asmlinkage void __naked cci_enable_port_for_self()

in arm-cci.c [298:374]

• 61 lines of code
• 1 McCabe index (conditional complexity)

asmlinkage void __naked cci_enable_port_for_self(void)
{
	asm volatile ("\n"
"	.arch armv7-a\n"
"	mrc	p15, 0, r0, c0, c0, 5	@ get MPIDR value \n"
"	and	r0, r0, #"__stringify(MPIDR_HWID_BITMASK)" \n"
"	adr	r1, 5f \n"
"	ldr	r2, [r1] \n"
"	add	r1, r1, r2		@ &cpu_port \n"
"	add	ip, r1, %[sizeof_cpu_port] \n"

	/* Loop over the cpu_port array looking for a matching MPIDR */
"1:	ldr	r2, [r1, %[offsetof_cpu_port_mpidr_lsb]] \n"
"	cmp	r2, r0 			@ compare MPIDR \n"
"	bne	2f \n"

	/* Found a match, now test port validity */
"	ldr	r3, [r1, %[offsetof_cpu_port_port]] \n"
"	tst	r3, #"__stringify(PORT_VALID)" \n"
"	bne	3f \n"

	/* no match, loop with the next cpu_port entry */
"2:	add	r1, r1, %[sizeof_struct_cpu_port] \n"
"	cmp	r1, ip			@ done? \n"
"	blo	1b \n"

	/* CCI port not found -- cheaply try to stall this CPU */
"cci_port_not_found: \n"
"	wfi \n"
"	wfe \n"
"	b	cci_port_not_found \n"

	/* Use matched port index to look up the corresponding ports entry */
"3:	bic	r3, r3, #"__stringify(PORT_VALID)" \n"
"	adr	r0, 6f \n"
"	ldmia	r0, {r1, r2} \n"
"	sub	r1, r1, r0 		@ virt - phys \n"
"	ldr	r0, [r0, r2] 		@ *(&ports) \n"
"	mov	r2, %[sizeof_struct_ace_port] \n"
"	mla	r0, r2, r3, r0		@ &ports[index] \n"
"	sub	r0, r0, r1		@ virt_to_phys() \n"

	/* Enable the CCI port */
"	ldr	r0, [r0, %[offsetof_port_phys]] \n"
"	mov	r3, %[cci_enable_req]\n"		   
"	str	r3, [r0, #"__stringify(CCI_PORT_CTRL)"] \n"

	/* poll the status reg for completion */
"	adr	r1, 7f \n"
"	ldr	r0, [r1] \n"
"	ldr	r0, [r0, r1]		@ cci_ctrl_base \n"
"4:	ldr	r1, [r0, #"__stringify(CCI_CTRL_STATUS)"] \n"
"	tst	r1, %[cci_control_status_bits] \n"			
"	bne	4b \n"

"	mov	r0, #0 \n"
"	bx	lr \n"

"	.align	2 \n"
"5:	.word	cpu_port - . \n"
"6:	.word	. \n"
"	.word	ports - 6b \n"
"7:	.word	cci_ctrl_phys - . \n"
	: :
	[sizeof_cpu_port] "i" (sizeof(cpu_port)),
	[cci_enable_req] "i" cpu_to_le32(CCI_ENABLE_REQ),
	[cci_control_status_bits] "i" cpu_to_le32(1),
#ifndef __ARMEB__
	[offsetof_cpu_port_mpidr_lsb] "i" (offsetof(struct cpu_port, mpidr)),
#else
	[offsetof_cpu_port_mpidr_lsb] "i" (offsetof(struct cpu_port, mpidr)+4),
#endif
	[offsetof_cpu_port_port] "i" (offsetof(struct cpu_port, port)),
	[sizeof_struct_cpu_port] "i" (sizeof(struct cpu_port)),
	[sizeof_struct_ace_port] "i" (sizeof(struct cci_ace_port)),
	[offsetof_port_phys] "i" (offsetof(struct cci_ace_port, phys)) );
}