diff mbox

[v16,1/6] efi: ARM/arm64: ignore DT memory nodes instead of removing them

Message ID 1460155828-8690-2-git-send-email-ddaney.cavm@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

David Daney April 8, 2016, 10:50 p.m. UTC
From: Ard Biesheuvel <ard.biesheuvel@linaro.org>

There are two problems with the UEFI stub DT memory node removal
routine:
- it deletes nodes as it traverses the tree, which happens to work
  but is not supported, as deletion invalidates the node iterator;
- deleting memory nodes entirely may discard annotations in the form
  of additional properties on the nodes.

Since the discovery of DT memory nodes occurs strictly before the
UEFI init sequence, we can simply clear the memblock memory table
before parsing the UEFI memory map. This way, it is no longer
necessary to remove the nodes, so we can remove that logic from the
stub as well.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: David Daney <david.daney@cavium.com>
---
 drivers/firmware/efi/arm-init.c    |  8 ++++++++
 drivers/firmware/efi/libstub/fdt.c | 24 +-----------------------
 2 files changed, 9 insertions(+), 23 deletions(-)

Comments

Steve Capper April 14, 2016, 11:02 a.m. UTC | #1
On Fri, Apr 08, 2016 at 03:50:23PM -0700, David Daney wrote:
> From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> 
> There are two problems with the UEFI stub DT memory node removal
> routine:
> - it deletes nodes as it traverses the tree, which happens to work
>   but is not supported, as deletion invalidates the node iterator;
> - deleting memory nodes entirely may discard annotations in the form
>   of additional properties on the nodes.
> 
> Since the discovery of DT memory nodes occurs strictly before the
> UEFI init sequence, we can simply clear the memblock memory table
> before parsing the UEFI memory map. This way, it is no longer
> necessary to remove the nodes, so we can remove that logic from the
> stub as well.
> 
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Signed-off-by: David Daney <david.daney@cavium.com>
> ---
>  drivers/firmware/efi/arm-init.c    |  8 ++++++++
>  drivers/firmware/efi/libstub/fdt.c | 24 +-----------------------
>  2 files changed, 9 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
> index aa1f743..5d6945b 100644
> --- a/drivers/firmware/efi/arm-init.c
> +++ b/drivers/firmware/efi/arm-init.c
> @@ -143,6 +143,14 @@ static __init void reserve_regions(void)
>  	if (efi_enabled(EFI_DBG))
>  		pr_info("Processing EFI memory map:\n");
>  
> +	/*
> +	 * Discard memblocks discovered so far: if there are any at this
> +	 * point, they originate from memory nodes in the DT, and UEFI
> +	 * uses its own memory map instead.
> +	 */
> +	memblock_dump_all();
> +	memblock_remove(0, ULLONG_MAX);
> +

Does this change need to be applied to any other architectures given
that deletion code has been removed from libstub below?

Cheers,
Ard Biesheuvel April 14, 2016, 11:10 a.m. UTC | #2
On 14 April 2016 at 13:02, Steve Capper <steve.capper@arm.com> wrote:
> On Fri, Apr 08, 2016 at 03:50:23PM -0700, David Daney wrote:
>> From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>>
>> There are two problems with the UEFI stub DT memory node removal
>> routine:
>> - it deletes nodes as it traverses the tree, which happens to work
>>   but is not supported, as deletion invalidates the node iterator;
>> - deleting memory nodes entirely may discard annotations in the form
>>   of additional properties on the nodes.
>>
>> Since the discovery of DT memory nodes occurs strictly before the
>> UEFI init sequence, we can simply clear the memblock memory table
>> before parsing the UEFI memory map. This way, it is no longer
>> necessary to remove the nodes, so we can remove that logic from the
>> stub as well.
>>
>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>> Signed-off-by: David Daney <david.daney@cavium.com>
>> ---
>>  drivers/firmware/efi/arm-init.c    |  8 ++++++++
>>  drivers/firmware/efi/libstub/fdt.c | 24 +-----------------------
>>  2 files changed, 9 insertions(+), 23 deletions(-)
>>
>> diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
>> index aa1f743..5d6945b 100644
>> --- a/drivers/firmware/efi/arm-init.c
>> +++ b/drivers/firmware/efi/arm-init.c
>> @@ -143,6 +143,14 @@ static __init void reserve_regions(void)
>>       if (efi_enabled(EFI_DBG))
>>               pr_info("Processing EFI memory map:\n");
>>
>> +     /*
>> +      * Discard memblocks discovered so far: if there are any at this
>> +      * point, they originate from memory nodes in the DT, and UEFI
>> +      * uses its own memory map instead.
>> +      */
>> +     memblock_dump_all();
>> +     memblock_remove(0, ULLONG_MAX);
>> +
>
> Does this change need to be applied to any other architectures given
> that deletion code has been removed from libstub below?
>

The 'generic' libstub code below is only used by ARM, so we're safe
here in that regard.


