Patchwork [U-Boot,v3,02/17] sandbox: Provide a way to map from host RAM to U-Boot RAM

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Submitter Simon Glass
Date April 20, 2013, 6:42 p.m.
Message ID <1366483372-16523-3-git-send-email-sjg@chromium.org>
Download mbox | patch
Permalink /patch/238162/
State Accepted, archived
Delegated to: Simon Glass
Headers show

Comments

Simon Glass - April 20, 2013, 6:42 p.m.
In many cases, pointers to memory are passed around, and these pointers
refer to U-Boot memory, not host memory. This in itself is not a
problem.

However, in a few places, we cast that pointer back to a ulong (being
a U-Boot memory address). It is possible to convert many of these cases
to avoid this. However there are data structures (e.g. struct
bootm_headers) which use pointers. We could with a lot of effort adjust
the structs and all code that uses them to use ulong instead of pointers.

This seems like an unacceptable cost, since our objective with sandbox
is to minimise the impact on U-Boot code while maximising the features
available to sandbox.

Therefore, create a map_to_sysmem() function which converts from a
pointer to a U-Boot address. This can be used sparingly when needed.

Signed-off-by: Simon Glass <sjg@chromium.org>
---
Changes in v3:
- Rebase on master, to take account of generic board

Changes in v2:
- Use gd->arch.ram_buf instead of gd->ram_buf (now that generic board is in)

 arch/sandbox/cpu/cpu.c        | 5 +++++
 arch/sandbox/include/asm/io.h | 3 +++
 include/common.h              | 5 +++++
 3 files changed, 13 insertions(+)

Patch

diff --git a/arch/sandbox/cpu/cpu.c b/arch/sandbox/cpu/cpu.c
index b2788d5..dd8d495 100644
--- a/arch/sandbox/cpu/cpu.c
+++ b/arch/sandbox/cpu/cpu.c
@@ -57,6 +57,11 @@  void *map_physmem(phys_addr_t paddr, unsigned long len, unsigned long flags)
 	return (void *)(gd->arch.ram_buf + paddr);
 }
 
+phys_addr_t map_to_sysmem(void *ptr)
+{
+	return (u8 *)ptr - gd->arch.ram_buf;
+}
+
 void flush_dcache_range(unsigned long start, unsigned long stop)
 {
 }
diff --git a/arch/sandbox/include/asm/io.h b/arch/sandbox/include/asm/io.h
index d8c0236..54051a3 100644
--- a/arch/sandbox/include/asm/io.h
+++ b/arch/sandbox/include/asm/io.h
@@ -49,3 +49,6 @@  static inline void *map_sysmem(phys_addr_t paddr, unsigned long len)
 static inline void unmap_sysmem(const void *vaddr)
 {
 }
+
+/* Map from a pointer to our RAM buffer */
+phys_addr_t map_to_sysmem(void *ptr);
diff --git a/include/common.h b/include/common.h
index 0cfa6a8..76c79ae 100644
--- a/include/common.h
+++ b/include/common.h
@@ -897,6 +897,11 @@  static inline void *map_sysmem(phys_addr_t paddr, unsigned long len)
 static inline void unmap_sysmem(const void *vaddr)
 {
 }
+
+static inline phys_addr_t map_to_sysmem(void *ptr)
+{
+	return (phys_addr_t)(uintptr_t)ptr;
+}
 # endif
 
 #endif /* __ASSEMBLY__ */