[PATCH v1 0/4] powerpc: Add support for GENERIC_EARLY_IOREMAP

[PATCH v1 0/4] powerpc: Add support for GENERIC_EARLY_IOREMAP

[Christophe Leroy]

This series adds support for GENERIC_EARLY_IOREMAP on powerpc.

It also adds a warning in the standard ioremap() when it's called
before vmalloc is available in order to help locate those users.

Next step will be to incrementaly migrate all early users of
ioremap() to using early_ioremap() or other method.

Once they are all converted we can drop all the logic
behind ioremap_bot.

Christophe Leroy (4):
  powerpc/fixmap: don't clear fixmap area in paging_init()
  powerpc/fixmap: Use __fix_to_virt() instead of fix_to_virt()
  powerpc: Add support for GENERIC_EARLY_IOREMAP
  powerpc/ioremap: warn on early use of ioremap()

 arch/powerpc/Kconfig              |  1 +
 arch/powerpc/include/asm/Kbuild   |  1 +
 arch/powerpc/include/asm/fixmap.h | 19 ++++++++++++++++++-
 arch/powerpc/kernel/setup_32.c    |  3 +++
 arch/powerpc/kernel/setup_64.c    |  3 +++
 arch/powerpc/mm/ioremap_32.c      |  1 +
 arch/powerpc/mm/ioremap_64.c      |  2 ++
 arch/powerpc/mm/mem.c             |  8 --------
 8 files changed, 29 insertions(+), 9 deletions(-)

-- 
2.13.3

[PATCH v1 1/4] powerpc/fixmap: don't clear fixmap area in paging_init()

[Christophe Leroy]

fixmap is intended to map things permanently like the IMMR region on
FSL SOC (8xx, 83xx, ...), so don't clear it when initialising paging()

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/mm/mem.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index be941d382c8d..278be4712e10 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -216,14 +216,6 @@ void __init paging_init(void)
 	unsigned long long total_ram = memblock_phys_mem_size();
 	phys_addr_t top_of_ram = memblock_end_of_DRAM();
 
-#ifdef CONFIG_PPC32
-	unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
-	unsigned long end = __fix_to_virt(FIX_HOLE);
-
-	for (; v < end; v += PAGE_SIZE)
-		map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */
-#endif
-
 #ifdef CONFIG_HIGHMEM
 	map_kernel_page(PKMAP_BASE, 0, __pgprot(0));	/* XXX gross */
 	pkmap_page_table = virt_to_kpte(PKMAP_BASE);
-- 
2.13.3

Re: [PATCH v1 1/4] powerpc/fixmap: don't clear fixmap area in paging_init()

[Michael Ellerman]

On Thu, 2019-09-12 at 13:49:41 UTC, Christophe Leroy wrote:
> fixmap is intended to map things permanently like the IMMR region on
> FSL SOC (8xx, 83xx, ...), so don't clear it when initialising paging()
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/f2bb86937d86ebcb0e52f95b6d19aba1d850e601

cheers

Re: [PATCH v1 1/4] powerpc/fixmap: don't clear fixmap area in paging_init()

[Christophe Leroy]

Le 26/11/2019 à 02:13, Michael Ellerman a écrit :
> On Thu, 2019-09-12 at 13:49:41 UTC, Christophe Leroy wrote:
>> fixmap is intended to map things permanently like the IMMR region on
>> FSL SOC (8xx, 83xx, ...), so don't clear it when initialising paging()
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> 
> Applied to powerpc next, thanks.
> 
> https://git.kernel.org/powerpc/c/f2bb86937d86ebcb0e52f95b6d19aba1d850e601
> 

Hi,

What happened ?

It looks like it is gone in today's powerpc next.

Christophe

Re: [PATCH v1 1/4] powerpc/fixmap: don't clear fixmap area in paging_init()

[Christophe Leroy]

Le 27/11/2019 à 15:43, Christophe Leroy a écrit :
> 
> 
> Le 26/11/2019 à 02:13, Michael Ellerman a écrit :
>> On Thu, 2019-09-12 at 13:49:41 UTC, Christophe Leroy wrote:
>>> fixmap is intended to map things permanently like the IMMR region on
>>> FSL SOC (8xx, 83xx, ...), so don't clear it when initialising paging()
>>>
>>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>>
>> Applied to powerpc next, thanks.
>>
>> https://git.kernel.org/powerpc/c/f2bb86937d86ebcb0e52f95b6d19aba1d850e601
>>
> 
> Hi,
> 
> What happened ?
> 
> It looks like it is gone in today's powerpc next.
> 

I see it back today in powerpc/merge, thanks.

