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authorAmaury Pouly <amaury.pouly@gmail.com>2016-08-04 17:06:11 +0100
committerAmaury Pouly <amaury.pouly@gmail.com>2017-01-24 15:25:14 +0100
commit8fabbb008c1a31c809a3d97f22351f141a2bd02d (patch)
tree6e16386a7348197920a5ce1d99f623d0e10b6c3c /utils/hwstub/stub
parentd91d9f6851bba401650912c5cabcfe4c5f1150df (diff)
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hwstub: add support for coprocessor operations
At the moment the stub only implement them for MIPS. Change-Id: Ica835a0e9c70fa5675c3d655eae986e812a47de8
Diffstat (limited to 'utils/hwstub/stub')
-rw-r--r--utils/hwstub/stub/main.c188
1 files changed, 176 insertions, 12 deletions
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);
}