powerpc: Fix early setup to make early_ioremap work

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.

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.

Signed-off-by: Alexey Kardashevskiy <redacted>
---
 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

-- 
2.30.2

Hm, my thunderbird says it is not cc:'ed but git sendmail says it did cc:


Server: localhost
MAIL FROM:[off-list ref]
RCPT TO:[off-list ref]
RCPT TO:[off-list ref]
RCPT TO:[off-list ref]
RCPT TO:[off-list ref]
From: Alexey Kardashevskiy <redacted>
To: <redacted>
Cc: Alexey Kardashevskiy <redacted>,
        Michael Ellerman [off-list ref],
        Christophe Leroy [off-list ref]
Subject: [RFC PATCH kernel] powerpc: Fix early setup to make early_ioremap work


Not sure what to believe.


On 20/05/2021 13:29, Alexey Kardashevskiy wrote:

15 more quoted lines

-- 
Alexey

Le 20/05/2021 à 05:33, Alexey Kardashevskiy a écrit :

Hm, my thunderbird says it is not cc:'ed but git sendmail says it did cc:


Server: localhost
MAIL FROM:[off-list ref]
RCPT TO:[off-list ref]
RCPT TO:[off-list ref]
RCPT TO:[off-list ref]
RCPT TO:[off-list ref]
From: Alexey Kardashevskiy <redacted>
To: <redacted>
Cc: Alexey Kardashevskiy <redacted>,
         Michael Ellerman [off-list ref],
         Christophe Leroy [off-list ref]
Subject: [RFC PATCH kernel] powerpc: Fix early setup to make early_ioremap work


Not sure what to believe.

I got the patch.

If you are looking at the mail you received from the ppc list, I think the list removes the members of the list from the Cc: in order to avoid the mail being received multiple times.

Christophe

On 20/05/2021 13:29, Alexey Kardashevskiy wrote:

quoted

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.

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.

Signed-off-by: Alexey Kardashevskiy <redacted>
---
  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

15 more quoted lines

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.

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.
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.

Signed-off-by: Alexey Kardashevskiy <redacted>

Reviewed-by: Christophe Leroy <redacted>

On 20/05/2021 15:46, Christophe Leroy wrote:

Le 20/05/2021 à 05:29, Alexey Kardashevskiy a écrit :

quoted

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.

quoted

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.

quoted

Signed-off-by: Alexey Kardashevskiy <redacted>

Reviewed-by: Christophe Leroy <redacted>

quoted

---
  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

Le 20/05/2021 à 07:52, Alexey Kardashevskiy a écrit :

On 20/05/2021 15:46, Christophe Leroy wrote:

quoted

Le 20/05/2021 à 05:29, Alexey Kardashevskiy a écrit :

quoted

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.

I forgot, your patch should include Fixes: tags.

Fixes: 265c3491c4bc ("powerpc: Add support for GENERIC_EARLY_IOREMAP")

If you still change the FIXADDR_SIZE, then it must also have:

Fixes: 9ccba66d4d2a ("powerpc/64: Fix the definition of the fixmap area")

quoted

quoted

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.

quoted

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.

quoted

quoted

Signed-off-by: Alexey Kardashevskiy <redacted>

Reviewed-by: Christophe Leroy <redacted>

quoted

---
  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)

23 more quoted lines

On Thu, 20 May 2021 13:29:19 +1000, Alexey Kardashevskiy wrote:

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().

[...]

Applied to powerpc/fixes.

[1/1] powerpc: Fix early setup to make early_ioremap work
      https://git.kernel.org/powerpc/c/e2f5efd0f0e229bd110eab513e7c0331d61a4649

cheers