[RFC PATCH 2/7] i386: Add PSP discovery code

[Sergii Dmytruk]

From: Alec Brown <alec.r.brown@oracle.com>

Add base code for PSP discovery in grub.

Signed-off-by: Alec Brown <alec.r.brown@oracle.com>
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
---
 grub-core/Makefile.core.def    |   1 +
 grub-core/loader/slaunch/psp.c | 133 +++++++++++++++++++++++++++++++++
 include/grub/i386/psp.h        |  42 +++++++++++
 3 files changed, 176 insertions(+)
 create mode 100644 grub-core/loader/slaunch/psp.c
 create mode 100644 include/grub/i386/psp.h

diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index aba480842..dabf8fb22 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -1883,6 +1883,7 @@ module = {
   x86 = loader/slaunch/acmod.c;
   x86 = loader/slaunch/verify.c;
   x86 = loader/slaunch/i386_linux.c;
+  x86 = loader/slaunch/psp.c;
   x86 = loader/slaunch/dlstub.c;
   x86 = loader/efi/dltrampoline.S;
   x86_64_efi = loader/slaunch/x86_efi_linux.c;
diff --git a/grub-core/loader/slaunch/psp.c b/grub-core/loader/slaunch/psp.c
new file mode 100644
index 000000000..3459f7e34
--- /dev/null
+++ b/grub-core/loader/slaunch/psp.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2024, Oracle and/or its affiliates.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above
+ *     copyright notice, this list of conditions and the following
+ *     disclaimer in the documentation and/or other materials provided
+ *     with the distribution.
+ *   * Neither the name of the Intel Corporation nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grub/types.h>
+#include <grub/misc.h>
+#include <grub/err.h>
+#include <grub/pci.h>
+#include <grub/i386/pci.h>
+#include <grub/i386/psp.h>
+
+struct psp_drtm_interface
+{
+  volatile grub_uint32_t *c2pmsg_72;
+  volatile grub_uint32_t *c2pmsg_93;
+  volatile grub_uint32_t *c2pmsg_94;
+  volatile grub_uint32_t *c2pmsg_95;
+};
+
+typedef enum
+{
+  PSP_NONE = 0,
+  PSP_V1,
+  PSP_V2,
+  PSP_V3
+} psp_version_t;
+
+static psp_version_t psp_version;
+static struct psp_drtm_interface psp_drtm;
+
+static grub_err_t init_drtm_interface (grub_addr_t base_addr, psp_version_t 
version);
+
+static void
+smn_register_read (grub_uint32_t address, grub_uint32_t *value)
+{
+  grub_pci_device_t dev = {0, 0, 0};
+  grub_pci_address_t addr;
+  grub_uint32_t val;
+
+  val = address;
+  addr = grub_pci_make_address (dev, 0xb8);
+  grub_pci_write (addr, val);
+  addr = grub_pci_make_address (dev, 0xbc);
+  val = grub_pci_read (addr);
+  *value = val;
+}
+
+#define IOHC0NBCFG_SMNBASE 0x13b00000
+#define PSP_BASE_ADDR_LO_SMN_ADDRESS (IOHC0NBCFG_SMNBASE + 0x102e0)
+
+static grub_uint64_t
+get_psp_bar_addr (void)
+{
+  grub_uint32_t pspbaselo;
+
+  pspbaselo = 0;
+  smn_register_read (PSP_BASE_ADDR_LO_SMN_ADDRESS, &pspbaselo);
+
+  /* Mask out the lower bits */
+  pspbaselo &= 0xfff00000;
+  return (grub_uint64_t) pspbaselo;
+}
+
+grub_err_t
+grub_psp_discover (void)
+{
+  grub_uint64_t bar2_addr = 0;
+  grub_err_t err;
+
+  bar2_addr = get_psp_bar_addr();
+  if (!bar2_addr)
+    return grub_error (GRUB_ERR_BAD_DEVICE, N_("DRTM: failed to find PSP\n"));
+
+  err = init_drtm_interface (bar2_addr, PSP_V2);
+  if (err)
+    return err;
+
+  psp_version = PSP_V2;
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+init_drtm_interface (grub_addr_t base_addr, psp_version_t version)
+{
+  switch (version)
+    {
+    case PSP_V2:
+    case PSP_V3:
+      psp_drtm.c2pmsg_72 = (volatile grub_uint32_t *)(base_addr + 0x10a20);
+      psp_drtm.c2pmsg_93 = (volatile grub_uint32_t *)(base_addr + 0x10a74);
+      psp_drtm.c2pmsg_94 = (volatile grub_uint32_t *)(base_addr + 0x10a78);
+      psp_drtm.c2pmsg_95 = (volatile grub_uint32_t *)(base_addr + 0x10a7c);
+      break;
+    default:
+      return grub_error (GRUB_ERR_BAD_DEVICE, N_("DRTM: Unrecognized PSP 
version %d\n"), version);
+    }
+
+  return GRUB_ERR_NONE;
+}
+
+grub_uint16_t
+grub_psp_version (void)
+{
+  return psp_version;
+}
diff --git a/include/grub/i386/psp.h b/include/grub/i386/psp.h
new file mode 100644
index 000000000..8373318ca
--- /dev/null
+++ b/include/grub/i386/psp.h
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2024, Oracle and/or its affiliates.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above
+ *     copyright notice, this list of conditions and the following
+ *     disclaimer in the documentation and/or other materials provided
+ *     with the distribution.
+ *   * Neither the name of the Intel Corporation nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef __PSP_H__
+#define __PSP_H__
+
+#include <grub/err.h>
+#include <grub/types.h>
+
+extern grub_err_t grub_psp_discover (void);
+extern grub_uint16_t grub_psp_version (void);
+
+#endif /* __PSP_H__ */
-- 
2.47.1