From 8fabbb008c1a31c809a3d97f22351f141a2bd02d Mon Sep 17 00:00:00 2001 From: Amaury Pouly Date: Thu, 4 Aug 2016 17:06:11 +0100 Subject: hwstub: add support for coprocessor operations At the moment the stub only implement them for MIPS. Change-Id: Ica835a0e9c70fa5675c3d655eae986e812a47de8 --- utils/hwstub/stub/main.c | 188 ++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 176 insertions(+), 12 deletions(-) (limited to 'utils/hwstub/stub') diff --git a/utils/hwstub/stub/main.c b/utils/hwstub/stub/main.c index c35872f320..3eee8b6a18 100644 --- a/utils/hwstub/stub/main.c +++ b/utils/hwstub/stub/main.c @@ -400,10 +400,12 @@ static bool read_atomic(void *dst, void *src, size_t sz) } } +static void *last_read_addr = 0; +static uint16_t last_read_id = 0xffff; +static size_t last_read_max_size = 0; + static void handle_read(struct usb_ctrlrequest *req) { - static uint32_t last_addr = 0; - static uint16_t last_id = 0xffff; uint16_t id = req->wValue; if(req->bRequest == HWSTUB_READ) @@ -413,26 +415,29 @@ static void handle_read(struct usb_ctrlrequest *req) return usb_drv_stall(EP_CONTROL, true, true); asm volatile("nop" : : : "memory"); struct hwstub_read_req_t *read = (void *)usb_buffer; - last_addr = read->dAddress; - last_id = id; + last_read_addr = (void *)read->dAddress; + last_read_max_size = usb_buffer_size; + last_read_id = id; usb_drv_send(EP_CONTROL, NULL, 0); } else { - if(id != last_id) + /* NOTE: READ2 is also called after a coprocessor operation */ + if(id != last_read_id) return usb_drv_stall(EP_CONTROL, true, true); + size_t len = MIN(req->wLength, last_read_max_size); if(req->bRequest == HWSTUB_READ2_ATOMIC) { if(set_data_abort_jmp() == 0) { - if(!read_atomic(usb_buffer, (void *)last_addr, req->wLength)) + if(!read_atomic(usb_buffer, last_read_addr, len)) return usb_drv_stall(EP_CONTROL, true, true); } else { - logf("trapped read data abort in [0x%x,0x%x]\n", last_addr, - last_addr + req->wLength); + logf("trapped read data abort in [0x%x,0x%x]\n", last_read_addr, + last_read_addr + len); return usb_drv_stall(EP_CONTROL, true, true); } } @@ -440,19 +445,19 @@ static void handle_read(struct usb_ctrlrequest *req) { if(set_data_abort_jmp() == 0) { - memcpy(usb_buffer, (void *)last_addr, req->wLength); + memcpy(usb_buffer, last_read_addr, len); asm volatile("nop" : : : "memory"); } else { - logf("trapped read data abort in [0x%x,0x%x]\n", last_addr, - last_addr + req->wLength); + logf("trapped read data abort in [0x%x,0x%x]\n", last_read_addr, + last_read_addr + len); return usb_drv_stall(EP_CONTROL, true, true); } } - usb_drv_send(EP_CONTROL, usb_buffer, req->wLength); + usb_drv_send(EP_CONTROL, usb_buffer, len); usb_drv_recv(EP_CONTROL, NULL, 0); } } @@ -562,6 +567,163 @@ static void handle_exec(struct usb_ctrlrequest *req) } } +#ifdef CPU_MIPS +static uint32_t rw_cp0_inst_buffer[3]; +typedef uint32_t (*read_cp0_inst_buffer_fn_t)(void); +typedef void (*write_cp0_inst_buffer_fn_t)(uint32_t); + +uint32_t mips_read_cp0(unsigned reg, unsigned sel) +{ + /* ok this is tricky because the coprocessor read instruction encoding + * contains the register and select, so we need to generate the instruction + * on the fly, we generate a "function like" buffer with three instructions: + * mfc0 v0, reg, sel + * jr ra + * nop + */ + rw_cp0_inst_buffer[0] = 0x40000000 | /*v0*/2 << 16 | (sel & 0x7) | (reg & 0x1f) << 11; + rw_cp0_inst_buffer[1] = /*ra*/31 << 21 | 0x8; /* jr ra */ + rw_cp0_inst_buffer[2] = 0; /* nop */ +#ifdef CONFIG_FLUSH_CACHES + target_flush_caches(); +#endif + read_cp0_inst_buffer_fn_t fn = (read_cp0_inst_buffer_fn_t)rw_cp0_inst_buffer; + return fn(); +} + +void mips_write_cp0(unsigned reg, unsigned sel, uint32_t val) +{ + /* ok this is tricky because the coprocessor write instruction encoding + * contains the register and select, so we need to generate the instruction + * on the fly, we generate a "function like" buffer with three instructions: + * mtc0 a0, reg, sel + * jr ra + * nop + */ + rw_cp0_inst_buffer[0] = 0x40800000 | /*a0*/4 << 16 | (sel & 0x7) | (reg & 0x1f) << 11; + rw_cp0_inst_buffer[1] = /*ra*/31 << 21 | 0x8; /* jr ra */ + rw_cp0_inst_buffer[2] = 0; /* nop */ +#ifdef CONFIG_FLUSH_CACHES + target_flush_caches(); +#endif + write_cp0_inst_buffer_fn_t fn = (write_cp0_inst_buffer_fn_t)rw_cp0_inst_buffer; + fn(val); +} +#endif + +/* coprocessor read: return <0 on error (-2 for dull dump), or size to return + * to host otherwise */ +int cop_read(uint8_t args[HWSTUB_COP_ARGS], void *out_data, size_t out_max_sz) +{ + /* virtually all targets do register-based operation, so 32-bit */ + if(out_max_sz < 4) + { + logf("cop read failed: output buffer is too small\n"); + return -1; + } +#ifdef CPU_MIPS + if(args[HWSTUB_COP_MIPS_COP] != 0) + { + logf("cop read failed: only mips cp0 is supported\n"); + return -2; + } + *(uint32_t *)out_data = mips_read_cp0(args[HWSTUB_COP_MIPS_REG], args[HWSTUB_COP_MIPS_SEL]); + return 4; +#else + (void) args; + (void) out_data; + (void) out_max_sz; + logf("cop read failed: unsupported cpu\n"); + return -1; +#endif +} + +/* coprocessor write: return <0 on error (-2 for dull dump), or 0 on success */ +int cop_write(uint8_t args[HWSTUB_COP_ARGS], const void *in_data, size_t in_sz) +{ + /* virtually all targets do register-based operation, so 32-bit */ + if(in_sz != 4) + { + logf("cop read failed: input buffer has wrong size\n"); + return -1; + } +#ifdef CPU_MIPS + if(args[HWSTUB_COP_MIPS_COP] != 0) + { + logf("cop read failed: only mips cp0 is supported\n"); + return -2; + } + mips_write_cp0(args[HWSTUB_COP_MIPS_REG], args[HWSTUB_COP_MIPS_SEL], *(uint32_t *)in_data); + return 0; +#else + (void) args; + (void) in_data; + (void) in_sz; + logf("cop write failed: unsupported cpu\n"); + return -1; +#endif +} + +/* return size to return to host or <0 on error */ +int do_cop_op(struct hwstub_cop_req_t *cop, void *in_data, size_t in_sz, + void *out_data, size_t out_max_sz) +{ + int ret = -2; /* -2 means full debug dump */ + /* handle operations */ + if(cop->bOp == HWSTUB_COP_READ) + { + /* read cannot have extra data */ + if(in_sz > 0) + goto Lerr; + ret = cop_read(cop->bArgs, out_data, out_max_sz); + } + else if(cop->bOp == HWSTUB_COP_WRITE) + { + ret = cop_write(cop->bArgs, in_data, in_sz); + } + +Lerr: + if(ret == -2) + { + /* debug output */ + logf("invalid cop op: %d, ", cop->bOp); + for(int i = 0; i < HWSTUB_COP_ARGS; i++) + logf("%c0x%x", i == 0 ? '[' : ',', cop->bArgs[i]); + logf("] in:%d\n", in_sz); + } + return ret; +} + +static void handle_cop(struct usb_ctrlrequest *req) +{ + int size = usb_drv_recv(EP_CONTROL, usb_buffer, req->wLength); + int hdr_sz = sizeof(struct hwstub_cop_req_t); + asm volatile("nop" : : : "memory"); + struct hwstub_cop_req_t *cop = (void *)usb_buffer; + /* request should at least contain the header */ + if(size < hdr_sz) + return usb_drv_stall(EP_CONTROL, true, true); + /* perform coprocessor operation: put output buffer after the input one, + * limit output buffer size to maximum buffer size */ + uint8_t *in_buf = usb_buffer + hdr_sz; + size_t in_sz = req->wLength - hdr_sz; + uint8_t *out_buf = in_buf + in_sz; + size_t out_max_sz = usb_buffer_size - req->wLength; + int ret = do_cop_op(cop, in_buf, in_sz, out_buf, out_max_sz); + /* STALL on error */ + if(ret < 0) + return usb_drv_stall(EP_CONTROL, true, true); + /* acknowledge */ + usb_drv_send(EP_CONTROL, NULL, 0); + /* if there is a read stage, prepare everything for the READ2 */ + if(ret > 0) + { + last_read_id = req->wValue; + last_read_addr = out_buf; + last_read_max_size = ret; + } +} + static void handle_class_intf_req(struct usb_ctrlrequest *req) { unsigned intf = req->wIndex & 0xff; @@ -581,6 +743,8 @@ static void handle_class_intf_req(struct usb_ctrlrequest *req) return handle_write(req); case HWSTUB_EXEC: return handle_exec(req); + case HWSTUB_COPROCESSOR_OP: + return handle_cop(req); default: usb_drv_stall(EP_CONTROL, true, true); } -- cgit v1.2.3