The issue is it is crashing with HIGHMEM, indeed exactly the same as you 
saw with "[PATCH] powerpc/8xx: Fix permanently mapped IMMR region.", 
since that was exactly the same code.

I sent a fix for it, and I also rebased "[PATCH] powerpc/8xx: Fix 
permanently mapped IMMR region." into v2 to exclude from it the already 
merged part.

It would be wise if you could merge both.

Thanks
Christophe

[PATCH v1 2/4] powerpc/fixmap: Use __fix_to_virt() instead of fix_to_virt()

[Christophe Leroy]

Modify back __set_fixmap() to using __fix_to_virt() instead
of fix_to_virt() otherwise the following happens because it
seems GCC doesn't see idx as a builtin const.

  CC      mm/early_ioremap.o
In file included from ./include/linux/kernel.h:11:0,
                 from mm/early_ioremap.c:11:
In function ‘fix_to_virt’,
    inlined from ‘__set_fixmap’ at ./arch/powerpc/include/asm/fixmap.h:87:2,
    inlined from ‘__early_ioremap’ at mm/early_ioremap.c:156:4:
./include/linux/compiler.h:350:38: error: call to ‘__compiletime_assert_32’ declared with attribute error: BUILD_BUG_ON failed: idx >= __end_of_fixed_addresses
  _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
                                      ^
./include/linux/compiler.h:331:4: note: in definition of macro ‘__compiletime_assert’
    prefix ## suffix();    \
    ^
./include/linux/compiler.h:350:2: note: in expansion of macro ‘_compiletime_assert’
  _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
  ^
./include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’
 #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
                                     ^
./include/linux/build_bug.h:50:2: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
  BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
  ^
./include/asm-generic/fixmap.h:32:2: note: in expansion of macro ‘BUILD_BUG_ON’
  BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
  ^

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Fixes: 4cfac2f9c7f1 ("powerpc/mm: Simplify __set_fixmap()")
---
 arch/powerpc/include/asm/fixmap.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/fixmap.h b/arch/powerpc/include/asm/fixmap.h
index 0cfc365d814b..722289a1d000 100644
--- a/arch/powerpc/include/asm/fixmap.h
+++ b/arch/powerpc/include/asm/fixmap.h
@@ -77,7 +77,12 @@ enum fixed_addresses {
 static inline void __set_fixmap(enum fixed_addresses idx,
 				phys_addr_t phys, pgprot_t flags)
 {
-	map_kernel_page(fix_to_virt(idx), phys, flags);
+	if (__builtin_constant_p(idx))
+		BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
+	else if (WARN_ON(idx >= __end_of_fixed_addresses))
+		return;
+
+	map_kernel_page(__fix_to_virt(idx), phys, flags);
 }
 
 #endif /* !__ASSEMBLY__ */
-- 
2.13.3

Re: [PATCH v1 2/4] powerpc/fixmap: Use __fix_to_virt() instead of fix_to_virt()

[Michael Ellerman]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 1884 bytes --]

On Thu, 2019-09-12 at 13:49:42 UTC, Christophe Leroy wrote:
> Modify back __set_fixmap() to using __fix_to_virt() instead
> of fix_to_virt() otherwise the following happens because it
> seems GCC doesn't see idx as a builtin const.
> 
>   CC      mm/early_ioremap.o
> In file included from ./include/linux/kernel.h:11:0,
>                  from mm/early_ioremap.c:11:
> In function ‘fix_to_virt’,
>     inlined from ‘__set_fixmap’ at ./arch/powerpc/include/asm/fixmap.h:87:2,
>     inlined from ‘__early_ioremap’ at mm/early_ioremap.c:156:4:
> ./include/linux/compiler.h:350:38: error: call to ‘__compiletime_assert_32’ declared with attribute error: BUILD_BUG_ON failed: idx >= __end_of_fixed_addresses
>   _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
>                                       ^
> ./include/linux/compiler.h:331:4: note: in definition of macro ‘__compiletime_assert’
>     prefix ## suffix();    \
>     ^
> ./include/linux/compiler.h:350:2: note: in expansion of macro ‘_compiletime_assert’
>   _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
>   ^
> ./include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’
>  #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
>                                      ^
> ./include/linux/build_bug.h:50:2: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
>   BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
>   ^
> ./include/asm-generic/fixmap.h:32:2: note: in expansion of macro ‘BUILD_BUG_ON’
>   BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
>   ^
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> Fixes: 4cfac2f9c7f1 ("powerpc/mm: Simplify __set_fixmap()")

