[PATCH v3 7/7] ocxl: Provide global MMIO accessors for external drivers

[Alastair D'Silva]

From: Alastair D'Silva <alastair@xxxxxxxxxxx>

External drivers that communicate via OpenCAPI will need to make
MMIO calls to interact with the devices.

Signed-off-by: Alastair D'Silva <alastair@xxxxxxxxxxx>
Reviewed-by: Greg Kurz <groug@xxxxxxxx>
---
 drivers/misc/ocxl/Makefile |   2 +-
 drivers/misc/ocxl/mmio.c   | 234 +++++++++++++++++++++++++++++++++++++
 include/misc/ocxl.h        | 110 +++++++++++++++++
 3 files changed, 345 insertions(+), 1 deletion(-)
 create mode 100644 drivers/misc/ocxl/mmio.c

diff --git a/drivers/misc/ocxl/Makefile b/drivers/misc/ocxl/Makefile
index bc4e39bfda7b..d07d1bb8e8d4 100644
--- a/drivers/misc/ocxl/Makefile
+++ b/drivers/misc/ocxl/Makefile
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0+
 ccflags-$(CONFIG_PPC_WERROR)	+= -Werror
 
-ocxl-y				+= main.o pci.o config.o file.o pasid.o
+ocxl-y				+= main.o pci.o config.o file.o pasid.o mmio.o
 ocxl-y				+= link.o context.o afu_irq.o sysfs.o trace.o
 ocxl-y				+= core.o
 obj-$(CONFIG_OCXL)		+= ocxl.o
diff --git a/drivers/misc/ocxl/mmio.c b/drivers/misc/ocxl/mmio.c
new file mode 100644
index 000000000000..aae713db4ebe
--- /dev/null
+++ b/drivers/misc/ocxl/mmio.c
@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright 2019 IBM Corp.
+#include <linux/sched/mm.h>
+#include "trace.h"
+#include "ocxl_internal.h"
+
+int ocxl_global_mmio_read32(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u32 *val)
+{
+	if (offset > afu->config.global_mmio_size - 4)
+		return -EINVAL;
+
+#ifdef __BIG_ENDIAN__
+	if (endian == OCXL_HOST_ENDIAN)
+		endian = OCXL_BIG_ENDIAN;
+#endif
+
+	switch (endian) {
+	case OCXL_BIG_ENDIAN:
+		*val = readl_be((char *)afu->global_mmio_ptr + offset);
+		break;
+
+	default:
+		*val = readl((char *)afu->global_mmio_ptr + offset);
+		break;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ocxl_global_mmio_read32);
+
+int ocxl_global_mmio_read64(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u64 *val)
+{
+	if (offset > afu->config.global_mmio_size - 8)
+		return -EINVAL;
+
+#ifdef __BIG_ENDIAN__
+	if (endian == OCXL_HOST_ENDIAN)
+		endian = OCXL_BIG_ENDIAN;
+#endif
+
+	switch (endian) {
+	case OCXL_BIG_ENDIAN:
+		*val = readq_be((char *)afu->global_mmio_ptr + offset);
+		break;
+
+	default:
+		*val = readq((char *)afu->global_mmio_ptr + offset);
+		break;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ocxl_global_mmio_read64);
+
+int ocxl_global_mmio_write32(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u32 val)
+{
+	if (offset > afu->config.global_mmio_size - 4)
+		return -EINVAL;
+
+#ifdef __BIG_ENDIAN__
+	if (endian == OCXL_HOST_ENDIAN)
+		endian = OCXL_BIG_ENDIAN;
+#endif
+
+	switch (endian) {
+	case OCXL_BIG_ENDIAN:
+		writel_be(val, (char *)afu->global_mmio_ptr + offset);
+		break;
+
+	default:
+		writel(val, (char *)afu->global_mmio_ptr + offset);
+		break;
+	}
+
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ocxl_global_mmio_write32);
+
+int ocxl_global_mmio_write64(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u64 val)
+{
+	if (offset > afu->config.global_mmio_size - 8)
+		return -EINVAL;
+
+#ifdef __BIG_ENDIAN__
+	if (endian == OCXL_HOST_ENDIAN)
+		endian = OCXL_BIG_ENDIAN;
+#endif
+
+	switch (endian) {
