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/misc/cb710/debug.c | 115 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 115 insertions(+) create mode 100644 drivers/misc/cb710/debug.c (limited to 'drivers/misc/cb710/debug.c') diff --git a/drivers/misc/cb710/debug.c b/drivers/misc/cb710/debug.c new file mode 100644 index 000000000..20d672edf --- /dev/null +++ b/drivers/misc/cb710/debug.c @@ -0,0 +1,115 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * cb710/debug.c + * + * Copyright by Michał Mirosław, 2008-2009 + */ +#include +#include +#include + +#define CB710_REG_COUNT 0x80 + +static const u16 allow[CB710_REG_COUNT/16] = { + 0xFFF0, 0xFFFF, 0xFFFF, 0xFFFF, + 0xFFF0, 0xFFFF, 0xFFFF, 0xFFFF, +}; +static const char *const prefix[ARRAY_SIZE(allow)] = { + "MMC", "MMC", "MMC", "MMC", + "MS?", "MS?", "SM?", "SM?" +}; + +static inline int allow_reg_read(unsigned block, unsigned offset, unsigned bits) +{ + unsigned mask = (1 << bits/8) - 1; + offset *= bits/8; + return ((allow[block] >> offset) & mask) == mask; +} + +#define CB710_READ_REGS_TEMPLATE(t) \ +static void cb710_read_regs_##t(void __iomem *iobase, \ + u##t *reg, unsigned select) \ +{ \ + unsigned i, j; \ + \ + for (i = 0; i < ARRAY_SIZE(allow); ++i, reg += 16/(t/8)) { \ + if (!(select & (1 << i))) \ + continue; \ + \ + for (j = 0; j < 0x10/(t/8); ++j) { \ + if (!allow_reg_read(i, j, t)) \ + continue; \ + reg[j] = ioread##t(iobase \ + + (i << 4) + (j * (t/8))); \ + } \ + } \ +} + +static const char cb710_regf_8[] = "%02X"; +static const char cb710_regf_16[] = "%04X"; +static const char cb710_regf_32[] = "%08X"; +static const char cb710_xes[] = "xxxxxxxx"; + +#define CB710_DUMP_REGS_TEMPLATE(t) \ +static void cb710_dump_regs_##t(struct device *dev, \ + const u##t *reg, unsigned select) \ +{ \ + const char *const xp = &cb710_xes[8 - t/4]; \ + const char *const format = cb710_regf_##t; \ + \ + char msg[100], *p; \ + unsigned i, j; \ + \ + for (i = 0; i < ARRAY_SIZE(allow); ++i, reg += 16/(t/8)) { \ + if (!(select & (1 << i))) \ + continue; \ + p = msg; \ + for (j = 0; j < 0x10/(t/8); ++j) { \ + *p++ = ' '; \ + if (j == 8/(t/8)) \ + *p++ = ' '; \ + if (allow_reg_read(i, j, t)) \ + p += sprintf(p, format, reg[j]); \ + else \ + p += sprintf(p, "%s", xp); \ + } \ + dev_dbg(dev, "%s 0x%02X %s\n", prefix[i], i << 4, msg); \ + } \ +} + +#define CB710_READ_AND_DUMP_REGS_TEMPLATE(t) \ +static void cb710_read_and_dump_regs_##t(struct cb710_chip *chip, \ + unsigned select) \ +{ \ + u##t regs[CB710_REG_COUNT/sizeof(u##t)]; \ + \ + memset(®s, 0, sizeof(regs)); \ + cb710_read_regs_##t(chip->iobase, regs, select); \ + cb710_dump_regs_##t(cb710_chip_dev(chip), regs, select); \ +} + +#define CB710_REG_ACCESS_TEMPLATES(t) \ + CB710_READ_REGS_TEMPLATE(t) \ + CB710_DUMP_REGS_TEMPLATE(t) \ + CB710_READ_AND_DUMP_REGS_TEMPLATE(t) + +CB710_REG_ACCESS_TEMPLATES(8) +CB710_REG_ACCESS_TEMPLATES(16) +CB710_REG_ACCESS_TEMPLATES(32) + +void cb710_dump_regs(struct cb710_chip *chip, unsigned select) +{ + if (!(select & CB710_DUMP_REGS_MASK)) + select = CB710_DUMP_REGS_ALL; + if (!(select & CB710_DUMP_ACCESS_MASK)) + select |= CB710_DUMP_ACCESS_8; + + if (select & CB710_DUMP_ACCESS_32) + cb710_read_and_dump_regs_32(chip, select); + if (select & CB710_DUMP_ACCESS_16) + cb710_read_and_dump_regs_16(chip, select); + if (select & CB710_DUMP_ACCESS_8) + cb710_read_and_dump_regs_8(chip, select); +} +EXPORT_SYMBOL_GPL(cb710_dump_regs); + -- cgit v1.3.1