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/77693a5fb57be4606a6024ec8e3076f9499b906b

cheers

[PATCH v1 3/4] powerpc: Add support for GENERIC_EARLY_IOREMAP

[Christophe Leroy]

Add support for GENERIC_EARLY_IOREMAP.

Let's define 16 slots of 256Kbytes each for early ioremap.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/Kconfig              |  1 +
 arch/powerpc/include/asm/Kbuild   |  1 +
 arch/powerpc/include/asm/fixmap.h | 12 ++++++++++++
 arch/powerpc/kernel/setup_32.c    |  3 +++
 arch/powerpc/kernel/setup_64.c    |  3 +++
 5 files changed, 20 insertions(+)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 6a7c797fa9d2..8fe252962518 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -161,6 +161,7 @@ config PPC
 	select GENERIC_CMOS_UPDATE
 	select GENERIC_CPU_AUTOPROBE
 	select GENERIC_CPU_VULNERABILITIES	if PPC_BARRIER_NOSPEC
+	select GENERIC_EARLY_IOREMAP
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IRQ_SHOW_LEVEL
 	select GENERIC_PCI_IOMAP		if PCI
diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild
index 9a1d2fc6ceb7..30829120659c 100644
--- a/arch/powerpc/include/asm/Kbuild
+++ b/arch/powerpc/include/asm/Kbuild
@@ -12,3 +12,4 @@ generic-y += preempt.h
 generic-y += vtime.h
 generic-y += msi.h
 generic-y += simd.h
+generic-y += early_ioremap.h
diff --git a/arch/powerpc/include/asm/fixmap.h b/arch/powerpc/include/asm/fixmap.h
index 722289a1d000..d5c4d357bd33 100644
--- a/arch/powerpc/include/asm/fixmap.h
+++ b/arch/powerpc/include/asm/fixmap.h
@@ -15,6 +15,7 @@
 #define _ASM_FIXMAP_H
 
 #ifndef __ASSEMBLY__
+#include <linux/sizes.h>
 #include <asm/page.h>
 #include <asm/pgtable.h>
 #ifdef CONFIG_HIGHMEM
@@ -64,6 +65,14 @@ enum fixed_addresses {
 		       FIX_IMMR_SIZE,
 #endif
 	/* FIX_PCIE_MCFG, */
+	__end_of_permanent_fixed_addresses,
+
+#define NR_FIX_BTMAPS		(SZ_256K / PAGE_SIZE)
+#define FIX_BTMAPS_SLOTS	16
+#define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
+
+	FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
+	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
 	__end_of_fixed_addresses
 };
 
@@ -71,6 +80,7 @@ enum fixed_addresses {
 #define FIXADDR_START		(FIXADDR_TOP - __FIXADDR_SIZE)
 
 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NCG
+#define FIXMAP_PAGE_IO	PAGE_KERNEL_NCG
 
 #include <asm-generic/fixmap.h>
 
@@ -85,5 +95,7 @@ static inline void __set_fixmap(enum fixed_addresses idx,
 	map_kernel_page(__fix_to_virt(idx), phys, flags);
 }
 
+#define __early_set_fixmap	__set_fixmap
+
 #endif /* !__ASSEMBLY__ */
 #endif
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index a7541edf0cdb..dcffe927f5b9 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -44,6 +44,7 @@
 #include <asm/asm-prototypes.h>
 #include <asm/kdump.h>
 #include <asm/feature-fixups.h>
+#include <asm/early_ioremap.h>
 
 #include "setup.h"
 
