From e31aa453bbc4886a7bd33e5c2afa526d6f55bd7a Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Sat, 30 Aug 2008 11:41:12 +1000 Subject: powerpc: Use LOAD_REG_IMMEDIATE only for constants on 64-bit Using LOAD_REG_IMMEDIATE to get the address of kernel symbols generates 5 instructions where LOAD_REG_ADDR can do it in one, and will generate R_PPC64_ADDR16_* relocations in the output when we get to making the kernel as a position-independent executable, which we'd rather not have to handle. This changes various bits of assembly code to use LOAD_REG_ADDR when we need to get the address of a symbol, or to use suitable position-independent code for cases where we can't access the TOC for various reasons, or if we're not running at the address we were linked at. It also cleans up a few minor things; there's no reason to save and restore SRR0/1 around RTAS calls, __mmu_off can get the return address from LR more conveniently than the caller can supply it in R4 (and we already assume elsewhere that EA == RA if the MMU is on in early boot), and enable_64b_mode was using 5 instructions where 2 would do. Signed-off-by: Paul Mackerras --- arch/powerpc/platforms/iseries/exception.S | 23 ++++++++++------------- 1 file changed, 10 insertions(+), 13 deletions(-) (limited to 'arch/powerpc/platforms/iseries') diff --git a/arch/powerpc/platforms/iseries/exception.S b/arch/powerpc/platforms/iseries/exception.S index 8ff330d026c..2f581521eb9 100644 --- a/arch/powerpc/platforms/iseries/exception.S +++ b/arch/powerpc/platforms/iseries/exception.S @@ -38,12 +38,13 @@ .globl system_reset_iSeries system_reset_iSeries: + bl .relative_toc mfspr r13,SPRN_SPRG3 /* Get alpaca address */ - LOAD_REG_IMMEDIATE(r23, alpaca) + LOAD_REG_ADDR(r23, alpaca) li r0,ALPACA_SIZE sub r23,r13,r23 divdu r23,r23,r0 /* r23 has cpu number */ - LOAD_REG_IMMEDIATE(r13, paca) + LOAD_REG_ADDR(r13, paca) mulli r0,r23,PACA_SIZE add r13,r13,r0 mtspr SPRN_SPRG3,r13 /* Save it away for the future */ @@ -60,14 +61,14 @@ system_reset_iSeries: mtspr SPRN_CTRLT,r4 /* Spin on __secondary_hold_spinloop until it is updated by the boot cpu. */ -/* In the UP case we'll yeild() later, and we will not access the paca anyway */ +/* In the UP case we'll yield() later, and we will not access the paca anyway */ #ifdef CONFIG_SMP 1: HMT_LOW - LOAD_REG_IMMEDIATE(r23, __secondary_hold_spinloop) + LOAD_REG_ADDR(r23, __secondary_hold_spinloop) ld r23,0(r23) sync - LOAD_REG_IMMEDIATE(r3,current_set) + LOAD_REG_ADDR(r3,current_set) sldi r28,r24,3 /* get current_set[cpu#] */ ldx r3,r3,r28 addi r1,r3,THREAD_SIZE @@ -90,7 +91,7 @@ system_reset_iSeries: lbz r23,PACAPROCSTART(r13) /* Test if this processor * should start */ sync - LOAD_REG_IMMEDIATE(r3,current_set) + LOAD_REG_ADDR(r3,current_set) sldi r28,r24,3 /* get current_set[cpu#] */ ldx r3,r3,r28 addi r1,r3,THREAD_SIZE @@ -255,8 +256,8 @@ hardware_interrupt_iSeries_masked: _INIT_STATIC(__start_initialization_iSeries) /* Clear out the BSS */ - LOAD_REG_IMMEDIATE(r11,__bss_stop) - LOAD_REG_IMMEDIATE(r8,__bss_start) + LOAD_REG_ADDR(r11,__bss_stop) + LOAD_REG_ADDR(r8,__bss_start) sub r11,r11,r8 /* bss size */ addi r11,r11,7 /* round up to an even double word */ rldicl. r11,r11,61,3 /* shift right by 3 */ @@ -267,15 +268,11 @@ _INIT_STATIC(__start_initialization_iSeries) 3: stdu r0,8(r8) bdnz 3b 4: - LOAD_REG_IMMEDIATE(r1,init_thread_union) + LOAD_REG_ADDR(r1,init_thread_union) addi r1,r1,THREAD_SIZE li r0,0 stdu r0,-STACK_FRAME_OVERHEAD(r1) - LOAD_REG_IMMEDIATE(r2,__toc_start) - addi r2,r2,0x4000 - addi r2,r2,0x4000 - bl .iSeries_early_setup bl .early_setup -- cgit v1.2.3