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| author | Paul Burton <paul.burton@imgtec.com> | 2015-09-22 21:12:14 +0300 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2015-11-11 10:35:08 +0300 |
| commit | a8c20614b0163a71f2df3f9788bfe8b9ff07d742 (patch) | |
| tree | dbd3396bca19f2cf0f0f2d86b3b5330c62f89ea7 /arch/mips/kernel | |
| parent | 192fbc20258c79e3f776a5ce6cea4654376f5af6 (diff) | |
| download | linux-a8c20614b0163a71f2df3f9788bfe8b9ff07d742.tar.xz | |
MIPS: CPS: Warn if a core doesn't start
When debugging core bringup it is useful to see the state of the CPC
sequencer, so output that value if the core hasn't started within a
reasonable amount of time (1 second). This avoids simply appearing to
the user to hang if a secondary core fails to start.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: linux-kernel@vger.kernel.org
Cc: Niklas Cassel <niklas.cassel@axis.com>
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11205/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel')
| -rw-r--r-- | arch/mips/kernel/smp-cps.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c index 8b967507e852..48b1b7554f05 100644 --- a/arch/mips/kernel/smp-cps.c +++ b/arch/mips/kernel/smp-cps.c @@ -8,6 +8,7 @@ * option) any later version. */ +#include <linux/delay.h> #include <linux/io.h> #include <linux/irqchip/mips-gic.h> #include <linux/sched.h> @@ -188,7 +189,8 @@ err_out: static void boot_core(unsigned core) { - u32 access; + u32 access, stat, seq_state; + unsigned timeout; /* Select the appropriate core */ write_gcr_cl_other(core << CM_GCR_Cx_OTHER_CORENUM_SHF); @@ -208,6 +210,28 @@ static void boot_core(unsigned core) /* Reset the core */ mips_cpc_lock_other(core); write_cpc_co_cmd(CPC_Cx_CMD_RESET); + + timeout = 100; + while (true) { + stat = read_cpc_co_stat_conf(); + seq_state = stat & CPC_Cx_STAT_CONF_SEQSTATE_MSK; + + /* U6 == coherent execution, ie. the core is up */ + if (seq_state == CPC_Cx_STAT_CONF_SEQSTATE_U6) + break; + + /* Delay a little while before we start warning */ + if (timeout) { + timeout--; + mdelay(10); + continue; + } + + pr_warn("Waiting for core %u to start... STAT_CONF=0x%x\n", + core, stat); + mdelay(1000); + } + mips_cpc_unlock_other(); } else { /* Take the core out of reset */ |