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Subject[PATCH -mm 1/4] RapidIO: Add definitions of Component Tag fields
Date
Add definition of the unique device identifier field in the component tag.
RIO_CTAG_UDEVID does not take all 32 bits of the component tag value to
allow future extensions to the component tag use.

Selected size of the RIO_CTAG_UDEVID field (17 bits) is sufficient to accommodate
maximum number of endpoints in large RIO network (16-bit id) plus switches.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Micha Nelissen <micha@neli.hopto.org>
---
drivers/rapidio/rio.c | 2 +-
include/linux/rio.h | 10 ++++++++++
2 files changed, 11 insertions(+), 1 deletions(-)
diff --git a/drivers/rapidio/rio.c b/drivers/rapidio/rio.c
index c13289e..cc2a3b7 100644
--- a/drivers/rapidio/rio.c
+++ b/drivers/rapidio/rio.c
@@ -710,7 +710,7 @@ int rio_inb_pwrite_handler(union rio_pw_msg *pw_msg)
u32 err_status, em_perrdet, em_ltlerrdet;
int rc, portnum;

- rdev = rio_get_comptag(pw_msg->em.comptag, NULL);
+ rdev = rio_get_comptag((pw_msg->em.comptag & RIO_CTAG_UDEVID), NULL);
if (rdev == NULL) {
/* Device removed or enumeration error */
pr_debug("RIO: %s No matching device for CTag 0x%08x\n",
diff --git a/include/linux/rio.h b/include/linux/rio.h
index 9b55885..ff681eb 100644
--- a/include/linux/rio.h
+++ b/include/linux/rio.h
@@ -66,6 +66,16 @@

#define RIO_PW_MSG_SIZE 64

+/*
+ * A component tag value (stored in the component tag CSR) is used as device's
+ * unique identifier assigned during enumeration. Besides being used for
+ * identifying switches (which do not have device ID register), it also is used
+ * by error management notification and therefore has to be assigned
+ * to endpoints as well.
+ */
+#define RIO_CTAG_RESRVD 0xfffe0000 /* Reserved */
+#define RIO_CTAG_UDEVID 0x0001ffff /* Unique device identifier */
+
extern struct bus_type rio_bus_type;
extern struct device rio_bus;
extern struct list_head rio_devices; /* list of all devices */
--
1.7.3.1


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