Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc

Pull sparc updates from David Miller:
 "Some 32-bit kgdb cleanups from Sam Ravnborg, and a hugepage TLB flush
  overhead fix on 64-bit from Nitin Gupta"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Reduce TLB flushes during hugepte changes
  aeroflex/greth: fix warning about unused variable
  openprom: fix warning
  sparc32: drop superfluous cast in calls to __nocache_pa()
  sparc32: fix build with STRICT_MM_TYPECHECKS
  sparc32: use proper prototype for trapbase
  sparc32: drop local prototype in kgdb_32
  sparc32: drop hardcoding trap_level in kgdb_trap

arch/sparc/include/asm/head_32.h

@@ -44,9 +44,9 @@
 
 #ifdef CONFIG_KGDB
 #define KGDB_TRAP(num)                  \
+	mov num, %l7;                   \
 	b kgdb_trap_low;                \
 	rd %psr,%l0;                    \
-	nop; \
 	nop;
 #else
 #define KGDB_TRAP(num) \

arch/sparc/include/asm/kgdb.h

@@ -28,10 +28,10 @@ enum regnames {
 #define NUMREGBYTES		((GDB_CSR + 1) * 4)
 #else
 #define NUMREGBYTES		((GDB_Y + 1) * 8)
+#endif
 
 struct pt_regs;
 asmlinkage void kgdb_trap(unsigned long trap_level, struct pt_regs *regs);
-#endif
 
 void arch_kgdb_breakpoint(void);
 

arch/sparc/include/asm/page_32.h

@@ -69,7 +69,6 @@ typedef struct { unsigned long iopgprot; } iopgprot_t;
 
 #define __pte(x)	((pte_t) { (x) } )
 #define __iopte(x)	((iopte_t) { (x) } )
-/* #define __pmd(x)        ((pmd_t) { (x) } ) */ /* XXX procedure with loop */
 #define __pgd(x)	((pgd_t) { (x) } )
 #define __ctxd(x)	((ctxd_t) { (x) } )
 #define __pgprot(x)	((pgprot_t) { (x) } )
@@ -97,7 +96,6 @@ typedef unsigned long iopgprot_t;
 
 #define __pte(x)	(x)
 #define __iopte(x)	(x)
-/* #define __pmd(x)        (x) */ /* XXX later */
 #define __pgd(x)	(x)
 #define __ctxd(x)	(x)
 #define __pgprot(x)	(x)

arch/sparc/include/asm/pgalloc_32.h

@@ -29,9 +29,9 @@ static inline void free_pgd_fast(pgd_t *pgd)
 
 static inline void pgd_set(pgd_t * pgdp, pmd_t * pmdp)
 {
-	unsigned long pa = __nocache_pa((unsigned long)pmdp);
+	unsigned long pa = __nocache_pa(pmdp);
 
-	set_pte((pte_t *)pgdp, (SRMMU_ET_PTD | (pa >> 4)));
+	set_pte((pte_t *)pgdp, __pte((SRMMU_ET_PTD | (pa >> 4))));
 }
 
 #define pgd_populate(MM, PGD, PMD)      pgd_set(PGD, PMD)

arch/sparc/include/asm/pgtable_32.h

@@ -298,7 +298,7 @@ static inline pte_t mk_pte_io(unsigned long page, pgprot_t pgprot, int space)
 #define pgprot_noncached pgprot_noncached
 static inline pgprot_t pgprot_noncached(pgprot_t prot)
 {
-	prot &= ~__pgprot(SRMMU_CACHE);
+	pgprot_val(prot) &= ~pgprot_val(__pgprot(SRMMU_CACHE));
 	return prot;
 }
 

arch/sparc/include/asm/pgtable_64.h

@@ -375,7 +375,7 @@ static inline pgprot_t pgprot_noncached(pgprot_t prot)
 #define pgprot_noncached pgprot_noncached
 
 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
-static inline pte_t pte_mkhuge(pte_t pte)
+static inline unsigned long __pte_huge_mask(void)
 {
 	unsigned long mask;
 
@@ -390,8 +390,19 @@ static inline pte_t pte_mkhuge(pte_t pte)
 	: "=r" (mask)
 	: "i" (_PAGE_SZHUGE_4U), "i" (_PAGE_SZHUGE_4V));
 
