| Message ID | 1364589490-2759-1-git-send-email-twarren@nvidia.com |
|---|---|
| State | Accepted |
| Delegated to: | Tom Warren |
| Headers | show |
On 03/29/2013 02:38 PM, Tom Warren wrote: > Without this change, kernel fails at calling function cache_clean_flush > during kernel early boot. > > Aprocryphally, intended for T114 only, so I check for a T114 SoC. > Works (i.e. dalmore 3.8 kernel now starts printing to console). I don't know enough about the caches to really review this, but I have no particular objection to it. My one comment is ... > diff --git a/arch/arm/cpu/tegra-common/cache.c b/arch/arm/cpu/tegra-common/cache.c > +void config_cache(void) > + /* Currently, only T114 needs this L2 cache change to boot Linux */ > + reg = (readl(&gp->hidrev) & HIDREV_CHIPID_MASK); > + if (reg != (CHIPID_TEGRA114 << HIDREV_CHIPID_SHIFT)) > + return; Can we introduce a standard function for that instead? We already have tegra_get_chip_type() which returns a SKU-based ID. I think we need to introduce a tegra_get_soc_type() that returns a pure Tegra20/30/114 value, and probably use this in most places we currently use the result of tegra_get_chip_type(), since most care about SW-compatibility of features rather than SKU which drivers performance levels instead typically. Then, perhaps rename tegra_get_chip_type() to tegra_get_soc_sku() and re-write it to use tegra_get_soc_type()?
Stephen, On Fri, Mar 29, 2013 at 3:43 PM, Stephen Warren <swarren@wwwdotorg.org>wrote: > On 03/29/2013 02:38 PM, Tom Warren wrote: > > Without this change, kernel fails at calling function cache_clean_flush > > during kernel early boot. > > > > Aprocryphally, intended for T114 only, so I check for a T114 SoC. > > Works (i.e. dalmore 3.8 kernel now starts printing to console). > > I don't know enough about the caches to really review this, but I have > no particular objection to it. My one comment is ... > > > diff --git a/arch/arm/cpu/tegra-common/cache.c > b/arch/arm/cpu/tegra-common/cache.c > > > +void config_cache(void) > > > + /* Currently, only T114 needs this L2 cache change to boot Linux */ > > + reg = (readl(&gp->hidrev) & HIDREV_CHIPID_MASK); > > + if (reg != (CHIPID_TEGRA114 << HIDREV_CHIPID_SHIFT)) > > + return; > > Can we introduce a standard function for that instead? We already have > tegra_get_chip_type() which returns a SKU-based ID. I think we need to > introduce a tegra_get_soc_type() that returns a pure Tegra20/30/114 > value, and probably use this in most places we currently use the result > of tegra_get_chip_type(), since most care about SW-compatibility of > features rather than SKU which drivers performance levels instead > typically. Then, perhaps rename tegra_get_chip_type() to > tegra_get_soc_sku() and re-write it to use tegra_get_soc_type()? > I can do that, but I'd prefer to do it as a separate patch since tegra_get_chip_type is used in a few other places. This patch is needed by a customer to get their kernel loading (or at least past the 'Decompressing Linux...' part). I'll correct this patch later to use tegra_get_soc_type(). Thanks, Tom
diff --git a/arch/arm/cpu/tegra-common/Makefile b/arch/arm/cpu/tegra-common/Makefile index 8e95c7e..4e0301c 100644 --- a/arch/arm/cpu/tegra-common/Makefile +++ b/arch/arm/cpu/tegra-common/Makefile @@ -28,7 +28,7 @@ include $(TOPDIR)/config.mk LIB = $(obj)libcputegra-common.o SOBJS += lowlevel_init.o -COBJS-y += ap.o board.o sys_info.o timer.o clock.o +COBJS-y += ap.o board.o sys_info.o timer.o clock.o cache.o SRCS := $(SOBJS:.o=.S) $(COBJS-y:.o=.c) OBJS := $(addprefix $(obj),$(SOBJS) $(COBJS-y)) diff --git a/arch/arm/cpu/tegra-common/ap.c b/arch/arm/cpu/tegra-common/ap.c index 3f30805..a739fe2 100644 --- a/arch/arm/cpu/tegra-common/ap.c +++ b/arch/arm/cpu/tegra-common/ap.c @@ -139,11 +139,6 @@ void s_init(void) enable_scu(); - /* enable SMP mode and FW for CPU0, by writing to Auxiliary Ctl reg */ - asm volatile( - "mrc p15, 0, r0, c1, c0, 1\n" - "orr r0, r0, #0x41\n" - "mcr p15, 0, r0, c1, c0, 1\n"); - - /* FIXME: should have SoC's L2 disabled too? */ + /* init the cache */ + config_cache(); } diff --git a/arch/arm/cpu/tegra-common/cache.c b/arch/arm/cpu/tegra-common/cache.c new file mode 100644 index 0000000..48e9319 --- /dev/null +++ b/arch/arm/cpu/tegra-common/cache.c @@ -0,0 +1,48 @@ +/* + * Copyright (c) 2013, NVIDIA CORPORATION. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +/* Tegra cache routines */ + +#include <common.h> +#include <asm/io.h> +#include <asm/arch-tegra/ap.h> +#include <asm/arch/gp_padctrl.h> + +void config_cache(void) +{ + struct apb_misc_gp_ctlr *gp = + (struct apb_misc_gp_ctlr *)NV_PA_APB_MISC_GP_BASE; + u32 reg = 0; + + /* enable SMP mode and FW for CPU0, by writing to Auxiliary Ctl reg */ + asm volatile( + "mrc p15, 0, r0, c1, c0, 1\n" + "orr r0, r0, #0x41\n" + "mcr p15, 0, r0, c1, c0, 1\n"); + + /* Currently, only T114 needs this L2 cache change to boot Linux */ + reg = (readl(&gp->hidrev) & HIDREV_CHIPID_MASK); + if (reg != (CHIPID_TEGRA114 << HIDREV_CHIPID_SHIFT)) + return; + /* + * Systems with an architectural L2 cache must not use the PL310. + * Config L2CTLR here for a data RAM latency of 3 cycles. + */ + asm("mrc p15, 1, %0, c9, c0, 2" : : "r" (reg)); + reg &= ~7; + reg |= 2; + asm("mcr p15, 1, %0, c9, c0, 2" : : "r" (reg)); +} diff --git a/arch/arm/include/asm/arch-tegra/ap.h b/arch/arm/include/asm/arch-tegra/ap.h index 73dfd39..5999f55 100644 --- a/arch/arm/include/asm/arch-tegra/ap.h +++ b/arch/arm/include/asm/arch-tegra/ap.h @@ -64,3 +64,4 @@ extern void _start(void); * @return SOC type - see TEGRA_SOC... */ int tegra_get_chip_type(void); +void config_cache(void);
Without this change, kernel fails at calling function cache_clean_flush during kernel early boot. Aprocryphally, intended for T114 only, so I check for a T114 SoC. Works (i.e. dalmore 3.8 kernel now starts printing to console). Signed-off-by: Tom Warren <twarren@nvidia.com> --- arch/arm/cpu/tegra-common/Makefile | 2 +- arch/arm/cpu/tegra-common/ap.c | 9 ++----- arch/arm/cpu/tegra-common/cache.c | 48 ++++++++++++++++++++++++++++++++++++ arch/arm/include/asm/arch-tegra/ap.h | 1 + 4 files changed, 52 insertions(+), 8 deletions(-) create mode 100644 arch/arm/cpu/tegra-common/cache.c