@@ -80,6 +81,8 @@ notrace void __init machine_init(u64 dt_ptr)
 	/* Configure static keys first, now that we're relocated. */
 	setup_feature_keys();
 
+	early_ioremap_setup();
+
 	/* Enable early debugging if any specified (see udbg.h) */
 	udbg_early_init();
 
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 44b4c432a273..b85f6a1cc3a1 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -65,6 +65,7 @@
 #include <asm/hw_irq.h>
 #include <asm/feature-fixups.h>
 #include <asm/kup.h>
+#include <asm/early_ioremap.h>
 
 #include "setup.h"
 
@@ -338,6 +339,8 @@ 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();
 
-- 
2.13.3

Re: [PATCH v1 3/4] powerpc: Add support for GENERIC_EARLY_IOREMAP

[Aneesh Kumar K.V]

Christophe Leroy <christophe.leroy@c-s.fr> writes:

> Add support for GENERIC_EARLY_IOREMAP.
>
> Let's define 16 slots of 256Kbytes each for early ioremap.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> ---
>  arch/powerpc/Kconfig              |  1 +
>  arch/powerpc/include/asm/Kbuild   |  1 +
>  arch/powerpc/include/asm/fixmap.h | 12 ++++++++++++
>  arch/powerpc/kernel/setup_32.c    |  3 +++
>  arch/powerpc/kernel/setup_64.c    |  3 +++
>  5 files changed, 20 insertions(+)
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 6a7c797fa9d2..8fe252962518 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -161,6 +161,7 @@ config PPC
>  	select GENERIC_CMOS_UPDATE
>  	select GENERIC_CPU_AUTOPROBE
>  	select GENERIC_CPU_VULNERABILITIES	if PPC_BARRIER_NOSPEC
> +	select GENERIC_EARLY_IOREMAP
>  	select GENERIC_IRQ_SHOW
>  	select GENERIC_IRQ_SHOW_LEVEL
>  	select GENERIC_PCI_IOMAP		if PCI
> diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild
> index 9a1d2fc6ceb7..30829120659c 100644
> --- a/arch/powerpc/include/asm/Kbuild
> +++ b/arch/powerpc/include/asm/Kbuild
> @@ -12,3 +12,4 @@ generic-y += preempt.h
>  generic-y += vtime.h
>  generic-y += msi.h
>  generic-y += simd.h
> +generic-y += early_ioremap.h
> diff --git a/arch/powerpc/include/asm/fixmap.h b/arch/powerpc/include/asm/fixmap.h
> index 722289a1d000..d5c4d357bd33 100644
> --- a/arch/powerpc/include/asm/fixmap.h
> +++ b/arch/powerpc/include/asm/fixmap.h
> @@ -15,6 +15,7 @@
>  #define _ASM_FIXMAP_H
>  
>  #ifndef __ASSEMBLY__
> +#include <linux/sizes.h>
>  #include <asm/page.h>
>  #include <asm/pgtable.h>
>  #ifdef CONFIG_HIGHMEM
> @@ -64,6 +65,14 @@ enum fixed_addresses {
>  		       FIX_IMMR_SIZE,
>  #endif
>  	/* FIX_PCIE_MCFG, */
> +	__end_of_permanent_fixed_addresses,
> +
> +#define NR_FIX_BTMAPS		(SZ_256K / PAGE_SIZE)
> +#define FIX_BTMAPS_SLOTS	16
> +#define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
> +
> +	FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
> +	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
>  	__end_of_fixed_addresses
>  };
>  
> @@ -71,6 +80,7 @@ enum fixed_addresses {
>  #define FIXADDR_START		(FIXADDR_TOP - __FIXADDR_SIZE)
>  
>  #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NCG
> +#define FIXMAP_PAGE_IO	PAGE_KERNEL_NCG
>  
>  #include <asm-generic/fixmap.h>
>  
> @@ -85,5 +95,7 @@ static inline void __set_fixmap(enum fixed_addresses idx,
>  	map_kernel_page(__fix_to_virt(idx), phys, flags);
>  }
>  
> +#define __early_set_fixmap	__set_fixmap
> +
>  #endif /* !__ASSEMBLY__ */
>  #endif
> diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
> index a7541edf0cdb..dcffe927f5b9 100644
> --- a/arch/powerpc/kernel/setup_32.c
> +++ b/arch/powerpc/kernel/setup_32.c
> @@ -44,6 +44,7 @@
>  #include <asm/asm-prototypes.h>
>  #include <asm/kdump.h>
>  #include <asm/feature-fixups.h>
> +#include <asm/early_ioremap.h>
>  
>  #include "setup.h"
>  
> @@ -80,6 +81,8 @@ notrace void __init machine_init(u64 dt_ptr)
>  	/* Configure static keys first, now that we're relocated. */
>  	setup_feature_keys();
>  
> +	early_ioremap_setup();
> +
>  	/* Enable early debugging if any specified (see udbg.h) */
>  	udbg_early_init();
>  
> diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
> index 44b4c432a273..b85f6a1cc3a1 100644
> --- a/arch/powerpc/kernel/setup_64.c
> +++ b/arch/powerpc/kernel/setup_64.c
> @@ -65,6 +65,7 @@
>  #include <asm/hw_irq.h>
>  #include <asm/feature-fixups.h>
>  #include <asm/kup.h>
> +#include <asm/early_ioremap.h>
>  
>  #include "setup.h"
>  
> @@ -338,6 +339,8 @@ 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();
>  