-	return __pte(pte_val(pte) | mask);
+	return mask;
+}
+
+static inline pte_t pte_mkhuge(pte_t pte)
+{
+	return __pte(pte_val(pte) | __pte_huge_mask());
+}
+
+static inline bool is_hugetlb_pte(pte_t pte)
+{
+	return !!(pte_val(pte) & __pte_huge_mask());
 }
+
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 static inline pmd_t pmd_mkhuge(pmd_t pmd)
 {
@@ -403,6 +414,11 @@ static inline pmd_t pmd_mkhuge(pmd_t pmd)
 	return __pmd(pte_val(pte));
 }
 #endif
+#else
+static inline bool is_hugetlb_pte(pte_t pte)
+{
+	return false;
+}
 #endif
 
 static inline pte_t pte_mkdirty(pte_t pte)
@@ -856,6 +872,19 @@ static inline unsigned long pud_pfn(pud_t pud)
 void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr,
 		   pte_t *ptep, pte_t orig, int fullmm);
 
+static void maybe_tlb_batch_add(struct mm_struct *mm, unsigned long vaddr,
+				pte_t *ptep, pte_t orig, int fullmm)
+{
+	/* It is more efficient to let flush_tlb_kernel_range()
+	 * handle init_mm tlb flushes.
+	 *
+	 * SUN4V NOTE: _PAGE_VALID is the same value in both the SUN4U
+	 *             and SUN4V pte layout, so this inline test is fine.
+	 */
+	if (likely(mm != &init_mm) && pte_accessible(mm, orig))
+		tlb_batch_add(mm, vaddr, ptep, orig, fullmm);
+}
+
 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
 					    unsigned long addr,
@@ -872,15 +901,7 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
 	pte_t orig = *ptep;
 
 	*ptep = pte;
-
-	/* It is more efficient to let flush_tlb_kernel_range()
-	 * handle init_mm tlb flushes.
-	 *
-	 * SUN4V NOTE: _PAGE_VALID is the same value in both the SUN4U
-	 *             and SUN4V pte layout, so this inline test is fine.
-	 */
-	if (likely(mm != &init_mm) && pte_accessible(mm, orig))
-		tlb_batch_add(mm, addr, ptep, orig, fullmm);
+	maybe_tlb_batch_add(mm, addr, ptep, orig, fullmm);
 }
 
 #define set_pte_at(mm,addr,ptep,pte)	\

arch/sparc/include/asm/tlbflush_64.h

@@ -8,6 +8,7 @@
 #define TLB_BATCH_NR	192
 
 struct tlb_batch {
+	bool huge;
 	struct mm_struct *mm;
 	unsigned long tlb_nr;
 	unsigned long active;
@@ -16,7 +17,7 @@ struct tlb_batch {
 
 void flush_tsb_kernel_range(unsigned long start, unsigned long end);
 void flush_tsb_user(struct tlb_batch *tb);
-void flush_tsb_user_page(struct mm_struct *mm, unsigned long vaddr);
+void flush_tsb_user_page(struct mm_struct *mm, unsigned long vaddr, bool huge);
 
 /* TLB flush operations. */
 

arch/sparc/kernel/entry.S

@@ -1225,20 +1225,18 @@ breakpoint_trap:
 	RESTORE_ALL
 
 #ifdef CONFIG_KGDB
-	.align	4
-	.globl	kgdb_trap_low
-	.type	kgdb_trap_low,#function
-kgdb_trap_low:
+	ENTRY(kgdb_trap_low)
 	rd	%wim,%l3
 	SAVE_ALL
 	wr 	%l0, PSR_ET, %psr
 	WRITE_PAUSE
 
+	mov	%l7, %o0		! trap_level
 	call	kgdb_trap
-	 add	%sp, STACKFRAME_SZ, %o0
+	 add	%sp, STACKFRAME_SZ, %o1	! struct pt_regs *regs
 
 	RESTORE_ALL
-	.size	kgdb_trap_low,.-kgdb_trap_low
+	ENDPROC(kgdb_trap_low)
 #endif
 
 	.align	4

arch/sparc/kernel/kernel.h

@@ -127,6 +127,7 @@ extern unsigned int t_nmi[];
 extern unsigned int linux_trap_ipi15_sun4d[];
 extern unsigned int linux_trap_ipi15_sun4m[];
 
