From b849a60e0903b1c5430c3859864554662e127a8d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>
Date: Mon, 16 Jan 2012 10:34:31 +0100
Subject: [PATCH 1/5] ARM: make cr_alignment read-only #ifndef CONFIG_CPU_CP15
MIME-Version: 1.0
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This makes cr_alignment a constant 0 to break code that tries to modify
the value as it's likely that it's built on wrong assumption when
CONFIG_CPU_CP15 isn't defined. For code that is only reading the value 0
is more or less a fine value to report.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Message-Id: 1358413196-5609-2-git-send-email-u.kleine-koenig@pengutronix.de (v8)
---
arch/arm/include/asm/cp15.h | 16 +++++++++++++++-
arch/arm/kernel/head-common.S | 9 +++++++--
arch/arm/mm/alignment.c | 2 ++
arch/arm/mm/mmu.c | 17 +++++++++++++++++
4 files changed, 41 insertions(+), 3 deletions(-)
diff --git a/arch/arm/include/asm/cp15.h b/arch/arm/include/asm/cp15.h
index 5ef4d8015a604..1f3262e99d81e 100644
--- a/arch/arm/include/asm/cp15.h
+++ b/arch/arm/include/asm/cp15.h
@@ -42,6 +42,8 @@
#define vectors_high() (0)
#endif
+#ifdef CONFIG_CPU_CP15
+
extern unsigned long cr_no_alignment; /* defined in entry-armv.S */
extern unsigned long cr_alignment; /* defined in entry-armv.S */
@@ -82,6 +84,18 @@ static inline void set_copro_access(unsigned int val)
isb();
}
-#endif
+#else /* ifdef CONFIG_CPU_CP15 */
+
+/*
+ * cr_alignment and cr_no_alignment are tightly coupled to cp15 (at least in the
+ * minds of the developers). Yielding 0 for machines without a cp15 (and making
+ * it read-only) is fine for most cases and saves quite some #ifdeffery.
+ */
+#define cr_no_alignment UL(0)
+#define cr_alignment UL(0)
+
+#endif /* ifdef CONFIG_CPU_CP15 / else */
+
+#endif /* ifndef __ASSEMBLY__ */
#endif
diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
index 854bd22380d33..5b391a689b47b 100644
--- a/arch/arm/kernel/head-common.S
+++ b/arch/arm/kernel/head-common.S
@@ -98,8 +98,9 @@ __mmap_switched:
str r9, [r4] @ Save processor ID
str r1, [r5] @ Save machine type
str r2, [r6] @ Save atags pointer
- bic r4, r0, #CR_A @ Clear 'A' bit
- stmia r7, {r0, r4} @ Save control register values
+ cmp r7, #0
+ bicne r4, r0, #CR_A @ Clear 'A' bit
+ stmneia r7, {r0, r4} @ Save control register values
b start_kernel
ENDPROC(__mmap_switched)
@@ -113,7 +114,11 @@ __mmap_switched_data:
.long processor_id @ r4
.long __machine_arch_type @ r5
.long __atags_pointer @ r6
+#ifdef CONFIG_CPU_CP15
.long cr_alignment @ r7
+#else
+ .long 0 @ r7
+#endif
.long init_thread_union + THREAD_START_SP @ sp
.size __mmap_switched_data, . - __mmap_switched_data
diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c
index b820edaf31843..feeb3eaccb1c4 100644
--- a/arch/arm/mm/alignment.c
+++ b/arch/arm/mm/alignment.c
@@ -964,12 +964,14 @@ static int __init alignment_init(void)
return -ENOMEM;
#endif
+#ifdef CONFIG_CPU_CP15
if (cpu_is_v6_unaligned()) {
cr_alignment &= ~CR_A;
cr_no_alignment &= ~CR_A;
set_cr(cr_alignment);
ai_usermode = safe_usermode(ai_usermode, false);
}
+#endif
hook_fault_code(FAULT_CODE_ALIGNMENT, do_alignment, SIGBUS, BUS_ADRALN,
"alignment exception");
