[PATCH 4.14 053/189] powerpc/powernv/memtrace: Let the arch hotunplug code flush cache

Greg Kroah-Hartman
2018-06-18T08:32:50Z

From: Balbir Singh <bsingharora@gmail.com>

[ Upstream commit 7fd6641de28fe9b5bce0c38d2adee0a72a72619e ]

Don't do this via custom code, instead now that we have support in the
arch hotplug/hotunplug code, rely on those routines to do the right
thing.

The existing flush doesn't work because it uses ppc64_caches.l1d.size
instead of ppc64_caches.l1d.line_size.

Fixes: 9d5171a8f248 ("powerpc/powernv: Enable removal of memory for in memory tracing")
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/platforms/powernv/memtrace.c | 17 -----------------
1 file changed, 17 deletions(-)

--- a/arch/powerpc/platforms/powernv/memtrace.c
+++ b/arch/powerpc/platforms/powernv/memtrace.c
@@ -82,19 +82,6 @@ static const struct file_operations memt
.open = simple_open,
};

-static void flush_memory_region(u64 base, u64 size)
-{
- unsigned long line_size = ppc64_caches.l1d.size;
- u64 end = base + size;
- u64 addr;
-
- base = round_down(base, line_size);
- end = round_up(end, line_size);
-
- for (addr = base; addr < end; addr += line_size)
- asm volatile("dcbf 0,%0" : "=r" (addr) :: "memory");
-}
-
static int check_memblock_online(struct memory_block *mem, void *arg)
{
if (mem->state != MEM_ONLINE)
@@ -132,10 +119,6 @@ static bool memtrace_offline_pages(u32 n
walk_memory_range(start_pfn, end_pfn, (void *)MEM_OFFLINE,
change_memblock_state);

- /* RCU grace period? */
- flush_memory_region((u64)__va(start_pfn << PAGE_SHIFT),
- nr_pages << PAGE_SHIFT);
-
lock_device_hotplug();
remove_memory(nid, start_pfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT);
unlock_device_hotplug();