+extern struct tt_entry trapbase;
 extern struct tt_entry trapbase_cpu1;
 extern struct tt_entry trapbase_cpu2;
 extern struct tt_entry trapbase_cpu3;

arch/sparc/kernel/kgdb_32.c

@@ -12,7 +12,8 @@
 #include <asm/irq.h>
 #include <asm/cacheflush.h>
 
-extern unsigned long trapbase;
+#include "kernel.h"
+#include "entry.h"
 
 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
 {
@@ -133,21 +134,19 @@ int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
 	return -1;
 }
 
-extern void do_hw_interrupt(struct pt_regs *regs, unsigned long type);
-
-asmlinkage void kgdb_trap(struct pt_regs *regs)
+asmlinkage void kgdb_trap(unsigned long trap_level, struct pt_regs *regs)
 {
 	unsigned long flags;
 
 	if (user_mode(regs)) {
-		do_hw_interrupt(regs, 0xfd);
+		do_hw_interrupt(regs, trap_level);
 		return;
 	}
 
 	flushw_all();
 
 	local_irq_save(flags);
-	kgdb_handle_exception(0x172, SIGTRAP, 0, regs);
+	kgdb_handle_exception(trap_level, SIGTRAP, 0, regs);
 	local_irq_restore(flags);
 }
 

arch/sparc/kernel/setup_32.c

@@ -68,8 +68,6 @@ struct screen_info screen_info = {
  * prints out pretty messages and returns.
  */
 
-extern unsigned long trapbase;
-
 /* Pretty sick eh? */
 static void prom_sync_me(void)
 {
@@ -300,7 +298,7 @@ void __init setup_arch(char **cmdline_p)
 	int i;
 	unsigned long highest_paddr;
 
-	sparc_ttable = (struct tt_entry *) &trapbase;
+	sparc_ttable = &trapbase;
 
 	/* Initialize PROM console and command line. */
 	*cmdline_p = prom_getbootargs();

arch/sparc/mm/hugetlbpage.c

@@ -176,17 +176,31 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 		     pte_t *ptep, pte_t entry)
 {
 	int i;
+	pte_t orig[2];
+	unsigned long nptes;
 
 	if (!pte_present(*ptep) && pte_present(entry))
 		mm->context.huge_pte_count++;
 
 	addr &= HPAGE_MASK;
-	for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
-		set_pte_at(mm, addr, ptep, entry);
+
+	nptes = 1 << HUGETLB_PAGE_ORDER;
+	orig[0] = *ptep;
+	orig[1] = *(ptep + nptes / 2);
+	for (i = 0; i < nptes; i++) {
+		*ptep = entry;
 		ptep++;
 		addr += PAGE_SIZE;
 		pte_val(entry) += PAGE_SIZE;
 	}
+
+	/* Issue TLB flush at REAL_HPAGE_SIZE boundaries */
+	addr -= REAL_HPAGE_SIZE;
+	ptep -= nptes / 2;
+	maybe_tlb_batch_add(mm, addr, ptep, orig[1], 0);
+	addr -= REAL_HPAGE_SIZE;
+	ptep -= nptes / 2;
+	maybe_tlb_batch_add(mm, addr, ptep, orig[0], 0);
 }
 
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
@@ -194,19 +208,28 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 {
 	pte_t entry;
 	int i;
+	unsigned long nptes;
 
 	entry = *ptep;
 	if (pte_present(entry))
 		mm->context.huge_pte_count--;
 
 	addr &= HPAGE_MASK;
-
-	for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
-		pte_clear(mm, addr, ptep);
+	nptes = 1 << HUGETLB_PAGE_ORDER;
+	for (i = 0; i < nptes; i++) {
+		*ptep = __pte(0UL);
 		addr += PAGE_SIZE;
 		ptep++;
 	}
 
+	/* Issue TLB flush at REAL_HPAGE_SIZE boundaries */
+	addr -= REAL_HPAGE_SIZE;
+	ptep -= nptes / 2;
+	maybe_tlb_batch_add(mm, addr, ptep, entry, 0);
+	addr -= REAL_HPAGE_SIZE;
+	ptep -= nptes / 2;
+	maybe_tlb_batch_add(mm, addr, ptep, entry, 0);
+
 	return entry;
 }
 

arch/sparc/mm/init_64.c

@@ -324,18 +324,6 @@ static void __update_mmu_tsb_insert(struct mm_struct *mm, unsigned long tsb_inde
 	tsb_insert(tsb, tag, tte);
 }
 
