On Tue, Aug 13, 2019 at 8:12 PM Aaro Koskinen <aaro.koskinen@xxxxxx> wrote: > On Tue, Aug 13, 2019 at 01:02:16PM +0200, Arnd Bergmann wrote: > > On Tue, Aug 13, 2019 at 12:36 PM Tony Lindgren <tony@xxxxxxxxxxx> wrote: > > > - I force CONFIG_PCI to be enabled here in order to keep the > > asm/io.h logic unchanged. If PCI support in itself is an issue, > > then turning on CONFIG_PCI without the rest of this patch > > should also break. > > The board dies early, probably in pci_reserve_io(): > > Starting kernel ... > > [ 0.000000] Booting Linux on physical CPU 0x0 > [ 0.000000] Linux version 5.3.0-rc4-osk-los_80efa+-00028-g09f6f22a63e9 (aaro@amd-fx-6350) (gcc version 8.3.0 (GCC)) #1 Tue Aug 13 20:50:11 EEST 2019 > [ 0.000000] CPU: ARM926EJ-S [41069263] revision 3 (ARMv5TEJ), cr=0005317f > [ 0.000000] CPU: VIVT data cache, VIVT instruction cache > [ 0.000000] Machine: TI-OSK > [ 0.000000] Ignoring tag cmdline (using the default kernel command line) > [ 0.000000] printk: bootconsole [earlycon0] enabled > [ 0.000000] Memory policy: Data cache writeback > [ 0.000000] Internal error: Oops - undefined instruction: 0 [#1] ARM > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.3.0-rc4-osk-los_80efa+-00028-g09f6f22a63e9 #1 > [ 0.000000] Hardware name: TI-OSK > [ 0.000000] PC is at vm_area_add_early+0x1c/0x74 That sounds like an address conflict in the virtual addres space. In multiplatform kernels, PCI I/O space is hardwired to addresses 0xfee00000-0xfeffffff, which happened to be available on all the other machines that needed it so far. OMAP1_IO_VIRT is 0xfefb0000-0xfefeffff, which clearly overlaps with the end of the PCI I/O area. We only really need 4KB of I/O space rather than the full 2MB, but it would also be good not to make this too machine specific. Could we change OMAP1_IO_OFFSET to stay out of that area? Something like diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug index 97c114c1ef80..3b66d203dc98 100644 --- a/arch/arm/Kconfig.debug +++ b/arch/arm/Kconfig.debug @@ -1794,9 +1794,9 @@ config DEBUG_UART_VIRT default 0xfef00000 if ARCH_IXP4XX && !CPU_BIG_ENDIAN default 0xfef00003 if ARCH_IXP4XX && CPU_BIG_ENDIAN default 0xfef36000 if DEBUG_HIGHBANK_UART - default 0xfefb0000 if DEBUG_OMAP1UART1 || DEBUG_OMAP7XXUART1 - default 0xfefb0800 if DEBUG_OMAP1UART2 || DEBUG_OMAP7XXUART2 - default 0xfefb9800 if DEBUG_OMAP1UART3 || DEBUG_OMAP7XXUART3 + default 0xff000000 if DEBUG_OMAP1UART1 || DEBUG_OMAP7XXUART1 + default 0xff000800 if DEBUG_OMAP1UART2 || DEBUG_OMAP7XXUART2 + default 0xff009800 if DEBUG_OMAP1UART3 || DEBUG_OMAP7XXUART3 default 0xff003000 if DEBUG_U300_UART default 0xffd01000 if DEBUG_HIP01_UART default DEBUG_UART_PHYS if !MMU diff --git a/arch/arm/mach-omap1/hardware.h b/arch/arm/mach-omap1/hardware.h index 232b8deef907..9fc76a3c9e57 100644 --- a/arch/arm/mach-omap1/hardware.h +++ b/arch/arm/mach-omap1/hardware.h @@ -61,7 +61,7 @@ static inline u32 omap_cs3_phys(void) #endif /* ifndef __ASSEMBLER__ */ -#define OMAP1_IO_OFFSET 0x01000000 /* Virtual IO = 0xfefb0000 */ +#define OMAP1_IO_OFFSET 0x00fb0000 /* Virtual IO = 0xff000000 */ #define OMAP1_IO_ADDRESS(pa) IOMEM((pa) - OMAP1_IO_OFFSET) #include "serial.h" There may be additional locations that hardcode the virtual address. Arnd