[PATCH 10/10] powerpc/vas, nx-842: Define and use chip_to_vas_id()

From: Sukadev Bhattiprolu
Date: Sun Sep 17 2017 - 00:06:00 EST


Define a helper, chip_to_vas_id() to map a given chip id to corresponding
vas id.

Normally, callers of vas_rx_win_open() and vas_tx_win_open() would need
the VAS window to be on the same chip where the calling thread is executing.
These callers can pass in -1 for the VAS id.

This interface will be useful if a thread running on one chip wants to open
a window on another chip (like the NX-842 driver does during start up).

Signed-off-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/vas.h | 9 +++++++++
arch/powerpc/platforms/powernv/vas.c | 11 +++++++++++
drivers/crypto/nx/nx-842-powernv.c | 18 +++---------------
3 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
index fd5963a..044748f 100644
--- a/arch/powerpc/include/asm/vas.h
+++ b/arch/powerpc/include/asm/vas.h
@@ -104,6 +104,15 @@ struct vas_tx_win_attr {
};

/*
+ * Helper to map a chip id to VAS id.
+ * For POWER9, this is a 1:1 mapping. In the future this maybe a 1:N
+ * mapping in which case, we will need to update this helper.
+ *
+ * Return the VAS id or -1 if no matching vasid is found.
+ */
+int chip_to_vas_id(int chipid);
+
+/*
* Helper to initialize receive window attributes to defaults for an
* NX window.
*/
diff --git a/arch/powerpc/platforms/powernv/vas.c b/arch/powerpc/platforms/powernv/vas.c
index abb7090..cd9a733 100644
--- a/arch/powerpc/platforms/powernv/vas.c
+++ b/arch/powerpc/platforms/powernv/vas.c
@@ -123,6 +123,17 @@ struct vas_instance *find_vas_instance(int vasid)
return NULL;
}

+int chip_to_vas_id(int chipid)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ if (cpu_to_chip_id(cpu) == chipid)
+ return per_cpu(cpu_vas_id, cpu);
+ }
+ return -1;
+}
+
static int vas_probe(struct platform_device *pdev)
{
return init_vas_instance(pdev);
diff --git a/drivers/crypto/nx/nx-842-powernv.c b/drivers/crypto/nx/nx-842-powernv.c
index 874ddf5..eb221ed 100644
--- a/drivers/crypto/nx/nx-842-powernv.c
+++ b/drivers/crypto/nx/nx-842-powernv.c
@@ -847,24 +847,12 @@ static int __init nx842_powernv_probe_vas(struct device_node *pn)
return -EINVAL;
}

- for_each_compatible_node(dn, NULL, "ibm,power9-vas-x") {
- if (of_get_ibm_chip_id(dn) == chip_id)
- break;
- }
-
- if (!dn) {
- pr_err("Missing VAS device node\n");
+ vasid = chip_to_vas_id(chip_id);
+ if (vasid < 0) {
+ pr_err("Unable to map chip_id %d to vasid\n", chip_id);
return -EINVAL;
}

- if (of_property_read_u32(dn, "ibm,vas-id", &vasid)) {
- pr_err("Missing ibm,vas-id device property\n");
- of_node_put(dn);
- return -EINVAL;
- }
-
- of_node_put(dn);
-
for_each_child_of_node(pn, dn) {
if (of_device_is_compatible(dn, "ibm,p9-nx-842")) {
ret = vas_cfg_coproc_info(dn, chip_id, vasid);
--
2.7.4