Handle systems, such as the Dell Precision 3640, that access

GenericSerialBus operating regions witout checking whether they're really
available.  This needs to work on RAMDISK kernels as well.  Since we
don't want to pull in the i2c subsystem on those, provide a separate
and much simpler dummy implementation of the GenericSerialBus access code
when SMALL_KERNEL is defined.

ok tb@

diff --git a/sys/dev/acpi/dsdt.c b/sys/dev/acpi/dsdt.c
index f25ab28..a9dd2a3 100644 (file)
--- a/sys/dev/acpi/dsdt.c
+++ b/sys/dev/acpi/dsdt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: dsdt.c,v 1.261 2021/03/18 00:17:26 yasuoka Exp $ */
+/* $OpenBSD: dsdt.c,v 1.262 2021/03/30 16:49:58 kettenis Exp $ */
 /*
  * Copyright (c) 2005 Jordan Hargrave <jordan@openbsd.org>
  *
@@ -2535,51 +2535,53 @@ aml_rwgsb(struct aml_value *conn, int alen, int bpos, int blen,
        i2c_tag_t tag;
        i2c_op_t op;
        i2c_addr_t addr;
-       int cmdlen, buflen;
+       int cmdlen, buflen, acclen;
        uint8_t cmd;
        uint8_t *buf;
-       int err;
+       int pos, err;
 
        if (conn->type != AML_OBJTYPE_BUFFER || conn->length < 5 ||
            AML_CRSTYPE(crs) != LR_SERBUS || AML_CRSLEN(crs) > conn->length ||
            crs->lr_i2cbus.revid != 1 || crs->lr_i2cbus.type != LR_SERBUS_I2C)
                aml_die("Invalid GenericSerialBus");
        if (AML_FIELD_ACCESS(flag) != AML_FIELD_BUFFERACC ||
-           bpos & 0x3 || blen != 8)
+           bpos & 0x3 || (blen % 8) != 0)
                aml_die("Invalid GenericSerialBus access");
 
        node = aml_searchname(conn->node,
            (char *)&crs->lr_i2cbus.vdata[crs->lr_i2cbus.tlength - 6]);
 
-       if (node == NULL || node->i2c == NULL)
-               aml_die("Could not find GenericSerialBus controller");
-
        switch (((flag >> 6) & 0x3)) {
        case 0:                 /* Normal */
                switch (AML_FIELD_ATTR(flag)) {
                case 0x02:      /* AttribQuick */
                        cmdlen = 0;
-                       buflen = 0;
+                       buflen = acclen = 0;
                        break;
                case 0x04:      /* AttribSendReceive */
                        cmdlen = 0;
-                       buflen = 1;
+                       acclen = 1;
+                       buflen = blen / 8;
                        break;
                case 0x06:      /* AttribByte */
                        cmdlen = 1;
-                       buflen = 1;
+                       acclen = 1;
+                       buflen = blen / 8;
                        break;
                case 0x08:      /* AttribWord */
                        cmdlen = 1;
-                       buflen = 2;
+                       acclen = 2;
+                       buflen = blen / 8;
                        break;
                case 0x0b:      /* AttribBytes */
                        cmdlen = 1;
-                       buflen = alen;
+                       acclen = alen;
+                       buflen = blen / 8;
                        break;
                case 0x0e:      /* AttribRawBytes */
                        cmdlen = 0;
-                       buflen = alen;
+                       acclen = alen;
+                       buflen = blen / 8;
                        break;
                default:
                        aml_die("unsupported access type 0x%x", flag);
@@ -2588,11 +2590,11 @@ aml_rwgsb(struct aml_value *conn, int alen, int bpos, int blen,
                break;
        case 1:                 /* AttribBytes */
                cmdlen = 1;
-               buflen = AML_FIELD_ATTR(flag);
+               acclen = buflen = AML_FIELD_ATTR(flag);
                break;
        case 2:                 /* AttribRawBytes */
                cmdlen = 0;
-               buflen = AML_FIELD_ATTR(flag);
+               acclen = buflen = AML_FIELD_ATTR(flag);
                break;
        default:
                aml_die("unsupported access type 0x%x", flag);
@@ -2606,13 +2608,29 @@ aml_rwgsb(struct aml_value *conn, int alen, int bpos, int blen,
                op = I2C_OP_WRITE_WITH_STOP;
        }
 
