85xx: Additional fixes and cleanup of MP code
* 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>
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 @@
}
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 @@
/* 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 @@
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 @@
mtspr SPRN_SRR1,r13
rfi
- .align 3
+ .align L1_CACHE_SHIFT
.globl __spin_table
__spin_table:
.space CONFIG_NR_CPUS*ENTRY_SIZE