Can we remove early_ioremap_range() after this?

-aneesh

Re: [PATCH v1 3/4] powerpc: Add support for GENERIC_EARLY_IOREMAP

[Christophe Leroy]

Le 12/09/2019 à 17:37, Aneesh Kumar K.V a écrit :
> Christophe Leroy <christophe.leroy@c-s.fr> writes:
> 
>> Add support for GENERIC_EARLY_IOREMAP.
>>
>> Let's define 16 slots of 256Kbytes each for early ioremap.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>> ---
>>   arch/powerpc/Kconfig              |  1 +
>>   arch/powerpc/include/asm/Kbuild   |  1 +
>>   arch/powerpc/include/asm/fixmap.h | 12 ++++++++++++
>>   arch/powerpc/kernel/setup_32.c    |  3 +++
>>   arch/powerpc/kernel/setup_64.c    |  3 +++
>>   5 files changed, 20 insertions(+)
>>
>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>> index 6a7c797fa9d2..8fe252962518 100644
>> --- a/arch/powerpc/Kconfig
>> +++ b/arch/powerpc/Kconfig
>> @@ -161,6 +161,7 @@ config PPC
>>   	select GENERIC_CMOS_UPDATE
>>   	select GENERIC_CPU_AUTOPROBE
>>   	select GENERIC_CPU_VULNERABILITIES	if PPC_BARRIER_NOSPEC
>> +	select GENERIC_EARLY_IOREMAP
>>   	select GENERIC_IRQ_SHOW
>>   	select GENERIC_IRQ_SHOW_LEVEL
>>   	select GENERIC_PCI_IOMAP		if PCI
>> diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild
>> index 9a1d2fc6ceb7..30829120659c 100644
>> --- a/arch/powerpc/include/asm/Kbuild
>> +++ b/arch/powerpc/include/asm/Kbuild
>> @@ -12,3 +12,4 @@ generic-y += preempt.h
>>   generic-y += vtime.h
>>   generic-y += msi.h
>>   generic-y += simd.h
>> +generic-y += early_ioremap.h
>> diff --git a/arch/powerpc/include/asm/fixmap.h b/arch/powerpc/include/asm/fixmap.h
>> index 722289a1d000..d5c4d357bd33 100644
>> --- a/arch/powerpc/include/asm/fixmap.h
>> +++ b/arch/powerpc/include/asm/fixmap.h
>> @@ -15,6 +15,7 @@
>>   #define _ASM_FIXMAP_H
>>   
>>   #ifndef __ASSEMBLY__
>> +#include <linux/sizes.h>
>>   #include <asm/page.h>
>>   #include <asm/pgtable.h>
>>   #ifdef CONFIG_HIGHMEM
>> @@ -64,6 +65,14 @@ enum fixed_addresses {
>>   		       FIX_IMMR_SIZE,
>>   #endif
>>   	/* FIX_PCIE_MCFG, */
>> +	__end_of_permanent_fixed_addresses,
>> +
>> +#define NR_FIX_BTMAPS		(SZ_256K / PAGE_SIZE)
>> +#define FIX_BTMAPS_SLOTS	16
>> +#define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
>> +
>> +	FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
>> +	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
>>   	__end_of_fixed_addresses
>>   };
>>   
>> @@ -71,6 +80,7 @@ enum fixed_addresses {
>>   #define FIXADDR_START		(FIXADDR_TOP - __FIXADDR_SIZE)
>>   
>>   #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NCG
>> +#define FIXMAP_PAGE_IO	PAGE_KERNEL_NCG
>>   
>>   #include <asm-generic/fixmap.h>
>>   
>> @@ -85,5 +95,7 @@ static inline void __set_fixmap(enum fixed_addresses idx,
>>   	map_kernel_page(__fix_to_virt(idx), phys, flags);
>>   }
>>   
>> +#define __early_set_fixmap	__set_fixmap
>> +
>>   #endif /* !__ASSEMBLY__ */
>>   #endif
>> diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
>> index a7541edf0cdb..dcffe927f5b9 100644
>> --- a/arch/powerpc/kernel/setup_32.c
>> +++ b/arch/powerpc/kernel/setup_32.c
>> @@ -44,6 +44,7 @@
>>   #include <asm/asm-prototypes.h>
>>   #include <asm/kdump.h>
>>   #include <asm/feature-fixups.h>
>> +#include <asm/early_ioremap.h>
>>   
>>   #include "setup.h"
>>   
>> @@ -80,6 +81,8 @@ notrace void __init machine_init(u64 dt_ptr)
>>   	/* Configure static keys first, now that we're relocated. */
>>   	setup_feature_keys();
>>   
>> +	early_ioremap_setup();
>> +
>>   	/* Enable early debugging if any specified (see udbg.h) */
>>   	udbg_early_init();
>>   
>> diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
>> index 44b4c432a273..b85f6a1cc3a1 100644
>> --- a/arch/powerpc/kernel/setup_64.c
>> +++ b/arch/powerpc/kernel/setup_64.c
>> @@ -65,6 +65,7 @@
>>   #include <asm/hw_irq.h>
>>   #include <asm/feature-fixups.h>
>>   #include <asm/kup.h>
>> +#include <asm/early_ioremap.h>
>>   
>>   #include "setup.h"
>>   
>> @@ -338,6 +339,8 @@ 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();
>>   
> 
> Can we remove early_ioremap_range() after this?
> 

