linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
* [PATCH V3 1/5] ARM: implement debug_ll_io_init()
@ 2012-10-19 22:41 Stephen Warren
  2012-10-19 22:41 ` [PATCH V3 2/5] ARM: tegra: simplify DEBUG_LL UART selection options Stephen Warren
                   ` (5 more replies)
  0 siblings, 6 replies; 10+ messages in thread
From: Stephen Warren @ 2012-10-19 22:41 UTC (permalink / raw)
  To: linux-arm-kernel

From: Rob Herring <robherring2@gmail.com>

When using DEBUG_LL, the UART's (or other HW's) registers are mapped
into early page tables based on the results of assembly macro addruart.
Later, when the page tables are replaced, the same virtual address must
remain valid. Historically, this has been ensured by using defines from
<mach/iomap.h> in both the implementation of addruart, and the machine's
.map_io() function. However, with the move to single zImage, we wish to
remove <mach/iomap.h>. To enable this, the macro addruart may be used
when constructing the late page tables too; addruart is exposed as a
C function debug_ll_addr(), and used to set up the required mapping in
debug_ll_io_init(), which may called on an opt-in basis from a machine's
.map_io() function.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
[swarren: Mask map.virtual with PAGE_MASK. Checked for NULL results from
 debug_ll_addr (e.g. when selected UART isn't valid). Fixed compile when
 either !CONFIG_DEBUG_LL or CONFIG_DEBUG_SEMIHOSTING.]
Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
I assume this first patch should actually go into some arm-soc branch so
that if others want to take advantage of it this kernel cycle, they can.

v3: New patch.
---
 arch/arm/include/asm/mach/map.h |    7 +++++++
 arch/arm/kernel/debug.S         |   13 +++++++++++++
 arch/arm/mm/mmu.c               |   16 ++++++++++++++++
 3 files changed, 36 insertions(+), 0 deletions(-)

diff --git a/arch/arm/include/asm/mach/map.h b/arch/arm/include/asm/mach/map.h
index 195ac2f..2fe141f 100644
--- a/arch/arm/include/asm/mach/map.h
+++ b/arch/arm/include/asm/mach/map.h
@@ -40,6 +40,13 @@ extern void iotable_init(struct map_desc *, int);
 extern void vm_reserve_area_early(unsigned long addr, unsigned long size,
 				  void *caller);
 
+#ifdef CONFIG_DEBUG_LL
+extern void debug_ll_addr(unsigned long *paddr, unsigned long *vaddr);
+extern void debug_ll_io_init(void);
+#else
+static inline void debug_ll_io_init(void) {}
+#endif
+
 struct mem_type;
 extern const struct mem_type *get_mem_type(unsigned int type);
 /*
diff --git a/arch/arm/kernel/debug.S b/arch/arm/kernel/debug.S
index 66f711b..7525ce4 100644
--- a/arch/arm/kernel/debug.S
+++ b/arch/arm/kernel/debug.S
@@ -100,6 +100,13 @@ ENTRY(printch)
 		b	1b
 ENDPROC(printch)
 
+ENTRY(debug_ll_addr)
+		addruart r2, r3, ip
+		str	r2, [r0]
+		str	r3, [r1]
+		mov	pc, lr
+ENDPROC(debug_ll_addr)
+
 #else
 
 ENTRY(printascii)
@@ -119,4 +126,10 @@ ENTRY(printch)
 		mov	pc, lr
 ENDPROC(printch)
 
+ENTRY(debug_ll_addr)
+		mov	r2, #0
+		mov	r3, #0
+		mov	pc, lr
+ENDPROC(debug_ll_addr)
+
 #endif
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 941dfb9..39719bb 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -876,6 +876,22 @@ static void __init pci_reserve_io(void)
 #define pci_reserve_io() do { } while (0)
 #endif
 
+#ifdef CONFIG_DEBUG_LL
+void __init debug_ll_io_init(void)
+{
+	struct map_desc map;
+
+	debug_ll_addr(&map.pfn, &map.virtual);
+	if (!map.pfn || !map.virtual)
+		return;
+	map.pfn = __phys_to_pfn(map.pfn);
+	map.virtual &= PAGE_MASK;
+	map.length = PAGE_SIZE;
+	map.type = MT_DEVICE;
+	create_mapping(&map);
+}
+#endif
+
 static void * __initdata vmalloc_min =
 	(void *)(VMALLOC_END - (240 << 20) - VMALLOC_OFFSET);
 
-- 
1.7.0.4

^ permalink raw reply related	[flat|nested] 10+ messages in thread
end of thread, other threads:[~2012-11-05 19:03 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-10-19 22:41 [PATCH V3 1/5] ARM: implement debug_ll_io_init() Stephen Warren
2012-10-19 22:41 ` [PATCH V3 2/5] ARM: tegra: simplify DEBUG_LL UART selection options Stephen Warren
2012-10-19 22:41 ` [PATCH V3 3/5] ARM: tegra: decouple uncompress.h and debug-macro.S Stephen Warren
2012-10-22  8:18   ` Peter De Schrijver
2012-10-22 16:24     ` Stephen Warren
2012-10-22 22:13       ` Russell King - ARM Linux
2012-10-19 22:41 ` [PATCH V3 4/5] ARM: tegra: don't include iomap.h from debug-macro.S Stephen Warren
2012-10-19 22:41 ` [PATCH V3 5/5] ARM: tegra: move debug-macro.S to include/debug Stephen Warren
2012-10-20 13:36 ` [PATCH V3 1/5] ARM: implement debug_ll_io_init() Rob Herring
2012-11-05 19:03 ` Stephen Warren

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).