From patchwork Thu Dec 20 09:08:27 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [v1,3/6] book3e/kgdb: update thread's dbcr0 Date: Wed, 19 Dec 2012 23:08:27 -0000 From: Tiejun Chen X-Patchwork-Id: 207627 Message-Id: <1355994510-11934-4-git-send-email-tiejun.chen@windriver.com> To: Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, jason.wessel@windriver.com gdb always need to generate a single step properly to invoke a kgdb state. But with lazy interrupt, book3e can't always trigger a debug exception with a single step since the current is blocked for handling those pending exception, then we miss that expected dbcr configuration at last to generate a debug exception. So here we also update thread's dbcr0 to make sure the current can go back with that missed dbcr0 configuration. Signed-off-by: Tiejun Chen --- arch/powerpc/kernel/kgdb.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c index c470a40..516b44b 100644 --- a/arch/powerpc/kernel/kgdb.c +++ b/arch/powerpc/kernel/kgdb.c @@ -426,8 +426,18 @@ int kgdb_arch_handle_exception(int vector, int signo, int err_code, /* set the trace bit if we're stepping */ if (remcom_in_buffer[0] == 's') { #ifdef CONFIG_PPC_ADV_DEBUG_REGS +#ifdef CONFIG_PPC_BOOK3E + /* With lazy interrut we have to update thread dbcr0 here + * to make sure we can set debug properly at last to invoke + * kgdb again to work well. + */ + current->thread.dbcr0 = + mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM; + mtspr(SPRN_DBCR0, current->thread.dbcr0); +#else mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM); +#endif linux_regs->msr |= MSR_DE; #else linux_regs->msr |= MSR_SE;