x86: Refactor PCI to permit alternate init

We want access PCI earlier in the init sequence, so refactor the code so
that it does not require use of a BSS variable to work. This will allow us
to use early malloc() to store information about a PCI hose.

Common PCI code moves to arch/x86/cpu/pci.c and a new
board_pci_setup_hose() function is provided by boards to set up the (single)
hose used by that board.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/cpu/Makefile

@@ -11,3 +11,4 @@
 extra-y	= start.o
 obj-$(CONFIG_X86_RESET_VECTOR) += resetvec.o start16.o
 obj-y	+= interrupts.o cpu.o call64.o
+obj-$(CONFIG_PCI) += pci.o

arch/x86/cpu/coreboot/pci.c

@@ -13,8 +13,6 @@
 #include <pci.h>
 #include <asm/pci.h>
 
-static struct pci_controller coreboot_hose;
-
 static void config_pci_bridge(struct pci_controller *hose, pci_dev_t dev,
 			      struct pci_config_table *table)
 {
@@ -31,19 +29,13 @@ static struct pci_config_table pci_coreboot_config_table[] = {
 	{}
 };
 
-void pci_init_board(void)
+void board_pci_setup_hose(struct pci_controller *hose)
 {
-	coreboot_hose.config_table = pci_coreboot_config_table;
-	coreboot_hose.first_busno = 0;
-	coreboot_hose.last_busno = 0;
-
-	pci_set_region(coreboot_hose.regions + 0, 0x0, 0x0, 0xffffffff,
-		PCI_REGION_MEM);
-	coreboot_hose.region_count = 1;
-
-	pci_setup_type1(&coreboot_hose);
-
-	pci_register_hose(&coreboot_hose);
+	hose->config_table = pci_coreboot_config_table;
+	hose->first_busno = 0;
+	hose->last_busno = 0;
 
-	pci_hose_scan(&coreboot_hose);
+	pci_set_region(hose->regions + 0, 0x0, 0x0, 0xffffffff,
+		       PCI_REGION_MEM);
+	hose->region_count = 1;
 }

arch/x86/cpu/pci.c

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * (C) Copyright 2008,2009
+ * Graeme Russ, <graeme.russ@gmail.com>
+ *
+ * (C) Copyright 2002
+ * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <pci.h>
+#include <asm/pci.h>
+
+static struct pci_controller x86_hose;
+
+void pci_init_board(void)
+{
+	struct pci_controller *hose = &x86_hose;
+
+	board_pci_setup_hose(hose);
+	pci_setup_type1(hose);
+	pci_register_hose(hose);
+
+	hose->last_busno = pci_hose_scan(hose);
+}

arch/x86/include/asm/pci.h

@@ -12,5 +12,16 @@
 #define DEFINE_PCI_DEVICE_TABLE(_table) \
 	const struct pci_device_id _table[]
 
+struct pci_controller;
+
 void pci_setup_type1(struct pci_controller *hose);
+
+/**
+ * board_pci_setup_hose() - Set up the PCI hose
+ *
+ * This is called by the common x86 PCI code to set up the PCI controller
+ * hose. It may be called when no memory/BSS is available so should just
+ * store things in 'hose' and not in BSS variables.
+ */
+void board_pci_setup_hose(struct pci_controller *hose);
 #endif