This patch adds helpers for implementing the memory mapped I/O host
operations that can be used by code that implements host
devices. Generic host operations for lkl_ioremap and lkl_iomem_access
are provided that allows multiplexing multiple I/O memory mapped
regions.
The host device code can create a new memory mapped I/O region with
register_iomem(). Read and write access functions need to be provided
by the caller.
Signed-off-by: Octavian Purdila <octavian.purd...@intel.com>
---
tools/lkl/lib/iomem.c | 119 ++++++++++++++++++++++++++++++++++++++++++++++++++
tools/lkl/lib/iomem.h | 14 ++++++
2 files changed, 133 insertions(+)
create mode 100644 tools/lkl/lib/iomem.c
create mode 100644 tools/lkl/lib/iomem.h
diff --git a/tools/lkl/lib/iomem.c b/tools/lkl/lib/iomem.c
new file mode 100644
index 0000000..bef6b71
--- /dev/null
+++ b/tools/lkl/lib/iomem.c
@@ -0,0 +1,119 @@
+#include <string.h>
+#include <stdint.h>
+#include <lkl_host.h>
+
+#include "iomem.h"
+
+#define IOMEM_OFFSET_BITS 24
+#define IOMEM_ADDR_MARK 0x8000000
+#define MAX_IOMEM_REGIONS (IOMEM_ADDR_MARK >> IOMEM_OFFSET_BITS)
+
+#define IOMEM_ADDR_TO_INDEX(addr) \
+ ((((uintptr_t)addr & ~IOMEM_ADDR_MARK) >> IOMEM_OFFSET_BITS))
+#define IOMEM_ADDR_TO_OFFSET(addr) \
+ (((uintptr_t)addr) & ((1 << IOMEM_OFFSET_BITS) - 1))
+#define IOMEM_INDEX_TO_ADDR(i) \
+ (void *)(uintptr_t)((i << IOMEM_OFFSET_BITS) | IOMEM_ADDR_MARK)
+
+static struct iomem_region {
+ void *base;
+ void *iomem_addr;
+ int size;
+ const struct lkl_iomem_ops *ops;
+} *iomem_regions[MAX_IOMEM_REGIONS];
+
+static struct iomem_region *find_iomem_reg(void *base)
+{
+ int i;
+
+ for (i = 0; i < MAX_IOMEM_REGIONS; i++)
+ if (iomem_regions[i] && iomem_regions[i]->base == base)
+ return iomem_regions[i];
+
+ return NULL;
+}
+
+int register_iomem(void *base, int size, const struct lkl_iomem_ops *ops)
+{
+ struct iomem_region *iomem_reg;
+ int i;
+
+ if (size > (1 << IOMEM_OFFSET_BITS) - 1)
+ return -1;
+
+ if (find_iomem_reg(base))
+ return -1;
+
+ for (i = 0; i < MAX_IOMEM_REGIONS; i++)
+ if (!iomem_regions[i])
+ break;
+
+ if (i >= MAX_IOMEM_REGIONS)
+ return -1;
+
+ iomem_reg = lkl_host_ops.mem_alloc(sizeof(*iomem_reg));
+ if (!iomem_reg)
+ return -1;
+
+ iomem_reg->base = base;
+ iomem_reg->size = size;
+ iomem_reg->ops = ops;
+ iomem_reg->iomem_addr = IOMEM_INDEX_TO_ADDR(i);
+
+ iomem_regions[i] = iomem_reg;
+
+ return 0;
+}
+
+void unregister_iomem(void *iomem_base)
+{
+ struct iomem_region *iomem_reg = find_iomem_reg(iomem_base);
+ unsigned int index;
+
+ if (!iomem_reg) {
+ lkl_printf("%s: invalid iomem base %p\n", __func__, iomem_base);
+ return;
+ }
+
+ index = IOMEM_ADDR_TO_INDEX(iomem_reg->iomem_addr);
+ if (index >= MAX_IOMEM_REGIONS) {
+ lkl_printf("%s: invalid iomem_addr %p\n", __func__,
+ iomem_reg->iomem_addr);
+ return;
+ }
+
+ iomem_regions[index] = NULL;
+ lkl_host_ops.mem_free(iomem_reg->base);
+ lkl_host_ops.mem_free(iomem_reg);
+}
+
+void *lkl_ioremap(long addr, int size)
+{
+ struct iomem_region *iomem_reg = find_iomem_reg((void *)addr);
+
+ if (iomem_reg && size <= iomem_reg->size)
+ return iomem_reg->iomem_addr;
+
+ return NULL;
+}
+
+int lkl_iomem_access(const volatile void *addr, void *res, int size, int write)
+{
+ struct iomem_region *iomem_reg;
+ int index = IOMEM_ADDR_TO_INDEX(addr);
+ int offset = IOMEM_ADDR_TO_OFFSET(addr);
+ int ret;
+
+ if (index > MAX_IOMEM_REGIONS || !iomem_regions[index] ||
+ offset + size > iomem_regions[index]->size)
+ return -1;
+
+ iomem_reg = iomem_regions[index];
+
+ if (write)
+ ret = iomem_reg->ops->write(iomem_reg->base, offset, res, size);
+ else
+ ret = iomem_reg->ops->read(iomem_reg->base, offset, res, size);
+
+ return ret;
+}
diff --git a/tools/lkl/lib/iomem.h b/tools/lkl/lib/iomem.h
new file mode 100644
index 0000000..53707d7
--- /dev/null
+++ b/tools/lkl/lib/iomem.h
@@ -0,0 +1,14 @@
+#ifndef _LKL_LIB_IOMEM_H
+#define _LKL_LIB_IOMEM_H
+
+struct lkl_iomem_ops {
+ int (*read)(void *data, int offset, void *res, int size);
+ int (*write)(void *data, int offset, void *value, int size);
+};
+
+int register_iomem(void *base, int size, const struct lkl_iomem_ops *ops);
+void unregister_iomem(void *iomem_base);
+void *lkl_ioremap(long addr, int size);
+int lkl_iomem_access(const volatile void *addr, void *res, int size, int
write);
+
+#endif /* _LKL_LIB_IOMEM_H */
--
2.1.0
--
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