Merge branch 'for_3.4/dt_base' of git://git.kernel.org/pub/scm/linux/kernel/git/bcousson/linux-omap-dt into dt

1 files changed, 58 insertions, 111 deletions

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index aa33949..bb7eac3 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -27,19 +27,6 @@
 
 #include "fault.h"
 
-/*
- * Fault status register encodings.  We steal bit 31 for our own purposes.
- */
-#define FSR_LNX_PF		(1 << 31)
-#define FSR_WRITE		(1 << 11)
-#define FSR_FS4			(1 << 10)
-#define FSR_FS3_0		(15)
-
-static inline int fsr_fs(unsigned int fsr)
-{
-	return (fsr & FSR_FS3_0) | (fsr & FSR_FS4) >> 6;
-}
-
 #ifdef CONFIG_MMU
 
 #ifdef CONFIG_KPROBES
@@ -123,8 +110,10 @@ void show_pte(struct mm_struct *mm, unsigned long addr)
 
 		pte = pte_offset_map(pmd, addr);
 		printk(", *pte=%08llx", (long long)pte_val(*pte));
+#ifndef CONFIG_ARM_LPAE
 		printk(", *ppte=%08llx",
 		       (long long)pte_val(pte[PTE_HWTABLE_PTRS]));
+#endif
 		pte_unmap(pte);
 	} while(0);
 
@@ -231,7 +220,7 @@ static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma)
 
 static int __kprobes
 __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
-		struct task_struct *tsk)
+		unsigned int flags, struct task_struct *tsk)
 {
 	struct vm_area_struct *vma;
 	int fault;
@@ -253,18 +242,7 @@ good_area:
 		goto out;
 	}
 
-	/*
-	 * If for any reason at all we couldn't handle the fault, make
-	 * sure we exit gracefully rather than endlessly redo the fault.
-	 */
-	fault = handle_mm_fault(mm, vma, addr & PAGE_MASK, (fsr & FSR_WRITE) ? FAULT_FLAG_WRITE : 0);
-	if (unlikely(fault & VM_FAULT_ERROR))
-		return fault;
-	if (fault & VM_FAULT_MAJOR)
-		tsk->maj_flt++;
-	else
-		tsk->min_flt++;
-	return fault;
+	return handle_mm_fault(mm, vma, addr & PAGE_MASK, flags);
 
 check_stack:
 	if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr))
@@ -279,6 +257,9 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	struct task_struct *tsk;
 	struct mm_struct *mm;
 	int fault, sig, code;
+	int write = fsr & FSR_WRITE;
+	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
+				(write ? FAULT_FLAG_WRITE : 0);
 
 	if (notify_page_fault(regs, fsr))
 		return 0;
@@ -305,6 +286,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	if (!down_read_trylock(&mm->mmap_sem)) {
 		if (!user_mode(regs) && !search_exception_tables(regs->ARM_pc))
 			goto no_context;
+retry:
 		down_read(&mm->mmap_sem);
 	} else {
 		/*
@@ -320,14 +302,41 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 #endif
 	}
 
-	fault = __do_page_fault(mm, addr, fsr, tsk);
-	up_read(&mm->mmap_sem);
+	fault = __do_page_fault(mm, addr, fsr, flags, tsk);
+
+	/* If we need to retry but a fatal signal is pending, handle the
+	 * signal first. We do not need to release the mmap_sem because
+	 * it would already be released in __lock_page_or_retry in
+	 * mm/filemap.c. */
+	if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+		return 0;
+
+	/*
+	 * Major/minor page fault accounting is only done on the
+	 * initial attempt. If we go through a retry, it is extremely
+	 * likely that the page will be found in page cache at that point.
+	 */
 
 	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
-	if (fault & VM_FAULT_MAJOR)
-		perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, addr);
-	else if (fault & VM_FAULT_MINOR)
-		perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, addr);
+	if (flags & FAULT_FLAG_ALLOW_RETRY) {
+		if (fault & VM_FAULT_MAJOR) {
+			tsk->maj_flt++;
+			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1,
+					regs, addr);
+		} else {
+			tsk->min_flt++;
+			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1,
+					regs, addr);
+		}
+		if (fault & VM_FAULT_RETRY) {
+			/* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk
+			* of starvation. */
+			flags &= ~FAULT_FLAG_ALLOW_RETRY;
+			goto retry;
+		}
+	}
+
+	up_read(&mm->mmap_sem);
 
 	/*
 	 * Handle the "normal" case first - VM_FAULT_MAJOR / VM_FAULT_MINOR
@@ -441,6 +450,12 @@ do_translation_fault(unsigned long addr, unsigned int fsr,
 	pmd = pmd_offset(pud, addr);
 	pmd_k = pmd_offset(pud_k, addr);
 
+#ifdef CONFIG_ARM_LPAE
+	/*
+	 * Only one hardware entry per PMD with LPAE.
+	 */
+	index = 0;
+#else
 	/*
 	 * On ARM one Linux PGD entry contains two hardware entries (see page
 	 * tables layout in pgtable.h). We normally guarantee that we always
@@ -450,6 +465,7 @@ do_translation_fault(unsigned long addr, unsigned int fsr,
 	 * for the first of pair.
 	 */
 	index = (addr >> SECTION_SHIFT) & 1;
+#endif
 	if (pmd_none(pmd_k[index]))
 		goto bad_area;
 
@@ -489,55 +505,20 @@ do_bad(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	return 1;
 }
 
