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-rw-r--r--arch/openrisc/kernel/head.S419
1 files changed, 127 insertions, 292 deletions
diff --git a/arch/openrisc/kernel/head.S b/arch/openrisc/kernel/head.S
index b0dc974f9a74..bd760066f1cd 100644
--- a/arch/openrisc/kernel/head.S
+++ b/arch/openrisc/kernel/head.S
@@ -16,25 +16,25 @@
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/serial_reg.h>
+#include <linux/pgtable.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/mmu.h>
-#include <asm/pgtable.h>
#include <asm/thread_info.h>
#include <asm/cache.h>
#include <asm/spr_defs.h>
#include <asm/asm-offsets.h>
#include <linux/of_fdt.h>
-#define tophys(rd,rs) \
- l.movhi rd,hi(-KERNELBASE) ;\
+#define tophys(rd,rs) \
+ l.movhi rd,hi(-KERNELBASE) ;\
l.add rd,rd,rs
-#define CLEAR_GPR(gpr) \
+#define CLEAR_GPR(gpr) \
l.movhi gpr,0x0
-#define LOAD_SYMBOL_2_GPR(gpr,symbol) \
- l.movhi gpr,hi(symbol) ;\
+#define LOAD_SYMBOL_2_GPR(gpr,symbol) \
+ l.movhi gpr,hi(symbol) ;\
l.ori gpr,gpr,lo(symbol)
@@ -297,19 +297,23 @@
/* temporary store r3, r9 into r1, r10 */ ;\
l.addi r1,r3,0x0 ;\
l.addi r10,r9,0x0 ;\
- /* the string referenced by r3 must be low enough */ ;\
+ LOAD_SYMBOL_2_GPR(r9,_string_unhandled_exception) ;\
+ tophys (r3,r9) ;\
l.jal _emergency_print ;\
- l.ori r3,r0,lo(_string_unhandled_exception) ;\
+ l.nop ;\
l.mfspr r3,r0,SPR_NPC ;\
l.jal _emergency_print_nr ;\
- l.andi r3,r3,0x1f00 ;\
- /* the string referenced by r3 must be low enough */ ;\
+ l.andi r3,r3,0x1f00 ;\
+ LOAD_SYMBOL_2_GPR(r9,_string_epc_prefix) ;\
+ tophys (r3,r9) ;\
l.jal _emergency_print ;\
- l.ori r3,r0,lo(_string_epc_prefix) ;\
+ l.nop ;\
l.jal _emergency_print_nr ;\
- l.mfspr r3,r0,SPR_EPCR_BASE ;\
+ l.mfspr r3,r0,SPR_EPCR_BASE ;\
+ LOAD_SYMBOL_2_GPR(r9,_string_nl) ;\
+ tophys (r3,r9) ;\
l.jal _emergency_print ;\
- l.ori r3,r0,lo(_string_nl) ;\
+ l.nop ;\
/* end of printing */ ;\
l.addi r3,r1,0x0 ;\
l.addi r9,r10,0x0 ;\
@@ -322,21 +326,21 @@
l.addi r1,r1,-(INT_FRAME_SIZE) ;\
/* r1 is KSP, r30 is __pa(KSP) */ ;\
tophys (r30,r1) ;\
- l.sw PT_GPR12(r30),r12 ;\
+ l.sw PT_GPR12(r30),r12 ;\
l.mfspr r12,r0,SPR_EPCR_BASE ;\
l.sw PT_PC(r30),r12 ;\
l.mfspr r12,r0,SPR_ESR_BASE ;\
l.sw PT_SR(r30),r12 ;\
/* save r31 */ ;\
EXCEPTION_T_LOAD_GPR30(r12) ;\
- l.sw PT_GPR30(r30),r12 ;\
+ l.sw PT_GPR30(r30),r12 ;\
/* save r10 as was prior to exception */ ;\
EXCEPTION_T_LOAD_GPR10(r12) ;\
- l.sw PT_GPR10(r30),r12 ;\
- /* save PT_SP as was prior to exception */ ;\
+ l.sw PT_GPR10(r30),r12 ;\
+ /* save PT_SP as was prior to exception */ ;\
EXCEPTION_T_LOAD_SP(r12) ;\
l.sw PT_SP(r30),r12 ;\
- l.sw PT_GPR13(r30),r13 ;\