>>       for_each_efi_memory_desc(&memmap, md) {
>>               paddr = md->phys_addr;
>>               npages = md->num_pages;
>> diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
>> index 6dba78a..e58abfa 100644
>> --- a/drivers/firmware/efi/libstub/fdt.c
>> +++ b/drivers/firmware/efi/libstub/fdt.c
>> @@ -24,7 +24,7 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
>>                       unsigned long map_size, unsigned long desc_size,
>>                       u32 desc_ver)
>>  {
>> -     int node, prev, num_rsv;
>> +     int node, num_rsv;
>>       int status;
>>       u32 fdt_val32;
>>       u64 fdt_val64;
>> @@ -54,28 +54,6 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
>>               goto fdt_set_fail;
>>
>>       /*
>> -      * Delete any memory nodes present. We must delete nodes which
>> -      * early_init_dt_scan_memory may try to use.
>> -      */
>> -     prev = 0;
>> -     for (;;) {
>> -             const char *type;
>> -             int len;
>> -
>> -             node = fdt_next_node(fdt, prev, NULL);
>> -             if (node < 0)
>> -                     break;
>> -
>> -             type = fdt_getprop(fdt, node, "device_type", &len);
>> -             if (type && strncmp(type, "memory", len) == 0) {
>> -                     fdt_del_node(fdt, node);
>> -                     continue;
>> -             }
>> -
>> -             prev = node;
>> -     }
>> -
>> -     /*
>>        * Delete all memory reserve map entries. When booting via UEFI,
>>        * kernel will use the UEFI memory map to find reserved regions.
>>        */
>> --
>> 1.8.3.1
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>
Steve Capper April 14, 2016, 12:09 p.m. UTC | #3
On Thu, Apr 14, 2016 at 01:10:35PM +0200, Ard Biesheuvel wrote:
> On 14 April 2016 at 13:02, Steve Capper <steve.capper@arm.com> wrote:
> > On Fri, Apr 08, 2016 at 03:50:23PM -0700, David Daney wrote:
> >> From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> >>
> >> There are two problems with the UEFI stub DT memory node removal
> >> routine:
> >> - it deletes nodes as it traverses the tree, which happens to work
> >>   but is not supported, as deletion invalidates the node iterator;
> >> - deleting memory nodes entirely may discard annotations in the form
> >>   of additional properties on the nodes.
> >>
> >> Since the discovery of DT memory nodes occurs strictly before the
> >> UEFI init sequence, we can simply clear the memblock memory table
> >> before parsing the UEFI memory map. This way, it is no longer
> >> necessary to remove the nodes, so we can remove that logic from the
> >> stub as well.
> >>
> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> >> Signed-off-by: David Daney <david.daney@cavium.com>
> >> ---
> >>  drivers/firmware/efi/arm-init.c    |  8 ++++++++
> >>  drivers/firmware/efi/libstub/fdt.c | 24 +-----------------------
> >>  2 files changed, 9 insertions(+), 23 deletions(-)
> >>
> >> diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
> >> index aa1f743..5d6945b 100644
> >> --- a/drivers/firmware/efi/arm-init.c
> >> +++ b/drivers/firmware/efi/arm-init.c
> >> @@ -143,6 +143,14 @@ static __init void reserve_regions(void)
> >>       if (efi_enabled(EFI_DBG))
> >>               pr_info("Processing EFI memory map:\n");
> >>
> >> +     /*
> >> +      * Discard memblocks discovered so far: if there are any at this
> >> +      * point, they originate from memory nodes in the DT, and UEFI
> >> +      * uses its own memory map instead.
> >> +      */
> >> +     memblock_dump_all();
> >> +     memblock_remove(0, ULLONG_MAX);
> >> +
> >
> > Does this change need to be applied to any other architectures given
> > that deletion code has been removed from libstub below?
> >
> 
> The 'generic' libstub code below is only used by ARM, so we're safe
> here in that regard.

Thanks Ard,
In that case, FWIW:
Acked-by: Steve Capper <steve.capper@arm.com>

Cheers,
Will Deacon April 15, 2016, 2:03 p.m. UTC | #4
On Fri, Apr 08, 2016 at 03:50:23PM -0700, David Daney wrote:
> From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> 
> There are two problems with the UEFI stub DT memory node removal
> routine:
> - it deletes nodes as it traverses the tree, which happens to work
>   but is not supported, as deletion invalidates the node iterator;
> - deleting memory nodes entirely may discard annotations in the form
>   of additional properties on the nodes.
> 
> Since the discovery of DT memory nodes occurs strictly before the
> UEFI init sequence, we can simply clear the memblock memory table
> before parsing the UEFI memory map. This way, it is no longer
> necessary to remove the nodes, so we can remove that logic from the
> stub as well.
> 
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Signed-off-by: David Daney <david.daney@cavium.com>
> ---
>  drivers/firmware/efi/arm-init.c    |  8 ++++++++
>  drivers/firmware/efi/libstub/fdt.c | 24 +-----------------------
>  2 files changed, 9 insertions(+), 23 deletions(-)

Matt, are you ok with me taking this through the arm64 tree? (since the
NUMA patches depend on it). If so, please can I have your ack?

