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authorChris Metcalf <cmetcalf@tilera.com>2013-05-02 15:29:04 -0400
committerChris Metcalf <cmetcalf@tilera.com>2013-05-02 16:20:31 -0400
commitc539914dcd9a68c63305e055b14115a6a19578a8 (patch)
treeb422139d5d4628c8472fdf740dced263bc238c30 /arch
parentc1be5a5b1b355d40e6cf79cc979eb66dafa24ad1 (diff)
tile: support new Tilera hypervisor
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
Diffstat (limited to 'arch')
-rw-r--r--arch/tile/Kconfig14
-rw-r--r--arch/tile/include/hv/hypervisor.h27
-rw-r--r--arch/tile/kernel/head_32.S2
-rw-r--r--arch/tile/kernel/head_64.S12
4 files changed, 44 insertions, 11 deletions
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 25877aebc685..41a2a0becc18 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -368,11 +368,17 @@ 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 ccd847e2347f..837dca5328c2 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 f71bfeeaf1a9..ac115307e5e4 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 f9a2734f7b82..6093964fa5c7 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