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index ce328c7f5c945..7c347bcc94211 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -97,6 +97,7 @@ static struct cachepolicy cache_policies[] __initdata = {
}
};
+#ifdef CONFIG_CPU_CP15
/*
* These are useful for identifying cache coherency
* problems by allowing the cache or the cache and
@@ -195,6 +196,22 @@ void adjust_cr(unsigned long mask, unsigned long set)
}
#endif
+#else /* ifdef CONFIG_CPU_CP15 */
+
+static int __init early_cachepolicy(char *p)
+{
+ pr_warning("cachepolicy kernel parameter not supported without cp15\n");
+}
+early_param("cachepolicy", early_cachepolicy);
+
+static int __init noalign_setup(char *__unused)
+{
+ pr_warning("noalign kernel parameter not supported without cp15\n");
+}
+__setup("noalign", noalign_setup);
+
+#endif /* ifdef CONFIG_CPU_CP15 / else */
+
#define PROT_PTE_DEVICE L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_XN
#define PROT_SECT_DEVICE PMD_TYPE_SECT|PMD_SECT_AP_WRITE
From bc7dea00a9a0ea385bbc4aed67dfdcf7d8879953 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>
Date: Fri, 9 Dec 2011 20:52:10 +0100
Subject: [PATCH 2/5] ARM: let CPUs not being able to run in ARM mode enter in
THUMB mode
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Some ARM cores are not capable to run in ARM mode (e.g. Cortex-M3). So
obviously these cannot enter the kernel in ARM mode. Make an exception
for them and let them enter in THUMB mode.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Message-Id: 1358162123-30113-1-git-send-email-u.kleine-koenig@pengutronix.de
Acked-by: Nicolas Pitre <nico@linaro.org>
---
arch/arm/Kconfig | 3 ++-
arch/arm/kernel/head-nommu.S | 8 +++++++-
arch/arm/mm/Kconfig | 9 ++++++++-
3 files changed, 17 insertions(+), 3 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 67874b82a4edf..e04c7793f47e2 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1656,8 +1656,9 @@ config HZ
default 100
config THUMB2_KERNEL
- bool "Compile the kernel in Thumb-2 mode"
+ bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
depends on CPU_V7 && !CPU_V6 && !CPU_V6K
+ default y if CPU_THUMBONLY
select AEABI
select ARM_ASM_UNIFIED
select ARM_UNWIND
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
index 2c228a07e58c7..6a2e09c952c71 100644
--- a/arch/arm/kernel/head-nommu.S
+++ b/arch/arm/kernel/head-nommu.S
@@ -32,15 +32,21 @@
* numbers for r1.
*
*/
- .arm
__HEAD
+
+#ifdef CONFIG_CPU_THUMBONLY
+ .thumb
+ENTRY(stext)
+#else
+ .arm
ENTRY(stext)
THUMB( adr r9, BSYM(1f) ) @ Kernel is always entered in ARM.
THUMB( bx r9 ) @ If this is a Thumb-2 kernel,
THUMB( .thumb ) @ switch to Thumb now.
THUMB(1: )
+#endif
setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode
@ and irqs disabled
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 3fd629d5a5132..8defd638c79e6 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -397,6 +397,13 @@ config CPU_V7
select CPU_PABRT_V7
select CPU_TLB_V7 if MMU
+config CPU_THUMBONLY
+ bool
+ # There are no CPUs available with MMU that don't implement an ARM ISA:
+ depends on !MMU
+ help
+ Select this if your CPU doesn't support the 32 bit ARM instructions.
