KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted

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 <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>

1 files changed, 327 insertions, 0 deletions

diff --git a/arch/mips/bcm63xx/dev-enet.c b/arch/mips/bcm63xx/dev-enet.c
new file mode 100644
index 000000000..8e73d65f3
--- /dev/null
+++ b/arch/mips/bcm63xx/dev-enet.c
@@ -0,0 +1,327 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/export.h>
+#include <bcm63xx_dev_enet.h>
+#include <bcm63xx_io.h>
+#include <bcm63xx_regs.h>
+
+static const unsigned long bcm6348_regs_enetdmac[] = {
+	[ENETDMAC_CHANCFG]	= ENETDMAC_CHANCFG_REG,
+	[ENETDMAC_IR]		= ENETDMAC_IR_REG,
+	[ENETDMAC_IRMASK]	= ENETDMAC_IRMASK_REG,
+	[ENETDMAC_MAXBURST]	= ENETDMAC_MAXBURST_REG,
+};
+
+static const unsigned long bcm6345_regs_enetdmac[] = {
+	[ENETDMAC_CHANCFG]	= ENETDMA_6345_CHANCFG_REG,
+	[ENETDMAC_IR]		= ENETDMA_6345_IR_REG,
+	[ENETDMAC_IRMASK]	= ENETDMA_6345_IRMASK_REG,
+	[ENETDMAC_MAXBURST]	= ENETDMA_6345_MAXBURST_REG,
+	[ENETDMAC_BUFALLOC]	= ENETDMA_6345_BUFALLOC_REG,
+	[ENETDMAC_RSTART]	= ENETDMA_6345_RSTART_REG,
+	[ENETDMAC_FC]		= ENETDMA_6345_FC_REG,
+	[ENETDMAC_LEN]		= ENETDMA_6345_LEN_REG,
+};
+
+const unsigned long *bcm63xx_regs_enetdmac;
+EXPORT_SYMBOL(bcm63xx_regs_enetdmac);
+
+static __init void bcm63xx_enetdmac_regs_init(void)
+{
+	if (BCMCPU_IS_6345())
+		bcm63xx_regs_enetdmac = bcm6345_regs_enetdmac;
+	else
+		bcm63xx_regs_enetdmac = bcm6348_regs_enetdmac;
+}
+
+static struct resource shared_res[] = {
+	{
+		.start		= -1, /* filled at runtime */
+		.end		= -1, /* filled at runtime */
+		.flags		= IORESOURCE_MEM,
+	},
+	{
+		.start		= -1, /* filled at runtime */
+		.end		= -1, /* filled at runtime */
+		.flags		= IORESOURCE_MEM,
+	},
+	{
+		.start		= -1, /* filled at runtime */
+		.end		= -1, /* filled at runtime */
+		.flags		= IORESOURCE_MEM,
+	},
+};
+
+static struct platform_device bcm63xx_enet_shared_device = {
+	.name		= "bcm63xx_enet_shared",
+	.id		= 0,
+	.num_resources	= ARRAY_SIZE(shared_res),
+	.resource	= shared_res,
+};
+
+static int shared_device_registered;
+
+static u64 enet_dmamask = DMA_BIT_MASK(32);
+
+static struct resource enet0_res[] = {
+	{
+		.start		= -1, /* filled at runtime */
+		.end		= -1, /* filled at runtime */
+		.flags		= IORESOURCE_MEM,
+	},
+	{
+		.start		= -1, /* filled at runtime */
+		.flags		= IORESOURCE_IRQ,
+	},
+	{
+		.start		= -1, /* filled at runtime */
+		.flags		= IORESOURCE_IRQ,
+	},
+	{
+		.start		= -1, /* filled at runtime */
+		.flags		= IORESOURCE_IRQ,
+	},
+};
+
+static struct bcm63xx_enet_platform_data enet0_pd;
+
+static struct platform_device bcm63xx_enet0_device = {
+	.name		= "bcm63xx_enet",
+	.id		= 0,
+	.num_resources	= ARRAY_SIZE(enet0_res),
+	.resource	= enet0_res,
+	.dev		= {
+		.platform_data = &enet0_pd,
+		.dma_mask = &enet_dmamask,
+		.coherent_dma_mask = DMA_BIT_MASK(32),
+	},
+};
+
