Commit 86c25466 authored by Noam Camus's avatar Noam Camus Committed by Vineet Gupta
Browse files

ARC: [plat-eznps] Use dedicated identity auxiliary register. 



With generic "identity" num of CPUs is limited to 256 (8 bit).
We use our alternative AUX register GLOBAL_ID (12 bit).
Now we can support up to 4096 CPUs.

Signed-off-by: default avatarNoam Camus <noamc@ezchip.com>
parent b1f2f6f3

arch/arc/include/asm/entry-compact.h

+6 −0
Original line number Diff line number Diff line
@@ -36,6 +36,10 @@ 
#include <asm/irqflags-compact.h>

#include <asm/thread_info.h>	/* For THREAD_SIZE */



#ifdef CONFIG_ARC_PLAT_EZNPS

#include <plat/ctop.h>

#endif



/*--------------------------------------------------------------

 * Switch to Kernel Mode stack if SP points to User Mode stack

 *
@@ -296,11 +300,13 @@ 
	bic \reg, sp, (THREAD_SIZE - 1)

.endm



#ifndef CONFIG_ARC_PLAT_EZNPS

/* Get CPU-ID of this core */

.macro  GET_CPU_ID  reg

	lr  \reg, [identity]

	lsr \reg, \reg, 8

	bmsk \reg, \reg, 7

.endm

#endif



#endif  /* __ASM_ARC_ENTRY_COMPACT_H */

arch/arc/kernel/ctx_sw.c

+13 −0
Original line number Diff line number Diff line
@@ -16,6 +16,9 @@ 


#include <asm/asm-offsets.h>

#include <linux/sched.h>

#ifdef CONFIG_ARC_PLAT_EZNPS

#include <plat/ctop.h>

#endif



#define KSP_WORD_OFF 	((TASK_THREAD + THREAD_KSP) / 4)
@@ -66,10 +69,17 @@ __switch_to(struct task_struct *prev_task, struct task_struct *next_task) 
		 */

#ifndef CONFIG_SMP

		"st  %2, [@_current_task]	\n\t"

#else

#ifdef CONFIG_ARC_PLAT_EZNPS

		"lr   r24, [%4]		\n\t"

#ifndef CONFIG_EZNPS_MTM_EXT

		"lsr  r24, r24, 4		\n\t"

#endif

#else

		"lr   r24, [identity]		\n\t"

		"lsr  r24, r24, 8		\n\t"

		"bmsk r24, r24, 7		\n\t"

#endif

		"add2 r24, @_current_task, r24	\n\t"

		"st   %2,  [r24]		\n\t"

#endif
@@ -107,6 +117,9 @@ __switch_to(struct task_struct *prev_task, struct task_struct *next_task) 


		: "=r"(tmp)

		: "n"(KSP_WORD_OFF), "r"(next), "r"(prev)

#ifdef CONFIG_ARC_PLAT_EZNPS

		, "i"(CTOP_AUX_LOGIC_GLOBAL_ID)

#endif

		: "blink"

	);

arch/arc/plat-eznps/include/plat/ctop.h

+9 −0
Original line number Diff line number Diff line
@@ -195,6 +195,15 @@ struct nps_host_reg_aux_lpc { 
#define REG_GIM_P_INT_DST_25    nps_host_reg_non_cl(NPS_GIM_BLKID, 0x149)

#define REG_GIM_P_INT_DST_26    nps_host_reg_non_cl(NPS_GIM_BLKID, 0x14A)



#else



.macro  GET_CPU_ID  reg

	lr  \reg, [CTOP_AUX_LOGIC_GLOBAL_ID]

#ifndef CONFIG_EZNPS_MTM_EXT

	lsr \reg, \reg, 4

#endif

.endm



#endif /* __ASSEMBLY__ */



#endif /* _PLAT_EZNPS_CTOP_H */

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