+       buf = val->v_buffer;
+
+       /*
+        * Return an error if we can't find the I2C controller that
+        * we're supposed to use for this request.
+        */
+       if (node == NULL || node->i2c == NULL) {
+               buf[0] = EIO;
+               return;
+       }
+
        tag = node->i2c;
        addr = crs->lr_i2cbus._adr;
        cmd = bpos >> 3;
-       buf = val->v_buffer;
 
        iic_acquire_bus(tag, 0);
-       err = iic_exec(tag, op, addr, &cmd, cmdlen, &buf[2], buflen, 0);
+       for (pos = 0; pos < buflen; pos += acclen) {
+               err = iic_exec(tag, op, addr, &cmd, cmdlen,
+                   &buf[pos + 2], acclen, 0);
+               if (err)
+                       break;
+               cmd++;
+       }
        iic_release_bus(tag, 0);
 
        /*
@@ -2624,6 +2642,58 @@ aml_rwgsb(struct aml_value *conn, int alen, int bpos, int blen,
        buf[0] = err;
 }
 
+#else
+
+/*
+ * We don't support GenericSerialBus in RAMDISK kernels.  Provide a
+ * dummy implementation that returns a non-zero error status.
+ */
+
+void
+aml_rwgsb(struct aml_value *conn, int alen, int bpos, int blen,
+    struct aml_value *val, int mode, int flag)
+{
+       int buflen;
+       uint8_t *buf;
+
+       if (AML_FIELD_ACCESS(flag) != AML_FIELD_BUFFERACC ||
+           bpos & 0x3 || (blen % 8) != 0)
+               aml_die("Invalid GenericSerialBus access");
+
+       switch (((flag >> 6) & 0x3)) {
+       case 0:                 /* Normal */
+               switch (AML_FIELD_ATTR(flag)) {
+               case 0x02:      /* AttribQuick */
+                       buflen = 0;
+                       break;
+               case 0x04:      /* AttribSendReceive */
+               case 0x06:      /* AttribByte */
+               case 0x08:      /* AttribWord */
+               case 0x0b:      /* AttribBytes */
+               case 0x0e:      /* AttribRawBytes */
+                       buflen = blen / 8;
+                       break;
+               default:
+                       aml_die("unsupported access type 0x%x", flag);
+                       break;
+               }
+               break;
+       case 1:                 /* AttribBytes */
+       case 2:                 /* AttribRawBytes */
+               buflen = AML_FIELD_ATTR(flag);
+               break;
+       default:
+               aml_die("unsupported access type 0x%x", flag);
+               break;
+       }
+
+       if (mode == ACPI_IOREAD)
+               _aml_setvalue(val, AML_OBJTYPE_BUFFER, buflen + 2, NULL);
+
+       buf = val->v_buffer;
+       buf[0] = EIO;
+}
+
 #endif
 
 void
@@ -2727,13 +2797,11 @@ aml_rwfield(struct aml_value *fld, int bpos, int blen, struct aml_value *val,
                        aml_rwgpio(ref2, bpos, blen, val, mode,
                            fld->v_field.flags);
                        break;
-#ifndef SMALL_KERNEL
                case ACPI_OPREG_GSB:
                        aml_rwgsb(ref2, fld->v_field.ref3,
                            fld->v_field.bitpos + bpos, blen,
                            val, mode, fld->v_field.flags);
                        break;
-#endif
                default:
                        aml_rwgen(ref1, fld->v_field.bitpos + bpos, blen,
                            val, mode, fld->v_field.flags);