+static struct resource enet1_res[] = {
+	{
+		.start		= -1, /* filled at runtime */
+		.end		= -1, /* filled at runtime */
+		.flags		= IORESOURCE_MEM,
+	},
+	{
+		.start		= -1, /* filled at runtime */
+		.flags		= IORESOURCE_IRQ,
+	},
+	{
+		.start		= -1, /* filled at runtime */
+		.flags		= IORESOURCE_IRQ,
+	},
+	{
+		.start		= -1, /* filled at runtime */
+		.flags		= IORESOURCE_IRQ,
+	},
+};
+
+static struct bcm63xx_enet_platform_data enet1_pd;
+
+static struct platform_device bcm63xx_enet1_device = {
+	.name		= "bcm63xx_enet",
+	.id		= 1,
+	.num_resources	= ARRAY_SIZE(enet1_res),
+	.resource	= enet1_res,
+	.dev		= {
+		.platform_data = &enet1_pd,
+		.dma_mask = &enet_dmamask,
+		.coherent_dma_mask = DMA_BIT_MASK(32),
+	},
+};
+
+static struct resource enetsw_res[] = {
+	{
+		/* start & end filled at runtime */
+		.flags		= IORESOURCE_MEM,
+	},
+	{
+		/* start filled at runtime */
+		.flags		= IORESOURCE_IRQ,
+	},
+	{
+		/* start filled at runtime */
+		.flags		= IORESOURCE_IRQ,
+	},
+};
+
+static struct bcm63xx_enetsw_platform_data enetsw_pd;
+
+static struct platform_device bcm63xx_enetsw_device = {
+	.name		= "bcm63xx_enetsw",
+	.num_resources	= ARRAY_SIZE(enetsw_res),
+	.resource	= enetsw_res,
+	.dev		= {
+		.platform_data = &enetsw_pd,
+		.dma_mask = &enet_dmamask,
+		.coherent_dma_mask = DMA_BIT_MASK(32),
+	},
+};
+
+static int __init register_shared(void)
+{
+	int ret, chan_count;
+
+	if (shared_device_registered)
+		return 0;
+
+	bcm63xx_enetdmac_regs_init();
+
+	shared_res[0].start = bcm63xx_regset_address(RSET_ENETDMA);
+	shared_res[0].end = shared_res[0].start;
+	if (BCMCPU_IS_6345())
+		shared_res[0].end += (RSET_6345_ENETDMA_SIZE) - 1;
+	else
+		shared_res[0].end += (RSET_ENETDMA_SIZE)  - 1;
+
+	if (BCMCPU_IS_6328() || BCMCPU_IS_6362() || BCMCPU_IS_6368())
+		chan_count = 32;
+	else if (BCMCPU_IS_6345())
+		chan_count = 8;
+	else
+		chan_count = 16;
+
+	shared_res[1].start = bcm63xx_regset_address(RSET_ENETDMAC);
+	shared_res[1].end = shared_res[1].start;
+	shared_res[1].end += RSET_ENETDMAC_SIZE(chan_count)  - 1;
+
+	shared_res[2].start = bcm63xx_regset_address(RSET_ENETDMAS);
+	shared_res[2].end = shared_res[2].start;
+	shared_res[2].end += RSET_ENETDMAS_SIZE(chan_count)  - 1;
+
+	ret = platform_device_register(&bcm63xx_enet_shared_device);
+	if (ret)
+		return ret;
+	shared_device_registered = 1;
+
+	return 0;
+}
+
+int __init bcm63xx_enet_register(int unit,
+				 const struct bcm63xx_enet_platform_data *pd)
+{
+	struct platform_device *pdev;
+	struct bcm63xx_enet_platform_data *dpd;
+	int ret;
+
+	if (unit > 1)
+		return -ENODEV;
+
+	if (unit == 1 && (BCMCPU_IS_6338() || BCMCPU_IS_6345()))
+		return -ENODEV;
+
+	ret = register_shared();
+	if (ret)
+		return ret;
+
+	if (unit == 0) {
+		enet0_res[0].start = bcm63xx_regset_address(RSET_ENET0);
+		enet0_res[0].end = enet0_res[0].start;
+		enet0_res[0].end += RSET_ENET_SIZE - 1;
