[PATCH 1/2] powerpc/pseries: Use a helper to fixup nr_cores

Sukadev Bhattiprolu
2016-08-05T06:10:57Z

>From d49b597623ac58fa1ab61ce0157470b6390e9a67 Mon Sep 17 00:00:00 2001
From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Date: Fri, 5 Aug 2016 00:01:54 -0400
Subject: [PATCH 1/2] powerpc/pseries: Use a helper to fixup nr_cores.

We have to fixup RMA size also, so using helpers will make it cleaner
and consistent.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
arch/powerpc/kernel/prom_init.c | 70 ++++++++++++++++++++++-------------------
1 file changed, 38 insertions(+), 32 deletions(-)

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 6ee4b72..f612a99 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -863,47 +863,53 @@ static int __init prom_count_smt_threads(void)

}

+static void fixup_nr_cores(void)
+{
+ u32 cores;
+ unsigned char *ptcores;
+
+ /* We need to tell the FW about the number of cores we support.
+ *
+ * To do that, we count the number of threads on the first core
+ * (we assume this is the same for all cores) and use it to
+ * divide NR_CPUS.
+ */
+
+ /* The core value may start at an odd address. If such a word
+ * access is made at a cache line boundary, this leads to an
+ * exception which may not be handled at this time.
+ * Forcing a per byte access to avoid exception.
+ */
+ ptcores = &ibm_architecture_vec[IBM_ARCH_VEC_NRCORES_OFFSET];
+ cores = 0;
+ cores |= ptcores[0] << 24;
+ cores |= ptcores[1] << 16;
+ cores |= ptcores[2] << 8;
+ cores |= ptcores[3];
+ if (cores != NR_CPUS) {
+ prom_printf("WARNING ! "
+ "ibm_architecture_vec structure inconsistent: %lu!\n",
+ cores);
+ } else {
+ cores = DIV_ROUND_UP(NR_CPUS, prom_count_smt_threads());
+ prom_printf("Max number of cores passed to firmware: %lu (NR_CPUS = %lu)\n",
+ cores, NR_CPUS);
+ ptcores[0] = (cores >> 24) & 0xff;
+ ptcores[1] = (cores >> 16) & 0xff;
+ ptcores[2] = (cores >> 8) & 0xff;
+ ptcores[3] = cores & 0xff;
+ }
+}

static void __init prom_send_capabilities(void)
{
ihandle root;
prom_arg_t ret;
- u32 cores;
- unsigned char *ptcores;

root = call_prom("open", 1, 1, ADDR("/"));
if (root != 0) {
- /* We need to tell the FW about the number of cores we support.
- *
- * To do that, we count the number of threads on the first core
- * (we assume this is the same for all cores) and use it to
- * divide NR_CPUS.
- */

- /* The core value may start at an odd address. If such a word
- * access is made at a cache line boundary, this leads to an
- * exception which may not be handled at this time.
- * Forcing a per byte access to avoid exception.
- */
- ptcores = &ibm_architecture_vec[IBM_ARCH_VEC_NRCORES_OFFSET];
- cores = 0;
- cores |= ptcores[0] << 24;
- cores |= ptcores[1] << 16;
- cores |= ptcores[2] << 8;
- cores |= ptcores[3];
- if (cores != NR_CPUS) {
- prom_printf("WARNING ! "
- "ibm_architecture_vec structure inconsistent: %lu!\n",
- cores);
- } else {
- cores = DIV_ROUND_UP(NR_CPUS, prom_count_smt_threads());
- prom_printf("Max number of cores passed to firmware: %lu (NR_CPUS = %lu)\n",
- cores, NR_CPUS);
- ptcores[0] = (cores >> 24) & 0xff;
- ptcores[1] = (cores >> 16) & 0xff;
- ptcores[2] = (cores >> 8) & 0xff;
- ptcores[3] = cores & 0xff;
- }
+ fixup_nr_cores();

/* try calling the ibm,client-architecture-support method */
prom_printf("Calling ibm,client-architecture-support...");
--
1.8.3.1