-#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
-static inline bool is_hugetlb_pte(pte_t pte)
-{
-	if ((tlb_type == hypervisor &&
-	     (pte_val(pte) & _PAGE_SZALL_4V) == _PAGE_SZHUGE_4V) ||
-	    (tlb_type != hypervisor &&
-	     (pte_val(pte) & _PAGE_SZALL_4U) == _PAGE_SZHUGE_4U))
-		return true;
-	return false;
-}
-#endif
-
 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
 {
 	struct mm_struct *mm;

arch/sparc/mm/io-unit.c

@@ -133,7 +133,7 @@ nexti:	scan = find_next_zero_bit(iounit->bmap, limit, scan);
 	vaddr = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT) + (vaddr & ~PAGE_MASK);
 	for (k = 0; k < npages; k++, iopte = __iopte(iopte_val(iopte) + 0x100), scan++) {
 		set_bit(scan, iounit->bmap);
-		sbus_writel(iopte, &iounit->page_table[scan]);
+		sbus_writel(iopte_val(iopte), &iounit->page_table[scan]);
 	}
 	IOD(("%08lx\n", vaddr));
 	return vaddr;
@@ -228,7 +228,7 @@ static int iounit_map_dma_area(struct device *dev, dma_addr_t *pba, unsigned lon
 			i = ((addr - IOUNIT_DMA_BASE) >> PAGE_SHIFT);
 
 			iopte = iounit->page_table + i;
-			sbus_writel(MKIOPTE(__pa(page)), iopte);
+			sbus_writel(iopte_val(MKIOPTE(__pa(page))), iopte);
 		}
 		addr += PAGE_SIZE;
 		va += PAGE_SIZE;

arch/sparc/mm/srmmu.c

@@ -107,17 +107,22 @@ static inline int srmmu_pmd_none(pmd_t pmd)
 
 /* XXX should we hyper_flush_whole_icache here - Anton */
 static inline void srmmu_ctxd_set(ctxd_t *ctxp, pgd_t *pgdp)
-{ set_pte((pte_t *)ctxp, (SRMMU_ET_PTD | (__nocache_pa((unsigned long) pgdp) >> 4))); }
+{
+	pte_t pte;
+
+	pte = __pte((SRMMU_ET_PTD | (__nocache_pa(pgdp) >> 4)));
+	set_pte((pte_t *)ctxp, pte);
+}
 
 void pmd_set(pmd_t *pmdp, pte_t *ptep)
 {
 	unsigned long ptp;	/* Physical address, shifted right by 4 */
 	int i;
 
-	ptp = __nocache_pa((unsigned long) ptep) >> 4;
+	ptp = __nocache_pa(ptep) >> 4;
 	for (i = 0; i < PTRS_PER_PTE/SRMMU_REAL_PTRS_PER_PTE; i++) {
-		set_pte((pte_t *)&pmdp->pmdv[i], SRMMU_ET_PTD | ptp);
-		ptp += (SRMMU_REAL_PTRS_PER_PTE*sizeof(pte_t) >> 4);
+		set_pte((pte_t *)&pmdp->pmdv[i], __pte(SRMMU_ET_PTD | ptp));
+		ptp += (SRMMU_REAL_PTRS_PER_PTE * sizeof(pte_t) >> 4);
 	}
 }
 
@@ -128,8 +133,8 @@ void pmd_populate(struct mm_struct *mm, pmd_t *pmdp, struct page *ptep)
 
 	ptp = page_to_pfn(ptep) << (PAGE_SHIFT-4);	/* watch for overflow */
 	for (i = 0; i < PTRS_PER_PTE/SRMMU_REAL_PTRS_PER_PTE; i++) {
-		set_pte((pte_t *)&pmdp->pmdv[i], SRMMU_ET_PTD | ptp);
-		ptp += (SRMMU_REAL_PTRS_PER_PTE*sizeof(pte_t) >> 4);
+		set_pte((pte_t *)&pmdp->pmdv[i], __pte(SRMMU_ET_PTD | ptp));
+		ptp += (SRMMU_REAL_PTRS_PER_PTE * sizeof(pte_t) >> 4);
 	}
 }
 
@@ -911,7 +916,7 @@ void __init srmmu_paging_init(void)
 