+ l.sw PT_GPR13(r30),r13 ;\
/* --> */ ;\
/* save exception r4, set r4 = EA */ ;\
l.sw PT_GPR4(r30),r4 ;\
@@ -353,6 +357,8 @@
/* =====================================================[ exceptions] === */
+ __HEAD
+
/* ---[ 0x100: RESET exception ]----------------------------------------- */
.org 0x100
/* Jump to .init code at _start which lives in the .head section
@@ -390,7 +396,7 @@ _dispatch_do_ipage_fault:
.org 0x500
EXCEPTION_HANDLE(_timer_handler)
-/* ---[ 0x600: Alignment exception ]-------------------------------------- */
+/* ---[ 0x600: Alignment exception ]------------------------------------- */
.org 0x600
EXCEPTION_HANDLE(_alignment_handler)
@@ -420,9 +426,9 @@ _dispatch_do_ipage_fault:
.org 0xc00
EXCEPTION_HANDLE(_sys_call_handler)
-/* ---[ 0xd00: Trap exception ]------------------------------------------ */
+/* ---[ 0xd00: Floating point exception ]-------------------------------- */
.org 0xd00
- UNHANDLED_EXCEPTION(_vector_0xd00)
+ EXCEPTION_HANDLE(_fpe_trap_handler)
/* ---[ 0xe00: Trap exception ]------------------------------------------ */
.org 0xe00
@@ -502,10 +508,10 @@ _dispatch_do_ipage_fault:
/* .text*/
-/* This early stuff belongs in HEAD, but some of the functions below definitely
+/* This early stuff belongs in the .init.text section, but some of the functions below definitely
* don't... */
- __HEAD
+ __INIT
.global _start
_start:
/* Init r0 to zero as per spec */
@@ -521,6 +527,15 @@ _start:
l.ori r3,r0,0x1
l.mtspr r0,r3,SPR_SR
+ /*
+ * Start the TTCR as early as possible, so that the RNG can make use of
+ * measurements of boot time from the earliest opportunity. Especially
+ * important is that the TTCR does not return zero by the time we reach
+ * random_init().
+ */
+ l.movhi r3,hi(SPR_TTMR_CR)
+ l.mtspr r0,r3,SPR_TTMR
+
CLEAR_GPR(r1)
CLEAR_GPR(r2)
CLEAR_GPR(r3)
@@ -599,7 +614,7 @@ flush_tlb:
l.jal _flush_tlb
l.nop
-/* The MMU needs to be enabled before or32_early_setup is called */
+/* The MMU needs to be enabled before or1k_early_setup is called */
enable_mmu:
/*
@@ -641,9 +656,9 @@ enable_mmu:
/* magic number mismatch, set fdt pointer to null */
l.or r25,r0,r0
_fdt_found:
- /* pass fdt pointer to or32_early_setup in r3 */
+ /* pass fdt pointer to or1k_early_setup in r3 */
l.or r3,r0,r25
- LOAD_SYMBOL_2_GPR(r24, or32_early_setup)
+ LOAD_SYMBOL_2_GPR(r24, or1k_early_setup)
l.jalr r24
l.nop
@@ -803,7 +818,7 @@ secondary_start:
#endif
-/* ========================================[ cache ]=== */
+/* ==========================================================[ cache ]=== */
/* alignment here so we don't change memory offsets with
* memory controller defined
@@ -1321,274 +1336,110 @@ i_pte_not_present:
/* =================================================[ debugging aids ]=== */
- .align 64
-_immu_trampoline:
- .space 64
-_immu_trampoline_top:
-
-#define TRAMP_SLOT_0 (0x0)
-#define TRAMP_SLOT_1 (0x4)
-#define TRAMP_SLOT_2 (0x8)
-#define TRAMP_SLOT_3 (0xc)
-#define TRAMP_SLOT_4 (0x10)
-#define TRAMP_SLOT_5 (0x14)
-#define TRAMP_FRAME_SIZE (0x18)
-
-ENTRY(_immu_trampoline_workaround)
- // r2 EEA
- // r6 is physical EEA
- tophys(r6,r2)
-
- LOAD_SYMBOL_2_GPR(r5,_immu_trampoline)
- tophys (r3,r5) // r3 is trampoline (physical)
-
- LOAD_SYMBOL_2_GPR(r4,0x15000000)
- l.sw TRAMP_SLOT_0(r3),r4
- l.sw TRAMP_SLOT_1(r3),r4
- l.sw TRAMP_SLOT_4(r3),r4
- l.sw TRAMP_SLOT_5(r3),r4
-
- // EPC = EEA - 0x4
- l.lwz r4,0x0(r6) // load op @ EEA + 0x0 (fc address)
- l.sw TRAMP_SLOT_3(r3),r4 // store it to _immu_trampoline_data
- l.lwz r4,-0x4(r6) // load op @ EEA - 0x4 (f8 address)
- l.sw TRAMP_SLOT_2(r3),r4 // store it to _immu_trampoline_data
-
- l.srli r5,r4,26 // check opcode for write access
- l.sfeqi r5,0 // l.j
- l.bf 0f
- l.sfeqi r5,0x11 // l.jr
- l.bf 1f
- l.sfeqi r5,1 // l.jal
- l.bf 2f
- l.sfeqi r5,0x12 // l.jalr
- l.bf 3f
- l.sfeqi r5,3 // l.bnf
- l.bf 4f
- l.sfeqi r5,4 // l.bf
- l.bf 5f
-99:
- l.nop
- l.j 99b // should never happen
- l.nop 1
-
- // r2 is EEA
- // r3 is trampoline address (physical)
- // r4 is instruction
- // r6 is physical(EEA)
- //
- // r5
-
-2: // l.jal
-
- /* 19 20 aa aa l.movhi r9,0xaaaa
- * a9 29 bb bb l.ori r9,0xbbbb
- *
- * where 0xaaaabbbb is EEA + 0x4 shifted right 2
- */
-
- l.addi r6,r2,0x4 // this is 0xaaaabbbb
-
- // l.movhi r9,0xaaaa
- l.ori r5,r0,0x1920 // 0x1920 == l.movhi r9
- l.sh (TRAMP_SLOT_0+0x0)(r3),r5
- l.srli r5,r6,16
- l.sh (TRAMP_SLOT_0+0x2)(r3),r5
-
- // l.ori r9,0xbbbb
- l.ori r5,r0,0xa929 // 0xa929 == l.ori r9
- l.sh (TRAMP_SLOT_1+0x0)(r3),r5
- l.andi r5,r6,0xffff
- l.sh (TRAMP_SLOT_1+0x2)(r3),r5
-
- /* falthrough, need to set up new jump offset */
-
-
-0: // l.j
- l.slli r6,r4,6 // original offset shifted left 6 - 2
-// l.srli r6,r6,6 // original offset shifted right 2
-
- l.slli r4,r2,4 // old jump position: EEA shifted left 4
-// l.srli r4,r4,6 // old jump position: shifted right 2
-
- l.addi r5,r3,0xc // new jump position (physical)
- l.slli r5,r5,4 // new jump position: shifted left 4
-
- // calculate new jump offset
- // new_off = old_off + (old_jump - new_jump)
-
- l.sub r5,r4,r5 // old_jump - new_jump
- l.add r5,r6,r5 // orig_off + (old_jump - new_jump)
- l.srli r5,r5,6 // new offset shifted right 2
-
- // r5 is new jump offset
- // l.j has opcode 0x0...
