ocxl: Provide global MMIO accessors for external drivers

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

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

2 files changed, 235 insertions, 1 deletions

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);