+
# Figure out what processor architecture version we should be using.
# This defines the compiler instruction set which depends on the machine type.
config CPU_32v3
@@ -608,7 +615,7 @@ config ARCH_DMA_ADDR_T_64BIT
bool
config ARM_THUMB
- bool "Support Thumb user binaries"
+ bool "Support Thumb user binaries" if !CPU_THUMBONLY
depends on CPU_ARM720T || CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_V6 || CPU_V6K || CPU_V7 || CPU_FEROCEON
default y
help
From 473296e072ae77e96586dcb39a1dd5d10db22611 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>
Date: Wed, 30 Jan 2013 12:07:14 +0100
Subject: [PATCH 3/5] ARM: sync comments about available data abort models with
the code
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
While at it bring both in the same increasing order.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Message-Id: 1359544151-26744-1-git-send-email-u.kleine-koenig@pengutronix.de
---
arch/arm/include/asm/glue-df.h | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/arch/arm/include/asm/glue-df.h b/arch/arm/include/asm/glue-df.h
index 8cacbcda76da9..b6e9f2c108b5d 100644
--- a/arch/arm/include/asm/glue-df.h
+++ b/arch/arm/include/asm/glue-df.h
@@ -18,12 +18,12 @@
* ================
*
* We have the following to choose from:
- * arm6 - ARM6 style
* arm7 - ARM7 style
* v4_early - ARMv4 without Thumb early abort handler
* v4t_late - ARMv4 with Thumb late abort handler
* v4t_early - ARMv4 with Thumb early abort handler
- * v5tej_early - ARMv5 with Thumb and Java early abort handler
+ * v5t_early - ARMv5 with Thumb early abort handler
+ * v5tj_early - ARMv5 with Thumb and Java early abort handler
* xscale - ARMv5 with Thumb with Xscale extensions
* v6_early - ARMv6 generic early abort handler
* v7_early - ARMv7 generic early abort handler
@@ -39,19 +39,19 @@
# endif
#endif
-#ifdef CONFIG_CPU_ABRT_LV4T
+#ifdef CONFIG_CPU_ABRT_EV4
# ifdef CPU_DABORT_HANDLER
# define MULTI_DABORT 1
# else
-# define CPU_DABORT_HANDLER v4t_late_abort
+# define CPU_DABORT_HANDLER v4_early_abort
# endif
#endif
-#ifdef CONFIG_CPU_ABRT_EV4
+#ifdef CONFIG_CPU_ABRT_LV4T
# ifdef CPU_DABORT_HANDLER
# define MULTI_DABORT 1
# else
-# define CPU_DABORT_HANDLER v4_early_abort
+# define CPU_DABORT_HANDLER v4t_late_abort
# endif
#endif
@@ -63,19 +63,19 @@
# endif
#endif
-#ifdef CONFIG_CPU_ABRT_EV5TJ
+#ifdef CONFIG_CPU_ABRT_EV5T
# ifdef CPU_DABORT_HANDLER
# define MULTI_DABORT 1
# else
-# define CPU_DABORT_HANDLER v5tj_early_abort
+# define CPU_DABORT_HANDLER v5t_early_abort
# endif
#endif
-#ifdef CONFIG_CPU_ABRT_EV5T
+#ifdef CONFIG_CPU_ABRT_EV5TJ
# ifdef CPU_DABORT_HANDLER
# define MULTI_DABORT 1
# else
-# define CPU_DABORT_HANDLER v5t_early_abort
+# define CPU_DABORT_HANDLER v5tj_early_abort
# endif
#endif
From ac52e83f4c76992925e13d0f4e901ffd4c207261 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>
Date: Wed, 30 Jan 2013 17:38:21 +0100
Subject: [PATCH 4/5] ARM: use read_cpuid_id() instead of read_cpuid(CPUID_ID)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Both calls are identical currently. This patch prepares to deprecate
read_cpuid on machines without cp15.
Also move an unconditional usage of read_cpuid_cachetype to a more local
scope as read_cpuid_cachetype uses read_cpuid, too.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Message-Id: 1359646587-1788-1-git-send-email-u.kleine-koenig@pengutronix.de
---
arch/arm/kernel/setup.c | 2 +-
arch/arm/kernel/smp_scu.c | 2 +-
arch/arm/mach-omap2/id.c | 4 ++--
arch/arm/mach-omap2/omap-smp.c | 2 +-
4 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 3f6cbb2e3edae..1cc9e1796415c 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -291,10 +291,10 @@ static int cpu_has_aliasing_icache(unsigned int arch)
static void __init cacheid_init(void)
{
- unsigned int cachetype = read_cpuid_cachetype();
unsigned int arch = cpu_architecture();
if (arch >= CPU_ARCH_ARMv6) {
+ unsigned int cachetype = read_cpuid_cachetype();
if ((cachetype & (7 << 29)) == 4 << 29) {
/* ARMv7 register format */
arch = CPU_ARCH_ARMv7;
diff --git a/arch/arm/kernel/smp_scu.c b/arch/arm/kernel/smp_scu.c
index b9f015e843d8d..743a3bfe6a675 100644
--- a/arch/arm/kernel/smp_scu.c
+++ b/arch/arm/kernel/smp_scu.c
@@ -41,7 +41,7 @@ void scu_enable(void __iomem *scu_base)
#ifdef CONFIG_ARM_ERRATA_764369
/* Cortex-A9 only */
- if ((read_cpuid(CPUID_ID) & 0xff0ffff0) == 0x410fc090) {
+ if ((read_cpuid_id() & 0xff0ffff0) == 0x410fc090) {
scu_ctrl = __raw_readl(scu_base + 0x30);
if (!(scu_ctrl & 1))
__raw_writel(scu_ctrl | 0x1, scu_base + 0x30);
diff --git a/arch/arm/mach-omap2/id.c b/arch/arm/mach-omap2/id.c
index 45cc7ed4dd587..1377c363fdedd 100644
--- a/arch/arm/mach-omap2/id.c
+++ b/arch/arm/mach-omap2/id.c
@@ -300,7 +300,7 @@ void __init omap3xxx_check_revision(void)
* If the processor type is Cortex-A8 and the revision is 0x0
* it means its Cortex r0p0 which is 3430 ES1.0.