+		enet0_res[1].start = bcm63xx_get_irq_number(IRQ_ENET0);
+		enet0_res[2].start = bcm63xx_get_irq_number(IRQ_ENET0_RXDMA);
+		enet0_res[3].start = bcm63xx_get_irq_number(IRQ_ENET0_TXDMA);
+		pdev = &bcm63xx_enet0_device;
+	} else {
+		enet1_res[0].start = bcm63xx_regset_address(RSET_ENET1);
+		enet1_res[0].end = enet1_res[0].start;
+		enet1_res[0].end += RSET_ENET_SIZE - 1;
+		enet1_res[1].start = bcm63xx_get_irq_number(IRQ_ENET1);
+		enet1_res[2].start = bcm63xx_get_irq_number(IRQ_ENET1_RXDMA);
+		enet1_res[3].start = bcm63xx_get_irq_number(IRQ_ENET1_TXDMA);
+		pdev = &bcm63xx_enet1_device;
+	}
+
+	/* copy given platform data */
+	dpd = pdev->dev.platform_data;
+	memcpy(dpd, pd, sizeof(*pd));
+
+	/* adjust them in case internal phy is used */
+	if (dpd->use_internal_phy) {
+
+		/* internal phy only exists for enet0 */
+		if (unit == 1)
+			return -ENODEV;
+
+		dpd->phy_id = 1;
+		dpd->has_phy_interrupt = 1;
+		dpd->phy_interrupt = bcm63xx_get_irq_number(IRQ_ENET_PHY);
+	}
+
+	dpd->dma_chan_en_mask = ENETDMAC_CHANCFG_EN_MASK;
+	dpd->dma_chan_int_mask = ENETDMAC_IR_PKTDONE_MASK;
+	if (BCMCPU_IS_6345()) {
+		dpd->dma_chan_en_mask |= ENETDMAC_CHANCFG_CHAINING_MASK;
+		dpd->dma_chan_en_mask |= ENETDMAC_CHANCFG_WRAP_EN_MASK;
+		dpd->dma_chan_en_mask |= ENETDMAC_CHANCFG_FLOWC_EN_MASK;
+		dpd->dma_chan_int_mask |= ENETDMA_IR_BUFDONE_MASK;
+		dpd->dma_chan_int_mask |= ENETDMA_IR_NOTOWNER_MASK;
+		dpd->dma_chan_width = ENETDMA_6345_CHAN_WIDTH;
+		dpd->dma_desc_shift = ENETDMA_6345_DESC_SHIFT;
+	} else {
+		dpd->dma_has_sram = true;
+		dpd->dma_chan_width = ENETDMA_CHAN_WIDTH;
+	}
+
+	if (unit == 0) {
+		dpd->rx_chan = 0;
+		dpd->tx_chan = 1;
+	} else {
+		dpd->rx_chan = 2;
+		dpd->tx_chan = 3;
+	}
+
+	ret = platform_device_register(pdev);
+	if (ret)
+		return ret;
+	return 0;
+}
+
+int __init
+bcm63xx_enetsw_register(const struct bcm63xx_enetsw_platform_data *pd)
+{
+	int ret;
+
+	if (!BCMCPU_IS_6328() && !BCMCPU_IS_6362() && !BCMCPU_IS_6368())
+		return -ENODEV;
+
+	ret = register_shared();
+	if (ret)
+		return ret;
+
+	enetsw_res[0].start = bcm63xx_regset_address(RSET_ENETSW);
+	enetsw_res[0].end = enetsw_res[0].start;
+	enetsw_res[0].end += RSET_ENETSW_SIZE - 1;
+	enetsw_res[1].start = bcm63xx_get_irq_number(IRQ_ENETSW_RXDMA0);
+	enetsw_res[2].start = bcm63xx_get_irq_number(IRQ_ENETSW_TXDMA0);
+	if (!enetsw_res[2].start)
+		enetsw_res[2].start = -1;
+
+	memcpy(bcm63xx_enetsw_device.dev.platform_data, pd, sizeof(*pd));
+
+	if (BCMCPU_IS_6328())
+		enetsw_pd.num_ports = ENETSW_PORTS_6328;
+	else if (BCMCPU_IS_6362() || BCMCPU_IS_6368())
+		enetsw_pd.num_ports = ENETSW_PORTS_6368;
+
+	enetsw_pd.dma_has_sram = true;
+	enetsw_pd.dma_chan_width = ENETDMA_CHAN_WIDTH;
+	enetsw_pd.dma_chan_en_mask = ENETDMAC_CHANCFG_EN_MASK;
+	enetsw_pd.dma_chan_int_mask = ENETDMAC_IR_PKTDONE_MASK;
+
+	ret = platform_device_register(&bcm63xx_enetsw_device);
+	if (ret)
+		return ret;
+
+	return 0;
+}