From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- arch/powerpc/boot/serial.c | 152 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 152 insertions(+) create mode 100644 arch/powerpc/boot/serial.c (limited to 'arch/powerpc/boot/serial.c') diff --git a/arch/powerpc/boot/serial.c b/arch/powerpc/boot/serial.c new file mode 100644 index 000000000..1d221ff42 --- /dev/null +++ b/arch/powerpc/boot/serial.c @@ -0,0 +1,152 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Generic serial console support + * + * Author: Mark A. Greer + * + * Code in serial_edit_cmdline() copied from + * and was written by Matt Porter . + * + * 2001,2006 (c) MontaVista Software, Inc. + */ +#include +#include +#include "types.h" +#include "string.h" +#include "stdio.h" +#include "io.h" +#include "ops.h" + +static int serial_open(void) +{ + struct serial_console_data *scdp = console_ops.data; + return scdp->open(); +} + +static void serial_write(const char *buf, int len) +{ + struct serial_console_data *scdp = console_ops.data; + + while (*buf != '\0') + scdp->putc(*buf++); +} + +static void serial_edit_cmdline(char *buf, int len, unsigned int timeout) +{ + int timer = 0, count; + char ch, *cp; + struct serial_console_data *scdp = console_ops.data; + + count = strlen(buf); + cp = &buf[count]; + count++; + + do { + if (scdp->tstc()) { + while (((ch = scdp->getc()) != '\n') && (ch != '\r')) { + /* Test for backspace/delete */ + if ((ch == '\b') || (ch == '\177')) { + if (cp != buf) { + cp--; + count--; + printf("\b \b"); + } + /* Test for ^x/^u (and wipe the line) */ + } else if ((ch == '\030') || (ch == '\025')) { + while (cp != buf) { + cp--; + count--; + printf("\b \b"); + } + } else if (count < len) { + *cp++ = ch; + count++; + scdp->putc(ch); + } + } + break; /* Exit 'timer' loop */ + } + udelay(1000); /* 1 msec */ + } while (timer++ < timeout); + *cp = 0; +} + +static void serial_close(void) +{ + struct serial_console_data *scdp = console_ops.data; + + if (scdp->close) + scdp->close(); +} + +static void *serial_get_stdout_devp(void) +{ + void *devp; + char devtype[MAX_PROP_LEN]; + char path[MAX_PATH_LEN]; + + devp = finddevice("/chosen"); + if (devp == NULL) + goto err_out; + + if (getprop(devp, "linux,stdout-path", path, MAX_PATH_LEN) > 0 || + getprop(devp, "stdout-path", path, MAX_PATH_LEN) > 0) { + devp = finddevice(path); + if (devp == NULL) + goto err_out; + + if ((getprop(devp, "device_type", devtype, sizeof(devtype)) > 0) + && !strcmp(devtype, "serial")) + return devp; + } +err_out: + return NULL; +} + +static struct serial_console_data serial_cd; + +/* Node's "compatible" property determines which serial driver to use */ +int serial_console_init(void) +{ + void *devp; + int rc = -1; + + devp = serial_get_stdout_devp(); + if (devp == NULL) + goto err_out; + + if (dt_is_compatible(devp, "ns16550") || + dt_is_compatible(devp, "pnpPNP,501")) + rc = ns16550_console_init(devp, &serial_cd); +#ifdef CONFIG_CPM + else if (dt_is_compatible(devp, "fsl,cpm1-scc-uart") || + dt_is_compatible(devp, "fsl,cpm1-smc-uart") || + dt_is_compatible(devp, "fsl,cpm2-scc-uart") || + dt_is_compatible(devp, "fsl,cpm2-smc-uart")) + rc = cpm_console_init(devp, &serial_cd); +#endif +#ifdef CONFIG_PPC_MPC52xx + else if (dt_is_compatible(devp, "fsl,mpc5200-psc-uart")) + rc = mpc5200_psc_console_init(devp, &serial_cd); +#endif +#ifdef CONFIG_PPC_POWERNV + else if (dt_is_compatible(devp, "ibm,opal-console-raw")) + rc = opal_console_init(devp, &serial_cd); +#endif + + /* Add other serial console driver calls here */ + + if (!rc) { + console_ops.open = serial_open; + console_ops.write = serial_write; + console_ops.close = serial_close; + console_ops.data = &serial_cd; + + if (serial_cd.getc) + console_ops.edit_cmdline = serial_edit_cmdline; + + return 0; + } +err_out: + return -1; +} -- cgit v1.3.1