Will

> diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
> index aa1f743..5d6945b 100644
> --- a/drivers/firmware/efi/arm-init.c
> +++ b/drivers/firmware/efi/arm-init.c
> @@ -143,6 +143,14 @@ static __init void reserve_regions(void)
>  	if (efi_enabled(EFI_DBG))
>  		pr_info("Processing EFI memory map:\n");
>  
> +	/*
> +	 * Discard memblocks discovered so far: if there are any at this
> +	 * point, they originate from memory nodes in the DT, and UEFI
> +	 * uses its own memory map instead.
> +	 */
> +	memblock_dump_all();
> +	memblock_remove(0, ULLONG_MAX);
> +
>  	for_each_efi_memory_desc(&memmap, md) {
>  		paddr = md->phys_addr;
>  		npages = md->num_pages;
> diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
> index 6dba78a..e58abfa 100644
> --- a/drivers/firmware/efi/libstub/fdt.c
> +++ b/drivers/firmware/efi/libstub/fdt.c
> @@ -24,7 +24,7 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
>  			unsigned long map_size, unsigned long desc_size,
>  			u32 desc_ver)
>  {
> -	int node, prev, num_rsv;
> +	int node, num_rsv;
>  	int status;
>  	u32 fdt_val32;
>  	u64 fdt_val64;
> @@ -54,28 +54,6 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
>  		goto fdt_set_fail;
>  
>  	/*
> -	 * Delete any memory nodes present. We must delete nodes which
> -	 * early_init_dt_scan_memory may try to use.
> -	 */
> -	prev = 0;
> -	for (;;) {
> -		const char *type;
> -		int len;
> -
> -		node = fdt_next_node(fdt, prev, NULL);
> -		if (node < 0)
> -			break;
> -
> -		type = fdt_getprop(fdt, node, "device_type", &len);
> -		if (type && strncmp(type, "memory", len) == 0) {
> -			fdt_del_node(fdt, node);
> -			continue;
> -		}
> -
> -		prev = node;
> -	}
> -
> -	/*
>  	 * Delete all memory reserve map entries. When booting via UEFI,
>  	 * kernel will use the UEFI memory map to find reserved regions.
>  	 */
> -- 
> 1.8.3.1
>
Ard Biesheuvel April 15, 2016, 2:06 p.m. UTC | #5
On 15 April 2016 at 16:03, Will Deacon <will.deacon@arm.com> wrote:
> On Fri, Apr 08, 2016 at 03:50:23PM -0700, David Daney wrote:
>> From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>>
>> There are two problems with the UEFI stub DT memory node removal
>> routine:
>> - it deletes nodes as it traverses the tree, which happens to work
>>   but is not supported, as deletion invalidates the node iterator;
>> - deleting memory nodes entirely may discard annotations in the form
>>   of additional properties on the nodes.
>>
>> Since the discovery of DT memory nodes occurs strictly before the
>> UEFI init sequence, we can simply clear the memblock memory table
>> before parsing the UEFI memory map. This way, it is no longer
>> necessary to remove the nodes, so we can remove that logic from the
>> stub as well.
>>
>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>> Signed-off-by: David Daney <david.daney@cavium.com>
>> ---
>>  drivers/firmware/efi/arm-init.c    |  8 ++++++++
>>  drivers/firmware/efi/libstub/fdt.c | 24 +-----------------------
>>  2 files changed, 9 insertions(+), 23 deletions(-)
>
> Matt, are you ok with me taking this through the arm64 tree? (since the
> NUMA patches depend on it). If so, please can I have your ack?
>

