From: Marek Marczykowski-Górecki Date: Mon, 8 May 2023 12:15:38 +0000 (+0200) Subject: ns16550: enable memory decoding on MMIO-based PCI console card X-Git-Tag: 4.18.0-rc1~746 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=a16fb78515d54be95f81c0d1c0a3a7b954a54d0a;p=xen.git ns16550: enable memory decoding on MMIO-based PCI console card pci_serial_early_init() enables PCI_COMMAND_IO for IO-based UART devices, add setting PCI_COMMAND_MEMORY for MMIO-based UART devices too. Note the MMIO-based devices in practice need a "pci" sub-option, otherwise a few parameters are not initialized (including bar_idx, reg_shift, reg_width etc). The "pci" is not supposed to be used with explicit BDF, so do not key setting PCI_COMMAND_MEMORY on explicit BDF being set. Contrary to the IO-based UART, pci_serial_early_init() will not attempt to set BAR0 address, even if user provided io_base manually - in most cases, those are with an offest and the current cmdline syntax doesn't allow expressing it. Due to this, enable PCI_COMMAND_MEMORY only if uart->bar is already populated. In similar spirit, this patch does not support setting BAR0 of the bridge. Signed-off-by: Marek Marczykowski-Górecki Acked-by: Jan Beulich --- diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c index 1b21eb93c4..212a9c49ae 100644 --- a/xen/drivers/char/ns16550.c +++ b/xen/drivers/char/ns16550.c @@ -272,6 +272,14 @@ static int cf_check ns16550_getc(struct serial_port *port, char *pc) static void pci_serial_early_init(struct ns16550 *uart) { #ifdef NS16550_PCI + if ( uart->bar && uart->io_base >= 0x10000 ) + { + pci_conf_write16(PCI_SBDF(0, uart->ps_bdf[0], uart->ps_bdf[1], + uart->ps_bdf[2]), + PCI_COMMAND, PCI_COMMAND_MEMORY); + return; + } + if ( !uart->ps_bdf_enable || uart->io_base >= 0x10000 ) return;