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Commit 07ae144b authored by Thomas Petazzoni's avatar Thomas Petazzoni Committed by Jason Cooper
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ARM: mvebu: returns ll_get_cpuid() to ll_get_coherency_cpumask() 



In the refactoring of the coherency fabric assembly code, a function
called ll_get_cpuid() was created to factorize common logic between
functions adding CPU to the SMP coherency group, enabling and
disabling the coherency.

However, the name of the function is highly misleading: ll_get_cpuid()
makes one think tat it returns the ID of the CPU, i.e 0 for CPU0, 1
for CPU1, etc. In fact, this is not at all what this function returns:
it returns a CPU mask for the current CPU, usable for the coherency
fabric configuration and control registers.

Therefore this commit renames this function to
ll_get_coherency_cpumask(), and adds additional comments on top of the
function to explain in more details what it does, and also how the
endianess issue is handled.

Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1400762882-10116-5-git-send-email-thomas.petazzoni@free-electrons.com


Acked-by: default avatarGregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: default avatarJason Cooper <jason@lakedaemon.net>
parent 4dd1b7fa

arch/arm/mach-mvebu/coherency_ll.S

+25 −18
Original line number Diff line number Diff line
@@ -49,15 +49,22 @@ ENTRY(ll_get_coherency_base) 
	mov	pc, lr

ENDPROC(ll_get_coherency_base)



/* Returns the CPU ID in r3 (r0 is untouched) */

ENTRY(ll_get_cpuid)

/*

 * Returns the coherency CPU mask in r3 (r0 is untouched). This

 * coherency CPU mask can be used with the coherency fabric

 * configuration and control registers. Note that the mask is already

 * endian-swapped as appropriate so that the calling functions do not

 * have to care about endianness issues while accessing the coherency

 * fabric registers

 */

ENTRY(ll_get_coherency_cpumask)

	mrc	15, 0, r3, cr0, cr0, 5

	and	r3, r3, #15

	mov	r2, #(1 << 24)

	lsl	r3, r2, r3

ARM_BE8(rev	r3, r3)

	mov	pc, lr

ENDPROC(ll_get_cpuid)

ENDPROC(ll_get_coherency_cpumask)



/*

 * ll_add_cpu_to_smp_group(), ll_enable_coherency() and
@@ -71,14 +78,14 @@ ENDPROC(ll_get_cpuid) 
ENTRY(ll_add_cpu_to_smp_group)

	/*

	 * As r0 is not modified by ll_get_coherency_base() and

	 * ll_get_cpuid(), we use it to temporarly save lr and avoid

	 * it being modified by the branch and link calls. This

	 * function is used very early in the secondary CPU boot, and

	 * no stack is available at this point.

	 * ll_get_coherency_cpumask(), we use it to temporarly save lr

	 * and avoid it being modified by the branch and link

	 * calls. This function is used very early in the secondary

	 * CPU boot, and no stack is available at this point.

	 */

	mov 	r0, lr

	bl	ll_get_coherency_base

	bl	ll_get_cpuid

	bl	ll_get_coherency_cpumask

	mov 	lr, r0

	add	r0, r1, #ARMADA_XP_CFB_CFG_REG_OFFSET

1:
@@ -93,14 +100,14 @@ ENDPROC(ll_add_cpu_to_smp_group) 
ENTRY(ll_enable_coherency)

	/*

	 * As r0 is not modified by ll_get_coherency_base() and

	 * ll_get_cpuid(), we use it to temporarly save lr and avoid

	 * it being modified by the branch and link calls. This

	 * function is used very early in the secondary CPU boot, and

	 * no stack is available at this point.

	 * ll_get_coherency_cpumask(), we use it to temporarly save lr

	 * and avoid it being modified by the branch and link

	 * calls. This function is used very early in the secondary

	 * CPU boot, and no stack is available at this point.

	 */

	mov r0, lr

	bl	ll_get_coherency_base

	bl	ll_get_cpuid

	bl	ll_get_coherency_cpumask

	mov lr, r0

	add	r0, r1, #ARMADA_XP_CFB_CTL_REG_OFFSET

1:
@@ -117,14 +124,14 @@ ENDPROC(ll_enable_coherency) 
ENTRY(ll_disable_coherency)

	/*

	 * As r0 is not modified by ll_get_coherency_base() and

	 * ll_get_cpuid(), we use it to temporarly save lr and avoid

	 * it being modified by the branch and link calls. This

	 * function is used very early in the secondary CPU boot, and

	 * no stack is available at this point.

	 * ll_get_coherency_cpumask(), we use it to temporarly save lr

	 * and avoid it being modified by the branch and link

	 * calls. This function is used very early in the secondary

	 * CPU boot, and no stack is available at this point.

	 */

	mov 	r0, lr

	bl	ll_get_coherency_base

	bl	ll_get_cpuid

	bl	ll_get_coherency_cpumask

	mov 	lr, r0

	add	r0, r1, #ARMADA_XP_CFB_CTL_REG_OFFSET

1: