[POWERPC] Consolidate feature fixup code

There are currently two versions of the functions for applying the
feature fixups, one for CPU features and one for firmware features. In
addition, they are both in assembly and with separate implementations
for 32 and 64 bits. identify_cpu() is also implemented in assembly and
separately for 32 and 64 bits.

This patch replaces them with a pair of C functions. The call sites are
slightly moved on ppc64 as well to be called from C instead of from
assembly, though it's a very small change, and thus shouldn't cause any
problem.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

6 files changed, 88 insertions, 220 deletions

diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
index f23aad66a79e..6fdfaa4a82b8 100644
--- a/arch/powerpc/kernel/cputable.c
+++ b/arch/powerpc/kernel/cputable.c
@@ -18,6 +18,7 @@
 
 #include <asm/oprofile_impl.h>
 #include <asm/cputable.h>
+#include <asm/prom.h>           /* for PTRRELOC on ARCH=ppc */
 
 struct cpu_spec* cur_cpu_spec = NULL;
 EXPORT_SYMBOL(cur_cpu_spec);
@@ -73,7 +74,7 @@ extern void __restore_cpu_ppc970(void);
 #define PPC_FEATURE_SPE_COMP    0
 #endif
 
-struct cpu_spec cpu_specs[] = {
+static struct cpu_spec cpu_specs[] = {
 #ifdef CONFIG_PPC64
         {       /* Power3 */
                 .pvr_mask               = 0xffff0000,
@@ -1167,3 +1168,72 @@ struct cpu_spec	cpu_specs[] = {
 #endif /* !CLASSIC_PPC */
 #endif /* CONFIG_PPC32 */
 };
+
+struct cpu_spec *identify_cpu(unsigned long offset)
+{
+        struct cpu_spec *s = cpu_specs;
+        struct cpu_spec **cur = &cur_cpu_spec;
+        unsigned int pvr = mfspr(SPRN_PVR);
+        int i;
+
+        s = PTRRELOC(s);
+        cur = PTRRELOC(cur);
+
+        if (*cur != NULL)
+                return PTRRELOC(*cur);
+
+        for (i = 0; i < ARRAY_SIZE(cpu_specs); i++,s++)
+                if ((pvr & s->pvr_mask) == s->pvr_value) {
+                        *cur = cpu_specs + i;
+#ifdef CONFIG_PPC64
+                        /* ppc64 expects identify_cpu to also call setup_cpu
+                         * for that processor. I will consolidate that at a
+                         * later time, for now, just use our friend #ifdef.
+                         * we also don't need to PTRRELOC the function pointer
+                         * on ppc64 as we are running at 0 in real mode.
+                         */
+                        if (s->cpu_setup) {
+                                s->cpu_setup(offset, s);
+                        }
+#endif /* CONFIG_PPC64 */
+                        return s;
+                }
+        BUG();
+        return NULL;
+}
+
+void do_feature_fixups(unsigned long offset, unsigned long value,
+                       void *fixup_start, void *fixup_end)
+{
+        struct fixup_entry {
+                unsigned long   mask;
+                unsigned long   value;
+                unsigned int    *start;
+                unsigned int    *end;
+        } *fcur, *fend;
+
+        fcur = fixup_start;
+        fend = fixup_end;
+
+        for (; fcur < fend; fcur++) {
+                unsigned int *pstart, *pend, *p;
+
+                if ((value & fcur->mask) == fcur->value)
+                        continue;
+
+                /* These PTRRELOCs will disappear once the new scheme for
+                 * modules and vdso is implemented
+                 */
+                pstart = PTRRELOC(fcur->start);
+                pend = PTRRELOC(fcur->end);
+
+                for (p = pstart; p < pend; p++) {
+                        *p = 0x60000000u;
+                        asm volatile ("dcbst 0, %0" : : "r" (p));
+                }
+                asm volatile ("sync" : : : "memory");
+                for (p = pstart; p < pend; p++)
+                        asm volatile ("icbi 0,%0" : : "r" (p));
+                asm volatile ("sync; isync" : : : "memory");
+        }
+}
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 645c7f10fb28..f12e3c55520d 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -1580,11 +1580,6 @@ _STATIC(__start_initialization_iSeries)
         li      r0,0
         stdu    r0,-STACK_FRAME_OVERHEAD(r1)
 
-        LOAD_REG_IMMEDIATE(r3,cpu_specs)
-        LOAD_REG_IMMEDIATE(r4,cur_cpu_spec)
-        li      r5,0
-        bl      .identify_cpu
-
         LOAD_REG_IMMEDIATE(r2,__toc_start)
         addi    r2,r2,0x4000
         addi    r2,r2,0x4000
@@ -1964,13 +1959,6 @@ _STATIC(start_here_multiplatform)
         addi    r2,r2,0x4000
         add     r2,r2,r26
 
-        LOAD_REG_IMMEDIATE(r3, cpu_specs)
-        add     r3,r3,r26
-        LOAD_REG_IMMEDIATE(r4,cur_cpu_spec)
-        add     r4,r4,r26
-        mr      r5,r26
-        bl      .identify_cpu
-
         /* Do very early kernel initializations, including initial hash table,
          * stab and slb setup before we turn on relocation.     */
 
@@ -2000,13 +1988,6 @@ _STATIC(start_here_common)
         li      r0,0
         stdu    r0,-STACK_FRAME_OVERHEAD(r1)
 
-        /* Apply the CPUs-specific fixups (nop out sections not relevant
-         * to this CPU
-         */
-        li      r3,0
-        bl      .do_cpu_ftr_fixups
-        bl      .do_fw_ftr_fixups
-
         /* ptr to current */
         LOAD_REG_IMMEDIATE(r4, init_task)
         std     r4,PACACURRENT(r13)
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 88fd73fdf048..412bea3cf813 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -102,80 +102,6 @@ _GLOBAL(reloc_got2)
         blr
 
 /*
- * identify_cpu,
- * called with r3 = data offset and r4 = CPU number
- * doesn't change r3
- */
-_GLOBAL(identify_cpu)
-        addis   r8,r3,cpu_specs@ha
-        addi    r8,r8,cpu_specs@l
-        mfpvr   r7
-1:
-        lwz     r5,CPU_SPEC_PVR_MASK(r8)
-        and     r5,r5,r7
-        lwz     r6,CPU_SPEC_PVR_VALUE(r8)
-        cmplw   0,r6,r5
-        beq     1f
-        addi    r8,r8,CPU_SPEC_ENTRY_SIZE
-        b       1b
-1:
-        addis   r6,r3,cur_cpu_spec@ha
-        addi    r6,r6,cur_cpu_spec@l
-        sub     r8,r8,r3
-        stw     r8,0(r6)
-        blr
-
-/*
- * do_cpu_ftr_fixups - goes through the list of CPU feature fixups
- * and writes nop's over sections of code that don't apply for this cpu.
- * r3 = data offset (not changed)
- */
-_GLOBAL(do_cpu_ftr_fixups)
-        /* Get CPU 0 features */
-        addis   r6,r3,cur_cpu_spec@ha
-        addi    r6,r6,cur_cpu_spec@l
-        lwz     r4,0(r6)
-        add     r4,r4,r3
-        lwz     r4,CPU_SPEC_FEATURES(r4)
-
-        /* Get the fixup table */
-        addis   r6,r3,__start___ftr_fixup@ha
-        addi    r6,r6,__start___ftr_fixup@l
-        addis   r7,r3,__stop___ftr_fixup@ha
-        addi    r7,r7,__stop___ftr_fixup@l
-
-        /* Do the fixup */
-1:      cmplw   0,r6,r7
-        bgelr
-        addi    r6,r6,16
-        lwz     r8,-16(r6)      /* mask */
-        and     r8,r8,r4
-        lwz     r9,-12(r6)      /* value */
-        cmplw   0,r8,r9
-        beq     1b
-        lwz     r8,-8(r6)       /* section begin */
-        lwz     r9,-4(r6)       /* section end */
-        subf.   r9,r8,r9
-        beq     1b
-        /* write nops over the section of code */
-        /* todo: if large section, add a branch at the start of it */
-        srwi    r9,r9,2
-        mtctr   r9
-        add     r8,r8,r3
-        lis     r0,0x60000000@h /* nop */
-3:      stw     r0,0(r8)
-        andi.   r10,r4,CPU_FTR_SPLIT_ID_CACHE@l
-        beq     2f
-        dcbst   0,r8            /* suboptimal, but simpler */
-        sync
-        icbi    0,r8
-2:      addi    r8,r8,4
-        bdnz    3b
-        sync                    /* additional sync needed on g4 */
-        isync
-        b       1b
-
-/*
  * call_setup_cpu - call the setup_cpu function for this cpu
  * r3 = data offset, r24 = cpu number
  *
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index c70e20708a1f..21fd2c662a99 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -246,130 +246,6 @@ _GLOBAL(__flush_dcache_icache)
         isync
         blr
 
