[PATCH 10/10] spi: espi_amd: Add eSPI PC channel MMIO read/write IOCTL commands

[Raju Rangoju <Raju.Rangoju@xxxxxxx>]

Add new IOCTL commands to perform eSPI peripheral channel(PC) MMIO
read/write operations with eSPI slave0. The changes include validation
of MMIO address ranges before initiating the read/write operations.

Co-developed-by: Krishnamoorthi M <krishnamoorthi.m@xxxxxxx>
Signed-off-by: Krishnamoorthi M <krishnamoorthi.m@xxxxxxx>
Co-developed-by: Akshata MukundShetty <akshata.mukundshetty@xxxxxxx>
Signed-off-by: Akshata MukundShetty <akshata.mukundshetty@xxxxxxx>
Signed-off-by: Raju Rangoju <Raju.Rangoju@xxxxxxx>
---
 drivers/spi/espi-amd-core.c | 80 +++++++++++++++++++++++++++++++++++++
 drivers/spi/espi-amd-dev.c  | 53 ++++++++++++++++++++++++
 drivers/spi/espi-amd.h      |  9 +++++
 3 files changed, 142 insertions(+)

diff --git a/drivers/spi/espi-amd-core.c b/drivers/spi/espi-amd-core.c
index 18bfd2ca2316..31069e86c704 100644
--- a/drivers/spi/espi-amd-core.c
+++ b/drivers/spi/espi-amd-core.c
@@ -805,6 +805,86 @@ int amd_espi_periph_io_read(struct amd_espi *amd_espi, struct periph_io_rw *msg_
 	return CB_SUCCESS;
 }
 
+static int is_mmio_address_valid(struct amd_espi *amd_espi,  struct periph_mem_rw *mem_data)
+{
+	struct io_mmio_decode_config io_conf;
+	u32 mmio_end_addr = mem_data->addr + 3;
+
+	amd_espi_get_io_mmio_decode_info(amd_espi, &io_conf);
+	if (mem_data->addr >= io_conf.mmio_target_range0 &&
+	    (mmio_end_addr <= ((u32)io_conf.mmio_target_range0 +
+			       io_conf.mmio_range4.mmio_range0_size))) {
+		if (!(io_conf.io_mmio_dc_enable & MMIO_DECODE_RANGE0)) {
+			dev_err(amd_espi->dev, "MMIO range0 not enabled for address: 0x%x\n",
+				mem_data->addr);
+			return -EINVAL;
+		}
+	} else if ((mem_data->addr >= io_conf.mmio_target_range1) &&
+		   (mmio_end_addr <= ((u32)io_conf.mmio_target_range1 +
+				      io_conf.mmio_range4.mmio_range1_size))) {
+		if (!(io_conf.io_mmio_dc_enable & MMIO_DECODE_RANGE1)) {
+			dev_err(amd_espi->dev, "MMIO range1 not enabled for address: 0x%x\n",
+				mem_data->addr);
+			return -EINVAL;
+		}
+	} else if ((mem_data->addr >= io_conf.mmio_target_range2) &&
+		   (mmio_end_addr <= ((u32)io_conf.mmio_target_range2 +
+				      io_conf.mmio_range5.mmio_range2_size))) {
+		if (!(io_conf.io_mmio_dc_enable & MMIO_DECODE_RANGE2)) {
+			dev_err(amd_espi->dev, "MMIO range2 not enabled for address: 0x%x\n",
+				mem_data->addr);
+			return -EINVAL;
+		}
+	} else if ((mem_data->addr >= io_conf.mmio_target_range3) &&
+		   (mmio_end_addr <= ((u32)io_conf.mmio_target_range3 +
+				      io_conf.mmio_range5.mmio_range3_size))) {
+		if (!(io_conf.io_mmio_dc_enable & MMIO_DECODE_RANGE3)) {
+			dev_err(amd_espi->dev, "MMIO range3 not enabled for address: 0x%x\n",
+				mem_data->addr);
+			return -EINVAL;
+		}
+	} else {
+		dev_err(amd_espi->dev, "Address 0x%x is invalid\n", mem_data->addr);
+		return -EINVAL;
+	}
+
+	return CB_SUCCESS;
+}
+
+int amd_espi_periph_mem_write(struct amd_espi *amd_espi, struct periph_mem_rw *mem_data)
+{
+	void __iomem *mmio_addr;
+
+	if (is_mmio_address_valid(amd_espi, mem_data) != CB_SUCCESS)
+		return -EINVAL;
+
+	mmio_addr = ioremap(mem_data->addr, 4);
+	if (!mmio_addr)
+		return -ENOMEM;
+
+	writel(mem_data->data, mmio_addr);
+	iounmap(mmio_addr);
+
+	return CB_SUCCESS;
+}
+
+int amd_espi_periph_mem_read(struct amd_espi *amd_espi, struct periph_mem_rw *mem_data)
+{
+	void __iomem *mmio_addr;
+
+	if (is_mmio_address_valid(amd_espi, mem_data) != CB_SUCCESS)
+		return -EINVAL;
+
+	mmio_addr = ioremap(mem_data->addr, 4);
+	if (!mmio_addr)
+		return -ENOMEM;
+
+	mem_data->data = readl(mmio_addr);
+	iounmap(mmio_addr);
+
+	return CB_SUCCESS;
+}
+
 static int amd_espi_get_master_cap(struct amd_espi *amd_espi, struct espi_master *master)
 {
 	u32 master_cap_reg, info;
diff --git a/drivers/spi/espi-amd-dev.c b/drivers/spi/espi-amd-dev.c
index 184ffdad4a48..7e4477dd17e5 100644
--- a/drivers/spi/espi-amd-dev.c
+++ b/drivers/spi/espi-amd-dev.c
@@ -372,6 +372,53 @@ static int amd_espi_ioctl_io_read(struct amd_espi *amd_espi, unsigned long arg)
 	return ret;
 }
 