+	case OCXL_BIG_ENDIAN:
+		writeq_be(val, (char *)afu->global_mmio_ptr + offset);
+		break;
+
+	default:
+		writeq(val, (char *)afu->global_mmio_ptr + offset);
+		break;
+	}
+
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ocxl_global_mmio_write64);
+
+int ocxl_global_mmio_set32(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u32 mask)
+{
+	u32 tmp;
+
+	if (offset > afu->config.global_mmio_size - 4)
+		return -EINVAL;
+
+#ifdef __BIG_ENDIAN__
+	if (endian == OCXL_HOST_ENDIAN)
+		endian = OCXL_BIG_ENDIAN;
+#endif
+
+	switch (endian) {
+	case OCXL_BIG_ENDIAN:
+		tmp = readl_be((char *)afu->global_mmio_ptr + offset);
+		tmp |= mask;
+		writel_be(tmp, (char *)afu->global_mmio_ptr + offset);
+		break;
+
+	default:
+		tmp = readl((char *)afu->global_mmio_ptr + offset);
+		tmp |= mask;
+		writel(tmp, (char *)afu->global_mmio_ptr + offset);
+		break;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ocxl_global_mmio_set32);
+
+int ocxl_global_mmio_set64(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u64 mask)
+{
+	u64 tmp;
+
+	if (offset > afu->config.global_mmio_size - 8)
+		return -EINVAL;
+
+#ifdef __BIG_ENDIAN__
+	if (endian == OCXL_HOST_ENDIAN)
+		endian = OCXL_BIG_ENDIAN;
+#endif
+
+	switch (endian) {
+	case OCXL_BIG_ENDIAN:
+		tmp = readq_be((char *)afu->global_mmio_ptr + offset);
+		tmp |= mask;
+		writeq_be(tmp, (char *)afu->global_mmio_ptr + offset);
+		break;
+
+	default:
+		tmp = readq((char *)afu->global_mmio_ptr + offset);
+		tmp |= mask;
+		writeq(tmp, (char *)afu->global_mmio_ptr + offset);
+		break;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ocxl_global_mmio_set64);
+
+int ocxl_global_mmio_clear32(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u32 mask)
+{
+	u32 tmp;
+
+	if (offset > afu->config.global_mmio_size - 4)
+		return -EINVAL;
+
+#ifdef __BIG_ENDIAN__
+	if (endian == OCXL_HOST_ENDIAN)
+		endian = OCXL_BIG_ENDIAN;
+#endif
+
+	switch (endian) {
+	case OCXL_BIG_ENDIAN:
+		tmp = readl_be((char *)afu->global_mmio_ptr + offset);
+		tmp &= ~mask;
+		writel_be(tmp, (char *)afu->global_mmio_ptr + offset);
+		break;
+
+	default:
+		tmp = readl((char *)afu->global_mmio_ptr + offset);
+		tmp &= ~mask;
+		writel(tmp, (char *)afu->global_mmio_ptr + offset);
+		break;
+	}
+
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ocxl_global_mmio_clear32);
+
+int ocxl_global_mmio_clear64(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u64 mask)
+{
+	u64 tmp;
+
+	if (offset > afu->config.global_mmio_size - 8)
+		return -EINVAL;
+
+#ifdef __BIG_ENDIAN__
+	if (endian == OCXL_HOST_ENDIAN)
+		endian = OCXL_BIG_ENDIAN;
+#endif
+
+	switch (endian) {
+	case OCXL_BIG_ENDIAN:
+		tmp = readq_be((char *)afu->global_mmio_ptr + offset);
+		tmp &= ~mask;
+		writeq_be(tmp, (char *)afu->global_mmio_ptr + offset);
+		break;
+
+	default:
+		tmp = readq((char *)afu->global_mmio_ptr + offset);
+		tmp &= ~mask;
+		writeq(tmp, (char *)afu->global_mmio_ptr + offset);
+		break;
+	}
+
+	writeq(tmp, (char *)afu->global_mmio_ptr + offset);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ocxl_global_mmio_clear64);
diff --git a/include/misc/ocxl.h b/include/misc/ocxl.h
index 1b48e9d63abb..e0742c00fb72 100644
--- a/include/misc/ocxl.h
+++ b/include/misc/ocxl.h
@@ -45,6 +45,12 @@ struct ocxl_fn_config {
 	s8 max_afu_index;
 };
 
