linux/arch/sparc/kernel/vmlinux.lds.S
Anthony Yznaga a7159a87a3 sparc64: speed up etrap/rtrap on NG2 and later processors
For many sun4v processor types, reading or writing a privileged register
has a latency of 40 to 70 cycles.  Use a combination of the low-latency
allclean, otherw, normalw, and nop instructions in etrap and rtrap to
replace 2 rdpr and 5 wrpr instructions and improve etrap/rtrap
performance.  allclean, otherw, and normalw are available on NG2 and
later processors.

The average ticks to execute the flush windows trap ("ta 0x3") with and
without this patch on select platforms:

 CPU            Not patched     Patched    % Latency Reduction

 NG2            1762            1558            -11.58
 NG4            3619            3204            -11.47
 M7             3015            2624            -12.97
 SPARC64-X      829             770              -7.12

Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-09 20:20:11 -07:00

186 lines
3.4 KiB
ArmAsm

/* ld script for sparc32/sparc64 kernel */
#include <asm-generic/vmlinux.lds.h>
#include <asm/page.h>
#include <asm/thread_info.h>
#ifdef CONFIG_SPARC32
#define INITIAL_ADDRESS 0x10000 + SIZEOF_HEADERS
#define TEXTSTART 0xf0004000
#define SMP_CACHE_BYTES_SHIFT 5
#else
#define SMP_CACHE_BYTES_SHIFT 6
#define INITIAL_ADDRESS 0x4000
#define TEXTSTART 0x0000000000404000
#endif
#define SMP_CACHE_BYTES (1 << SMP_CACHE_BYTES_SHIFT)
#ifdef CONFIG_SPARC32
OUTPUT_FORMAT("elf32-sparc", "elf32-sparc", "elf32-sparc")
OUTPUT_ARCH(sparc)
ENTRY(_start)
jiffies = jiffies_64 + 4;
#else
/* sparc64 */
OUTPUT_FORMAT("elf64-sparc", "elf64-sparc", "elf64-sparc")
OUTPUT_ARCH(sparc:v9a)
ENTRY(_start)
jiffies = jiffies_64;
#endif
#ifdef CONFIG_SPARC64
ASSERT((swapper_tsb == 0x0000000000408000), "Error: sparc64 early assembler too large")
#endif
SECTIONS
{
#ifdef CONFIG_SPARC64
swapper_pg_dir = 0x0000000000402000;
#endif
. = INITIAL_ADDRESS;
.text TEXTSTART :
{
_text = .;
HEAD_TEXT
TEXT_TEXT
SCHED_TEXT
CPUIDLE_TEXT
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
*(.gnu.warning)
} = 0
_etext = .;
RO_DATA(PAGE_SIZE)
/* Start of data section */
_sdata = .;
.data1 : {
*(.data1)
}
RW_DATA_SECTION(SMP_CACHE_BYTES, 0, THREAD_SIZE)
/* End of data section */
_edata = .;
.fixup : {
__start___fixup = .;
*(.fixup)
__stop___fixup = .;
}
EXCEPTION_TABLE(16)
NOTES
. = ALIGN(PAGE_SIZE);
__init_begin = ALIGN(PAGE_SIZE);
INIT_TEXT_SECTION(PAGE_SIZE)
__init_text_end = .;
INIT_DATA_SECTION(16)
. = ALIGN(4);
.tsb_ldquad_phys_patch : {
__tsb_ldquad_phys_patch = .;
*(.tsb_ldquad_phys_patch)
__tsb_ldquad_phys_patch_end = .;
}
.tsb_phys_patch : {
__tsb_phys_patch = .;
*(.tsb_phys_patch)
__tsb_phys_patch_end = .;
}
.cpuid_patch : {
__cpuid_patch = .;
*(.cpuid_patch)
__cpuid_patch_end = .;
}
.sun4v_1insn_patch : {
__sun4v_1insn_patch = .;
*(.sun4v_1insn_patch)
__sun4v_1insn_patch_end = .;
}
.sun4v_2insn_patch : {
__sun4v_2insn_patch = .;
*(.sun4v_2insn_patch)
__sun4v_2insn_patch_end = .;
}
.leon_1insn_patch : {
__leon_1insn_patch = .;
*(.leon_1insn_patch)
__leon_1insn_patch_end = .;
}
.swapper_tsb_phys_patch : {
__swapper_tsb_phys_patch = .;
*(.swapper_tsb_phys_patch)
__swapper_tsb_phys_patch_end = .;
}
.swapper_4m_tsb_phys_patch : {
__swapper_4m_tsb_phys_patch = .;
*(.swapper_4m_tsb_phys_patch)
__swapper_4m_tsb_phys_patch_end = .;
}
.popc_3insn_patch : {
__popc_3insn_patch = .;
*(.popc_3insn_patch)
__popc_3insn_patch_end = .;
}
.popc_6insn_patch : {
__popc_6insn_patch = .;
*(.popc_6insn_patch)
__popc_6insn_patch_end = .;
}
.pause_3insn_patch : {
__pause_3insn_patch = .;
*(.pause_3insn_patch)
__pause_3insn_patch_end = .;
}
.sun_m7_2insn_patch : {
__sun_m7_2insn_patch = .;
*(.sun_m7_2insn_patch)
__sun_m7_2insn_patch_end = .;
}
.get_tick_patch : {
__get_tick_patch = .;
*(.get_tick_patch)
__get_tick_patch_end = .;
}
.pud_huge_patch : {
__pud_huge_patch = .;
*(.pud_huge_patch)
__pud_huge_patch_end = .;
}
.fast_win_ctrl_1insn_patch : {
__fast_win_ctrl_1insn_patch = .;
*(.fast_win_ctrl_1insn_patch)
__fast_win_ctrl_1insn_patch_end = .;
}
PERCPU_SECTION(SMP_CACHE_BYTES)
#ifdef CONFIG_JUMP_LABEL
. = ALIGN(PAGE_SIZE);
.exit.text : {
EXIT_TEXT
}
#endif
. = ALIGN(PAGE_SIZE);
__init_end = .;
BSS_SECTION(0, 0, 0)
_end = . ;
STABS_DEBUG
DWARF_DEBUG
DISCARDS
}