Yes, once all early callers of ioremap functions are converted to using 
early_ioremap()

Christophe

Re: [PATCH v1 3/4] powerpc: Add support for GENERIC_EARLY_IOREMAP

[Christophe Leroy]

Le 12/09/2019 à 17:50, Aneesh Kumar K.V a écrit :
> Christophe Leroy <christophe.leroy@c-s.fr> writes:
> 
>> Le 12/09/2019 à 17:37, Aneesh Kumar K.V a écrit :
>>> Christophe Leroy <christophe.leroy@c-s.fr> writes:
>>>
>>>> Add support for GENERIC_EARLY_IOREMAP.
>>>>
>>>> Let's define 16 slots of 256Kbytes each for early ioremap.
>>>>
>>>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>>>> ---
>>>>    arch/powerpc/Kconfig              |  1 +
>>>>    arch/powerpc/include/asm/Kbuild   |  1 +
>>>>    arch/powerpc/include/asm/fixmap.h | 12 ++++++++++++
>>>>    arch/powerpc/kernel/setup_32.c    |  3 +++
>>>>    arch/powerpc/kernel/setup_64.c    |  3 +++
>>>>    5 files changed, 20 insertions(+)
>>>>
>>>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>>>> index 6a7c797fa9d2..8fe252962518 100644
>>>> --- a/arch/powerpc/Kconfig
>>>> +++ b/arch/powerpc/Kconfig
>>>> @@ -161,6 +161,7 @@ config PPC
>>>>    	select GENERIC_CMOS_UPDATE
>>>>    	select GENERIC_CPU_AUTOPROBE
>>>>    	select GENERIC_CPU_VULNERABILITIES	if PPC_BARRIER_NOSPEC
>>>> +	select GENERIC_EARLY_IOREMAP
>>>>    	select GENERIC_IRQ_SHOW
>>>>    	select GENERIC_IRQ_SHOW_LEVEL
>>>>    	select GENERIC_PCI_IOMAP		if PCI
>>>> diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild
>>>> index 9a1d2fc6ceb7..30829120659c 100644
>>>> --- a/arch/powerpc/include/asm/Kbuild
>>>> +++ b/arch/powerpc/include/asm/Kbuild
>>>> @@ -12,3 +12,4 @@ generic-y += preempt.h
>>>>    generic-y += vtime.h
>>>>    generic-y += msi.h
>>>>    generic-y += simd.h
>>>> +generic-y += early_ioremap.h
>>>> diff --git a/arch/powerpc/include/asm/fixmap.h b/arch/powerpc/include/asm/fixmap.h
>>>> index 722289a1d000..d5c4d357bd33 100644
>>>> --- a/arch/powerpc/include/asm/fixmap.h
>>>> +++ b/arch/powerpc/include/asm/fixmap.h
>>>> @@ -15,6 +15,7 @@
>>>>    #define _ASM_FIXMAP_H
>>>>    
>>>>    #ifndef __ASSEMBLY__
>>>> +#include <linux/sizes.h>
>>>>    #include <asm/page.h>
>>>>    #include <asm/pgtable.h>
>>>>    #ifdef CONFIG_HIGHMEM
>>>> @@ -64,6 +65,14 @@ enum fixed_addresses {
>>>>    		       FIX_IMMR_SIZE,
>>>>    #endif
>>>>    	/* FIX_PCIE_MCFG, */
>>>> +	__end_of_permanent_fixed_addresses,
>>>> +
>>>> +#define NR_FIX_BTMAPS		(SZ_256K / PAGE_SIZE)
