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authorLinus Torvalds <torvalds@linux-foundation.org>2014-04-27 12:55:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-27 12:55:04 -0700
commit2b9d1c050d291693f257c98605028325f8146c84 (patch)
tree756d061271ae942141aaecd8656b035f562f4906
parentafa3cad746cc0fb547f1ab8d881db445e237840f (diff)
parentd93003e8e4e1fbbc8a06ec561a63f5aa105a4c45 (diff)
downloadlinux-2b9d1c050d291693f257c98605028325f8146c84.tar.gz
Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
Pull arm fixes from Russell King: "A number of fixes for the PJ4/iwmmxt changes which arm-soc forced me to take during the merge window. This stuff should have been better tested and sorted out *before* the merge window" * 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: ARM: 8042/1: iwmmxt: allow to build iWMMXt on Marvell PJ4B ARM: 8041/1: pj4: fix cpu_is_pj4 check ARM: 8040/1: pj4: properly detect existence of iWMMXt coprocessor ARM: 8039/1: pj4: enable iWMMXt only if CONFIG_IWMMXT is set ARM: 8038/1: iwmmxt: explicitly check for supported architectures
-rw-r--r--arch/arm/Kconfig6
-rw-r--r--arch/arm/include/asm/cputype.h14
-rw-r--r--arch/arm/kernel/Makefile1
-rw-r--r--arch/arm/kernel/iwmmxt.S8
-rw-r--r--arch/arm/kernel/pj4-cp0.c42
5 files changed, 56 insertions, 15 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 9916e4d206a3..db3c5414223e 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1111,9 +1111,9 @@ config ARM_NR_BANKS
default 8
config IWMMXT
- bool "Enable iWMMXt support" if !CPU_PJ4
- depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4
- default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4
+ bool "Enable iWMMXt support"
+ depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
+ default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
help
Enable support for iWMMXt context switching at run time if
running on a CPU that supports it.
diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h
index c651e3b26ec7..4764344367d4 100644
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h
@@ -222,22 +222,22 @@ static inline int cpu_is_xsc3(void)
#endif
/*
- * Marvell's PJ4 core is based on V7 version. It has some modification
- * for coprocessor setting. For this reason, we need a way to distinguish
- * it.
+ * Marvell's PJ4 and PJ4B cores are based on V7 version,
+ * but require a specical sequence for enabling coprocessors.
+ * For this reason, we need a way to distinguish them.
*/
-#ifndef CONFIG_CPU_PJ4
-#define cpu_is_pj4() 0
-#else
+#if defined(CONFIG_CPU_PJ4) || defined(CONFIG_CPU_PJ4B)
static inline int cpu_is_pj4(void)
{
unsigned int id;
id = read_cpuid_id();
- if ((id & 0xfffffff0) == 0x562f5840)
+ if ((id & 0xff0fff00) == 0x560f5800)
return 1;
return 0;
}
+#else
+#define cpu_is_pj4() 0
#endif
#endif
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index a766bcbaf8ad..040619c32d68 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -79,6 +79,7 @@ obj-$(CONFIG_CPU_XSCALE) += xscale-cp0.o
obj-$(CONFIG_CPU_XSC3) += xscale-cp0.o
obj-$(CONFIG_CPU_MOHAWK) += xscale-cp0.o
obj-$(CONFIG_CPU_PJ4) += pj4-cp0.o
+obj-$(CONFIG_CPU_PJ4B) += pj4-cp0.o
obj-$(CONFIG_IWMMXT) += iwmmxt.o
obj-$(CONFIG_PERF_EVENTS) += perf_regs.o
obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o perf_event_cpu.o
diff --git a/arch/arm/kernel/iwmmxt.S b/arch/arm/kernel/iwmmxt.S
index a08783823b32..2452dd1bef53 100644
--- a/arch/arm/kernel/iwmmxt.S
+++ b/arch/arm/kernel/iwmmxt.S
@@ -19,12 +19,16 @@
#include <asm/thread_info.h>
#include <asm/asm-offsets.h>
-#if defined(CONFIG_CPU_PJ4)
+#if defined(CONFIG_CPU_PJ4) || defined(CONFIG_CPU_PJ4B)
#define PJ4(code...) code
#define XSC(code...)
-#else
+#elif defined(CONFIG_CPU_MOHAWK) || \
+ defined(CONFIG_CPU_XSC3) || \
+ defined(CONFIG_CPU_XSCALE)
#define PJ4(code...)
#define XSC(code...) code
+#else
+#error "Unsupported iWMMXt architecture"
#endif
#define MMX_WR0 (0x00)
diff --git a/arch/arm/kernel/pj4-cp0.c b/arch/arm/kernel/pj4-cp0.c
index fc7208636284..8153e36b2491 100644
--- a/arch/arm/kernel/pj4-cp0.c
+++ b/arch/arm/kernel/pj4-cp0.c
@@ -45,7 +45,7 @@ static int iwmmxt_do(struct notifier_block *self, unsigned long cmd, void *t)
return NOTIFY_DONE;
}
-static struct notifier_block iwmmxt_notifier_block = {
+static struct notifier_block __maybe_unused iwmmxt_notifier_block = {
.notifier_call = iwmmxt_do,
};
@@ -72,6 +72,33 @@ static void __init pj4_cp_access_write(u32 value)
: "=r" (temp) : "r" (value));
}
+static int __init pj4_get_iwmmxt_version(void)
+{
+ u32 cp_access, wcid;
+
+ cp_access = pj4_cp_access_read();
+ pj4_cp_access_write(cp_access | 0xf);
+
+ /* check if coprocessor 0 and 1 are available */
+ if ((pj4_cp_access_read() & 0xf) != 0xf) {
+ pj4_cp_access_write(cp_access);
+ return -ENODEV;
+ }
+
+ /* read iWMMXt coprocessor id register p1, c0 */
+ __asm__ __volatile__ ("mrc p1, 0, %0, c0, c0, 0\n" : "=r" (wcid));
+
+ pj4_cp_access_write(cp_access);
+
+ /* iWMMXt v1 */
+ if ((wcid & 0xffffff00) == 0x56051000)
+ return 1;
+ /* iWMMXt v2 */
+ if ((wcid & 0xffffff00) == 0x56052000)
+ return 2;
+
+ return -EINVAL;
+}
/*
* Disable CP0/CP1 on boot, and let call_fpe() and the iWMMXt lazy
@@ -79,17 +106,26 @@ static void __init pj4_cp_access_write(u32 value)
*/
static int __init pj4_cp0_init(void)
{
- u32 cp_access;
+ u32 __maybe_unused cp_access;
+ int vers;
if (!cpu_is_pj4())
return 0;
+ vers = pj4_get_iwmmxt_version();
+ if (vers < 0)
+ return 0;
+
+#ifndef CONFIG_IWMMXT
+ pr_info("PJ4 iWMMXt coprocessor detected, but kernel support is missing.\n");
+#else
cp_access = pj4_cp_access_read() & ~0xf;
pj4_cp_access_write(cp_access);
- printk(KERN_INFO "PJ4 iWMMXt coprocessor enabled.\n");
+ pr_info("PJ4 iWMMXt v%d coprocessor enabled.\n", vers);
elf_hwcap |= HWCAP_IWMMXT;
thread_register_notifier(&iwmmxt_notifier_block);
+#endif
return 0;
}