Re: [PATCH v2 7/8] powerpc/fsl_booke: make sure PAGE_OFFSET map to memstart_addr for relocatable kernel
On Sun, 2013-08-04 at 08:50 +0800, Kevin Hao wrote: On Fri, Jul 26, 2013 at 07:17:57PM -0500, Scott Wood wrote: diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c index 8f60ef8..dd283fd 100644 --- a/arch/powerpc/mm/fsl_booke_mmu.c +++ b/arch/powerpc/mm/fsl_booke_mmu.c @@ -224,7 +224,7 @@ void __init adjust_total_lowmem(void) i = switch_to_as1(); __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM); - restore_to_as0(i); + restore_to_as0(i, 0, 0); The device tree virtual address is zero? No. But if the __pa(PAGE_OFFSET in AS0) is equal to __pa(PAGE_OFFSET in AS1), that mean we don't need to do another relocation and the device tree virtual address is useless in this case. The documentation of restore_to_as0() should make it clear that r5 is ignored if r4 is zero. -Scott ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH v2 7/8] powerpc/fsl_booke: make sure PAGE_OFFSET map to memstart_addr for relocatable kernel
On Thu, 2013-07-04 at 20:54 +0800, Kevin Hao wrote: @@ -1222,6 +1266,9 @@ _GLOBAL(switch_to_as1) /* * Restore to the address space 0 and also invalidate the tlb entry created * by switch_to_as1. + * r3 - the tlb entry which should be invalidated + * r4 - __pa(PAGE_OFFSET in AS0) - pa(PAGE_OFFSET in AS1) + * r5 - device tree virtual address */ _GLOBAL(restore_to_as0) [snip] diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index 3a65644..8280dbb 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -149,7 +149,7 @@ extern void MMU_init_hw(void); extern unsigned long mmu_mapin_ram(unsigned long top); extern void adjust_total_lowmem(void); extern int switch_to_as1(void); -extern void restore_to_as0(int); +extern void restore_to_as0(int, int, void *); int seems wrong for the second argument. Shouldn't it be phys_addr_t? Also, please use parameter names. -Scott ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH v2 7/8] powerpc/fsl_booke: make sure PAGE_OFFSET map to memstart_addr for relocatable kernel
On Mon, Aug 05, 2013 at 07:10:06PM -0500, Scott Wood wrote: On Sun, 2013-08-04 at 08:50 +0800, Kevin Hao wrote: On Fri, Jul 26, 2013 at 07:17:57PM -0500, Scott Wood wrote: diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c index 8f60ef8..dd283fd 100644 --- a/arch/powerpc/mm/fsl_booke_mmu.c +++ b/arch/powerpc/mm/fsl_booke_mmu.c @@ -224,7 +224,7 @@ void __init adjust_total_lowmem(void) i = switch_to_as1(); __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM); -restore_to_as0(i); +restore_to_as0(i, 0, 0); The device tree virtual address is zero? No. But if the __pa(PAGE_OFFSET in AS0) is equal to __pa(PAGE_OFFSET in AS1), that mean we don't need to do another relocation and the device tree virtual address is useless in this case. The documentation of restore_to_as0() should make it clear that r5 is ignored if r4 is zero. OK, will add. Thanks, Kevin -Scott pgpkR9S0bUIcI.pgp Description: PGP signature ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH v2 7/8] powerpc/fsl_booke: make sure PAGE_OFFSET map to memstart_addr for relocatable kernel