-/*
- * identify_cpu and calls setup_cpu
- * In:  r3 = base of the cpu_specs array
- *      r4 = address of cur_cpu_spec
- *      r5 = relocation offset
- */
-_GLOBAL(identify_cpu)
-        mfpvr   r7
-1:
-        lwz     r8,CPU_SPEC_PVR_MASK(r3)
-        and     r8,r8,r7
-        lwz     r9,CPU_SPEC_PVR_VALUE(r3)
-        cmplw   0,r9,r8
-        beq     1f
-        addi    r3,r3,CPU_SPEC_ENTRY_SIZE
-        b       1b
-1:
-        sub     r0,r3,r5
-        std     r0,0(r4)
-        ld      r4,CPU_SPEC_SETUP(r3)
-        cmpdi   0,r4,0
-        add     r4,r4,r5
-        beqlr
-        ld      r4,0(r4)
-        add     r4,r4,r5
-        mtctr   r4
-        /* Calling convention for cpu setup is r3=offset, r4=cur_cpu_spec */
-        mr      r4,r3
-        mr      r3,r5
-        bctr
-
-/*
- * do_cpu_ftr_fixups - goes through the list of CPU feature fixups
- * and writes nop's over sections of code that don't apply for this cpu.
- * r3 = data offset (not changed)
- */
-_GLOBAL(do_cpu_ftr_fixups)
-        /* Get CPU 0 features */
-        LOAD_REG_IMMEDIATE(r6,cur_cpu_spec)
-        sub     r6,r6,r3
-        ld      r4,0(r6)
-        sub     r4,r4,r3
-        ld      r4,CPU_SPEC_FEATURES(r4)
-        /* Get the fixup table */
-        LOAD_REG_IMMEDIATE(r6,__start___ftr_fixup)
-        sub     r6,r6,r3
-        LOAD_REG_IMMEDIATE(r7,__stop___ftr_fixup)
-        sub     r7,r7,r3
-        /* Do the fixup */
-1:      cmpld   r6,r7
-        bgelr
-        addi    r6,r6,32
-        ld      r8,-32(r6)      /* mask */
-        and     r8,r8,r4
-        ld      r9,-24(r6)      /* value */
-        cmpld   r8,r9
-        beq     1b
-        ld      r8,-16(r6)      /* section begin */
-        ld      r9,-8(r6)       /* section end */
-        subf.   r9,r8,r9
-        beq     1b
-        /* write nops over the section of code */
-        /* todo: if large section, add a branch at the start of it */
-        srwi    r9,r9,2
-        mtctr   r9
-        sub     r8,r8,r3
-        lis     r0,0x60000000@h /* nop */
-3:      stw     r0,0(r8)
-        andi.   r10,r4,CPU_FTR_SPLIT_ID_CACHE@l
-        beq     2f
-        dcbst   0,r8            /* suboptimal, but simpler */
-        sync
-        icbi    0,r8
-2:      addi    r8,r8,4
-        bdnz    3b
-        sync                    /* additional sync needed on g4 */
-        isync
-        b       1b
-
-/*
- * do_fw_ftr_fixups - goes through the list of firmware feature fixups
- * and writes nop's over sections of code that don't apply for this firmware.
- * r3 = data offset (not changed)
- */
-_GLOBAL(do_fw_ftr_fixups)
-        /* Get firmware features */
-        LOAD_REG_IMMEDIATE(r6,powerpc_firmware_features)
-        sub     r6,r6,r3
-        ld      r4,0(r6)
-        /* Get the fixup table */
-        LOAD_REG_IMMEDIATE(r6,__start___fw_ftr_fixup)
-        sub     r6,r6,r3
-        LOAD_REG_IMMEDIATE(r7,__stop___fw_ftr_fixup)
-        sub     r7,r7,r3
-        /* Do the fixup */
-1:      cmpld   r6,r7
-        bgelr
-        addi    r6,r6,32
-        ld      r8,-32(r6)      /* mask */
-        and     r8,r8,r4
-        ld      r9,-24(r6)      /* value */
-        cmpld   r8,r9
-        beq     1b
-        ld      r8,-16(r6)      /* section begin */
-        ld      r9,-8(r6)       /* section end */
-        subf.   r9,r8,r9
-        beq     1b
-        /* write nops over the section of code */
-        /* todo: if large section, add a branch at the start of it */
-        srwi    r9,r9,2
-        mtctr   r9
-        sub     r8,r8,r3
-        lis     r0,0x60000000@h /* nop */
-3:      stw     r0,0(r8)
-BEGIN_FTR_SECTION
-        dcbst   0,r8            /* suboptimal, but simpler */
-        sync
-        icbi    0,r8
-END_FTR_SECTION_IFSET(CPU_FTR_SPLIT_ID_CACHE)
-        addi    r8,r8,4
-        bdnz    3b
-        sync                    /* additional sync needed on g4 */
-        isync
-        b       1b
 
