This is a note to let you know that I've just added the patch titled
ARC: Disable caches in early boot if so configured
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arc-disable-caches-in-early-boot-if-so-configured.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ef680cdc24376f394841a3f19b3a7ef6d57a009d Mon Sep 17 00:00:00 2001
From: Vineet Gupta <vgupta@xxxxxxxxxxxx>
Date: Fri, 7 Mar 2014 18:08:11 +0530
Subject: ARC: Disable caches in early boot if so configured
From: Vineet Gupta <vgupta@xxxxxxxxxxxx>
commit ef680cdc24376f394841a3f19b3a7ef6d57a009d upstream.
Requested-by: Noam Camus <noamc@xxxxxxxxxx>
Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arc/include/asm/cache.h | 27 ++++++++++
arch/arc/kernel/head.S | 38 +++++++++++++-
arch/arc/mm/cache_arc700.c | 112 ++++++++++---------------------------------
3 files changed, 90 insertions(+), 87 deletions(-)
--- a/arch/arc/include/asm/cache.h
+++ b/arch/arc/include/asm/cache.h
@@ -55,4 +55,31 @@ extern void read_decode_cache_bcr(void);
#endif /* !__ASSEMBLY__ */
+/* Instruction cache related Auxiliary registers */
+#define ARC_REG_IC_BCR 0x77 /* Build Config reg */
+#define ARC_REG_IC_IVIC 0x10
+#define ARC_REG_IC_CTRL 0x11
+#define ARC_REG_IC_IVIL 0x19
+#if defined(CONFIG_ARC_MMU_V3) || defined (CONFIG_ARC_MMU_V4)
+#define ARC_REG_IC_PTAG 0x1E
+#endif
+
+/* Bit val in IC_CTRL */
+#define IC_CTRL_CACHE_DISABLE 0x1
+
+/* Data cache related Auxiliary registers */
+#define ARC_REG_DC_BCR 0x72 /* Build Config reg */
+#define ARC_REG_DC_IVDC 0x47
+#define ARC_REG_DC_CTRL 0x48
+#define ARC_REG_DC_IVDL 0x4A
+#define ARC_REG_DC_FLSH 0x4B
+#define ARC_REG_DC_FLDL 0x4C
+#if defined(CONFIG_ARC_MMU_V3) || defined (CONFIG_ARC_MMU_V4)
+#define ARC_REG_DC_PTAG 0x5C
+#endif
+
+/* Bit val in DC_CTRL */
+#define DC_CTRL_INV_MODE_FLUSH 0x40
+#define DC_CTRL_FLUSH_STATUS 0x100
+
#endif /* _ASM_CACHE_H */
--- a/arch/arc/kernel/head.S
+++ b/arch/arc/kernel/head.S
@@ -12,10 +12,42 @@
* to skip certain things during boot on simulator
*/
+#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/entry.h>
-#include <linux/linkage.h>
#include <asm/arcregs.h>
+#include <asm/cache.h>
+
+.macro CPU_EARLY_SETUP
+
+ ; Setting up Vectror Table (in case exception happens in early boot
+ sr @_int_vec_base_lds, [AUX_INTR_VEC_BASE]
+
+ ; Disable I-cache/D-cache if kernel so configured
+ lr r5, [ARC_REG_IC_BCR]
+ breq r5, 0, 1f ; I$ doesn't exist
+ lr r5, [ARC_REG_IC_CTRL]
+#ifdef CONFIG_ARC_HAS_ICACHE
+ bclr r5, r5, 0 ; 0 - Enable, 1 is Disable
+#else
+ bset r5, r5, 0 ; I$ exists, but is not used
+#endif
+ sr r5, [ARC_REG_IC_CTRL]
+
+1:
+ lr r5, [ARC_REG_DC_BCR]
+ breq r5, 0, 1f ; D$ doesn't exist
+ lr r5, [ARC_REG_DC_CTRL]
+ bclr r5, r5, 6 ; Invalidate (discard w/o wback)
+#ifdef CONFIG_ARC_HAS_DCACHE
+ bclr r5, r5, 0 ; Enable (+Inv)
+#else
+ bset r5, r5, 0 ; Disable (+Inv)
+#endif
+ sr r5, [ARC_REG_DC_CTRL]
+
+1:
+.endm
.cpu A7
@@ -27,7 +59,7 @@ stext:
; Don't clobber r0-r2 yet. It might have bootloader provided info
;-------------------------------------------------------------------
- sr @_int_vec_base_lds, [AUX_INTR_VEC_BASE]
+ CPU_EARLY_SETUP
#ifdef CONFIG_SMP
; Ensure Boot (Master) proceeds. Others wait in platform dependent way
@@ -90,7 +122,7 @@ stext:
first_lines_of_secondary:
- sr @_int_vec_base_lds, [AUX_INTR_VEC_BASE]
+ CPU_EARLY_SETUP
; setup per-cpu idle task as "current" on this CPU
ld r0, [@secondary_idle_tsk]
--- a/arch/arc/mm/cache_arc700.c
+++ b/arch/arc/mm/cache_arc700.c
@@ -73,33 +73,6 @@
#include <asm/cachectl.h>
#include <asm/setup.h>
-/* Instruction cache related Auxiliary registers */
-#define ARC_REG_IC_BCR 0x77 /* Build Config reg */
-#define ARC_REG_IC_IVIC 0x10
-#define ARC_REG_IC_CTRL 0x11
-#define ARC_REG_IC_IVIL 0x19
-#if (CONFIG_ARC_MMU_VER > 2)
-#define ARC_REG_IC_PTAG 0x1E
-#endif
-
-/* Bit val in IC_CTRL */
