Commit b66da4a4 authored by Russell King's avatar Russell King Committed by Russell King
Browse files

[PATCH] ARM: Remove global nwfpe register variable 



Recent changes to nwfpe broke the build with some gcc versions:

In file included from arch/arm/nwfpe/softfloat.c:33:
arch/arm/nwfpe/fpa11.h:32: global register variable follows a function definition
make[1]: *** [arch/arm/nwfpe/softfloat.o] Error 1

Since we now ensure that the kernel stack is empty when returning
to user space, we can now access the userspace registers with
reference to the kernel stack using current_thread_info(), rather
than remembering the stack pointer at the time nwfpe was called.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent f60f7008

arch/arm/nwfpe/fpa11.h

+1 −3
Original line number Diff line number Diff line
@@ -29,9 +29,7 @@ 
 * stack+task struct.  Use the same method as 'current' uses to

 * reach them.

 */

register unsigned long *user_registers asm("sl");



#define GET_USERREG() (user_registers)

#define GET_USERREG() ((struct pt_regs *)(THREAD_START_SP + (unsigned long)current_thread_info()) - 1)



#include <linux/config.h>

#include <linux/thread_info.h>

arch/arm/nwfpe/fpmodule.c

+1 −1
Original line number Diff line number Diff line
@@ -132,7 +132,7 @@ void float_raise(signed char flags) 
	printk(KERN_DEBUG

	       "NWFPE: %s[%d] takes exception %08x at %p from %08lx\n",

	       current->comm, current->pid, flags,

	       __builtin_return_address(0), GET_USERREG()[15]);

	       __builtin_return_address(0), GET_USERREG()->ARM_pc);

#endif



	/* Keep SoftFloat exception flags up to date.  */

arch/arm/nwfpe/fpmodule.inl

+7 −7
Original line number Diff line number Diff line
@@ -28,8 +28,8 @@ static inline unsigned long readRegister(const unsigned int nReg) 
	   for this in this routine.  LDF/STF instructions with Rn = PC

	   depend on the PC being correct, as they use PC+8 in their

	   address calculations. */

	unsigned long *userRegisters = GET_USERREG();

	unsigned int val = userRegisters[nReg];

	struct pt_regs *regs = GET_USERREG();

	unsigned int val = regs->uregs[nReg];

	if (REG_PC == nReg)

		val -= 4;

	return val;
@@ -38,8 +38,8 @@ static inline unsigned long readRegister(const unsigned int nReg) 
static inline void

writeRegister(const unsigned int nReg, const unsigned long val)

{

	unsigned long *userRegisters = GET_USERREG();

	userRegisters[nReg] = val;

	struct pt_regs *regs = GET_USERREG();

	regs->uregs[nReg] = val;

}



static inline unsigned long readCPSR(void)
@@ -63,12 +63,12 @@ static inline unsigned long readConditionCodes(void) 


static inline void writeConditionCodes(const unsigned long val)

{

	unsigned long *userRegisters = GET_USERREG();

	struct pt_regs *regs = GET_USERREG();

	unsigned long rval;

	/*

	 * Operate directly on userRegisters since

	 * the CPSR may be the PC register itself.

	 */

	rval = userRegisters[REG_CPSR] & ~CC_MASK;

	userRegisters[REG_CPSR] = rval | (val & CC_MASK);

	rval = regs->ARM_cpsr & ~CC_MASK;

	regs->ARM_cpsr = rval | (val & CC_MASK);

}

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