[PATCH 1/10] powerpc/4xx: Extended DCR support v2
Benjamin Herrenschmidt
benh at kernel.crashing.org
Fri Dec 19 16:13:22 EST 2008
This adds supports to the "extended" DCR addressing via
the indirect mfdcrx/mtdcrx instructions supported by some
4xx cores (440H6 and later)
I enabled the feature for now only on AMCC 460 chips
Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---
This variant uses "440x6" instead of "440H6". I made no other
changes to the code as I think the codegen is the less bad I've
had so far and I rely on Josh further work on cleaning up the
type of 440core selection at Kconfig time so the feature are
properly reflected in the POSSIBLE and ALWAYS masks based on
the core selection. That way, if only one core type is selected
the feature test should resolve at compile time.
arch/powerpc/include/asm/cputable.h | 7 ++-
arch/powerpc/include/asm/dcr-native.h | 63 +++++++++++++++++++++++++++-------
arch/powerpc/kernel/cputable.c | 4 +-
arch/powerpc/sysdev/dcr-low.S | 8 +++-
4 files changed, 65 insertions(+), 17 deletions(-)
--- linux-work.orig/arch/powerpc/include/asm/cputable.h 2008-12-17 12:28:23.000000000 +1100
+++ linux-work/arch/powerpc/include/asm/cputable.h 2008-12-17 12:30:52.000000000 +1100
@@ -164,6 +164,7 @@ extern const char *powerpc_base_platform
#define CPU_FTR_NEED_PAIRED_STWCX ASM_CONST(0x0000000004000000)
#define CPU_FTR_LWSYNC ASM_CONST(0x0000000008000000)
#define CPU_FTR_NOEXECUTE ASM_CONST(0x0000000010000000)
+#define CPU_FTR_INDEXED_DCR ASM_CONST(0x0000000020000000)
/*
* Add the 64-bit processor unique features in the top half of the word;
@@ -369,6 +370,8 @@ extern const char *powerpc_base_platform
#define CPU_FTRS_8XX (CPU_FTR_USE_TB)
#define CPU_FTRS_40X (CPU_FTR_USE_TB | CPU_FTR_NODSISRALIGN | CPU_FTR_NOEXECUTE)
#define CPU_FTRS_44X (CPU_FTR_USE_TB | CPU_FTR_NODSISRALIGN | CPU_FTR_NOEXECUTE)
+#define CPU_FTRS_440x6 (CPU_FTR_USE_TB | CPU_FTR_NODSISRALIGN | CPU_FTR_NOEXECUTE | \
+ CPU_FTR_INDEXED_DCR)
#define CPU_FTRS_E200 (CPU_FTR_USE_TB | CPU_FTR_SPE_COMP | \
CPU_FTR_NODSISRALIGN | CPU_FTR_COHERENT_ICACHE | \
CPU_FTR_UNIFIED_ID_CACHE | CPU_FTR_NOEXECUTE)
@@ -455,7 +458,7 @@ enum {
CPU_FTRS_40X |
#endif
#ifdef CONFIG_44x
- CPU_FTRS_44X |
+ CPU_FTRS_44X | CPU_FTRS_440x6 |
#endif
#ifdef CONFIG_E200
CPU_FTRS_E200 |
@@ -495,7 +498,7 @@ enum {
CPU_FTRS_40X &
#endif
#ifdef CONFIG_44x
- CPU_FTRS_44X &
+ CPU_FTRS_44X & CPU_FTRS_440x6 &
#endif
#ifdef CONFIG_E200
CPU_FTRS_E200 &
Index: linux-work/arch/powerpc/include/asm/dcr-native.h
===================================================================
--- linux-work.orig/arch/powerpc/include/asm/dcr-native.h 2008-09-29 14:21:37.000000000 +1000
+++ linux-work/arch/powerpc/include/asm/dcr-native.h 2008-12-17 12:30:52.000000000 +1100
@@ -23,6 +23,7 @@
#ifndef __ASSEMBLY__
#include <linux/spinlock.h>
+#include <asm/cputable.h>
typedef struct {
unsigned int base;
@@ -39,23 +40,45 @@ static inline bool dcr_map_ok_native(dcr
#define dcr_read_native(host, dcr_n) mfdcr(dcr_n + host.base)
#define dcr_write_native(host, dcr_n, value) mtdcr(dcr_n + host.base, value)
-/* Device Control Registers */
-void __mtdcr(int reg, unsigned int val);
-unsigned int __mfdcr(int reg);
+/* Table based DCR accessors */
+extern void __mtdcr(unsigned int reg, unsigned int val);
+extern unsigned int __mfdcr(unsigned int reg);
+
+/* mfdcrx/mtdcrx instruction based accessors. We hand code
+ * the opcodes in order not to depend on newer binutils
+ */
+static inline unsigned int mfdcrx(unsigned int reg)
+{
+ unsigned int ret;
+ asm volatile(".long 0x7c000206 | (%0 << 21) | (%1 << 16)"
+ : "=r" (ret) : "r" (reg));
+ return ret;
+}
+
+static inline void mtdcrx(unsigned int reg, unsigned int val)