On Mon, Aug 05, 2013 at 07:14:00PM -0500, Scott Wood wrote: On Thu, 2013-07-04 at 20:54 +0800, Kevin Hao wrote: @@ -1222,6 +1266,9 @@ _GLOBAL(switch_to_as1) /* * Restore to the address space 0 and also invalidate the tlb entry created * by switch_to_as1. + * r3 - the tlb entry which should be invalidated + * r4 - __pa(PAGE_OFFSET in AS0) - pa(PAGE_OFFSET in AS1) + * r5 - device tree virtual address */ _GLOBAL(restore_to_as0) [snip] diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index 3a65644..8280dbb 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -149,7 +149,7 @@ extern void MMU_init_hw(void); extern unsigned long mmu_mapin_ram(unsigned long top); extern void adjust_total_lowmem(void); extern int switch_to_as1(void); -extern void restore_to_as0(int); +extern void restore_to_as0(int, int, void *); int seems wrong for the second argument. Shouldn't it be phys_addr_t? This is the offset between __pa(PAGE_OFFSET in AS0) and __pa(PAGE_OFFSET in AS1). And the max offset should never exceed 768M. So a int type is safe here and using this type also avoid the ugly #ifdef CONFIG_PHYS_64BIT. Also, please use parameter names. Sure. Thanks, Kevin -Scott pgpwn9LUSY7M9.pgp Description: PGP signature ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH v2 7/8] powerpc/fsl_booke: make sure PAGE_OFFSET map to memstart_addr for relocatable kernel
On Fri, Jul 26, 2013 at 07:17:57PM -0500, Scott Wood wrote:
On 07/04/2013 07:54:13 AM, Kevin Hao wrote:
@@ -1222,6 +1266,9 @@ _GLOBAL(switch_to_as1)
/*
* Restore to the address space 0 and also invalidate the tlb
entry created
* by switch_to_as1.
+ * r3 - the tlb entry which should be invalidated
+ * r4 - __pa(PAGE_OFFSET in AS0) - pa(PAGE_OFFSET in AS1)
+ * r5 - device tree virtual address
*/
_GLOBAL(restore_to_as0)
mflrr0
@@ -1230,7 +1277,15 @@ _GLOBAL(restore_to_as0)
0: mflrr9
addir9,r9,1f - 0b
-mfmsr r7
+/*
+ * We may map the PAGE_OFFSET in AS0 to a different physical
address,
+ * so we need calculate the right jump and device tree address
based
+ * on the offset passed by r4.
+*/
Whitespace
Fixed.
+subfr9,r4,r9
+subfr5,r4,r5
+
+2: mfmsr r7
li r8,(MSR_IS | MSR_DS)
andcr7,r7,r8
@@ -1249,9 +1304,19 @@ _GLOBAL(restore_to_as0)
mtspr SPRN_MAS1,r9
tlbwe
isync
+
+cmpwi r4,0
+bne 3f
mtlrr0
blr
+/*
+ * The PAGE_OFFSET will map to a different physical address,
+ * jump to _start to do another relocation again.
+*/
+3: mr r3,r5
+bl _start
+
/*
* We put a few things here that have to be page-aligned. This stuff
* goes at the beginning of the data segment, which is page-aligned.
diff --git a/arch/powerpc/mm/fsl_booke_mmu.c
b/arch/powerpc/mm/fsl_booke_mmu.c
index 8f60ef8..dd283fd 100644
--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -224,7 +224,7 @@ void __init adjust_total_lowmem(void)
i = switch_to_as1();
__max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
-restore_to_as0(i);
+restore_to_as0(i, 0, 0);
The device tree virtual address is zero?
No. But if the __pa(PAGE_OFFSET in AS0) is equal to __pa(PAGE_OFFSET in AS1),
that mean we don't need to do another relocation and the device tree virtual
address is useless in this case.
pr_info(Memory CAM mapping: );
for (i = 0; i tlbcam_index - 1; i++)
@@ -245,30 +245,56 @@ void setup_initial_memory_limit(phys_addr_t
first_memblock_base,
}
#ifdef CONFIG_RELOCATABLE
-notrace void __init relocate_init(phys_addr_t start)
+int __initdata is_second_reloc;
+notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
{
unsigned long base = KERNELBASE;
-/*
- * Relocatable kernel support based on processing of dynamic
- * relocation entries.
