diff options
| -rw-r--r-- | arch/blackfin/kernel/Makefile | 3 | ||||
| -rw-r--r-- | arch/blackfin/kernel/fixed_code.S | 132 | ||||
| -rw-r--r-- | arch/blackfin/kernel/process.c | 65 | ||||
| -rw-r--r-- | arch/blackfin/kernel/setup.c | 22 | ||||
| -rw-r--r-- | arch/blackfin/mach-common/entry.S | 4 | ||||
| -rw-r--r-- | include/asm-blackfin/Kbuild | 2 | ||||
| -rw-r--r-- | include/asm-blackfin/bfin-global.h | 12 | ||||
| -rw-r--r-- | include/asm-blackfin/cplbinit.h | 4 | ||||
| -rw-r--r-- | include/asm-blackfin/fixed_code.h | 20 |
9 files changed, 261 insertions, 3 deletions
diff --git a/arch/blackfin/kernel/Makefile b/arch/blackfin/kernel/Makefile index 93d2140..b7b6de8 100644 --- a/arch/blackfin/kernel/Makefile +++ b/arch/blackfin/kernel/Makefile @@ -6,7 +6,8 @@ extra-y := init_task.o vmlinux.lds obj-y := \ entry.o process.o bfin_ksyms.o ptrace.o setup.o signal.o \ - sys_bfin.o time.o traps.o irqchip.o dma-mapping.o flat.o + sys_bfin.o time.o traps.o irqchip.o dma-mapping.o flat.o \ + fixed_code.o obj-$(CONFIG_BF53x) += bfin_gpio.o obj-$(CONFIG_BF561) += bfin_gpio.o diff --git a/arch/blackfin/kernel/fixed_code.S b/arch/blackfin/kernel/fixed_code.S new file mode 100644 index 0000000..99ea296 --- /dev/null +++ b/arch/blackfin/kernel/fixed_code.S @@ -0,0 +1,132 @@ +/* + * This file contains sequences of code that will be copied to a + * fixed location, defined in <asm/atomic_seq.h>. The interrupt + * handlers ensure that these sequences appear to be atomic when + * executed from userspace. + * These are aligned to 16 bytes, so that we have some space to replace + * these sequences with something else (e.g. kernel traps if we ever do + * BF561 SMP). + */ +#include <linux/linkage.h> +#include <asm/entry.h> +#include <asm/unistd.h> + +.text +ENTRY(_fixed_code_start) + +.align 16 +ENTRY(_sigreturn_stub) + P0 = __NR_rt_sigreturn; + EXCPT 0; + /* Speculative execution paranoia. */ +0: JUMP.S 0b; +ENDPROC (_sigreturn_stub) + +.align 16 + /* + * Atomic swap, 8 bit. + * Inputs: P0: memory address to use + * R1: value to store + * Output: R0: old contents of the memory address, zero extended. + */ +ENTRY(_atomic_xchg32) + R0 = [P0]; + [P0] = R1; + rts; +ENDPROC (_atomic_xchg32) + +.align 16 + /* + * Compare and swap, 32 bit. + * Inputs: P0: memory address to use + * R1: compare value + * R2: new value to store + * The new value is stored if the contents of the memory + * address is equal to the compare value. + * Output: R0: old contents of the memory address. + */ +ENTRY(_atomic_cas32) + R0 = [P0]; + CC = R0 == R1; + IF !CC JUMP 1f; + [P0] = R2; +1: + rts; +ENDPROC (_atomic_cas32) + +.align 16 + /* + * Atomic add, 32 bit. + * Inputs: P0: memory address to use + * R0: value to add + * Outputs: R0: new contents of the memory address. + * R1: previous contents of the memory address. + */ +ENTRY(_atomic_add32) + R1 = [P0]; + R0 = R1 + R0; + [P0] = R0; + rts; +ENDPROC (_atomic_add32) + +.align 16 + /* + * Atomic sub, 32 bit. + * Inputs: P0: memory address to use + * R0: value to subtract + * Outputs: R0: new contents of the memory address. + * R1: previous contents of the memory address. + */ +ENTRY(_atomic_sub32) + R1 = [P0]; + R0 = R1 - R0; + [P0] = R0; + rts; +ENDPROC (_atomic_sub32) + +.align 16 + /* + * Atomic ior, 32 bit. + * Inputs: P0: memory address to use + * R0: value to ior + * Outputs: R0: new contents of the memory address. + * R1: previous contents