From 86c25466f7414d6396f1aaa13e4b34f36ec272d5 Mon Sep 17 00:00:00 2001
From: Noam Camus <noamc@ezchip.com>
Date: Mon, 3 Jun 2013 15:17:25 +0300
Subject: [PATCH] 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: Noam Camus <noamc@ezchip.com>
---
 arch/arc/include/asm/entry-compact.h    |  6 ++++++
 arch/arc/kernel/ctx_sw.c                | 13 +++++++++++++
 arch/arc/plat-eznps/include/plat/ctop.h |  9 +++++++++
 3 files changed, 28 insertions(+)

diff --git a/arch/arc/include/asm/entry-compact.h b/arch/arc/include/asm/entry-compact.h
index 1d8f57cd6057..e0e1faf03c50 100644
--- a/arch/arc/include/asm/entry-compact.h
+++ b/arch/arc/include/asm/entry-compact.h
@@ -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 */
diff --git a/arch/arc/kernel/ctx_sw.c b/arch/arc/kernel/ctx_sw.c
index 5d446df2c413..6f4cb0dab1b9 100644
--- a/arch/arc/kernel/ctx_sw.c
+++ b/arch/arc/kernel/ctx_sw.c
@@ -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"
 	);
 
diff --git a/arch/arc/plat-eznps/include/plat/ctop.h b/arch/arc/plat-eznps/include/plat/ctop.h
index 91b25f3dd39a..9d6718c1a199 100644
--- a/arch/arc/plat-eznps/include/plat/ctop.h
+++ b/arch/arc/plat-eznps/include/plat/ctop.h
@@ -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 */
-- 
2.20.1