powerpc: Add A2 cpu support

Add the cputable entry, regs and setup & restore entries for
the PowerPC A2 core.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 114 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/cpu_setup_a2.S b/arch/powerpc/kernel/cpu_setup_a2.S
new file mode 100644
index 000000000000..7f818feaa7a5
--- /dev/null
+++ b/arch/powerpc/kernel/cpu_setup_a2.S
@@ -0,0 +1,114 @@
+/*
+ *  A2 specific assembly support code
+ *
+ *  Copyright 2009 Ben Herrenschmidt, IBM Corp.
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ */
+
+#include <asm/asm-offsets.h>
+#include <asm/ppc_asm.h>
+#include <asm/ppc-opcode.h>
+#include <asm/processor.h>
+#include <asm/reg_a2.h>
+#include <asm/reg.h>
+#include <asm/thread_info.h>
+
+/*
+ * Disable thdid and class fields in ERATs to bump PID to full 14 bits capacity.
+ * This also prevents external LPID accesses but that isn't a problem when not a
+ * guest. Under PV, this setting will be ignored and MMUCR will return the right
+ * number of PID bits we can use.
+ */
+#define MMUCR1_EXTEND_PID \
+	(MMUCR1_ICTID | MMUCR1_ITTID | MMUCR1_DCTID | \
+	 MMUCR1_DTTID | MMUCR1_DCCD)
+
+/*
+ * Use extended PIDs if enabled.
+ * Don't clear the ERATs on context sync events and enable I & D LRU.
+ * Enable ERAT back invalidate when tlbwe overwrites an entry.
+ */
+#define INITIAL_MMUCR1 \
+	(MMUCR1_EXTEND_PID | MMUCR1_CSINV_NEVER | MMUCR1_IRRE | \
+	 MMUCR1_DRRE | MMUCR1_TLBWE_BINV)
+
+_GLOBAL(__setup_cpu_a2)
+	/* Some of these are actually thread local and some are
+	 * core local but doing it always won't hurt
+	 */
+
+#ifdef CONFIG_PPC_WSP_COPRO
+	/* Make sure ACOP starts out as zero */
+	li	r3,0
+	mtspr   SPRN_ACOP,r3
+
+	/* Enable icswx instruction */
+	mfspr   r3,SPRN_A2_CCR2
+	ori     r3,r3,A2_CCR2_ENABLE_ICSWX
+	mtspr   SPRN_A2_CCR2,r3
+
+	/* Unmask all CTs in HACOP */
+	li      r3,-1
+	mtspr   SPRN_HACOP,r3
+#endif /* CONFIG_PPC_WSP_COPRO */
+
+	/* Enable doorbell */
+	mfspr   r3,SPRN_A2_CCR2
+	oris     r3,r3,A2_CCR2_ENABLE_PC@h
+	mtspr   SPRN_A2_CCR2,r3
+	isync
+
+	/* Setup CCR0 to disable power saving for now as it's busted
+	 * in the current implementations. Setup CCR1 to wake on
+	 * interrupts normally (we write the default value but who
+	 * knows what FW may have clobbered...)
+	 */
+	li	r3,0
+	mtspr	SPRN_A2_CCR0, r3
+	LOAD_REG_IMMEDIATE(r3,0x0f0f0f0f)
+	mtspr	SPRN_A2_CCR1, r3
+
+	/* Initialise MMUCR1 */
+	lis	r3,INITIAL_MMUCR1@h
+	ori	r3,r3,INITIAL_MMUCR1@l
+	mtspr	SPRN_MMUCR1,r3
+
+	/* Set MMUCR2 to enable 4K, 64K, 1M, 16M and 1G pages */
+	LOAD_REG_IMMEDIATE(r3, 0x000a7531)
+	mtspr	SPRN_MMUCR2,r3
+
+	/* Set MMUCR3 to write all thids bit to the TLB */
+	LOAD_REG_IMMEDIATE(r3, 0x0000000f)
+	mtspr	SPRN_MMUCR3,r3
+
+	/* Don't do ERAT stuff if running guest mode */
+	mfmsr	r3
+	andis.	r0,r3,MSR_GS@h
+	bne	1f
+
+	/* Now set the I-ERAT watermark to 15 */
+	lis	r4,(MMUCR0_TLBSEL_I|MMUCR0_ECL)@h
+	mtspr	SPRN_MMUCR0, r4
+	li	r4,A2_IERAT_SIZE-1
+	PPC_ERATWE(r4,r4,3)
+
+	/* Now set the D-ERAT watermark to 31 */
+	lis	r4,(MMUCR0_TLBSEL_D|MMUCR0_ECL)@h
+	mtspr	SPRN_MMUCR0, r4
+	li	r4,A2_DERAT_SIZE-1
+	PPC_ERATWE(r4,r4,3)
+
+	/* And invalidate the beast just in case. That won't get rid of
+	 * a bolted entry though it will be in LRU and so will go away eventually
+	 * but let's not bother for now
+	 */
+	PPC_ERATILX(0,0,0)
+1:
+	blr
+
+_GLOBAL(__restore_cpu_a2)
+	b	__setup_cpu_a2