdev->dev;
+       int nr_irq, irq, err, size;
+       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->ch_init_lock);
+       dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
+       if (device_property_read_u32(dev, "dmam_size", &size))
+               return -ENODEV;
+       size = roundup_pow_of_two(size);
+       se->mem_base = dmam_alloc_coherent(dev, size, &paddr, GFP_KERNEL);
+       if (!se->mem_base)
+               return -ENOMEM;
+       se->mem_map_pages = size / PAGE_SIZE;
+       se->mem_map = devm_bitmap_zalloc(dev, se->mem_map_pages, GFP_KERNEL);
+       if (!se->mem_map)
+               return -ENOMEM;
+
+       se->base = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(se->base))
+               return PTR_ERR(se->base);
+
+       nr_irq = platform_irq_count(pdev);
+       if (nr_irq <= 0)
+               return -ENODEV;
+       while (nr_irq) {
+               irq = platform_get_irq(pdev, --nr_irq);
+               /* Use the same interrupt handler address.
+                * Determine which irq it is accroding
+                * SE_S2LINT_STAT register.
+                */
+               err = devm_request_irq(dev, irq, se_irq, 0, "ls6000se", se);
+               if (err)
+                       dev_err(dev, "failed to request irq: %d\n", irq);
+       }
+
+       err = se_init_hw(se, paddr, size);
+       if (err)
+               return err;
+
+       return devm_mfd_add_devices(dev, 0, se_devs, ARRAY_SIZE(se_devs),
+                                   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  = "ls6000se",
+               .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/include/linux/mfd/ls6000se.h b/include/linux/mfd/ls6000se.h
new file mode 100644
index 0000000000..f70e9f196a
--- /dev/null
+++ b/include/linux/mfd/ls6000se.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/* Copyright (C) 2025 Loongson Technology Corporation Limited */
+
+#ifndef __LOONGSON_SE_H__
+#define __LOONGSON_SE_H__
+
+#define SE_DATA_S                      0x0
+#define SE_DATA_L                      0x20
+#define SE_S2LINT_STAT                 0x88
+#define SE_S2LINT_EN                   0x8c
+#define SE_S2LINT_SET                  0x90
+#define SE_S2LINT_CL                   0x94
+#define SE_L2SINT_STAT                 0x98
+#define SE_L2SINT_EN                   0x9c
+#define SE_L2SINT_SET                  0xa0
+#define SE_L2SINT_CL                   0xa4
+
+/* INT bit definition */
+#define SE_INT_SETUP                   BIT(0)
+#define SE_INT_TPM                     BIT(5)
+
+#define SE_CMD_START                   0x0
+#define SE_CMD_STOP                    0x1
+#define SE_CMD_GETVER                  0x2
+#define SE_CMD_SETBUF                  0x3
+#define SE_CMD_SETMSG                  0x4
+
+#define SE_CMD_RNG                     0x100
+#define SE_CMD_SM2_SIGN                        0x200
+#define SE_CMD_SM2_VSIGN               0x201
+#define SE_CMD_SM3_DIGEST              0x300
+#define SE_CMD_SM3_UPDATE              0x301
+#define SE_CMD_SM3_FINISH              0x302
+#define SE_CMD_SM4_ECB_ENCRY           0x400
+#define SE_CMD_SM4_ECB_DECRY           0x401
+#define SE_CMD_SM4_CBC_ENCRY           0x402
+#define SE_CMD_SM4_CBC_DECRY           0x403
+#define SE_CMD_SM4_CTR                 0x404
+#define SE_CMD_TPM                     0x500
+#define SE_CMD_ZUC_INIT_READ           0x600
+#define SE_CMD_ZUC_READ                        0x601
+#define SE_CMD_SDF                     0x700
+
+#define SE_CH_MAX                      32
+#define SE_CH_RNG                      1
+#define SE_CH_SM2                      2
+#define SE_CH_SM3                      3
+#define SE_CH_SM4                      4
+#define SE_CH_TPM                      5
+#define SE_CH_ZUC                      6
+#define SE_CH_SDF                      7
+
+struct lsse_ch {
+       struct loongson_se *se;
+       void *priv;
+       u32 version;
+       u32 id;
+       u32 int_bit;
+
+       void *smsg;
+       void *rmsg;
+       int msg_size;
+
+       void *data_buffer;
+       int data_size;
+       u32 off;
+
+       void (*complete)(struct lsse_ch *se_ch);
+};
+
+struct lsse_ch *se_init_ch(struct device *dev, int id, int data_size, int 
msg_size,
+                          void *priv, void (*complete)(struct lsse_ch *se_ch));
+int se_send_ch_requeset(struct lsse_ch *ch);
+
+#endif
-- 
2.43.0


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