powerpc: Disable doorbells on Power8 DD1.x

shenki · ozbenh · commit bd6ba3518fcb · 2014-07-22T15:55:24.000+10:00
These processors do not currently support doorbell IPIs, so remove them from the feature list if we are at DD 1.xx for the 0x004d part. This fixes a regression caused by d4e58e5 (powerpc/powernv: Enable POWER8 doorbell IPIs). With that patch the kernel would hang at boot when calling smp_call_function_many, as the doorbell would not be received by the target CPUs: .smp_call_function_many+0x2bc/0x3c0 (unreliable) .on_each_cpu_mask+0x30/0x100 .cpuidle_register_driver+0x158/0x1a0 .cpuidle_register+0x2c/0x110 .powernv_processor_idle_init+0x23c/0x2c0 .do_one_initcall+0xd4/0x260 .kernel_init_freeable+0x25c/0x33c .kernel_init+0x1c/0x120 .ret_from_kernel_thread+0x58/0x7c Fixes: d4e58e5 (powerpc/powernv: Enable POWER8 doorbell IPIs) Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
@@ -447,6 +447,7 @@ extern const char *powerpc_base_platform;
 	    CPU_FTR_DBELL | CPU_FTR_HAS_PPR | CPU_FTR_DAWR | \
 	    CPU_FTR_ARCH_207S | CPU_FTR_TM_COMP)
 #define CPU_FTRS_POWER8E (CPU_FTRS_POWER8 | CPU_FTR_PMAO_BUG)
+#define CPU_FTRS_POWER8_DD1 (CPU_FTRS_POWER8 & ~CPU_FTR_DBELL)
 #define CPU_FTRS_CELL	(CPU_FTR_USE_TB | CPU_FTR_LWSYNC | \
 	    CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
 	    CPU_FTR_ALTIVEC_COMP | CPU_FTR_MMCRA | CPU_FTR_SMT | \
diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
@@ -527,6 +527,26 @@ static struct cpu_spec __initdata cpu_specs[] = {
 		.machine_check_early	= __machine_check_early_realmode_p8,
 		.platform		= "power8",
 	},
+	{	/* Power8 DD1: Does not support doorbell IPIs */
+		.pvr_mask		= 0xffffff00,
+		.pvr_value		= 0x004d0100,
+		.cpu_name		= "POWER8 (raw)",
+		.cpu_features		= CPU_FTRS_POWER8_DD1,
+		.cpu_user_features	= COMMON_USER_POWER8,
+		.cpu_user_features2	= COMMON_USER2_POWER8,
+		.mmu_features		= MMU_FTRS_POWER8,
+		.icache_bsize		= 128,
+		.dcache_bsize		= 128,
+		.num_pmcs		= 6,
+		.pmc_type		= PPC_PMC_IBM,
+		.oprofile_cpu_type	= "ppc64/power8",
+		.oprofile_type		= PPC_OPROFILE_INVALID,
+		.cpu_setup		= __setup_cpu_power8,
+		.cpu_restore		= __restore_cpu_power8,
+		.flush_tlb		= __flush_tlb_power8,
+		.machine_check_early	= __machine_check_early_realmode_p8,
+		.platform		= "power8",
+	},
 	{	/* Power8 */
 		.pvr_mask		= 0xffff0000,
 		.pvr_value		= 0x004d0000,
