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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /arch/x86/pci/legacy.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | arch/x86/pci/legacy.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/arch/x86/pci/legacy.c b/arch/x86/pci/legacy.c new file mode 100644 index 000000000..467311b1e --- /dev/null +++ b/arch/x86/pci/legacy.c @@ -0,0 +1,77 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * legacy.c - traditional, old school PCI bus probing + */ +#include <linux/init.h> +#include <linux/export.h> +#include <linux/pci.h> +#include <asm/jailhouse_para.h> +#include <asm/pci_x86.h> + +/* + * Discover remaining PCI buses in case there are peer host bridges. + * We use the number of last PCI bus provided by the PCI BIOS. + */ +static void pcibios_fixup_peer_bridges(void) +{ + int n; + + if (pcibios_last_bus <= 0 || pcibios_last_bus > 0xff) + return; + DBG("PCI: Peer bridge fixup\n"); + + for (n=0; n <= pcibios_last_bus; n++) + pcibios_scan_specific_bus(n); +} + +int __init pci_legacy_init(void) +{ + if (!raw_pci_ops) + return 1; + + pr_info("PCI: Probing PCI hardware\n"); + pcibios_scan_root(0); + return 0; +} + +void pcibios_scan_specific_bus(int busn) +{ + int stride = jailhouse_paravirt() ? 1 : 8; + int devfn; + u32 l; + + if (pci_find_bus(0, busn)) + return; + + for (devfn = 0; devfn < 256; devfn += stride) { + if (!raw_pci_read(0, busn, devfn, PCI_VENDOR_ID, 2, &l) && + l != 0x0000 && l != 0xffff) { + DBG("Found device at %02x:%02x [%04x]\n", busn, devfn, l); + pr_info("PCI: Discovered peer bus %02x\n", busn); + pcibios_scan_root(busn); + return; + } + } +} +EXPORT_SYMBOL_GPL(pcibios_scan_specific_bus); + +static int __init pci_subsys_init(void) +{ + /* + * The init function returns an non zero value when + * pci_legacy_init should be invoked. + */ + if (x86_init.pci.init()) { + if (pci_legacy_init()) { + pr_info("PCI: System does not support PCI\n"); + return -ENODEV; + } + } + + pcibios_fixup_peer_bridges(); + x86_init.pci.init_irq(); + pcibios_init(); + + return 0; +} +subsys_initcall(pci_subsys_init); |