s390/nmi: get rid of private slab cache

Get rid of private "nmi_save_areas" slab cache. The only reason this was
introduced years ago was that with some slab debugging options allocations
would only guarantee a minimum alignment of ARCH_KMALLOC_MINALIGN, which
was eight bytes back then. This is not sufficient for the extended machine
check save area.

However since commit 59bb47985c1d ("mm, sl[aou]b: guarantee natural
alignment for kmalloc(power-of-two)") kmalloc guarantees a power-of-two
alignment even with debugging options enabled.

Therefore the private slab cache can be removed.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c
index b54d4aa3385144da8761fb195e2bb42ccf188984..5dbf274719a9596937f07ca026cb546977e8a5c9 100644 (file)
--- a/arch/s390/kernel/nmi.c
+++ b/arch/s390/kernel/nmi.c
@@ -42,21 +42,12 @@ struct mcck_struct {
 };
 
 static DEFINE_PER_CPU(struct mcck_struct, cpu_mcck);
-static struct kmem_cache *mcesa_cache;
-static unsigned long mcesa_origin_lc;
 
 static inline int nmi_needs_mcesa(void)
 {
        return MACHINE_HAS_VX || MACHINE_HAS_GS;
 }
 
-static inline unsigned long nmi_get_mcesa_size(void)
-{
-       if (MACHINE_HAS_GS)
-               return MCESA_MAX_SIZE;
-       return MCESA_MIN_SIZE;
-}
-
 /*
  * The initial machine check extended save area for the boot CPU.
  * It will be replaced on the boot CPU reinit with an allocated
@@ -74,36 +65,23 @@ void __init nmi_alloc_mcesa_early(u64 *mcesad)
                *mcesad |= ilog2(MCESA_MAX_SIZE);
 }
 
-static void __init nmi_alloc_cache(void)
+int nmi_alloc_mcesa(u64 *mcesad)
 {
        unsigned long size;
-
-       if (!nmi_needs_mcesa())
-               return;
-       size = nmi_get_mcesa_size();
-       if (size > MCESA_MIN_SIZE)
-               mcesa_origin_lc = ilog2(size);
-       /* create slab cache for the machine-check-extended-save-areas */
-       mcesa_cache = kmem_cache_create("nmi_save_areas", size, size, 0, NULL);
-       if (!mcesa_cache)
-               panic("Couldn't create nmi save area cache");
-}
-
-int __ref nmi_alloc_mcesa(u64 *mcesad)
-{
-       unsigned long origin;
+       void *origin;
 
        *mcesad = 0;
        if (!nmi_needs_mcesa())
                return 0;
-       if (!mcesa_cache)
-               nmi_alloc_cache();
-       origin = (unsigned long) kmem_cache_alloc(mcesa_cache, GFP_KERNEL);
+       size = MACHINE_HAS_GS ? MCESA_MAX_SIZE : MCESA_MIN_SIZE;
+       origin = kmalloc(size, GFP_KERNEL);
        if (!origin)
                return -ENOMEM;
        /* The pointer is stored with mcesa_bits ORed in */
-       kmemleak_not_leak((void *) origin);
-       *mcesad = __pa(origin) | mcesa_origin_lc;
+       kmemleak_not_leak(origin);
+       *mcesad = __pa(origin);
+       if (MACHINE_HAS_GS)
+               *mcesad |= ilog2(MCESA_MAX_SIZE);
        return 0;
 }
 
@@ -111,7 +89,7 @@ void nmi_free_mcesa(u64 *mcesad)
 {
        if (!nmi_needs_mcesa())
                return;
-       kmem_cache_free(mcesa_cache, __va(*mcesad & MCESA_ORIGIN_MASK));
+       kfree(__va(*mcesad & MCESA_ORIGIN_MASK));
 }
 
 static __always_inline char *nmi_puts(char *dest, const char *src)