From bc12b70f7d216b36bd87701349374a13e486f8eb Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 25 Aug 2022 13:36:40 +0200 Subject: [PATCH] x86/earlyprintk: Clean up pciserial While working on a GRUB patch to support PCI-serial, a number of cleanups were suggested that apply to the code I took inspiration from. Signed-off-by: Peter Zijlstra (Intel) Acked-by: Bjorn Helgaas # pci_ids.h Reviewed-by: Greg Kroah-Hartman Link: https://lkml.kernel.org/r/YwdeyCEtW+wa+QhH@worktop.programming.kicks-ass.net --- arch/x86/kernel/early_printk.c | 14 +++++++------- include/linux/pci_ids.h | 3 +++ 2 files changed, 10 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c index 68b38925a74f..44f937015e1e 100644 --- a/arch/x86/kernel/early_printk.c +++ b/arch/x86/kernel/early_printk.c @@ -264,11 +264,11 @@ static __init void early_pci_serial_init(char *s) bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0); /* - * Verify it is a UART type device + * Verify it is a 16550-UART type device */ if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) && (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) || - (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */ { + (((classcode >> 8) & 0xff) != PCI_SERIAL_16550_COMPATIBLE)) { if (!force) return; } @@ -276,22 +276,22 @@ static __init void early_pci_serial_init(char *s) /* * Determine if it is IO or memory mapped */ - if (bar0 & 0x01) { + if ((bar0 & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) { /* it is IO mapped */ serial_in = io_serial_in; serial_out = io_serial_out; - early_serial_base = bar0&0xfffffffc; + early_serial_base = bar0 & PCI_BASE_ADDRESS_IO_MASK; write_pci_config(bus, slot, func, PCI_COMMAND, - cmdreg|PCI_COMMAND_IO); + cmdreg|PCI_COMMAND_IO); } else { /* It is memory mapped - assume 32-bit alignment */ serial_in = mem32_serial_in; serial_out = mem32_serial_out; /* WARNING! assuming the address is always in the first 4G */ early_serial_base = - (unsigned long)early_ioremap(bar0 & 0xfffffff0, 0x10); + (unsigned long)early_ioremap(bar0 & PCI_BASE_ADDRESS_MEM_MASK, 0x10); write_pci_config(bus, slot, func, PCI_COMMAND, - cmdreg|PCI_COMMAND_MEMORY); + cmdreg|PCI_COMMAND_MEMORY); } /* diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h index 6feade66efdb..41b3fffdbb8e 100644 --- a/include/linux/pci_ids.h +++ b/include/linux/pci_ids.h @@ -75,6 +75,9 @@ #define PCI_CLASS_COMMUNICATION_MODEM 0x0703 #define PCI_CLASS_COMMUNICATION_OTHER 0x0780 +/* Interface for SERIAL/MODEM */ +#define PCI_SERIAL_16550_COMPATIBLE 0x02 + #define PCI_BASE_CLASS_SYSTEM 0x08 #define PCI_CLASS_SYSTEM_PIC 0x0800 #define PCI_CLASS_SYSTEM_PIC_IOAPIC 0x080010