- * Compute the virt_phys_offset :
- * virt_phys_offset = stext.run - kernstart_addr
- *
- * stext.run = (KERNELBASE ~0xfff) + (kernstart_addr
0xfff)
- * When we relocate, we have :
- *
- * (kernstart_addr 0xfff) = (stext.run 0xfff)
- *
- * hence:
- * virt_phys_offset = (KERNELBASE ~0xfff) -
- * (kernstart_addr ~0xfff)
- *
- */
kernstart_addr = start;
-start = ~0xfff;
-base = ~0xfff;
-virt_phys_offset = base - start;
+if (!is_second_reloc) {
Since it's at the end of a function and one side is much shorter
than the
other, please do:
if (is_second_reloc) {
virt_phys_offset = PAGE_OFFSET - memstart_addr;
return;
}
/* the rest of the code goes here without having to indent
everything */
Yes, this looks much better. Changed.
Otherwise, please use positive logic for if/else constructs.
+phys_addr_t size;
+
+/*
+ * Relocatable kernel support based on processing of dynamic
+ * relocation entries. Before we get the real memstart_addr,
+ * We will compute the virt_phys_offset like this:
+ * virt_phys_offset = stext.run - kernstart_addr
+ *
+ * stext.run = (KERNELBASE ~0xfff) +
+ * (kernstart_addr 0xfff)
+ * When we relocate, we have :
+ *
+ * (kernstart_addr 0xfff) = (stext.run 0xfff)
+ *
+ * hence:
+ * virt_phys_offset = (KERNELBASE ~0xfff) -
+ * (kernstart_addr ~0xfff)
+ *
+ */
+start = ~0xfff;
+base = ~0xfff;
+virt_phys_offset = base - start;
+early_get_first_memblock_info(__va(dt_ptr), size);
+/*
+ * We now get the memstart_addr, then we should check if this
+ * address is the same as what the PAGE_OFFSET map to now. If
+ * not we have to change the map of PAGE_OFFSET to
memstart_addr
+ * and do a second relocation.
+ */
+if (start != memstart_addr) {
+unsigned
Re: [PATCH v2 7/8] powerpc/fsl_booke: make sure PAGE_OFFSET map to memstart_addr for relocatable kernel
On 07/04/2013 07:54:13 AM, Kevin Hao wrote:
@@ -1222,6 +1266,9 @@ _GLOBAL(switch_to_as1)
/*
* Restore to the address space 0 and also invalidate the tlb entry
created
* by switch_to_as1.
+ * r3 - the tlb entry which should be invalidated
+ * r4 - __pa(PAGE_OFFSET in AS0) - pa(PAGE_OFFSET in AS1)
+ * r5 - device tree virtual address
*/
_GLOBAL(restore_to_as0)
mflrr0
@@ -1230,7 +1277,15 @@ _GLOBAL(restore_to_as0)
0: mflrr9
addir9,r9,1f - 0b
- mfmsr r7
+ /*
+ * We may map the PAGE_OFFSET in AS0 to a different physical
address,
+ * so we need calculate the right jump and device tree address
based
+* on the offset passed by r4.
+ */
Whitespace
+ subfr9,r4,r9
+ subfr5,r4,r5
+
+2: mfmsr r7
li r8,(MSR_IS | MSR_DS)
andcr7,r7,r8
@@ -1249,9 +1304,19 @@ _GLOBAL(restore_to_as0)
mtspr SPRN_MAS1,r9
tlbwe
isync
+
+ cmpwi r4,0
+ bne 3f
mtlrr0
blr
+ /*
+* The PAGE_OFFSET will map to a different physical address,
+* jump to _start to do another relocation again.