of the memory address. + */ +ENTRY(_atomic_ior32) + R1 = [P0]; + R0 = R1 | R0; + [P0] = R0; + rts; +ENDPROC (_atomic_ior32) + +.align 16 + /* + * Atomic ior, 32 bit. + * Inputs: P0: memory address to use + * R0: value to ior + * Outputs: R0: new contents of the memory address. + * R1: previous contents of the memory address. + */ +ENTRY(_atomic_and32) + R1 = [P0]; + R0 = R1 & R0; + [P0] = R0; + rts; +ENDPROC (_atomic_ior32) + +.align 16 + /* + * Atomic ior, 32 bit. + * Inputs: P0: memory address to use + * R0: value to ior + * Outputs: R0: new contents of the memory address. + * R1: previous contents of the memory address. + */ +ENTRY(_atomic_xor32) + R1 = [P0]; + R0 = R1 ^ R0; + [P0] = R0; + rts; +ENDPROC (_atomic_ior32) + +ENTRY(_fixed_code_end) diff --git a/arch/blackfin/kernel/process.c b/arch/blackfin/kernel/process.c index 3eff743..6b7a94a 100644 --- a/arch/blackfin/kernel/process.c +++ b/arch/blackfin/kernel/process.c @@ -35,6 +35,7 @@ #include <asm/blackfin.h> #include <asm/uaccess.h> +#include <asm/fixed_code.h> #define LED_ON 0 #define LED_OFF 1 @@ -350,6 +351,70 @@ unsigned long get_wchan(struct task_struct *p) return 0; } +void finish_atomic_sections (struct pt_regs *regs) +{ + if (regs->pc < ATOMIC_SEQS_START || regs->pc >= ATOMIC_SEQS_END) + return; + + switch (regs->pc) { + case ATOMIC_XCHG32 + 2: + put_user(regs->r1, (int *)regs->p0); + regs->pc += 2; + break; + + case ATOMIC_CAS32 + 2: + case ATOMIC_CAS32 + 4: + if (regs->r0 == regs->r1) + put_user(regs->r2, (int *)regs->p0); + regs->pc = ATOMIC_CAS32 + 8; + break; + case ATOMIC_CAS32 + 6: + put_user(regs->r2, (int *)regs->p0); + regs->pc += 2; + break; + + case ATOMIC_ADD32 + 2: + regs->r0 = regs->r1 + regs->r0; + /* fall through */ + case ATOMIC_ADD32 + 4: + put_user(regs->r0, (int *)regs->p0); + regs->pc = ATOMIC_ADD32 + 6; + break; + + case ATOMIC_SUB32 + 2: + regs->r0 = regs->r1 - regs->r0; + /* fall through */ + case ATOMIC_SUB32 + 4: + put_user(regs->r0, (int *)regs->p0); + regs->pc = ATOMIC_SUB32 + 6; + break; + + case ATOMIC_IOR32 + 2: + regs->r0 = regs->r1 | regs->r0; + /* fall through */ + case ATOMIC_IOR32 + 4: + put_user(regs->r0, (int *)regs->p0); + regs->pc = ATOMIC_IOR32 + 6; + break; + + case ATOMIC_AND32 + 2: + regs->r0 = regs->r1 & regs->r0; + /* fall through */ + case ATOMIC_AND32 + 4: + put_user(regs->r0, (int *)regs->p0); + regs->pc = ATOMIC_AND32 + 6; + break; + + case ATOMIC_XOR32 + 2: + regs->r0 = regs->r1 ^ regs->r0; + /* fall through */ + case ATOMIC_XOR32 + 4: + put_user(regs->r0, (int *)regs->p0); + regs->pc = ATOMIC_XOR32 + 6; + break; + } +} + #if defined(CONFIG_ACCESS_CHECK) int _access_ok(unsigned long addr, unsigned long size) { diff --git a/arch/blackfin/kernel/setup.c b/arch/blackfin/kernel/setup.c index 76bf2ce..534227f 100644 --- a/arch/blackfin/kernel/setup.c +++ b/arch/blackfin/kernel/setup.c @@ -42,6 +42,7 @@ #include <asm/cacheflush.h> #include <asm/blackfin.h> #include <asm/cplbinit.h> +#include <asm/fixed_code.h> u16 _bfin_swrst; @@ -404,6 +405,27 @@ void __init setup_arch(char **cmdline_p) printk(KERN_INFO "Hardware Trace Enabled\n"); bfin_write_TBUFCTL(0x03); + + /* Copy atomic sequences to their fixed location, and sanity check that + these locations are the ones that we advertise to userspace. */ + memcpy((void *)FIXED_CODE_START, &fixed_code_start, + FIXED_CODE_END - FIXED_CODE_START); + BUG_ON((char *)&sigreturn_stub - (char *)&fixed_code_start + != SIGRETURN_STUB - FIXED_CODE_START); + BUG_ON((char *)&atomic_xchg32 - (char *)&fixed_code_start + != ATOMIC_XCHG32 - FIXED_CODE_START); + BUG_ON((char *)&atomic_cas32 - (char *)&fixed_code_start + != ATOMIC_CAS32 - FIXED_CODE_START); + BUG_ON((char *)&atomic_add32 - (char *)&fixed_code_start + != ATOMIC_ADD32 - FIXED_CODE_START); + BUG_ON((char *)&atomic_sub32 - (char *)&fixed_code_start + != ATOMIC_SUB32 - FIXED_CODE_START); + BUG_ON((char *)&atomic_ior32 - (char *)&fixed_code_start + != ATOMIC_IOR32 - FIXED_CODE_START); + BUG_ON((char *)&atomic_and32 - (char *)&fixed_code_start + != ATOMIC_AND32 - FIXED_CODE_START); + BUG_ON((char *)&atomic_xor32 - (char *)&fixed_code_start + != ATOMIC_XOR32 - FIXED_CODE_START); } static int __init topology_init(void) diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S index 40045b1..c4a32ea 100644 --- a/arch/blackfin/mach-common/entry.S +++ b/arch/blackfin/mach-common/entry.S @@ -741,6 +741,10 @@ _schedule_and_signal_from_int: r0 = [p0]; sti r0; + r0 = sp; + sp += -12; + call _finish_atomic_sections; + sp += 12; jump.s .Lresume_userspace; _schedule_and_signal: diff --git a/include/asm-blackfin/Kbuild b/include/asm-blackfin/Kbuild index c68e168..71f8fe7 100644 --- a/include/asm-blackfin/Kbuild +++ b/include/asm-blackfin/Kbuild @@ -1 +1,3 @@ include include/asm-generic/Kbuild.asm + +header-y += fixed_code.h diff --git a/include/asm-blackfin/bfin-global.h b/include/asm-blackfin/bfin-global.h index 57f37cc..c4d6cbb 100644 --- a/include/asm-blackfin/bfin-global.h +++ b/include/asm-blackfin/bfin-global.h @@ -67,6 +67,18 @@ extern void evt14_softirq(void); extern asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs); extern void bfin_gpio_interrupt_setup(int irq, int irq_pfx, int type); +extern asmlinkage void finish_atomic_sections (struct pt_regs *regs); +extern char fixed_code_start; +extern char fixed_code_end; +extern int atomic_xchg32(void); +extern int atomic_cas32(void); +extern int atomic_add32(void); +extern int atomic_sub32(void); +extern int atomic_ior32(void); +extern int atomic_and32(void); +extern int atomic_xor32(void); +extern void sigreturn_stub(void); + extern void *l1_data_A_sram_alloc(size_t); extern void *l1_data_B_sram_alloc(size_t); extern void *l1_inst_sram_alloc(size_t); diff --git a/include/asm-blackfin/cplbinit.h b/include/asm-blackfin/cplbinit.h index 3bad2d1..e14ea39 100644 --- a/include/asm-blackfin/cplbinit.h +++ b/include/asm-blackfin/cplbinit.h @@ -101,8 +101,8 @@ struct s_cplb { static struct cplb_desc cplb_data[] = { { .start = 0, - .end = SIZE_4K, - .psize = SIZE_4K, + .end = SIZE_1K, + .psize = SIZE_1K, .attr = INITIAL_T | SWITCH_T | I_CPLB | D_CPLB, .i_conf = SDRAM_OOPS, .d_conf = SDRAM_OOPS, diff --git a/include/asm-blackfin/fixed_code.h b/include/asm-blackfin/fixed_code.h new file mode 100644 index 0000000..e6df84e --- /dev/null +++ b/include/asm-blackfin/fixed_code.h @@ -0,0 +1,20 @@ +/* This file defines the fixed addresses where userspace programs can find + atomic code sequences. */ + +#define FIXED_CODE_START 0x400 + +#define SIGRETURN_STUB 0x400 + +#define ATOMIC_SEQS_START 0x410 + +#define ATOMIC_XCHG32 0x410 +#define ATOMIC_CAS32 0x420 +#define ATOMIC_ADD32 0x430 +#define ATOMIC_SUB32 0x440 +#define ATOMIC_IOR32 0x450 +#define ATOMIC_AND32 0x460 +#define ATOMIC_XOR32 0x470 + +#define ATOMIC_SEQS_END 0x480 + +#define FIXED_CODE_END 0x480 |