From c539914dcd9a68c63305e055b14115a6a19578a8 Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Thu, 2 May 2013 15:29:04 -0400 Subject: 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 Cc: stable@vger.linux.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 +++++++++--- 4 files changed, 44 insertions(+), 11 deletions(-) (limited to 'arch') 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 -- cgit v1.2.1