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 --- drivers/mtd/maps/solutionengine.c | 95 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 drivers/mtd/maps/solutionengine.c (limited to 'drivers/mtd/maps/solutionengine.c') diff --git a/drivers/mtd/maps/solutionengine.c b/drivers/mtd/maps/solutionengine.c new file mode 100644 index 000000000..c07f21b20 --- /dev/null +++ b/drivers/mtd/maps/solutionengine.c @@ -0,0 +1,95 @@ +/* + * Flash and EPROM on Hitachi Solution Engine and similar boards. + * + * (C) 2001 Red Hat, Inc. + * + * GPL'd + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static struct mtd_info *flash_mtd; +static struct mtd_info *eprom_mtd; + +struct map_info soleng_eprom_map = { + .name = "Solution Engine EPROM", + .size = 0x400000, + .bankwidth = 4, +}; + +struct map_info soleng_flash_map = { + .name = "Solution Engine FLASH", + .size = 0x400000, + .bankwidth = 4, +}; + +static const char * const probes[] = { "RedBoot", "cmdlinepart", NULL }; + +static int __init init_soleng_maps(void) +{ + /* First probe at offset 0 */ + soleng_flash_map.phys = 0; + soleng_flash_map.virt = (void __iomem *)P2SEGADDR(0); + soleng_eprom_map.phys = 0x01000000; + soleng_eprom_map.virt = (void __iomem *)P1SEGADDR(0x01000000); + simple_map_init(&soleng_eprom_map); + simple_map_init(&soleng_flash_map); + + printk(KERN_NOTICE "Probing for flash chips at 0x00000000:\n"); + flash_mtd = do_map_probe("cfi_probe", &soleng_flash_map); + if (!flash_mtd) { + /* Not there. Try swapping */ + printk(KERN_NOTICE "Probing for flash chips at 0x01000000:\n"); + soleng_flash_map.phys = 0x01000000; + soleng_flash_map.virt = P2SEGADDR(0x01000000); + soleng_eprom_map.phys = 0; + soleng_eprom_map.virt = P1SEGADDR(0); + flash_mtd = do_map_probe("cfi_probe", &soleng_flash_map); + if (!flash_mtd) { + /* Eep. */ + printk(KERN_NOTICE "Flash chips not detected at either possible location.\n"); + return -ENXIO; + } + } + printk(KERN_NOTICE "Solution Engine: Flash at 0x%pap, EPROM at 0x%pap\n", + &soleng_flash_map.phys, + &soleng_eprom_map.phys); + flash_mtd->owner = THIS_MODULE; + + eprom_mtd = do_map_probe("map_rom", &soleng_eprom_map); + if (eprom_mtd) { + eprom_mtd->owner = THIS_MODULE; + mtd_device_register(eprom_mtd, NULL, 0); + } + + mtd_device_parse_register(flash_mtd, probes, NULL, NULL, 0); + + return 0; +} + +static void __exit cleanup_soleng_maps(void) +{ + if (eprom_mtd) { + mtd_device_unregister(eprom_mtd); + map_destroy(eprom_mtd); + } + + mtd_device_unregister(flash_mtd); + map_destroy(flash_mtd); +} + +module_init(init_soleng_maps); +module_exit(cleanup_soleng_maps); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("David Woodhouse "); +MODULE_DESCRIPTION("MTD map driver for Hitachi SolutionEngine (and similar) boards"); + -- cgit v1.3.1