[25/65] tile: support new Tilera hypervisor

Steven Rostedt
2013-06-03T22:22:15Z

[-- Attachment #1: 0025-tile-support-new-Tilera-hypervisor.patch --]
[-- Type: text/plain, Size: 6187 bytes --]

3.6.11.5 stable review patch.
If anyone has any objections, please let me know.

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

From: Chris Metcalf <cmetcalf@tilera.com>

[ Upstream commit c539914dcd9a68c63305e055b14115a6a19578a8 ]

The Tilera hypervisor shipped in releases up through MDE 4.1 launches
the client operating system (i.e. Linux) at privilege level 1 (PL1).
Starting with MDE 4.2, as part of the work to enable KVM, the
Tilera hypervisor launches Linux at PL2 instead.

This commit makes the KERNEL_PL option default to 2 for tilegx, while
still saying at 1 for tilepro, which doesn't have an updated hypervisor.
It also explains how and when you might want to choose another value.
In addition, we change a small buglet in the on-chip Ethernet driver,
where we were failing to use the KERNEL_PL constant in an API call.

To make the transition cleaner, this change also provides the updated
hv_init() API for the new hypervisor that supports announcing Linux's
compiled-in PL, so the hypervisor can generate a suitable error in the
case of a mismatched hypervisor and Linux binary.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: stable@vger.linux.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
arch/tile/Kconfig | 14 ++++++++++----
arch/tile/include/hv/hypervisor.h | 27 ++++++++++++++++++++++++---
arch/tile/kernel/head_32.S | 2 +-
arch/tile/kernel/head_64.S | 12 +++++++++---
drivers/net/ethernet/tile/tilegx.c | 2 +-
5 files changed, 45 insertions(+), 12 deletions(-)

diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 932e443..569f719 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -360,11 +360,17 @@ config HARDWALL
config KERNEL_PL
int "Processor protection level for kernel"
range 1 2
- default "1"
+ default 2 if TILEGX
+ default 1 if !TILEGX
---help---
- This setting determines the processor protection level the
- kernel will be built to run at. Generally you should use
- the default value here.
+ Since MDE 4.2, the Tilera hypervisor runs the kernel
+ at PL2 by default. If running under an older hypervisor,
+ or as a KVM guest, you must run at PL1. (The current
+ hypervisor may also be recompiled with "make HV_PL=2" to
+ allow it to run a kernel at PL1, but clients running at PL1
+ are not expected to be supported indefinitely.)
+
+ If you're not sure, don't change the default.

source "arch/tile/gxio/Kconfig"

diff --git a/arch/tile/include/hv/hypervisor.h b/arch/tile/include/hv/hypervisor.h
index ccd847e..837dca5 100644
--- a/arch/tile/include/hv/hypervisor.h
+++ b/arch/tile/include/hv/hypervisor.h
@@ -107,7 +107,22 @@
#define HV_DISPATCH_ENTRY_SIZE 32

/** Version of the hypervisor interface defined by this file */
-#define _HV_VERSION 11
+#define _HV_VERSION 13
+
+/** Last version of the hypervisor interface with old hv_init() ABI.
+ *
+ * The change from version 12 to version 13 corresponds to launching
+ * the client by default at PL2 instead of PL1 (corresponding to the
+ * hv itself running at PL3 instead of PL2). To make this explicit,
+ * the hv_init() API was also extended so the client can report its
+ * desired PL, resulting in a more helpful failure diagnostic. If you
+ * call hv_init() with _HV_VERSION_OLD_HV_INIT and omit the client_pl
+ * argument, the hypervisor will assume client_pl = 1.
+ *
+ * Note that this is a deprecated solution and we do not expect to
+ * support clients of the Tilera hypervisor running at PL1 indefinitely.
+ */
+#define _HV_VERSION_OLD_HV_INIT 12

/* Index into hypervisor interface dispatch code blocks.
*
@@ -377,7 +392,11 @@ typedef int HV_Errno;
#ifndef __ASSEMBLER__

/** Pass HV_VERSION to hv_init to request this version of the interface. */
-typedef enum { HV_VERSION = _HV_VERSION } HV_VersionNumber;
+typedef enum {
+ HV_VERSION = _HV_VERSION,
+ HV_VERSION_OLD_HV_INIT = _HV_VERSION_OLD_HV_INIT,
+
+} HV_VersionNumber;

/** Initializes the hypervisor.
*
@@ -385,9 +404,11 @@ typedef enum { HV_VERSION = _HV_VERSION } HV_VersionNumber;
* that this program expects, typically HV_VERSION.
* @param chip_num Architecture number of the chip the client was built for.
* @param chip_rev_num Revision number of the chip the client was built for.
+ * @param client_pl Privilege level the client is built for
+ * (not required if interface_version_number == HV_VERSION_OLD_HV_INIT).
*/
void hv_init(HV_VersionNumber interface_version_number,
- int chip_num, int chip_rev_num);
+ int chip_num, int chip_rev_num, int client_pl);

/** Queries we can make for hv_sysconf().
diff --git a/arch/tile/kernel/head_32.S b/arch/tile/kernel/head_32.S
index f71bfee..ac11530 100644
--- a/arch/tile/kernel/head_32.S
+++ b/arch/tile/kernel/head_32.S
@@ -38,7 +38,7 @@ ENTRY(_start)
movei r2, TILE_CHIP_REV
}
{
- moveli r0, _HV_VERSION
+ moveli r0, _HV_VERSION_OLD_HV_INIT
jal hv_init
}
/* Get a reasonable default ASID in r0 */
diff --git a/arch/tile/kernel/head_64.S b/arch/tile/kernel/head_64.S
index f9a2734..6093964 100644
--- a/arch/tile/kernel/head_64.S
+++ b/arch/tile/kernel/head_64.S
@@ -34,13 +34,19 @@
ENTRY(_start)
/* Notify the hypervisor of what version of the API we want */
{
+#if KERNEL_PL == 1 && _HV_VERSION == 13
+ /* Support older hypervisors by asking for API version 12. */
+ movei r0, _HV_VERSION_OLD_HV_INIT
+#else
+ movei r0, _HV_VERSION
+#endif
movei r1, TILE_CHIP
- movei r2, TILE_CHIP_REV
}
{
- moveli r0, _HV_VERSION
- jal hv_init
+ movei r2, TILE_CHIP_REV
+ movei r3, KERNEL_PL
}
+ jal hv_init
/* Get a reasonable default ASID in r0 */
{
move r0, zero
diff --git a/drivers/net/ethernet/tile/tilegx.c b/drivers/net/ethernet/tile/tilegx.c
index 4e98100..04a321a 100644
--- a/drivers/net/ethernet/tile/tilegx.c
+++ b/drivers/net/ethernet/tile/tilegx.c
@@ -930,7 +930,7 @@ static int tile_net_setup_interrupts(struct net_device *dev)
if (info->has_iqueue) {
gxio_mpipe_request_notif_ring_interrupt(
&context, cpu_x(cpu), cpu_y(cpu),
- 1, ingress_irq, info->iqueue.ring);
+ KERNEL_PL, ingress_irq, info->iqueue.ring);
}
}

--
1.7.10.4