Matt gave his Reviewed-by for v15

http://www.gossamer-threads.com/lists/linux/kernel/2390242
Matt Fleming April 15, 2016, 2:08 p.m. UTC | #6
On Fri, 15 Apr, at 04:06:08PM, Ard Biesheuvel wrote:
> On 15 April 2016 at 16:03, Will Deacon <will.deacon@arm.com> wrote:
> > On Fri, Apr 08, 2016 at 03:50:23PM -0700, David Daney wrote:
> >> From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> >>
> >> There are two problems with the UEFI stub DT memory node removal
> >> routine:
> >> - it deletes nodes as it traverses the tree, which happens to work
> >>   but is not supported, as deletion invalidates the node iterator;
> >> - deleting memory nodes entirely may discard annotations in the form
> >>   of additional properties on the nodes.
> >>
> >> Since the discovery of DT memory nodes occurs strictly before the
> >> UEFI init sequence, we can simply clear the memblock memory table
> >> before parsing the UEFI memory map. This way, it is no longer
> >> necessary to remove the nodes, so we can remove that logic from the
> >> stub as well.
> >>
> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> >> Signed-off-by: David Daney <david.daney@cavium.com>
> >> ---
> >>  drivers/firmware/efi/arm-init.c    |  8 ++++++++
> >>  drivers/firmware/efi/libstub/fdt.c | 24 +-----------------------
> >>  2 files changed, 9 insertions(+), 23 deletions(-)
> >
> > Matt, are you ok with me taking this through the arm64 tree? (since the
> > NUMA patches depend on it). If so, please can I have your ack?
> >
> 
> Matt gave his Reviewed-by for v15
> 
> http://www.gossamer-threads.com/lists/linux/kernel/2390242

Heh, you beat me to it!

Will, go ahead and take this through the arm64 tree.
Will Deacon April 15, 2016, 2:08 p.m. UTC | #7
On Fri, Apr 15, 2016 at 04:06:08PM +0200, Ard Biesheuvel wrote:
> On 15 April 2016 at 16:03, Will Deacon <will.deacon@arm.com> wrote:
> > On Fri, Apr 08, 2016 at 03:50:23PM -0700, David Daney wrote:
> >> From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> >>
> >> There are two problems with the UEFI stub DT memory node removal
> >> routine:
> >> - it deletes nodes as it traverses the tree, which happens to work
> >>   but is not supported, as deletion invalidates the node iterator;
> >> - deleting memory nodes entirely may discard annotations in the form
> >>   of additional properties on the nodes.
> >>
> >> Since the discovery of DT memory nodes occurs strictly before the
> >> UEFI init sequence, we can simply clear the memblock memory table
> >> before parsing the UEFI memory map. This way, it is no longer
> >> necessary to remove the nodes, so we can remove that logic from the
> >> stub as well.
> >>
> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> >> Signed-off-by: David Daney <david.daney@cavium.com>
> >> ---
> >>  drivers/firmware/efi/arm-init.c    |  8 ++++++++
> >>  drivers/firmware/efi/libstub/fdt.c | 24 +-----------------------
> >>  2 files changed, 9 insertions(+), 23 deletions(-)
> >
> > Matt, are you ok with me taking this through the arm64 tree? (since the
> > NUMA patches depend on it). If so, please can I have your ack?
> >
> 
> Matt gave his Reviewed-by for v15
> 
> http://www.gossamer-threads.com/lists/linux/kernel/2390242

Brill, thanks. Looks like it got dropped by accident for the latest posting.

Will
diff mbox

Patch

diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
index aa1f743..5d6945b 100644
--- a/drivers/firmware/efi/arm-init.c
+++ b/drivers/firmware/efi/arm-init.c
@@ -143,6 +143,14 @@  static __init void reserve_regions(void)
 	if (efi_enabled(EFI_DBG))
 		pr_info("Processing EFI memory map:\n");
 
+	/*
+	 * Discard memblocks discovered so far: if there are any at this
+	 * point, they originate from memory nodes in the DT, and UEFI
+	 * uses its own memory map instead.
+	 */
+	memblock_dump_all();
+	memblock_remove(0, ULLONG_MAX);
+
 	for_each_efi_memory_desc(&memmap, md) {
 		paddr = md->phys_addr;
 		npages = md->num_pages;
diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
index 6dba78a..e58abfa 100644
--- a/drivers/firmware/efi/libstub/fdt.c
+++ b/drivers/firmware/efi/libstub/fdt.c
@@ -24,7 +24,7 @@  efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
 			unsigned long map_size, unsigned long desc_size,
 			u32 desc_ver)
 {
-	int node, prev, num_rsv;
+	int node, num_rsv;
 	int status;
 	u32 fdt_val32;
 	u64 fdt_val64;
@@ -54,28 +54,6 @@  efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
 		goto fdt_set_fail;
 
 	/*
-	 * Delete any memory nodes present. We must delete nodes which
-	 * early_init_dt_scan_memory may try to use.
-	 */
-	prev = 0;
-	for (;;) {
-		const char *type;
-		int len;
-
-		node = fdt_next_node(fdt, prev, NULL);
-		if (node < 0)
-			break;
-
-		type = fdt_getprop(fdt, node, "device_type", &len);
-		if (type && strncmp(type, "memory", len) == 0) {
-			fdt_del_node(fdt, node);
-			continue;
-		}
-
-		prev = node;
-	}
-
-	/*
 	 * Delete all memory reserve map entries. When booting via UEFI,
 	 * kernel will use the UEFI memory map to find reserved regions.
 	 */