- l.sw TRAMP_SLOT_2(r3),r5 // write it back
-
- l.j trampoline_out
- l.nop
-
-/* ----------------------------- */
-
-3: // l.jalr
-
- /* 19 20 aa aa l.movhi r9,0xaaaa
- * a9 29 bb bb l.ori r9,0xbbbb
- *
- * where 0xaaaabbbb is EEA + 0x4 shifted right 2
- */
-
- l.addi r6,r2,0x4 // this is 0xaaaabbbb
-
- // l.movhi r9,0xaaaa
- l.ori r5,r0,0x1920 // 0x1920 == l.movhi r9
- l.sh (TRAMP_SLOT_0+0x0)(r3),r5
- l.srli r5,r6,16
- l.sh (TRAMP_SLOT_0+0x2)(r3),r5
-
- // l.ori r9,0xbbbb
- l.ori r5,r0,0xa929 // 0xa929 == l.ori r9
- l.sh (TRAMP_SLOT_1+0x0)(r3),r5
- l.andi r5,r6,0xffff
- l.sh (TRAMP_SLOT_1+0x2)(r3),r5
-
- l.lhz r5,(TRAMP_SLOT_2+0x0)(r3) // load hi part of jump instruction
- l.andi r5,r5,0x3ff // clear out opcode part
- l.ori r5,r5,0x4400 // opcode changed from l.jalr -> l.jr
- l.sh (TRAMP_SLOT_2+0x0)(r3),r5 // write it back
-
- /* falthrough */
-
-1: // l.jr
- l.j trampoline_out
- l.nop
-
-/* ----------------------------- */
-
-4: // l.bnf
-5: // l.bf
- l.slli r6,r4,6 // original offset shifted left 6 - 2
-// l.srli r6,r6,6 // original offset shifted right 2
-
- l.slli r4,r2,4 // old jump position: EEA shifted left 4
-// l.srli r4,r4,6 // old jump position: shifted right 2
-
- l.addi r5,r3,0xc // new jump position (physical)
- l.slli r5,r5,4 // new jump position: shifted left 4
-
- // calculate new jump offset
- // new_off = old_off + (old_jump - new_jump)
-
- l.add r6,r6,r4 // (orig_off + old_jump)
- l.sub r6,r6,r5 // (orig_off + old_jump) - new_jump
- l.srli r6,r6,6 // new offset shifted right 2
-
- // r6 is new jump offset
- l.lwz r4,(TRAMP_SLOT_2+0x0)(r3) // load jump instruction
- l.srli r4,r4,16
- l.andi r4,r4,0xfc00 // get opcode part
- l.slli r4,r4,16
- l.or r6,r4,r6 // l.b(n)f new offset
- l.sw TRAMP_SLOT_2(r3),r6 // write it back
-
- /* we need to add l.j to EEA + 0x8 */
- tophys (r4,r2) // may not be needed (due to shifts down_
- l.addi r4,r4,(0x8 - 0x8) // jump target = r2 + 0x8 (compensate for 0x8)
- // jump position = r5 + 0x8 (0x8 compensated)
- l.sub r4,r4,r5 // jump offset = target - new_position + 0x8
-
- l.slli r4,r4,4 // the amount of info in imediate of jump
- l.srli r4,r4,6 // jump instruction with offset
- l.sw TRAMP_SLOT_4(r3),r4 // write it to 4th slot
-
- /* fallthrough */
-
-trampoline_out:
- // set up new EPC to point to our trampoline code
- LOAD_SYMBOL_2_GPR(r5,_immu_trampoline)
- l.mtspr r0,r5,SPR_EPCR_BASE
-
- // immu_trampoline is (4x) CACHE_LINE aligned
- // and only 6 instructions long,
- // so we need to invalidate only 2 lines
-
- /* Establish cache block size
- If BS=0, 16;
- If BS=1, 32;
- r14 contain block size
- */
- l.mfspr r21,r0,SPR_ICCFGR
- l.andi r21,r21,SPR_ICCFGR_CBS
- l.srli r21,r21,7
- l.ori r23,r0,16
- l.sll r14,r23,r21
-
- l.mtspr r0,r5,SPR_ICBIR
- l.add r5,r5,r14
- l.mtspr r0,r5,SPR_ICBIR
-
- l.jr r9
- l.nop
-
-
/*
- * DSCR: prints a string referenced by r3.
