[v3, 3/7] powerpc: enable the relocatable support for the fsl booke 32bit kernel

[Kevin Hao]

On Wed, Dec 18, 2013 at 05:48:25PM -0600, Scott Wood wrote:
> On Wed, Aug 07, 2013 at 09:18:31AM +0800, Kevin Hao wrote:
> > This is based on the codes in the head_44x.S. The difference is that
> > the init tlb size we used is 64M. With this patch we can only load the
> > kernel at address between memstart_addr ~ memstart_addr + 64M. We will
> > fix this restriction in the following patches.
> 
> Which following patch fixes the restriction?  With all seven patches
> applied, I was still only successful booting within 64M of memstart_addr.

There is bug in this patch series when booting above the 64M. It seems
that I missed to test this previously. Sorry for that. With the following
change I can boot the kernel at 0x5000000.

diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c
index 048d716ae706..ce0c7d7db6c3 100644
--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -171,11 +171,10 @@ unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
 	return 1UL << camsize;
 }
 
-unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
+static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt,
+					unsigned long ram, int max_cam_idx)
 {
 	int i;
-	unsigned long virt = PAGE_OFFSET;
-	phys_addr_t phys = memstart_addr;
 	unsigned long amount_mapped = 0;
 
 	/* Calculate CAM values */
@@ -195,6 +194,14 @@ unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
 	return amount_mapped;
 }
 
+unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
+{
+	unsigned long virt = PAGE_OFFSET;
+	phys_addr_t phys = memstart_addr;
+
+	return map_mem_in_cams_addr(phys, virt, ram, max_cam_idx);
+}
+
 #ifdef CONFIG_PPC32
 
 #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
@@ -289,7 +296,11 @@ notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
 		is_second_reloc = 1;
 		n = switch_to_as1();
 		/* map a 64M area for the second relocation */
-		map_mem_in_cams(0x4000000UL, CONFIG_LOWMEM_CAM_NUM);
+		if (memstart_addr > start)
+			map_mem_in_cams(0x4000000, CONFIG_LOWMEM_CAM_NUM);
+		else
+			map_mem_in_cams_addr(start, PAGE_OFFSET - offset,
+					0x4000000, CONFIG_LOWMEM_CAM_NUM);
 		restore_to_as0(n, offset, __va(dt_ptr));
 		/* We should never reach here */
 		panic("Relocation error");

I will do more test and then create a new spin to merge this change and rebase
on the latest kernel. Thanks for the review.

Kevin
> 
> -Scott
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