[PATCH v2 09/18] powerpc/vas: Create cpu to vas id mapping

From: Sukadev Bhattiprolu
Date: Fri Oct 06 2017 - 22:31:15 EST


Create a cpu to vasid mapping so callers can specify -1 instead of
trying to find a VAS id.

Changelog[v2]
[Michael Ellerman] Use per-cpu variables to simplify code.

Signed-off-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/platforms/powernv/vas.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/powernv/vas.c b/arch/powerpc/platforms/powernv/vas.c
index 565a487..abb7090 100644
--- a/arch/powerpc/platforms/powernv/vas.c
+++ b/arch/powerpc/platforms/powernv/vas.c
@@ -18,15 +18,18 @@
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/of.h>
+#include <asm/prom.h>

#include "vas.h"

static DEFINE_MUTEX(vas_mutex);
static LIST_HEAD(vas_instances);

+static DEFINE_PER_CPU(int, cpu_vas_id);
+
static int init_vas_instance(struct platform_device *pdev)
{
- int rc, vasid;
+ int rc, cpu, vasid;
struct resource *res;
struct vas_instance *vinst;
struct device_node *dn = pdev->dev.of_node;
@@ -74,6 +77,11 @@ static int init_vas_instance(struct platform_device *pdev)
"paste_win_id_shift 0x%llx\n", pdev->name, vasid,
vinst->paste_base_addr, vinst->paste_win_id_shift);

+ for_each_possible_cpu(cpu) {
+ if (cpu_to_chip_id(cpu) == of_get_ibm_chip_id(dn))
+ per_cpu(cpu_vas_id, cpu) = vasid;
+ }
+
mutex_lock(&vas_mutex);
list_add(&vinst->node, &vas_instances);
mutex_unlock(&vas_mutex);
@@ -98,6 +106,10 @@ struct vas_instance *find_vas_instance(int vasid)
struct vas_instance *vinst;

mutex_lock(&vas_mutex);
+
+ if (vasid == -1)
+ vasid = per_cpu(cpu_vas_id, smp_processor_id());
+
list_for_each(ent, &vas_instances) {
vinst = list_entry(ent, struct vas_instance, node);
if (vinst->vas_id == vasid) {
--
2.7.4