+enum ocxl_endian {
+	OCXL_BIG_ENDIAN = 0,    /**< AFU data is big-endian */
+	OCXL_LITTLE_ENDIAN = 1, /**< AFU data is little-endian */
+	OCXL_HOST_ENDIAN = 2,   /**< AFU data is the same endianness as the host */
+};
+
 // These are opaque outside the ocxl driver
 struct ocxl_afu;
 struct ocxl_fn;
@@ -236,6 +242,110 @@ void ocxl_afu_set_private(struct ocxl_afu *afu, void *private);
  */
 void *ocxl_afu_get_private(struct ocxl_afu *dev);
 
+// Global MMIO
+/**
+ * Read a 32 bit value from global MMIO
+ *
+ * @afu: The AFU
+ * @offset: The Offset from the start of MMIO
+ * @endian: the endianness that the MMIO data is in
+ * @val: returns the value
+ *
+ * Returns 0 for success, negative on error
+ */
+int ocxl_global_mmio_read32(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u32 *val);
+
+/**
+ * Read a 64 bit value from global MMIO
+ *
+ * @afu: The AFU
+ * @offset: The Offset from the start of MMIO
+ * @endian: the endianness that the MMIO data is in
+ * @val: returns the value
+ *
+ * Returns 0 for success, negative on error
+ */
+int ocxl_global_mmio_read64(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u64 *val);
+
+/**
+ * Write a 32 bit value to global MMIO
+ *
+ * @afu: The AFU
+ * @offset: The Offset from the start of MMIO
+ * @endian: the endianness that the MMIO data is in
+ * @val: The value to write
+ *
+ * Returns 0 for success, negative on error
+ */
+int ocxl_global_mmio_write32(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u32 val);
+
+/**
+ * Write a 64 bit value to global MMIO
+ *
+ * @afu: The AFU
+ * @offset: The Offset from the start of MMIO
+ * @endian: the endianness that the MMIO data is in
+ * @val: The value to write
+ *
+ * Returns 0 for success, negative on error
+ */
+int ocxl_global_mmio_write64(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u64 val);
+
+/**
+ * Set bits in a 32 bit global MMIO register
+ *
+ * @afu: The AFU
+ * @offset: The Offset from the start of MMIO
+ * @endian: the endianness that the MMIO data is in
+ * @mask: a mask of the bits to set
+ *
+ * Returns 0 for success, negative on error
+ */
+int ocxl_global_mmio_set32(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u32 mask);
+
+/**
+ * Set bits in a 64 bit global MMIO register
+ *
+ * @afu: The AFU
+ * @offset: The Offset from the start of MMIO
+ * @endian: the endianness that the MMIO data is in
+ * @mask: a mask of the bits to set
+ *
+ * Returns 0 for success, negative on error
+ */
+int ocxl_global_mmio_set64(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u64 mask);
+
+/**
+ * Set bits in a 32 bit global MMIO register
+ *
+ * @afu: The AFU
+ * @offset: The Offset from the start of MMIO
+ * @endian: the endianness that the MMIO data is in
+ * @mask: a mask of the bits to set
+ *
+ * Returns 0 for success, negative on error
+ */
+int ocxl_global_mmio_clear32(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u32 mask);
+
+/**
+ * Set bits in a 64 bit global MMIO register
+ *
+ * @afu: The AFU
+ * @offset: The Offset from the start of MMIO
+ * @endian: the endianness that the MMIO data is in
+ * @mask: a mask of the bits to set
+ *
+ * Returns 0 for success, negative on error
+ */
+int ocxl_global_mmio_clear64(struct ocxl_afu *afu, size_t offset,
+				enum ocxl_endian endian, u64 mask);
 
 // Functions left here are for compatibility with the cxlflash driver
 
-- 
2.20.1