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[PATCH 05/26] MIPS: For Cavium OCTEON set hwrena and lazily restore CP2

To: linux-mips@linux-mips.org
Subject: [PATCH 05/26] MIPS: For Cavium OCTEON set hwrena and lazily restore CP2 state.
From: David Daney <ddaney@caviumnetworks.com>
Date: Tue, 18 Nov 2008 14:23:20 -0800
Cc: David Daney <ddaney@caviumnetworks.com>, Tomaso Paoletti <tpaoletti@caviumnetworks.com>, Paul Gortmaker <Paul.Gortmaker@windriver.com>
In-reply-to: <49233FDE.3010404@caviumnetworks.com>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <49233FDE.3010404@caviumnetworks.com>
Sender: linux-mips-bounce@linux-mips.org
If on Cavium, be aware of cop2 and hwrena during do_cpu().

Signed-off-by: Tomaso Paoletti <tpaoletti@caviumnetworks.com>
Signed-off-by: Paul Gortmaker <Paul.Gortmaker@windriver.com>
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
---
 arch/mips/kernel/traps.c |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 3530561..f6083c6 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -47,6 +47,7 @@
 #include <asm/mmu_context.h>
 #include <asm/types.h>
 #include <asm/stacktrace.h>
+#include <asm/irq.h>
 
 extern void check_wait(void);
 extern asmlinkage void r4k_wait(void);
@@ -78,6 +79,10 @@ extern asmlinkage void handle_reserved(void);
 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
        struct mips_fpu_struct *ctx, int has_fpu);
 
+#ifdef CONFIG_CPU_CAVIUM_OCTEON
+extern asmlinkage void octeon_cop2_restore(struct octeon_cop2_state *task);
+#endif
+
 void (*board_be_init)(void);
 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
 void (*board_nmi_handler_setup)(void);
@@ -860,6 +865,7 @@ asmlinkage void do_cpu(struct pt_regs *regs)
        unsigned int opcode;
        unsigned int cpid;
        int status;
+       unsigned long __maybe_unused flags;
 
        die_if_kernel("do_cpu invoked from kernel context!", regs);
 
@@ -915,6 +921,17 @@ asmlinkage void do_cpu(struct pt_regs *regs)
                return;
 
        case 2:
+#ifdef CONFIG_CPU_CAVIUM_OCTEON
+               prefetch(&current->thread.cp2);
+               local_irq_save(flags);
+               KSTK_STATUS(current) |= ST0_CU2;
+               status = read_c0_status();
+               write_c0_status(status | ST0_CU2);
+               octeon_cop2_restore(&(current->thread.cp2));
+               write_c0_status(status & ~ST0_CU2);
+               local_irq_restore(flags);
+               return;
+#endif
        case 3:
                break;
        }
@@ -1488,6 +1505,10 @@ void __cpuinit per_cpu_trap_init(void)
                write_c0_hwrena(enable);
        }
 
+#ifdef CONFIG_CPU_CAVIUM_OCTEON
+       write_c0_hwrena(0xc000000f); /* Octeon has register 30 and 31 */
+#endif
+
 #ifdef CONFIG_MIPS_MT_SMTC
        if (!secondaryTC) {
 #endif /* CONFIG_MIPS_MT_SMTC */
-- 
1.5.6.5


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