+ */
+3: mr r3,r5
+ bl _start
+
/*
* We put a few things here that have to be page-aligned. This stuff
* goes at the beginning of the data segment, which is page-aligned.
diff --git a/arch/powerpc/mm/fsl_booke_mmu.c
b/arch/powerpc/mm/fsl_booke_mmu.c
index 8f60ef8..dd283fd 100644
--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -224,7 +224,7 @@ void __init adjust_total_lowmem(void)
i = switch_to_as1();
__max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
- restore_to_as0(i);
+ restore_to_as0(i, 0, 0);
The device tree virtual address is zero?
pr_info(Memory CAM mapping: );
for (i = 0; i tlbcam_index - 1; i++)
@@ -245,30 +245,56 @@ void setup_initial_memory_limit(phys_addr_t
first_memblock_base,
}
#ifdef CONFIG_RELOCATABLE
-notrace void __init relocate_init(phys_addr_t start)
+int __initdata is_second_reloc;
+notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
{
unsigned long base = KERNELBASE;
- /*
-* Relocatable kernel support based on processing of dynamic
-* relocation entries.
-* Compute the virt_phys_offset :
-* virt_phys_offset = stext.run - kernstart_addr
-*
- * stext.run = (KERNELBASE ~0xfff) + (kernstart_addr
0xfff)
-* When we relocate, we have :
-*
-* (kernstart_addr 0xfff) = (stext.run 0xfff)
-*
-* hence:
-* virt_phys_offset = (KERNELBASE ~0xfff) -
-* (kernstart_addr ~0xfff)
-*
-*/
kernstart_addr = start;
- start = ~0xfff;
- base = ~0xfff;
- virt_phys_offset = base - start;
+ if (!is_second_reloc) {
Since it's at the end of a function and one side is much shorter than
the
other, please do:
if (is_second_reloc) {
virt_phys_offset = PAGE_OFFSET - memstart_addr;
return;
}
/* the rest of the code goes here without having to indent
everything */
Otherwise, please use positive logic for if/else constructs.
+ phys_addr_t size;
+
+ /*
+ * Relocatable kernel support based on processing of
dynamic
+ * relocation entries. Before we get the real
memstart_addr,
+* We will compute the virt_phys_offset like this:
+* virt_phys_offset = stext.run - kernstart_addr
+*
+* stext.run = (KERNELBASE ~0xfff) +
+ *(kernstart_addr
0xfff)
+* When we relocate, we have :
+*
+ * (kernstart_addr 0xfff) = (stext.run
0xfff)
+*
+* hence:
+* virt_phys_offset = (KERNELBASE ~0xfff) -
+ * (kernstart_addr
~0xfff)
+*
+*/
+ start = ~0xfff;
+ base = ~0xfff;
+ virt_phys_offset = base - start;
+ early_get_first_memblock_info(__va(dt_ptr), size);
+ /*
+ * We now get the memstart_addr, then we should check
if this
+ * address is the same as what the PAGE_OFFSET map to
now. If
+ * not we have to change the map of PAGE_OFFSET to
memstart_addr
+* and do a second relocation.
+*/
+ if (start != memstart_addr) {
+ unsigned long ram;
+ int n, offset = memstart_addr - start;
+
+ is_second_reloc = 1;
+ ram = size;
+ n = switch_to_as1();
+ map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
Do we really need this
[PATCH v2 7/8] powerpc/fsl_booke: make sure PAGE_OFFSET map to memstart_addr for relocatable kernel
This is always true for a non-relocatable kernel. Otherwise the kernel would get stuck. But for a relocatable kernel, it seems a little complicated. When booting a relocatable kernel, we just align the kernel start addr to 256M and map the PAGE_OFFSET from there. The relocation will base on this virtual address. But if this address is not the same as the memstart_addr, we will have to change the map of PAGE_OFFSET to the real memstart_addr and do another relocation again. Signed-off-by: Kevin Hao haoke...