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/sysdev/grackle.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 arch/powerpc/sysdev/grackle.c (limited to 'arch/powerpc/sysdev/grackle.c') diff --git a/arch/powerpc/sysdev/grackle.c b/arch/powerpc/sysdev/grackle.c new file mode 100644 index 000000000..7dce8278b --- /dev/null +++ b/arch/powerpc/sysdev/grackle.c @@ -0,0 +1,43 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Functions for setting up and using a MPC106 northbridge + * Extracted from arch/powerpc/platforms/powermac/pci.c. + * + * Copyright (C) 2003 Benjamin Herrenschmuidt (benh@kernel.crashing.org) + * Copyright (C) 1997 Paul Mackerras (paulus@samba.org) + */ +#include +#include +#include +#include + +#include +#include +#include + +#define GRACKLE_CFA(b, d, o) (0x80 | ((b) << 8) | ((d) << 16) \ + | (((o) & ~3) << 24)) + +#define GRACKLE_PICR1_LOOPSNOOP 0x00000010 + +static inline void grackle_set_loop_snoop(struct pci_controller *bp, int enable) +{ + unsigned int val; + + out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8)); + val = in_le32(bp->cfg_data); + val = enable? (val | GRACKLE_PICR1_LOOPSNOOP) : + (val & ~GRACKLE_PICR1_LOOPSNOOP); + out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8)); + out_le32(bp->cfg_data, val); + (void)in_le32(bp->cfg_data); +} + +void __init setup_grackle(struct pci_controller *hose) +{ + setup_indirect_pci(hose, 0xfec00000, 0xfee00000, 0); + if (of_machine_is_compatible("PowerMac1,1")) + pci_add_flags(PCI_REASSIGN_ALL_BUS); + if (of_machine_is_compatible("AAPL,PowerBook1998")) + grackle_set_loop_snoop(hose, 1); +} -- cgit v1.3.1