>>>> +#define FIX_BTMAPS_SLOTS	16
>>>> +#define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
>>>> +
>>>> +	FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
>>>> +	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
>>>>    	__end_of_fixed_addresses
>>>>    };
>>>>    
>>>> @@ -71,6 +80,7 @@ enum fixed_addresses {
>>>>    #define FIXADDR_START		(FIXADDR_TOP - __FIXADDR_SIZE)
>>>>    
>>>>    #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NCG
>>>> +#define FIXMAP_PAGE_IO	PAGE_KERNEL_NCG
>>>>    
>>>>    #include <asm-generic/fixmap.h>
>>>>    
>>>> @@ -85,5 +95,7 @@ static inline void __set_fixmap(enum fixed_addresses idx,
>>>>    	map_kernel_page(__fix_to_virt(idx), phys, flags);
>>>>    }
>>>>    
>>>> +#define __early_set_fixmap	__set_fixmap
>>>> +
>>>>    #endif /* !__ASSEMBLY__ */
>>>>    #endif
>>>> diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
>>>> index a7541edf0cdb..dcffe927f5b9 100644
>>>> --- a/arch/powerpc/kernel/setup_32.c
>>>> +++ b/arch/powerpc/kernel/setup_32.c
>>>> @@ -44,6 +44,7 @@
>>>>    #include <asm/asm-prototypes.h>
>>>>    #include <asm/kdump.h>
>>>>    #include <asm/feature-fixups.h>
>>>> +#include <asm/early_ioremap.h>
>>>>    
>>>>    #include "setup.h"
>>>>    
>>>> @@ -80,6 +81,8 @@ notrace void __init machine_init(u64 dt_ptr)
>>>>    	/* Configure static keys first, now that we're relocated. */
>>>>    	setup_feature_keys();
>>>>    
>>>> +	early_ioremap_setup();
>>>> +
>>>>    	/* Enable early debugging if any specified (see udbg.h) */
>>>>    	udbg_early_init();
>>>>    
>>>> diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
>>>> index 44b4c432a273..b85f6a1cc3a1 100644
>>>> --- a/arch/powerpc/kernel/setup_64.c
>>>> +++ b/arch/powerpc/kernel/setup_64.c
>>>> @@ -65,6 +65,7 @@
>>>>    #include <asm/hw_irq.h>
>>>>    #include <asm/feature-fixups.h>
>>>>    #include <asm/kup.h>
>>>> +#include <asm/early_ioremap.h>
>>>>    
>>>>    #include "setup.h"
>>>>    
>>>> @@ -338,6 +339,8 @@ 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();
>>>>    
>>>
>>> Can we remove early_ioremap_range() after this?
>>>
>>
>> Yes, once all early callers of ioremap functions are converted to using
>> early_ioremap()
> 
> Why can't we switch the early callers to early_ioremap and print a
> warning?
> 
> ie,
> if (!slab_available()) {
>     pr_warn("switch to early_ioremap");
>     early_ioremap();
> }
> 