@gmail.com --- A new patch in v2. arch/powerpc/kernel/head_fsl_booke.S | 75 +--- arch/powerpc/mm/fsl_booke_mmu.c | 68 ++-- arch/powerpc/mm/mmu_decl.h | 2 +- 3 files changed, 118 insertions(+), 27 deletions(-) diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S index 0cbfe95..00cfb7e 100644 --- a/arch/powerpc/kernel/head_fsl_booke.S +++ b/arch/powerpc/kernel/head_fsl_booke.S @@ -84,6 +84,39 @@ _ENTRY(_start); mr r23,r3 mr r25,r4 + bl 0f +0: mflrr8 + addis r3,r8,(is_second_reloc - 0b)@ha + lwz r19,(is_second_reloc - 0b)@l(r3) + + /* Check if this is the second relocation. */ + cmpwi r19,1 + bne 1f + + /* +* For the second relocation, we already get the real memstart_addr +* from device tree. So we will map PAGE_OFFSET to memstart_addr, +* then the virtual address of start kernel should be: +* PAGE_OFFSET + (kernstart_addr - memstart_addr) +* Since the offset between kernstart_addr and memstart_addr should +* never be beyond 1G, so we can just use the lower 32bit of them +* for the calculation. +*/ + lis r3,PAGE_OFFSET@h + + addis r4,r8,(kernstart_addr - 0b)@ha + addir4,r4,(kernstart_addr - 0b)@l + lwz r5,4(r4) + + addis r6,r8,(memstart_addr - 0b)@ha + addir6,r6,(memstart_addr - 0b)@l + lwz r7,4(r6) + + subfr5,r7,r5 + add r3,r3,r5 + b 2f + +1: /* * We have the runtime (virutal) address of our base. * We calculate our shift of offset from a 256M page. @@ -97,7 +130,7 @@ _ENTRY(_start); subfr3,r5,r6/* r3 = r6 - r5 */ add r3,r4,r3/* Required Virutal Address */ - bl relocate +2: bl relocate #endif /* We try to not make any assumptions about how the boot loader @@ -121,10 +154,19 @@ _ENTRY(_start); _ENTRY(__early_start) +#ifdef CONFIG_RELOCATABLE + /* +* For the second relocation, we already set the right tlb entries +* for the kernel space, so skip the code in fsl_booke_entry_mapping.S + */ + cmpwi r19,1 + beq set_ivor +#endif #define ENTRY_MAPPING_BOOT_SETUP #include fsl_booke_entry_mapping.S #undef ENTRY_MAPPING_BOOT_SETUP +set_ivor: /* Establish the interrupt vector offsets */ SET_IVOR(0, CriticalInput); SET_IVOR(1, MachineCheck); @@ -210,11 +252,13 @@ _ENTRY(__early_start) bl early_init #ifdef CONFIG_RELOCATABLE + mr r3,r30 + mr r4,r31 #ifdef CONFIG_PHYS_64BIT - mr r3,r23 - mr r4,r25 + mr r5,r23 + mr r6,r25 #else - mr r3,r25 + mr r5,r25 #endif bl relocate_init #endif @@ -1222,6 +1266,9 @@ _GLOBAL(switch_to_as1) /* * Restore to the address space 0 and also invalidate the tlb entry created * by switch_to_as1. + * r3 - the tlb entry which should be invalidated + * r4 - __pa(PAGE_OFFSET in AS0) - pa(PAGE_OFFSET in AS1) + * r5 - device tree virtual address */ _GLOBAL(restore_to_as0) mflrr0 @@ -1230,7 +1277,15 @@ _GLOBAL(restore_to_as0) 0: mflrr9 addir9,r9,1f - 0b - mfmsr r7 + /* +* We may map the PAGE_OFFSET in AS0 to a different physical address, +* so we need calculate the right jump and device tree address based +* on the offset passed by r4. + */ + subfr9,r4,r9 + subfr5,r4,r5 + +2: mfmsr r7 li r8,(MSR_IS | MSR_DS) andcr7,r7,r8 @@ -1249,9 +1304,19 @@ _GLOBAL(restore_to_as0) mtspr SPRN_MAS1,r9 tlbwe isync + + cmpwi r4,0 + bne 3f mtlrr0 blr + /* +* The PAGE_OFFSET will map to a different physical address, +* jump to _start to do another relocation again. + */ +3: mr r3,r5 + bl _start + /* * We put a few things here that have to be page-aligned. This stuff * goes at the beginning of the data segment, which is page-aligned. diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c index 8f60ef8..dd283fd 100644 ---