-static struct fsr_info {
+struct fsr_info {
 	int	(*fn)(unsigned long addr, unsigned int fsr, struct pt_regs *regs);
 	int	sig;
 	int	code;
 	const char *name;
-} fsr_info[] = {
-	/*
-	 * The following are the standard ARMv3 and ARMv4 aborts.  ARMv5
-	 * defines these to be "precise" aborts.
-	 */
-	{ do_bad,		SIGSEGV, 0,		"vector exception"		   },
-	{ do_bad,		SIGBUS,	 BUS_ADRALN,	"alignment exception"		   },
-	{ do_bad,		SIGKILL, 0,		"terminal exception"		   },
-	{ do_bad,		SIGBUS,	 BUS_ADRALN,	"alignment exception"		   },
-	{ do_bad,		SIGBUS,	 0,		"external abort on linefetch"	   },
-	{ do_translation_fault,	SIGSEGV, SEGV_MAPERR,	"section translation fault"	   },
-	{ do_bad,		SIGBUS,	 0,		"external abort on linefetch"	   },
-	{ do_page_fault,	SIGSEGV, SEGV_MAPERR,	"page translation fault"	   },
-	{ do_bad,		SIGBUS,	 0,		"external abort on non-linefetch"  },
-	{ do_bad,		SIGSEGV, SEGV_ACCERR,	"section domain fault"		   },
-	{ do_bad,		SIGBUS,	 0,		"external abort on non-linefetch"  },
-	{ do_bad,		SIGSEGV, SEGV_ACCERR,	"page domain fault"		   },
-	{ do_bad,		SIGBUS,	 0,		"external abort on translation"	   },
-	{ do_sect_fault,	SIGSEGV, SEGV_ACCERR,	"section permission fault"	   },
-	{ do_bad,		SIGBUS,	 0,		"external abort on translation"	   },
-	{ do_page_fault,	SIGSEGV, SEGV_ACCERR,	"page permission fault"		   },
-	/*
-	 * The following are "imprecise" aborts, which are signalled by bit
-	 * 10 of the FSR, and may not be recoverable.  These are only
-	 * supported if the CPU abort handler supports bit 10.
-	 */
-	{ do_bad,		SIGBUS,  0,		"unknown 16"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 17"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 18"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 19"			   },
-	{ do_bad,		SIGBUS,  0,		"lock abort"			   }, /* xscale */
-	{ do_bad,		SIGBUS,  0,		"unknown 21"			   },
-	{ do_bad,		SIGBUS,  BUS_OBJERR,	"imprecise external abort"	   }, /* xscale */
-	{ do_bad,		SIGBUS,  0,		"unknown 23"			   },
-	{ do_bad,		SIGBUS,  0,		"dcache parity error"		   }, /* xscale */
-	{ do_bad,		SIGBUS,  0,		"unknown 25"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 26"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 27"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 28"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 29"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 30"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 31"			   }
 };
 
+/* FSR definition */
+#ifdef CONFIG_ARM_LPAE
+#include "fsr-3level.c"
+#else
+#include "fsr-2level.c"
+#endif
+
 void __init
 hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *),
 		int sig, int code, const char *name)
@@ -573,42 +554,6 @@ do_DataAbort(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	arm_notify_die("", regs, &info, fsr, 0);
 }
 
-
-static struct fsr_info ifsr_info[] = {
-	{ do_bad,		SIGBUS,  0,		"unknown 0"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 1"			   },
-	{ do_bad,		SIGBUS,  0,		"debug event"			   },
-	{ do_bad,		SIGSEGV, SEGV_ACCERR,	"section access flag fault"	   },
-	{ do_bad,		SIGBUS,  0,		"unknown 4"			   },
-	{ do_translation_fault,	SIGSEGV, SEGV_MAPERR,	"section translation fault"	   },
-	{ do_bad,		SIGSEGV, SEGV_ACCERR,	"page access flag fault"	   },
-	{ do_page_fault,	SIGSEGV, SEGV_MAPERR,	"page translation fault"	   },
-	{ do_bad,		SIGBUS,	 0,		"external abort on non-linefetch"  },
-	{ do_bad,		SIGSEGV, SEGV_ACCERR,	"section domain fault"		   },
-	{ do_bad,		SIGBUS,  0,		"unknown 10"			   },
-	{ do_bad,		SIGSEGV, SEGV_ACCERR,	"page domain fault"		   },
-	{ do_bad,		SIGBUS,	 0,		"external abort on translation"	   },
-	{ do_sect_fault,	SIGSEGV, SEGV_ACCERR,	"section permission fault"	   },
-	{ do_bad,		SIGBUS,	 0,		"external abort on translation"	   },
-	{ do_page_fault,	SIGSEGV, SEGV_ACCERR,	"page permission fault"		   },
-	{ do_bad,		SIGBUS,  0,		"unknown 16"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 17"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 18"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 19"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 20"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 21"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 22"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 23"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 24"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 25"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 26"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 27"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 28"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 29"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 30"			   },
-	{ do_bad,		SIGBUS,  0,		"unknown 31"			   },
-};
-
 void __init
 hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *),
 		 int sig, int code, const char *name)
@@ -641,6 +586,7 @@ do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs)
 	arm_notify_die("", regs, &info, ifsr, 0);
 }
 
+#ifndef CONFIG_ARM_LPAE
 static int __init exceptions_init(void)
 {
 	if (cpu_architecture() >= CPU_ARCH_ARMv6) {
@@ -663,3 +609,4 @@ static int __init exceptions_init(void)
 }
 
 arch_initcall(exceptions_init);
+#endif