Because:
- early_iounmap() requires the size of the area to be freed unlike iounmap()
- early_ioremap() is for ephemeral mappings. All early mapping must be 
gone at the end of init (this is verified by 
late_initcall(check_early_ioremap_leak))

Second point means another approach has to be taken for installing early 
permanent mapping, for instance by using fixmaps.

Christophe

Re: [PATCH v1 3/4] powerpc: Add support for GENERIC_EARLY_IOREMAP

[Michael Ellerman]

On Thu, 2019-09-12 at 13:49:43 UTC, Christophe Leroy wrote:
> Add support for GENERIC_EARLY_IOREMAP.
> 
> Let's define 16 slots of 256Kbytes each for early ioremap.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/265c3491c4bc8d40587996d6ee2f447a7ccfb4f3

cheers

[PATCH v1 4/4] powerpc/ioremap: warn on early use of ioremap()

[Christophe Leroy]

Powerpc now has EARLY_IOREMAP.

Next step is to convert all early users of ioremap() to
early_ioremap().

Add a warning to help locate those users.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/mm/ioremap_32.c | 1 +
 arch/powerpc/mm/ioremap_64.c | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/arch/powerpc/mm/ioremap_32.c b/arch/powerpc/mm/ioremap_32.c
index f36121f25243..743e11384dea 100644
--- a/arch/powerpc/mm/ioremap_32.c
+++ b/arch/powerpc/mm/ioremap_32.c
@@ -68,6 +68,7 @@ __ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *call
 	/*
 	 * Should check if it is a candidate for a BAT mapping
 	 */
+	pr_warn("ioremap() called early from %pS. Use early_ioremap() instead\n", caller);
 
 	err = early_ioremap_range(ioremap_bot - size, p, size, prot);
 	if (err)
diff --git a/arch/powerpc/mm/ioremap_64.c b/arch/powerpc/mm/ioremap_64.c
index fd29e51700cd..50a99d9684f7 100644
--- a/arch/powerpc/mm/ioremap_64.c
+++ b/arch/powerpc/mm/ioremap_64.c
@@ -81,6 +81,8 @@ void __iomem *__ioremap_caller(phys_addr_t addr, unsigned long size,
 	if (slab_is_available())
 		return do_ioremap(paligned, offset, size, prot, caller);
 
+	pr_warn("ioremap() called early from %pS. Use early_ioremap() instead\n", caller);
+
 	err = early_ioremap_range(ioremap_bot, paligned, size, prot);
 	if (err)
 		return NULL;
-- 
2.13.3

Re: [PATCH v1 4/4] powerpc/ioremap: warn on early use of ioremap()

[Michael Ellerman]

On Thu, 2019-09-12 at 13:49:44 UTC, Christophe Leroy wrote:
> Powerpc now has EARLY_IOREMAP.
> 
> Next step is to convert all early users of ioremap() to
> early_ioremap().
> 
> Add a warning to help locate those users.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/d538aadc2718a95bfd80095c66ea814824535b34

cheers

Re: [PATCH v1 0/4] powerpc: Add support for GENERIC_EARLY_IOREMAP

[Christoph Hellwig]

On Thu, Sep 12, 2019 at 01:49:40PM +0000, Christophe Leroy wrote:
> This series adds support for GENERIC_EARLY_IOREMAP on powerpc.
> 
> It also adds a warning in the standard ioremap() when it's called
> before vmalloc is available in order to help locate those users.
> 
> Next step will be to incrementaly migrate all early users of
> ioremap() to using early_ioremap() or other method.
> 
> Once they are all converted we can drop all the logic
> behind ioremap_bot.

Thanks, this looks pretty nice!