+ * DESC: Prints ASCII character stored in r7
*
- * PRMS: r3 - address of the first character of null
- * terminated string to be printed
+ * PRMS: r7 - a 32-bit value with an ASCII character in the first byte
+ * position.
*
- * PREQ: UART at UART_BASE_ADD has to be initialized
+ * PREQ: The UART at UART_BASE_ADD has to be initialized
*
- * POST: caller should be aware that r3, r9 are changed
+ * POST: internally used but restores:
+ * r4 - to store UART_BASE_ADD
+ * r5 - for loading OFF_TXFULL / THRE,TEMT
+ * r6 - for storing bitmask (SERIAL_8250)
*/
-ENTRY(_emergency_print)
+ENTRY(_emergency_putc)
EMERGENCY_PRINT_STORE_GPR4
EMERGENCY_PRINT_STORE_GPR5
EMERGENCY_PRINT_STORE_GPR6
- EMERGENCY_PRINT_STORE_GPR7
-2:
- l.lbz r7,0(r3)
- l.sfeq r7,r0
- l.bf 9f
- l.nop
-// putc:
l.movhi r4,hi(UART_BASE_ADD)
+ l.ori r4,r4,lo(UART_BASE_ADD)
+#if defined(CONFIG_SERIAL_LITEUART)
+ /* Check OFF_TXFULL status */
+1: l.lwz r5,4(r4)
+ l.andi r5,r5,0xff
+ l.sfnei r5,0
+ l.bf 1b
+ l.nop
+
+ /* Write character */
+ l.andi r7,r7,0xff
+ l.sw 0(r4),r7
+#elif defined(CONFIG_SERIAL_8250)
+ /* Check UART LSR THRE (hold) bit */
l.addi r6,r0,0x20
1: l.lbz r5,5(r4)
l.andi r5,r5,0x20
l.sfeq r5,r6
l.bnf 1b
- l.nop
+ l.nop
+ /* Write character */
l.sb 0(r4),r7
+ /* Check UART LSR THRE|TEMT (hold, empty) bits */
l.addi r6,r0,0x60
1: l.lbz r5,5(r4)
l.andi r5,r5,0x60
l.sfeq r5,r6
l.bnf 1b
- l.nop
+ l.nop
+#endif
+ EMERGENCY_PRINT_LOAD_GPR6
+ EMERGENCY_PRINT_LOAD_GPR5
+ EMERGENCY_PRINT_LOAD_GPR4
+ l.jr r9
+ l.nop
+
+/*
+ * DSCR: prints a string referenced by r3.
+ *
+ * PRMS: r3 - address of the first character of null
+ * terminated string to be printed
+ *
+ * PREQ: UART at UART_BASE_ADD has to be initialized
+ *
+ * POST: caller should be aware that r3, r9 are changed
+ */
+ENTRY(_emergency_print)
+ EMERGENCY_PRINT_STORE_GPR7
+ EMERGENCY_PRINT_STORE_GPR9
+
+ /* Load character to r7, check for null terminator */
+2: l.lbz r7,0(r3)
+ l.sfeqi r7,0x0
+ l.bf 9f
+ l.nop
+
+ l.jal _emergency_putc
+ l.nop
/* next character */
l.j 2b
- l.addi r3,r3,0x1
+ l.addi r3,r3,0x1
9:
+ EMERGENCY_PRINT_LOAD_GPR9
EMERGENCY_PRINT_LOAD_GPR7
- EMERGENCY_PRINT_LOAD_GPR6
- EMERGENCY_PRINT_LOAD_GPR5
- EMERGENCY_PRINT_LOAD_GPR4
l.jr r9
- l.nop
+ l.nop
+/*
+ * DSCR: prints a number in r3 in hex.
