[U-Boot-Users] [PATCH] 85xx: Additional fixes and cleanup of MP code

[U-Boot-Users] [PATCH] 85xx: Additional fixes and cleanup of MP code

[Kumar Gala]

* adjust __spin_table alignment to match ePAPR v0.94 spec
* loop over all cpus when determing who is up.  This fixes an issue if
  the "boot cpu" isn't core0.  The "boot cpu" will already be in the
  cpu_up_mask so there is no harm
* Added some protection in the code to ensure proper behavior.  These
  changes are explicitly needed but don't hurt:
  - Added eieio to ensure the "hot word" of the table is written after
    all other table updates have occurred.
  - Added isync to ensure we don't prefetch loading of table entries
    until we a released

These issues we raised by Dave Liu.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---

For 1.3.3

 cpu/mpc85xx/mp.c      |    6 +++++-
 cpu/mpc85xx/release.S |    3 ++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/cpu/mpc85xx/mp.c b/cpu/mpc85xx/mp.c
index e733f7b..a527cf3 100644
--- a/cpu/mpc85xx/mp.c
+++ b/cpu/mpc85xx/mp.c
@@ -103,6 +103,10 @@ int cpu_release(int nr, int argc, char *argv[])
 	}

 	table[BOOT_ENTRY_ADDR_UPPER] = (u32)(boot_addr >> 32);
+
+	/* ensure all table updates complete before final address write */
+	eieio();
+
 	table[BOOT_ENTRY_ADDR_LOWER] = (u32)(boot_addr & 0xffffffff);

 	return 0;
@@ -153,7 +157,7 @@ static void pq3_mp_up(unsigned long bootpg)
 	/* wait for everyone */
 	while (timeout) {
 		int i;
-		for (i = 1; i < CONFIG_NR_CPUS; i++) {
+		for (i = 0; i < CONFIG_NR_CPUS; i++) {
 			if (table[i * NUM_BOOT_ENTRY + BOOT_ENTRY_ADDR_LOWER])
 				cpu_up_mask |= (1 << i);
 		};
diff --git a/cpu/mpc85xx/release.S b/cpu/mpc85xx/release.S
index 3b7366f..a47edae 100644
--- a/cpu/mpc85xx/release.S
+++ b/cpu/mpc85xx/release.S
@@ -114,6 +114,7 @@ __secondary_start_page:
 	lwz	r4,ENTRY_ADDR_LOWER(r10)
 	andi.	r11,r4,1
 	bne	2b
+	isync

 	/* get the upper bits of the addr */
 	lwz	r11,ENTRY_ADDR_UPPER(r10)
@@ -169,7 +170,7 @@ __secondary_start_page:
 	mtspr	SPRN_SRR1,r13
 	rfi

-	.align 3
+	.align L1_CACHE_SHIFT
 	.globl __spin_table
 __spin_table:
 	.space CONFIG_NR_CPUS*ENTRY_SIZE
-- 
1.5.4.1

[U-Boot-Users] [PATCH] 85xx: Additional fixes and cleanup of MP code

[Wolfgang Denk]

In message <Pine.LNX.4.64.0804280223420.4305@blarg.am.freescale.net> you wrote:
> * adjust __spin_table alignment to match ePAPR v0.94 spec
> * loop over all cpus when determing who is up.  This fixes an issue if
>   the "boot cpu" isn't core0.  The "boot cpu" will already be in the
>   cpu_up_mask so there is no harm
> * Added some protection in the code to ensure proper behavior.  These
>   changes are explicitly needed but don't hurt:
>   - Added eieio to ensure the "hot word" of the table is written after
>     all other table updates have occurred.
>   - Added isync to ensure we don't prefetch loading of table entries
>     until we a released
> 
> These issues we raised by Dave Liu.
> 
> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

Will Andy send a pull request or shall I apply directly?

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The management question ... is not _whether_ to build a pilot  system
and  throw  it away. You _will_ do that. The only question is whether
to plan in advance to build a throwaway, or to promise to deliver the
throwaway to customers.       - Fred Brooks, "The Mythical Man Month"

[U-Boot-Users] [PATCH] 85xx: Additional fixes and cleanup of MP code

[Kumar Gala]

On Apr 28, 2008, at 4:07 AM, Wolfgang Denk wrote:
> In message <Pine.LNX.4.64.0804280223420.4305@blarg.am.freescale.net>  
> you wrote:
>> * adjust __spin_table alignment to match ePAPR v0.94 spec
>> * loop over all cpus when determing who is up.  This fixes an issue  
>> if
>>  the "boot cpu" isn't core0.  The "boot cpu" will already be in the
>>  cpu_up_mask so there is no harm
>> * Added some protection in the code to ensure proper behavior.  These
>>  changes are explicitly needed but don't hurt:
>>  - Added eieio to ensure the "hot word" of the table is written after
>>    all other table updates have occurred.
>>  - Added isync to ensure we don't prefetch loading of table entries
>>    until we a released
>>
>> These issues we raised by Dave Liu.
>>
>> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
>
> Will Andy send a pull request or shall I apply directly?

just apply directly.

- k