On 20/05/2021 15:46, Christophe Leroy wrote:
Le 20/05/2021 à 05:29, Alexey Kardashevskiy a écrit :
The immediate problem is that after
0bd3f9e953bd ("powerpc/legacy_serial: Use early_ioremap()")
the kernel silently reboots. The reason is that early_ioremap() returns
broken addresses as it uses slot_virt[] array which initialized with
offsets from FIXADDR_TOP == IOREMAP_END+FIXADDR_SIZE ==
KERN_IO_END- FIXADDR_SIZ + FIXADDR_SIZE == __kernel_io_end which is 0
when early_ioremap_setup() is called. __kernel_io_end is initialized
little bit later in early_init_mmu().
This fixes the initialization by swapping early_ioremap_setup and
early_init_mmu.
Hum ... Chris tested it on a T2080RDB, that must be a book3e.
So we missed it. I guess your fix is right.
Oh cool.
This also fixes IOREMAP_END to use FIXADDR_SIZE defined just next to it,
seems to make sense, unless there is some weird logic with redefining
FIXADDR_SIZE as the compiling goes.
Well, I don't think the order of defines matters, the change should be
kept out of the fix.
When I see this:
#define IOREMAP_END (KERN_IO_END - FIXADDR_SIZE)
#define FIXADDR_SIZE SZ_32M
... I have to think harder what FIXADDR_SIZE was in the first macro and
in what order the preprocessor expands them.
But if you want it anyway, then I'd suggest to move it before
IOREMAP_BASE in order to keep the 3 IOREMAP_xxx together.
Up to Michael, I guess.
Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
Reviewed-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
arch/powerpc/include/asm/book3s/64/pgtable.h | 2 +-
arch/powerpc/kernel/setup_64.c | 3 ++-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h
b/arch/powerpc/include/asm/book3s/64/pgtable.h
index a666d561b44d..54a06129794b 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -325,8 +325,8 @@ extern unsigned long pci_io_base;
#define PHB_IO_END (KERN_IO_START + FULL_IO_SIZE)
#define IOREMAP_BASE (PHB_IO_END)
#define IOREMAP_START (ioremap_bot)
-#define IOREMAP_END (KERN_IO_END - FIXADDR_SIZE)
#define FIXADDR_SIZE SZ_32M
+#define IOREMAP_END (KERN_IO_END - FIXADDR_SIZE)
/* Advertise special mapping type for AGP */
#define HAVE_PAGE_AGP
diff --git a/arch/powerpc/kernel/setup_64.c
b/arch/powerpc/kernel/setup_64.c
index b779d25761cf..ce09fe5debf4 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -369,11 +369,12 @@ void __init early_setup(unsigned long dt_ptr)
apply_feature_fixups();
setup_feature_keys();
- early_ioremap_setup();
/* Initialize the hash table or TLB handling */
early_init_mmu();
+ early_ioremap_setup();
+
/*
* After firmware and early platform setup code has set things up,
* we note the SPR values for configurable control/performance
--
Alexey
