@@ -10,16 +10,21 @@
/* This is for the serialisation of PxTLB broadcasts. At least on the
* N class systems, only one PxTLB inter processor broadcast can be
- * active at any one time on the Merced bus. This tlb purge
- * synchronisation is fairly lightweight and harmless so we activate
- * it on all SMP systems not just the N class. We also need to have
- * preemption disabled on uniprocessor machines, and spin_lock does that
- * nicely.
+ * active at any one time on the Merced bus. To be on the safe side, we
+ * unconditionally protect those broadcasts for all SMP kernels with a
+ * spinlock.
+ * On uniprocessor machines we save this overhead by just disabling
+ * preemption.
*/
-extern spinlock_t pa_tlb_lock;
-#define purge_tlb_start(x) spin_lock(&pa_tlb_lock)
-#define purge_tlb_end(x) spin_unlock(&pa_tlb_lock)
+#ifdef CONFIG_SMP
+extern spinlock_t pa_tlb_lock;
+# define purge_tlb_start(flags) spin_lock_irqsave(&pa_tlb_lock, flags)
+# define purge_tlb_end(flags) spin_unlock_irqrestore(&pa_tlb_lock, flags)
+#else
+# define purge_tlb_start(flags) preempt_disable()
+# define purge_tlb_end(flags) preempt_enable()
+#endif
extern void flush_tlb_all(void);
extern void flush_tlb_all_local(void *);
@@ -64,13 +69,14 @@ static inline void flush_tlb_page(struct vm_area_struct *vma,
unsigned long addr)
{
/* For one page, it's not worth testing the split_tlb variable */
+ unsigned long flags __maybe_unused;
mb();
mtsp(vma->vm_mm->context,1);
- purge_tlb_start();
+ purge_tlb_start(flags);
pdtlb(addr);
pitlb(addr);
- purge_tlb_end();
+ purge_tlb_end(flags);
}
void __flush_tlb_range(unsigned long sid,
@@ -35,12 +35,14 @@ int icache_stride __read_mostly;
EXPORT_SYMBOL(dcache_stride);
+#ifdef CONFIG_SMP
/* On some machines (e.g. ones with the Merced bus), there can be
* only a single PxTLB broadcast at a time; this must be guaranteed
- * by software. We put a spinlock around all TLB flushes to
- * ensure this.
+ * by software. We put a spinlock around all TLB flushes on SMP
+ * kernels to ensure this.
*/
DEFINE_SPINLOCK(pa_tlb_lock);
+#endif
struct pdc_cache_info cache_info __read_mostly;
#ifndef CONFIG_PA20
@@ -400,10 +402,11 @@ void clear_user_page_asm(void *page, unsigned long vaddr)
{
/* This function is implemented in assembly in pacache.S */
extern void __clear_user_page_asm(void *page, unsigned long vaddr);
+ unsigned long flags __maybe_unused;
- purge_tlb_start();
+ purge_tlb_start(flags);
__clear_user_page_asm(page, vaddr);
- purge_tlb_end();
+ purge_tlb_end(flags);
}
#define FLUSH_THRESHOLD 0x80000 /* 0.5MB */
@@ -444,20 +447,22 @@ extern void clear_user_page_asm(void *page, unsigned long vaddr);
void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
{
+ unsigned long flags __maybe_unused;
purge_kernel_dcache_page((unsigned long)page);
- purge_tlb_start();
+ purge_tlb_start(flags);
pdtlb_kernel(page);
- purge_tlb_end();
+ purge_tlb_end(flags);
clear_user_page_asm(page, vaddr);
}
EXPORT_SYMBOL(clear_user_page);
void flush_kernel_dcache_page_addr(void *addr)
{
+ unsigned long flags __maybe_unused;
flush_kernel_dcache_page_asm(addr);
- purge_tlb_start();
+ purge_tlb_start(flags);
pdtlb_kernel(addr);
- purge_tlb_end();
+ purge_tlb_end(flags);
}
EXPORT_SYMBOL(flush_kernel_dcache_page_addr);
@@ -490,8 +495,9 @@ void __flush_tlb_range(unsigned long sid, unsigned long start,
if (npages >= 512) /* 2MB of space: arbitrary, should be tuned */
flush_tlb_all();
else {
+ unsigned long flags __maybe_unused;
mtsp(sid, 1);
- purge_tlb_start();
+ purge_tlb_start(flags);
if (split_tlb) {
while (npages--) {
pdtlb(start);
@@ -504,7 +510,7 @@ void __flush_tlb_range(unsigned long sid, unsigned long start,
start += PAGE_SIZE;
}
}
- purge_tlb_end();
+ purge_tlb_end(flags);
}
}
@@ -90,12 +90,13 @@ static inline int map_pte_uncached(pte_t * pte,
if (end > PMD_SIZE)
end = PMD_SIZE;
do {
+ unsigned long flags __maybe_unused;
if (!pte_none(*pte))
printk(KERN_ERR "map_pte_uncached: page already exists\n");
set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC));
- purge_tlb_start();
+ purge_tlb_start(flags);
pdtlb_kernel(orig_vaddr);
- purge_tlb_end();
+ purge_tlb_end(flags);
vaddr += PAGE_SIZE;
orig_vaddr += PAGE_SIZE;
(*paddr_ptr) += PAGE_SIZE;
@@ -168,11 +169,12 @@ static inline void unmap_uncached_pte(pmd_t * pmd, unsigned long vaddr,
if (end > PMD_SIZE)
end = PMD_SIZE;
do {
+ unsigned long flags __maybe_unused;
pte_t page = *pte;
pte_clear(&init_mm, vaddr, pte);
- purge_tlb_start();
+ purge_tlb_start(flags);
pdtlb_kernel(orig_vaddr);
- purge_tlb_end();
+ purge_tlb_end(flags);
vaddr += PAGE_SIZE;
orig_vaddr += PAGE_SIZE;
pte++;