+{
+ asm volatile(".long 0x7c000306 | (%0 << 21) | (%1 << 16)"
+ : : "r" (val), "r" (reg));
+}
+
#define mfdcr(rn) \
({unsigned int rval; \
- if (__builtin_constant_p(rn)) \
+ if (__builtin_constant_p(rn) && rn < 1024) \
asm volatile("mfdcr %0," __stringify(rn) \
: "=r" (rval)); \
+ else if (likely(cpu_has_feature(CPU_FTR_INDEXED_DCR))) \
+ rval = mfdcrx(rn); \
else \
rval = __mfdcr(rn); \
rval;})
#define mtdcr(rn, v) \
do { \
- if (__builtin_constant_p(rn)) \
+ if (__builtin_constant_p(rn) && rn < 1024) \
asm volatile("mtdcr " __stringify(rn) ",%0" \
: : "r" (v)); \
+ else if (likely(cpu_has_feature(CPU_FTR_INDEXED_DCR))) \
+ mtdcrx(rn, v); \
else \
__mtdcr(rn, v); \
} while (0)
@@ -69,8 +92,13 @@ static inline unsigned __mfdcri(int base
unsigned int val;
spin_lock_irqsave(&dcr_ind_lock, flags);
- __mtdcr(base_addr, reg);
- val = __mfdcr(base_data);
+ if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
+ mtdcrx(base_addr, reg);
+ val = mfdcrx(base_data);
+ } else {
+ __mtdcr(base_addr, reg);
+ val = __mfdcr(base_data);
+ }
spin_unlock_irqrestore(&dcr_ind_lock, flags);
return val;
}
@@ -81,8 +109,13 @@ static inline void __mtdcri(int base_add
unsigned long flags;
spin_lock_irqsave(&dcr_ind_lock, flags);
- __mtdcr(base_addr, reg);
- __mtdcr(base_data, val);
+ if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
+ mtdcrx(base_addr, reg);
+ mtdcrx(base_data, val);
+ } else {
+ __mtdcr(base_addr, reg);
+ __mtdcr(base_data, val);
+ }
spin_unlock_irqrestore(&dcr_ind_lock, flags);
}
@@ -93,9 +126,15 @@ static inline void __dcri_clrset(int bas
unsigned int val;
spin_lock_irqsave(&dcr_ind_lock, flags);
- __mtdcr(base_addr, reg);
- val = (__mfdcr(base_data) & ~clr) | set;
- __mtdcr(base_data, val);
+ if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
+ mtdcrx(base_addr, reg);
+ val = (mfdcrx(base_data) & ~clr) | set;
+ mtdcrx(base_data, val);
+ } else {
+ __mtdcr(base_addr, reg);
+ val = (__mfdcr(base_data) & ~clr) | set;
+ __mtdcr(base_data, val);
+ }
spin_unlock_irqrestore(&dcr_ind_lock, flags);
}
Index: linux-work/arch/powerpc/sysdev/dcr-low.S
===================================================================
--- linux-work.orig/arch/powerpc/sysdev/dcr-low.S 2008-07-07 13:45:04.000000000 +1000
+++ linux-work/arch/powerpc/sysdev/dcr-low.S 2008-12-17 12:30:52.000000000 +1100
@@ -11,14 +11,20 @@
#include <asm/ppc_asm.h>
#include <asm/processor.h>
+#include <asm/bug.h>
#define DCR_ACCESS_PROLOG(table) \
+ cmpli cr0,r3,1024; \
rlwinm r3,r3,4,18,27; \
lis r5,table at h; \
ori r5,r5,table at l; \
add r3,r3,r5; \
+ bge- 1f; \
mtctr r3; \
- bctr
+ bctr; \
+1: trap; \
+ EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0; \
+ blr
_GLOBAL(__mfdcr)
DCR_ACCESS_PROLOG(__mfdcr_table)
Index: linux-work/arch/powerpc/kernel/cputable.c
===================================================================
--- linux-work.orig/arch/powerpc/kernel/cputable.c 2008-12-17 12:28:23.000000000 +1100
+++ linux-work/arch/powerpc/kernel/cputable.c 2008-12-17 12:30:52.000000000 +1100
@@ -1509,7 +1509,7 @@ static struct cpu_spec __initdata cpu_sp
.pvr_mask = 0xffff0002,
.pvr_value = 0x13020002,
.cpu_name = "460EX",
- .cpu_features = CPU_FTRS_44X,
+ .cpu_features = CPU_FTRS_440x6,
.cpu_user_features = COMMON_USER_BOOKE | PPC_FEATURE_HAS_FPU,
.icache_bsize = 32,
.dcache_bsize = 32,
@@ -1521,7 +1521,7 @@ static struct cpu_spec __initdata cpu_sp
.pvr_mask = 0xffff0002,
.pvr_value = 0x13020000,
.cpu_name = "460GT",
- .cpu_features = CPU_FTRS_44X,
+ .cpu_features = CPU_FTRS_440x6,
.cpu_user_features = COMMON_USER_BOOKE | PPC_FEATURE_HAS_FPU,
.icache_bsize = 32,
.dcache_bsize = 32,
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