tile: make __write_once a synonym for __read_mostly

This was really only useful for TILE64 when we mapped the
kernel data with small pages. Now we use a huge page and we
really don't want to map different parts of the kernel
data in different ways.

We retain the __write_once name in case we want to bring
it back to life at some point in the future.

Note that this change uncovered a latent bug where the
"smp_topology" variable happened to always be aligned mod 8
so we could store two "int" values at once, but when we
eliminated __write_once it ended up only aligned mod 4.
Fix with an explicit annotation.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

1 files changed, 2 insertions, 11 deletions

diff --git a/arch/tile/mm/init.c b/arch/tile/mm/init.c
index 22e41cf5a2a9..4e316deb92fd 100644
--- a/arch/tile/mm/init.c
+++ b/arch/tile/mm/init.c
@@ -271,21 +271,13 @@ static pgprot_t __init init_pgprot(ulong address)
                 return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
 
         /*
-         * Make the w1data homed like heap to start with, to avoid
-         * making it part of the page-striped data area when we're just
-         * going to convert it to read-only soon anyway.
-         */
-        if (address >= (ulong)__w1data_begin && address < (ulong)__w1data_end)
-                return construct_pgprot(PAGE_KERNEL, initial_heap_home());
-
-        /*
          * Otherwise we just hand out consecutive cpus.  To avoid
          * requiring this function to hold state, we just walk forward from
          * _sdata by PAGE_SIZE, skipping the readonly and init data, to reach
          * the requested address, while walking cpu home around kdata_mask.
          * This is typically no more than a dozen or so iterations.
          */
-        page = (((ulong)__w1data_end) + PAGE_SIZE - 1) & PAGE_MASK;
+        page = (((ulong)__end_rodata) + PAGE_SIZE - 1) & PAGE_MASK;
         BUG_ON(address < page || address >= (ulong)_end);
         cpu = cpumask_first(&kdata_mask);
         for (; page < address; page += PAGE_SIZE) {
@@ -980,8 +972,7 @@ void free_initmem(void)
         const unsigned long text_delta = MEM_SV_START - PAGE_OFFSET;
 
         /*
-         * Evict the dirty initdata on the boot cpu, evict the w1data
-         * wherever it's homed, and evict all the init code everywhere.
+         * Evict the cache on all cores to avoid incoherence.
          * We are guaranteed that no one will touch the init pages any more.
          */
         homecache_evict(&cpu_cacheable_map);