 	/* ctx table has to be physically aligned to its size */
 	srmmu_context_table = __srmmu_get_nocache(num_contexts * sizeof(ctxd_t), num_contexts * sizeof(ctxd_t));
-	srmmu_ctx_table_phys = (ctxd_t *)__nocache_pa((unsigned long)srmmu_context_table);
+	srmmu_ctx_table_phys = (ctxd_t *)__nocache_pa(srmmu_context_table);
 
 	for (i = 0; i < num_contexts; i++)
 		srmmu_ctxd_set((ctxd_t *)__nocache_fix(&srmmu_context_table[i]), srmmu_swapper_pg_dir);

arch/sparc/mm/tlb.c

@@ -67,7 +67,7 @@ void arch_leave_lazy_mmu_mode(void)
 }
 
 static void tlb_batch_add_one(struct mm_struct *mm, unsigned long vaddr,
-			      bool exec)
+			      bool exec, bool huge)
 {
 	struct tlb_batch *tb = &get_cpu_var(tlb_batch);
 	unsigned long nr;
@@ -84,13 +84,21 @@ static void tlb_batch_add_one(struct mm_struct *mm, unsigned long vaddr,
 	}
 
 	if (!tb->active) {
-		flush_tsb_user_page(mm, vaddr);
+		flush_tsb_user_page(mm, vaddr, huge);
 		global_flush_tlb_page(mm, vaddr);
 		goto out;
 	}
 
-	if (nr == 0)
+	if (nr == 0) {
 		tb->mm = mm;
+		tb->huge = huge;
+	}
+
+	if (tb->huge != huge) {
+		flush_tlb_pending();
+		tb->huge = huge;
+		nr = 0;
+	}
 
 	tb->vaddrs[nr] = vaddr;
 	tb->tlb_nr = ++nr;
@@ -104,6 +112,8 @@ static void tlb_batch_add_one(struct mm_struct *mm, unsigned long vaddr,
 void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr,
 		   pte_t *ptep, pte_t orig, int fullmm)
 {
+	bool huge = is_hugetlb_pte(orig);
+
 	if (tlb_type != hypervisor &&
 	    pte_dirty(orig)) {
 		unsigned long paddr, pfn = pte_pfn(orig);
@@ -129,7 +139,7 @@ void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr,
 
 no_cache_flush:
 	if (!fullmm)
-		tlb_batch_add_one(mm, vaddr, pte_exec(orig));
+		tlb_batch_add_one(mm, vaddr, pte_exec(orig), huge);
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -145,7 +155,7 @@ static void tlb_batch_pmd_scan(struct mm_struct *mm, unsigned long vaddr,
 		if (pte_val(*pte) & _PAGE_VALID) {
 			bool exec = pte_exec(*pte);
 
-			tlb_batch_add_one(mm, vaddr, exec);
+			tlb_batch_add_one(mm, vaddr, exec, false);
 		}
 		pte++;
 		vaddr += PAGE_SIZE;
@@ -185,8 +195,9 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 			pte_t orig_pte = __pte(pmd_val(orig));
 			bool exec = pte_exec(orig_pte);
 
-			tlb_batch_add_one(mm, addr, exec);
-			tlb_batch_add_one(mm, addr + REAL_HPAGE_SIZE, exec);
+			tlb_batch_add_one(mm, addr, exec, true);
+			tlb_batch_add_one(mm, addr + REAL_HPAGE_SIZE, exec,
+					true);
 		} else {
 			tlb_batch_pmd_scan(mm, addr, orig);
 		}

arch/sparc/mm/tsb.c

@@ -76,14 +76,15 @@ void flush_tsb_user(struct tlb_batch *tb)
 
 	spin_lock_irqsave(&mm->context.lock, flags);
 
+	if (!tb->huge) {
 		base = (unsigned long) mm->context.tsb_block[MM_TSB_BASE].tsb;
 		nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
 		if (tlb_type == cheetah_plus || tlb_type == hypervisor)
 			base = __pa(base);
 		__flush_tsb_one(tb, PAGE_SHIFT, base, nentries);
-
+	}
 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
-	if (mm->context.tsb_block[MM_TSB_HUGE].tsb) {
+	if (tb->huge && mm->context.tsb_block[MM_TSB_HUGE].tsb) {
 		base = (unsigned long) mm->context.tsb_block[MM_TSB_HUGE].tsb;
 		nentries = mm->context.tsb_block[MM_TSB_HUGE].tsb_nentries;
 		if (tlb_type == cheetah_plus || tlb_type == hypervisor)
@@ -94,20 +95,21 @@ void flush_tsb_user(struct tlb_batch *tb)
 	spin_unlock_irqrestore(&mm->context.lock, flags);
 }
 