+ *
+ * PRMS: r3 - a 32-bit unsigned integer
+ *
+ * PREQ: UART at UART_BASE_ADD has to be initialized
+ *
+ * POST: caller should be aware that r3, r9 are changed
+ */
ENTRY(_emergency_print_nr)
- EMERGENCY_PRINT_STORE_GPR4
- EMERGENCY_PRINT_STORE_GPR5
- EMERGENCY_PRINT_STORE_GPR6
EMERGENCY_PRINT_STORE_GPR7
EMERGENCY_PRINT_STORE_GPR8
+ EMERGENCY_PRINT_STORE_GPR9
l.addi r8,r0,32 // shift register
@@ -1600,58 +1451,39 @@ ENTRY(_emergency_print_nr)
/* don't skip the last zero if number == 0x0 */
l.sfeqi r8,0x4
l.bf 2f
- l.nop
+ l.nop
l.sfeq r7,r0
l.bf 1b
- l.nop
+ l.nop
2:
l.srl r7,r3,r8
l.andi r7,r7,0xf
l.sflts r8,r0
- l.bf 9f
+ l.bf 9f
+ /* Numbers greater than 9 translate to a-f */
l.sfgtui r7,0x9
l.bnf 8f
- l.nop
+ l.nop
l.addi r7,r7,0x27
-8:
- l.addi r7,r7,0x30
-// putc:
- l.movhi r4,hi(UART_BASE_ADD)
-
- l.addi r6,r0,0x20
-1: l.lbz r5,5(r4)
- l.andi r5,r5,0x20
- l.sfeq r5,r6
- l.bnf 1b
- l.nop
-
- l.sb 0(r4),r7
-
- l.addi r6,r0,0x60
-1: l.lbz r5,5(r4)
- l.andi r5,r5,0x60
- l.sfeq r5,r6
- l.bnf 1b
- l.nop
+ /* Convert to ascii and output character */
+8: l.jal _emergency_putc
+ l.addi r7,r7,0x30
/* next character */
l.j 2b
l.addi r8,r8,-0x4
9:
+ EMERGENCY_PRINT_LOAD_GPR9
EMERGENCY_PRINT_LOAD_GPR8
EMERGENCY_PRINT_LOAD_GPR7
- EMERGENCY_PRINT_LOAD_GPR6
- EMERGENCY_PRINT_LOAD_GPR5
- EMERGENCY_PRINT_LOAD_GPR4
l.jr r9
- l.nop
-
+ l.nop
/*
* This should be used for debugging only.
@@ -1676,7 +1508,9 @@ ENTRY(_emergency_print_nr)
ENTRY(_early_uart_init)
l.movhi r3,hi(UART_BASE_ADD)
+ l.ori r3,r3,lo(UART_BASE_ADD)
+#if defined(CONFIG_SERIAL_8250)
l.addi r4,r0,0x7
l.sb 0x2(r3),r4
@@ -1694,9 +1528,10 @@ ENTRY(_early_uart_init)
l.addi r4,r0,((UART_DIVISOR) & 0x000000ff)
l.sb UART_DLL(r3),r4
l.sb 0x3(r3),r5
+#endif
l.jr r9
- l.nop
+ l.nop
.align 0x1000
.global _secondary_evbar
@@ -1711,13 +1546,13 @@ _secondary_evbar:
.section .rodata
_string_unhandled_exception:
- .string "\n\rRunarunaround: Unhandled exception 0x\0"
+ .string "\r\nRunarunaround: Unhandled exception 0x\0"
_string_epc_prefix:
.string ": EPC=0x\0"
_string_nl:
- .string "\n\r\0"
+ .string "\r\n\0"
/* ========================================[ page aligned structures ]=== */
generated by cgit (git 2.34.1) at 2025-07-12 05:56:54 +0000