 #if defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE)
 /*
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 191d0ab09222..769e511783b0 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -91,6 +91,7 @@ int ucache_bsize;
 unsigned long __init early_init(unsigned long dt_ptr)
 {
         unsigned long offset = reloc_offset();
+        struct cpu_spec *spec;
 
         /* First zero the BSS -- use memset_io, some platforms don't have
          * caches on yet */
@@ -100,8 +101,11 @@ unsigned long __init early_init(unsigned long dt_ptr)
          * Identify the CPU type and fix up code sections
          * that depend on which cpu we have.
          */
-        identify_cpu(offset, 0);
-        do_cpu_ftr_fixups(offset);
+        spec = identify_cpu(offset);
+
+        do_feature_fixups(offset, spec->cpu_features,
+                          PTRRELOC(&__start___ftr_fixup),
+                          PTRRELOC(&__stop___ftr_fixup));
 
         return KERNELBASE + offset;
 }
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 4b2e32eab9dc..1969b5686eee 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -170,6 +170,9 @@ void __init setup_paca(int cpu)
 
 void __init early_setup(unsigned long dt_ptr)
 {
+        /* Identify CPU type */
+        identify_cpu(0);
+
         /* Assume we're on cpu 0 for now. Don't write to the paca yet! */
         setup_paca(0);
 
@@ -348,6 +351,14 @@ void __init setup_system(void)
 {
         DBG(" -> setup_system()\n");
 
+        /* Apply the CPUs-specific and firmware specific fixups to kernel
+         * text (nop out sections not relevant to this CPU or this firmware)
+         */
+        do_feature_fixups(0, cur_cpu_spec->cpu_features,
+                          &__start___ftr_fixup, &__stop___ftr_fixup);
+        do_feature_fixups(0, powerpc_firmware_features,
+                          &__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
+
         /*
          * Unflatten the device-tree passed by prom_init or kexec
          */