*/
- cpuid = read_cpuid(CPUID_ID);
+ cpuid = read_cpuid_id();
if ((((cpuid >> 4) & 0xfff) == 0xc08) && ((cpuid & 0xf) == 0x0)) {
omap_revision = OMAP3430_REV_ES1_0;
cpu_rev = "1.0";
@@ -450,7 +450,7 @@ void __init omap4xxx_check_revision(void)
* Use ARM register to detect the correct ES version
*/
if (!rev && (hawkeye != 0xb94e) && (hawkeye != 0xb975)) {
- idcode = read_cpuid(CPUID_ID);
+ idcode = read_cpuid_id();
rev = (idcode & 0xf) - 1;
}
diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c
index cd42d921940dc..707098ecf8d3b 100644
--- a/arch/arm/mach-omap2/omap-smp.c
+++ b/arch/arm/mach-omap2/omap-smp.c
@@ -209,7 +209,7 @@ static void __init omap4_smp_init_cpus(void)
unsigned int i = 0, ncores = 1, cpu_id;
/* Use ARM cpuid check here, as SoC detection will not work so early */
- cpu_id = read_cpuid(CPUID_ID) & CPU_MASK;
+ cpu_id = read_cpuid_id() & CPU_MASK;
if (cpu_id == CPU_CORTEX_A9) {
/*
* Currently we can't call ioremap here because
From 6ebd4d038dbb626a43d87db3007e71f92f49d7b3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>
Date: Thu, 31 Jan 2013 11:08:03 +0100
Subject: [PATCH 5/5] ARM: stub out read_cpuid and read_cpuid_ext for
CPU_CP15=n
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Traditionally for !CPU_CP15 read_cpuid and read_cpuid_ext returned the
processor id independent of the parameter passed in. This is wrong of
course but theoretically this doesn't harm because it's only called on
machines having a cp15.
Instead return 0 unconditionally which might make unused code paths be
better optimizable and so smaller and warn about unexpected usage.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Message-Id: 1359646587-1788-2-git-send-email-u.kleine-koenig@pengutronix.de
---
arch/arm/include/asm/cputype.h | 31 +++++++++++++++++++++++++++----
1 file changed, 27 insertions(+), 4 deletions(-)
diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h
index a59dcb5ab5fce..574269ed2232d 100644
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h
@@ -50,6 +50,7 @@ extern unsigned int processor_id;
: "cc"); \
__val; \
})
+
#define read_cpuid_ext(ext_reg) \
({ \
unsigned int __val; \
@@ -59,11 +60,24 @@ extern unsigned int processor_id;
: "cc"); \
__val; \
})
-#else
-#define read_cpuid(reg) (processor_id)
-#define read_cpuid_ext(reg) 0
-#endif
+
+#else /* ifdef CONFIG_CPU_CP15 */
+/*
+ * read_cpuid and read_cpuid_ext should only ever be called on machines that
+ * have cp15 so warn on other usages.
+ */
+#define read_cpuid(reg) \
+ ({ \
+ WARN_ON_ONCE(1); \
+ 0; \
+ })
+
+#define read_cpuid_ext(reg) read_cpuid(reg)
+
+#endif /* ifdef CONFIG_CPU_CP15 / else */
+
+#ifdef CONFIG_CPU_CP15
/*
* The CPU ID never changes at run time, so we might as well tell the
* compiler that it's constant. Use this function to read the CPU ID
@@ -74,6 +88,15 @@ static inline unsigned int __attribute_const__ read_cpuid_id(void)
return read_cpuid(CPUID_ID);
}
+#else /* ifdef CONFIG_CPU_CP15 */
+
+static inline unsigned int __attribute_const__ read_cpuid_id(void)
+{
+ return processor_id;
+}
+
+#endif /* ifdef CONFIG_CPU_CP15 / else */
+
static inline unsigned int __attribute_const__ read_cpuid_cachetype(void)
{
return read_cpuid(CPUID_CACHETYPE);