[PATCH 3.19.y-ckt 028/107] MIPS: kernel: smp-cps: Fix 64-bit compatibility errors due to pointer casting

From: Kamal Mostafa
Date: Wed Aug 05 2015 - 18:16:42 EST


3.19.8-ckt5 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Markos Chandras <markos.chandras@xxxxxxxxxx>

commit fd5ed3066bb2f47814fe53cdc56d11a678551ae1 upstream.

Commit 1d8f1f5a780a ("MIPS: smp-cps: hotplug support") added hotplug
support in the SMP/CPS implementation but it introduced a few build problems
on 64-bit kernels due to pointer being casted to and from 'int' C types. We
fix this problem by using 'unsigned long' instead which should match the size
of the pointers in 32/64-bit kernels. Finally, we fix the comment since the
CM base address is loaded to v1($3) instead of v0.

Fixes the following build problems:

arch/mips/kernel/smp-cps.c: In function 'wait_for_sibling_halt':
arch/mips/kernel/smp-cps.c:366:17: error: cast from pointer to integer of
different size [-Werror=pointer-to-int-cast]
[...]
arch/mips/kernel/smp-cps.c: In function 'cps_cpu_die':
arch/mips/kernel/smp-cps.c:427:13: error: cast to pointer
from integer of different size [-Werror=int-to-pointer-cast]

cc1: all warnings being treated as errors

Fixes: 1d8f1f5a780a ("MIPS: smp-cps: hotplug support")
Reviewed-by: Paul Burton <paul.burton@xxxxxxxxxx>
Signed-off-by: Markos Chandras <markos.chandras@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Patchwork: https://patchwork.linux-mips.org/patch/10586/
Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
arch/mips/kernel/smp-cps.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
index bed7590..81012b9 100644
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -127,7 +127,7 @@ static void __init cps_prepare_cpus(unsigned int max_cpus)
/*
* Patch the start of mips_cps_core_entry to provide:
*
- * v0 = CM base address
+ * v1 = CM base address
* s0 = kseg0 CCA
*/
entry_code = (u32 *)&mips_cps_core_entry;
@@ -363,7 +363,7 @@ void play_dead(void)

static void wait_for_sibling_halt(void *ptr_cpu)
{
- unsigned cpu = (unsigned)ptr_cpu;
+ unsigned cpu = (unsigned long)ptr_cpu;
unsigned vpe_id = cpu_vpe_id(&cpu_data[cpu]);
unsigned halted;
unsigned long flags;
@@ -424,7 +424,7 @@ static void cps_cpu_die(unsigned int cpu)
*/
err = smp_call_function_single(cpu_death_sibling,
wait_for_sibling_halt,
- (void *)cpu, 1);
+ (void *)(unsigned long)cpu, 1);
if (err)
panic("Failed to call remote sibling CPU\n");
}
--
1.9.1

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