Once stop_machine() is gone from the CPU offline path, we won't be able
to depend on disabling preemption to prevent CPUs from going offline
from under us.
Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going
offline, while invoking from atomic context.
Cc: Chris Metcalf <cmetc...@tilera.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.b...@linux.vnet.ibm.com>
---
arch/tile/kernel/module.c | 3 +++
arch/tile/kernel/tlb.c | 15 +++++++++++++++
arch/tile/mm/homecache.c | 3 +++
3 files changed, 21 insertions(+)
diff --git a/arch/tile/kernel/module.c b/arch/tile/kernel/module.c
index 4918d91..db7d858 100644
--- a/arch/tile/kernel/module.c
+++ b/arch/tile/kernel/module.c
@@ -20,6 +20,7 @@
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
+#include <linux/cpu.h>
#include <asm/pgtable.h>
#include <asm/homecache.h>
#include <arch/opcode.h>
@@ -79,8 +80,10 @@ void module_free(struct module *mod, void *module_region)
vfree(module_region);
/* Globally flush the L1 icache. */
+ get_online_cpus_atomic();
flush_remote(0, HV_FLUSH_EVICT_L1I, cpu_online_mask,
0, 0, 0, NULL, NULL, 0);
+ put_online_cpus_atomic();
/*
* FIXME: If module_region == mod->module_init, trim exception
diff --git a/arch/tile/kernel/tlb.c b/arch/tile/kernel/tlb.c
index 3fd54d5..a32b9dd 100644
--- a/arch/tile/kernel/tlb.c
+++ b/arch/tile/kernel/tlb.c
@@ -14,6 +14,7 @@
*/
#include <linux/cpumask.h>
+#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/hugetlb.h>
#include <asm/tlbflush.h>
@@ -35,6 +36,8 @@ void flush_tlb_mm(struct mm_struct *mm)
{
HV_Remote_ASID asids[NR_CPUS];
int i = 0, cpu;
+
+ get_online_cpus_atomic();
for_each_cpu(cpu, mm_cpumask(mm)) {
HV_Remote_ASID *asid = &asids[i++];
asid->y = cpu / smp_topology.width;
@@ -43,6 +46,7 @@ void flush_tlb_mm(struct mm_struct *mm)
}
flush_remote(0, HV_FLUSH_EVICT_L1I, mm_cpumask(mm),
0, 0, 0, NULL, asids, i);
+ put_online_cpus_atomic();
}
void flush_tlb_current_task(void)
@@ -55,8 +59,11 @@ void flush_tlb_page_mm(struct vm_area_struct *vma, struct
mm_struct *mm,
{
unsigned long size = vma_kernel_pagesize(vma);
int cache = (vma->vm_flags & VM_EXEC) ? HV_FLUSH_EVICT_L1I : 0;
+
+ get_online_cpus_atomic();
flush_remote(0, cache, mm_cpumask(mm),
va, size, size, mm_cpumask(mm), NULL, 0);
+ put_online_cpus_atomic();
}
void flush_tlb_page(struct vm_area_struct *vma, unsigned long va)
@@ -71,13 +78,18 @@ void flush_tlb_range(struct vm_area_struct *vma,
unsigned long size = vma_kernel_pagesize(vma);
struct mm_struct *mm = vma->vm_mm;
int cache = (vma->vm_flags & VM_EXEC) ? HV_FLUSH_EVICT_L1I : 0;
+
+ get_online_cpus_atomic();
flush_remote(0, cache, mm_cpumask(mm), start, end - start, size,
mm_cpumask(mm), NULL, 0);
+ put_online_cpus_atomic();
}
void flush_tlb_all(void)
{
int i;
+
+ get_online_cpus_atomic();
for (i = 0; ; ++i) {
HV_VirtAddrRange r = hv_inquire_virtual(i);
if (r.size == 0)
@@ -89,10 +101,13 @@ void flush_tlb_all(void)
r.start, r.size, HPAGE_SIZE, cpu_online_mask,
NULL, 0);
}
+ put_online_cpus_atomic();
}
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
+ get_online_cpus_atomic();
flush_remote(0, HV_FLUSH_EVICT_L1I, cpu_online_mask,
start, end - start, PAGE_SIZE, cpu_online_mask, NULL, 0);
+ put_online_cpus_atomic();
}
diff --git a/arch/tile/mm/homecache.c b/arch/tile/mm/homecache.c
index 1ae9119..7ff5bf0 100644
--- a/arch/tile/mm/homecache.c
+++ b/arch/tile/mm/homecache.c
@@ -397,9 +397,12 @@ void homecache_change_page_home(struct page *page, int
order, int home)
BUG_ON(page_count(page) > 1);
BUG_ON(page_mapcount(page) != 0);
kva = (unsigned long) page_address(page);
+
+ get_online_cpus_atomic();
flush_remote(0, HV_FLUSH_EVICT_L2, &cpu_cacheable_map,
kva, pages * PAGE_SIZE, PAGE_SIZE, cpu_online_mask,
NULL, 0);
+ put_online_cpus_atomic();
for (i = 0; i < pages; ++i, kva += PAGE_SIZE) {
pte_t *ptep = virt_to_pte(NULL, kva);
--
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