Differential D20772 Diff 59074 sys/riscv/riscv/support.S

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sys/riscv/riscv/support.S

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	* int casueword32(volatile uint32_t , uint32_t, uint32_t , uint32_t)			* int casueword32(volatile uint32_t , uint32_t, uint32_t , uint32_t)
	*/			*/
	ENTRY(casueword32)			ENTRY(casueword32)
	li a4, (VM_MAXUSER_ADDRESS-3)			li a4, (VM_MAXUSER_ADDRESS-3)
	bgt a0, a4, fsu_fault_nopcb			bgt a0, a4, fsu_fault_nopcb
	la a6, fsu_fault /* Load the fault handler */			la a6, fsu_fault /* Load the fault handler */
	SET_FAULT_HANDLER(a6, a4) /* And set it */			SET_FAULT_HANDLER(a6, a4) /* And set it */
	ENTER_USER_ACCESS(a4)			ENTER_USER_ACCESS(a4)
	1: lr.w a4, 0(a0) /* Load-exclusive the data */			lr.w a4, 0(a0) /* Load-exclusive the data */
	bne a4, a1, 2f /* If not equal then exit */			bne a4, a1, 1f /* If not equal then exit */
				markjUnsubmitted Done Inline Actions Suppose we follow the branch. Aren't we going to return the uninitialized contents of a5? markj: Suppose we follow the branch. Aren't we going to return the uninitialized contents of a5?
	sc.w a5, a3, 0(a0) /* Store the new data */			sc.w a5, a3, 0(a0) /* Store the new data */
	bnez a5, 1b /* Retry on failure */			beq x0, a5, 1f /* Success */
	2: EXIT_USER_ACCESS(a5)			li a5, 1 /* Normalize failure result */
				1: EXIT_USER_ACCESS(a5)
	SET_FAULT_HANDLER(x0, a5) /* Reset the fault handler */			SET_FAULT_HANDLER(x0, a5) /* Reset the fault handler */
				markjUnsubmitted Done Inline Actions Why not use beqz? markj: Why not use beqz?
	sw a4, 0(a2) /* Store the read data */			sw a4, 0(a2) /* Store the read data */
	li a0, 0 /* Success */			mv a0, a5 /* Success indicator */
				jillesUnsubmitted Done Inline Actions Hmm, a5 seems to have been overwritten twice with temporary addresses (in EXIT_USER_ACCESS and SET_FAULT_HANDLER). jilles: Hmm, a5 seems to have been overwritten twice with temporary addresses (in EXIT_USER_ACCESS and…
	ret /* Return */			ret /* Return */
	END(casueword32)			END(casueword32)

	/*			/*
	* int casueword(volatile u_long , u_long, u_long , u_long)			* int casueword(volatile u_long , u_long, u_long , u_long)
	*/			*/
	ENTRY(casueword)			ENTRY(casueword)
	li a4, (VM_MAXUSER_ADDRESS-7)			li a4, (VM_MAXUSER_ADDRESS-7)
	bgt a0, a4, fsu_fault_nopcb			bgt a0, a4, fsu_fault_nopcb
	la a6, fsu_fault /* Load the fault handler */			la a6, fsu_fault /* Load the fault handler */
	SET_FAULT_HANDLER(a6, a4) /* And set it */			SET_FAULT_HANDLER(a6, a4) /* And set it */
	ENTER_USER_ACCESS(a4)			ENTER_USER_ACCESS(a4)
	1: lr.d a4, 0(a0) /* Load-exclusive the data */			lr.d a4, 0(a0) /* Load-exclusive the data */
	bne a4, a1, 2f /* If not equal then exit */			bne a4, a1, 1f /* If not equal then exit */
	sc.d a5, a3, 0(a0) /* Store the new data */			sc.d a5, a3, 0(a0) /* Store the new data */
	bnez a5, 1b /* Retry on failure */			beq x0, a5, 1f /* Success */
	2: EXIT_USER_ACCESS(a5)			li a5, 1 /* Normalize failure result */
				1: EXIT_USER_ACCESS(a5)
	SET_FAULT_HANDLER(x0, a5) /* Reset the fault handler */			SET_FAULT_HANDLER(x0, a5) /* Reset the fault handler */
	sd a4, 0(a2) /* Store the read data */			sd a4, 0(a2) /* Store the read data */
	li a0, 0 /* Success */			mv a0, a5 /* Success indicator */
	ret /* Return */			ret /* Return */
	END(casueword)			END(casueword)

	/*			/*
	* int fubyte(volatile const void *)			* int fubyte(volatile const void *)
	*/			*/
	ENTRY(fubyte)			ENTRY(fubyte)
	li a1, VM_MAXUSER_ADDRESS			li a1, VM_MAXUSER_ADDRESS
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