+static int amd_espi_ioctl_mem_write(struct amd_espi *amd_espi, unsigned long arg)
+{
+	struct periph_mem_rw *mem_data;
+	int ret;
+
+	mem_data = kzalloc(sizeof(*mem_data), GFP_KERNEL);
+	if (!mem_data)
+		return -ENOMEM;
+
+	if (copy_from_user(mem_data, (void __user *)arg, sizeof(struct periph_mem_rw))) {
+		ret = -EFAULT;
+		goto mem_write_free;
+	}
+
+	ret = amd_espi_periph_mem_write(amd_espi, mem_data);
+
+mem_write_free:
+	kfree(mem_data);
+	return ret;
+}
+
+static int amd_espi_ioctl_mem_read(struct amd_espi *amd_espi, unsigned long arg)
+{
+	struct periph_mem_rw *mem_data;
+	int ret;
+
+	mem_data = kzalloc(sizeof(*mem_data), GFP_KERNEL);
+	if (!mem_data)
+		return -ENOMEM;
+
+	if (copy_from_user(mem_data, (void __user *)arg, sizeof(struct periph_mem_rw))) {
+		ret = -EFAULT;
+		goto mem_read_free;
+	}
+
+	ret = amd_espi_periph_mem_read(amd_espi, mem_data);
+	if (ret != CB_SUCCESS)
+		goto mem_read_free;
+
+	if (copy_to_user((void __user *)arg, mem_data, sizeof(struct periph_mem_rw)))
+		ret = -EFAULT;
+
+mem_read_free:
+	kfree(mem_data);
+	return ret;
+}
+
 static long amd_espi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct amd_espi *amd_espi = filp->private_data;
@@ -422,6 +469,12 @@ static long amd_espi_ioctl(struct file *filp, unsigned int cmd, unsigned long ar
 	case ESPI_IO_READ:
 		ret = amd_espi_ioctl_io_read(amd_espi, arg);
 		break;
+	case ESPI_MEM_WRITE:
+		ret = amd_espi_ioctl_mem_write(amd_espi, arg);
+		break;
+	case ESPI_MEM_READ:
+		ret = amd_espi_ioctl_mem_read(amd_espi, arg);
+		break;
 	default:
 		dev_err(amd_espi->dev, "ESPI command not found, returning error\n");
 		ret = -EINVAL;
diff --git a/drivers/spi/espi-amd.h b/drivers/spi/espi-amd.h
index 4c67aa9f45a6..9e084bec8ff5 100644
--- a/drivers/spi/espi-amd.h
+++ b/drivers/spi/espi-amd.h
@@ -178,6 +178,8 @@
 #define ESPI_DS_IODECODE_CONFIG      _IOWR(ESPI_MAGIC_NUMBER, 0x9, u32)
 #define ESPI_IO_WRITE                _IOWR(ESPI_MAGIC_NUMBER, 0xa, struct periph_io_rw)
 #define ESPI_IO_READ                 _IOWR(ESPI_MAGIC_NUMBER, 0xb, struct periph_io_rw)
+#define ESPI_MEM_WRITE               _IOWR(ESPI_MAGIC_NUMBER, 0xc, struct periph_mem_rw)
+#define ESPI_MEM_READ                _IOWR(ESPI_MAGIC_NUMBER, 0xd, struct periph_mem_rw)
 
 /*
  * enum amd_espi_versions - eSPI controller versions
@@ -382,6 +384,11 @@ struct periph_io_rw {
 	union io_data data;
 } __packed;
 
+struct periph_mem_rw {
+	u32 addr;
+	u32 data;
+};
+
 /* Function prototypes */
 int amd_espi_device_create(struct amd_espi *amd_espi, struct device *dev);
 void amd_espi_device_remove(struct amd_espi *amd_espi);
@@ -404,4 +411,6 @@ void amd_espi_set_io_mmio_decode_config(struct amd_espi *amd_espi,
 void amd_espi_disable_io_decode_range(struct amd_espi *amd_espi, u32 io_range);
 int amd_espi_periph_io_write(struct amd_espi *amd_espi, struct periph_io_rw *message_io);
 int amd_espi_periph_io_read(struct amd_espi *amd_espi, struct periph_io_rw *message_io);
+int amd_espi_periph_mem_write(struct amd_espi *amd_espi, struct periph_mem_rw *mem_data);
+int amd_espi_periph_mem_read(struct amd_espi *amd_espi, struct periph_mem_rw *mem_data);
 #endif
-- 
2.34.1