-#define IC_CTRL_CACHE_DISABLE 0x1
-
-/* Data cache related Auxiliary registers */
-#define ARC_REG_DC_BCR 0x72 /* Build Config reg */
-#define ARC_REG_DC_IVDC 0x47
-#define ARC_REG_DC_CTRL 0x48
-#define ARC_REG_DC_IVDL 0x4A
-#define ARC_REG_DC_FLSH 0x4B
-#define ARC_REG_DC_FLDL 0x4C
-#if (CONFIG_ARC_MMU_VER > 2)
-#define ARC_REG_DC_PTAG 0x5C
-#endif
-
-/* Bit val in DC_CTRL */
-#define DC_CTRL_INV_MODE_FLUSH 0x40
-#define DC_CTRL_FLUSH_STATUS 0x100
-
char *arc_cache_mumbojumbo(int c, char *buf, int len)
{
int n = 0;
@@ -168,72 +141,43 @@ void read_decode_cache_bcr(void)
*/
void arc_cache_init(void)
{
- unsigned int cpu = smp_processor_id();
- struct cpuinfo_arc_cache *ic = &cpuinfo_arc700[cpu].icache;
- struct cpuinfo_arc_cache *dc = &cpuinfo_arc700[cpu].dcache;
- unsigned int dcache_does_alias, temp;
+ unsigned int __maybe_unused cpu = smp_processor_id();
+ struct cpuinfo_arc_cache __maybe_unused *ic, __maybe_unused *dc;
char str[256];
printk(arc_cache_mumbojumbo(0, str, sizeof(str)));
- if (!ic->ver)
- goto chk_dc;
-
-#ifdef CONFIG_ARC_HAS_ICACHE
- /* 1. Confirm some of I-cache params which Linux assumes */
- if (ic->line_len != L1_CACHE_BYTES)
- panic("Cache H/W doesn't match kernel Config");
-
- if (ic->ver != CONFIG_ARC_MMU_VER)
- panic("Cache ver doesn't match MMU ver\n");
-#endif
-
- /* Enable/disable I-Cache */
- temp = read_aux_reg(ARC_REG_IC_CTRL);
-
#ifdef CONFIG_ARC_HAS_ICACHE
- temp &= ~IC_CTRL_CACHE_DISABLE;
-#else
- temp |= IC_CTRL_CACHE_DISABLE;
-#endif
-
- write_aux_reg(ARC_REG_IC_CTRL, temp);
-
-chk_dc:
- if (!dc->ver)
- return;
-
-#ifdef CONFIG_ARC_HAS_DCACHE
- if (dc->line_len != L1_CACHE_BYTES)
- panic("Cache H/W doesn't match kernel Config");
-
- /* check for D-Cache aliasing */
- dcache_does_alias = (dc->sz / dc->assoc) > PAGE_SIZE;
-
- if (dcache_does_alias && !cache_is_vipt_aliasing())
- panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
- else if (!dcache_does_alias && cache_is_vipt_aliasing())
- panic("Don't need CONFIG_ARC_CACHE_VIPT_ALIASING\n");
+ ic = &cpuinfo_arc700[cpu].icache;
+ if (ic->ver) {
+ if (ic->line_len != L1_CACHE_BYTES)
+ panic("ICache line [%d] != kernel Config [%d]",
+ ic->line_len, L1_CACHE_BYTES);
+
+ if (ic->ver != CONFIG_ARC_MMU_VER)
+ panic("Cache ver [%d] doesn't match MMU ver [%d]\n",
+ ic->ver, CONFIG_ARC_MMU_VER);
+ }
#endif
- /* Set the default Invalidate Mode to "simpy discard dirty lines"
- * as this is more frequent then flush before invalidate
- * Ofcourse we toggle this default behviour when desired
- */
- temp = read_aux_reg(ARC_REG_DC_CTRL);
- temp &= ~DC_CTRL_INV_MODE_FLUSH;
-
#ifdef CONFIG_ARC_HAS_DCACHE
- /* Enable D-Cache: Clear Bit 0 */
- write_aux_reg(ARC_REG_DC_CTRL, temp & ~IC_CTRL_CACHE_DISABLE);
-#else
- /* Flush D cache */
- write_aux_reg(ARC_REG_DC_FLSH, 0x1);
- /* Disable D cache */
- write_aux_reg(ARC_REG_DC_CTRL, temp | IC_CTRL_CACHE_DISABLE);
+ dc = &cpuinfo_arc700[cpu].dcache;
+ if (dc->ver) {
+ unsigned int dcache_does_alias;
+
+ if (dc->line_len != L1_CACHE_BYTES)
+ panic("DCache line [%d] != kernel Config [%d]",
+ dc->line_len, L1_CACHE_BYTES);
+
+ /* check for D-Cache aliasing */
+ dcache_does_alias = (dc->sz / dc->assoc) > PAGE_SIZE;
+
+ if (dcache_does_alias && !cache_is_vipt_aliasing())
+ panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
+ else if (!dcache_does_alias && cache_is_vipt_aliasing())
+ panic("Don't need CONFIG_ARC_CACHE_VIPT_ALIASING\n");
+ }
#endif
-
- return;
}
#define OP_INV 0x1
Patches currently in stable-queue which might be from vgupta@xxxxxxxxxxxx are
queue-3.14/arc-update-order-of-registers-in-kgdb-to-match-gdb-7.5.patch
queue-3.14/arc-general-fixes.patch
queue-3.14/arc-allow-headless-models-to-boot.patch
queue-3.14/arc-disable-caches-in-early-boot-if-so-configured.patch
queue-3.14/arc-fix-mmuv2-warning.patch
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