-void flush_tsb_user_page(struct mm_struct *mm, unsigned long vaddr)
+void flush_tsb_user_page(struct mm_struct *mm, unsigned long vaddr, bool huge)
 {
 	unsigned long nentries, base, flags;
 
 	spin_lock_irqsave(&mm->context.lock, flags);
 
+	if (!huge) {
 		base = (unsigned long) mm->context.tsb_block[MM_TSB_BASE].tsb;
 		nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
 		if (tlb_type == cheetah_plus || tlb_type == hypervisor)
 			base = __pa(base);
 		__flush_tsb_one_entry(base, vaddr, PAGE_SHIFT, nentries);
-
+	}
 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
-	if (mm->context.tsb_block[MM_TSB_HUGE].tsb) {
+	if (huge && mm->context.tsb_block[MM_TSB_HUGE].tsb) {
 		base = (unsigned long) mm->context.tsb_block[MM_TSB_HUGE].tsb;
 		nentries = mm->context.tsb_block[MM_TSB_HUGE].tsb_nentries;
 		if (tlb_type == cheetah_plus || tlb_type == hypervisor)

drivers/net/ethernet/aeroflex/greth.c

@@ -1323,7 +1323,7 @@ static inline int phy_aneg_done(struct phy_device *phydev)
 
 static int greth_mdio_init(struct greth_private *greth)
 {
-	int ret, phy;
+	int ret;
 	unsigned long timeout;
 
 	greth->mdio = mdiobus_alloc();

drivers/sbus/char/openprom.c

@@ -383,20 +383,12 @@ static struct device_node *get_node(phandle n, DATA *data)
 }
 
 /* Copy in a whole string from userspace into kernelspace. */
-static int copyin_string(char __user *user, size_t len, char **ptr)
+static char * copyin_string(char __user *user, size_t len)
 {
-	char *tmp;
-
 	if ((ssize_t)len < 0 || (ssize_t)(len + 1) < 0)
-		return -EINVAL;
-
-	tmp = memdup_user_nul(user, len);
-	if (IS_ERR(tmp))
-		return PTR_ERR(tmp);
+		return ERR_PTR(-EINVAL);
 
-	*ptr = tmp;
-
-	return 0;
+	return memdup_user_nul(user, len);
 }
 
 /*
@@ -415,9 +407,9 @@ static int opiocget(void __user *argp, DATA *data)
 
 	dp = get_node(op.op_nodeid, data);
 
-	err = copyin_string(op.op_name, op.op_namelen, &str);
-	if (err)
-		return err;
+	str = copyin_string(op.op_name, op.op_namelen);
+	if (IS_ERR(str))
+		return PTR_ERR(str);
 
 	pval = of_get_property(dp, str, &len);
 	err = 0;
@@ -440,7 +432,7 @@ static int opiocnextprop(void __user *argp, DATA *data)
 	struct device_node *dp;
 	struct property *prop;
 	char *str;
-	int err, len;
+	int len;
 
 	if (copy_from_user(&op, argp, sizeof(op)))
 		return -EFAULT;
@@ -449,9 +441,9 @@ static int opiocnextprop(void __user *argp, DATA *data)
 	if (!dp)
 		return -EINVAL;
 
-	err = copyin_string(op.op_name, op.op_namelen, &str);
-	if (err)
-		return err;
+	str = copyin_string(op.op_name, op.op_namelen);
+	if (IS_ERR(str))
+		return PTR_ERR(str);
 
 	if (str[0] == '\0') {
 		prop = dp->properties;
@@ -494,14 +486,14 @@ static int opiocset(void __user *argp, DATA *data)
 	if (!dp)
 		return -EINVAL;
 
-	err = copyin_string(op.op_name, op.op_namelen, &str);
-	if (err)
-		return err;
+	str = copyin_string(op.op_name, op.op_namelen);
+	if (IS_ERR(str))
+		return PTR_ERR(str);
 
-	err = copyin_string(op.op_buf, op.op_buflen, &tmp);
-	if (err) {
+	tmp = copyin_string(op.op_buf, op.op_buflen);
+	if (IS_ERR(tmp)) {
 		kfree(str);
-		return err;
+		return PTR_ERR(tmp);
 	}
 
 	err = of_set_property(dp, str, tmp, op.op_buflen);