[PATCH libacpica] Allow read/write to pci config

[Damien Zammit]

This allows hurd's acpi translator to read/write pci config.

Note that hurd needs to be changed to link acpi translator
with libpciaccess once this patch is merged.

Also, the boot order needs to be pci-arbiter then acpi.

TESTED: on qemu with a rump patch to enable acpi it boots via rumpdisk.
On a T500 laptop acpi crashes at boot.

---
 debian/patches/acgnu.diff           | 13 +++---
 debian/patches/acpi-init-files.diff | 66 +++++++++++++++++++++++++++--
 debian/patches/add-makefile.diff    |  4 +-
 3 files changed, 74 insertions(+), 9 deletions(-)

diff --git a/debian/patches/acgnu.diff b/debian/patches/acgnu.diff
index fc59992..6fdb440 100644
--- a/debian/patches/acgnu.diff
+++ b/debian/patches/acgnu.diff
@@ -163,7 +163,7 @@ Add acgnu.h and acgnuex.h
 +#endif                                /* __ACGNU_H__ */
 --- /dev/null
 +++ b/include/acpi/platform/acgnuex.h
-@@ -0,0 +1,256 @@
+@@ -0,0 +1,259 @@
 +// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
 +
 +#ifndef __ACGNUEX_H__
@@ -181,6 +181,8 @@ Add acgnu.h and acgnuex.h
 +acpi_status ACPI_INIT_FUNCTION acpi_os_initialize(void);
 +acpi_status acpi_os_terminate(void);
 +void acpi_os_printf(const char *format, ...);
++struct pci_device;
++struct pci_device *lookup_pci_dev(struct acpi_pci_id *pci_id);
 +
 +static inline void *acpi_os_allocate(acpi_size size)
 +{
@@ -232,6 +234,7 @@ Add acgnu.h and acgnuex.h
 +#include <stdarg.h>
 +#include <limits.h>
 +#include <hurd.h>
++#include <pciaccess.h>
 +
 +#define ACPI_MAX_TABLES 128
 +
@@ -405,16 +408,16 @@ Add acgnu.h and acgnuex.h
 +acpi_os_read_pci_configuration(struct acpi_pci_id * pci_id, u32 reg,
 +             u64 *value, u32 width)
 +{
-+  acpi_os_printf("ACPI: Tried to read pci config\n");
-+  return 1;
++  pci_device_cfg_read(lookup_pci_dev(pci_id), (void *)value, reg, width, 
NULL);
++  return 0;
 +}
 +
 +static inline acpi_status
 +acpi_os_write_pci_configuration(struct acpi_pci_id * pci_id, u32 reg,
 +        u64 value, u32 width)
 +{
-+  acpi_os_printf("ACPI: Tried to write pci config\n");
-+  return 1;
++  pci_device_cfg_write(lookup_pci_dev(pci_id), (const void *)&value, reg, 
width, NULL);
++  return 0;
 +}
 +
 +#endif                                /* __KERNEL__ */
diff --git a/debian/patches/acpi-init-files.diff 
b/debian/patches/acpi-init-files.diff
index b83eafd..2fead2b 100644
--- a/debian/patches/acpi-init-files.diff
+++ b/debian/patches/acpi-init-files.diff
@@ -1,6 +1,6 @@
 --- /dev/null
 +++ b/acpi_init.c
-@@ -0,0 +1,510 @@
+@@ -0,0 +1,570 @@
 +// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
 +#include <acpi/acpi.h>
 +
@@ -24,14 +24,22 @@
 +
 +#include <device/device.h>
 +#include <hurd.h>
++#include <pciaccess.h>
 +
 +#define ACPI_MAX_TABLES 128
 +
++#define PCI_CFG1_START 0xcf8
++#define PCI_CFG1_END   0xcff
++
 +extern acpi_status acpi_hw_legacy_sleep(u8 sleep_state);
 +
 +// Lets keep the ACPI tables in this module
 +static struct acpi_table_desc initial_tables[ACPI_MAX_TABLES];
 +
++#define NUMDEVS 32
++static struct pci_device *pci_devices[NUMDEVS];
++static int numdevs = -1;
++
 +struct slots {
 +  uint8_t bus;
 +  uint16_t dev;
@@ -40,6 +48,43 @@
 +  struct slots *next;
 +};
 +
++static void
++pci_init(void)
++{
++  int i = 0;
++  struct pci_device_iterator *dev_iter;
++  struct pci_device *pci_dev;
++
++  pci_system_init ();
++
++  dev_iter = pci_slot_match_iterator_create (NULL);
++  while (((pci_dev = pci_device_next (dev_iter)) != NULL)
++      && (i < NUMDEVS))
++    {
++      pci_device_probe(pci_dev);
++      pci_devices[i++] = pci_dev;
++    }
++  numdevs = i;
++}
++
++struct pci_device *
++lookup_pci_dev(struct acpi_pci_id *pci_id)
++{
++  int i;
++
++  for (i = 0; i < numdevs; i++)
++    {
++      if ((pci_devices[i]->bus == pci_id->bus)
++       && (pci_devices[i]->dev == pci_id->device)
++       && (pci_devices[i]->func == pci_id->function))
++        {
++          return pci_devices[i];
++        }
++    }
++    acpi_os_printf("Can't find pci dev %d:%02x.%d\n", pci_id->bus, 
pci_id->device, pci_id->function);
++    return NULL;
++}
++
 +void
 +acpi_ds_dump_method_stack(acpi_status status, ...)
 +//    struct acpi_walk_state *walk_state, union acpi_parse_object *op)
@@ -224,11 +269,26 @@
 +acpi_status
 +acpi_os_initialize(void)
 +{
-+  if (ioperm(0, 0x10000, 1))
++  /* Avoid giving ioperm to the PCI cfg registers
++   * since GNU/Hurd controls these
++   */
++
++  /* 0-0xcf7 */
++  if (ioperm(0, PCI_CFG1_START, 1))
 +    {
-+      acpi_os_printf("EPERM on ioperm\n");
++      acpi_os_printf("EPERM on ioperm 1\n");
 +      return AE_ERROR;
 +    }
++
++  /* 0xd00-0xffff */
++  if (ioperm(PCI_CFG1_END+1, 0x10000 - (PCI_CFG1_END+1), 1))
++    {
++      acpi_os_printf("EPERM on ioperm 2\n");
++      return AE_ERROR;
++    }
++
++  pci_init();
++
 +  return AE_OK;
 +}
 +
diff --git a/debian/patches/add-makefile.diff b/debian/patches/add-makefile.diff
index da2edc3..a78d8d0 100644
--- a/debian/patches/add-makefile.diff
+++ b/debian/patches/add-makefile.diff
@@ -1,6 +1,6 @@
 --- /dev/null
 +++ b/Makefile
-@@ -0,0 +1,216 @@
+@@ -0,0 +1,218 @@
 +# Copyright (C) 2022 Free Software Foundation, Inc.
 +#
 +# This is free software; you can redistribute it and/or modify
@@ -37,6 +37,8 @@
 +PREFIX ?= /usr/local
 +libdir ?= $(PREFIX)/lib
 +
++LDLIBS = -lpciaccess
++
 +SRCS =        global_state.c          \
 +      acpi_init.c             \
 +      $(BASE)/dsargs.c        \
-- 
2.40.1