litmus-rt.git - The LITMUS^RT kernel.

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author	H. Peter Anvin <hpa@zytor.com>	2010-02-17 21:32:06 -0500
committer	H. Peter Anvin <hpa@zytor.com>	2010-02-17 21:32:06 -0500
commit	f1f6baf8f1df29be38003089787e378567ce0086 (patch)
tree	241bbc2e266f5d08cec510064fc4a2cc0417c46e /kernel/mutex-debug.c
parent	b0483e78e5c4c9871fc5541875b3bc006846d46b (diff)

x86, setup: When restoring the screen, update boot_params.screen_info

When we restore the screen content after a mode change, we return the cursor to its former position. However, we need to also update boot_params.screen_info accordingly, so that the decompression code knows where on the screen the cursor is. Just in case the video BIOS does something extra screwy, read the cursor position back from the BIOS instead of relying on it doing the right thing. While we're at it, make sure we cap the cursor position to the new screen coordinates. Reported-by: Wim Osterholt <wim@djo.tudelft.nl> Bugzilla-Reference: http://bugzilla.kernel.org/show_bug.cgi?id=15329 Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Diffstat (limited to 'kernel/mutex-debug.c')

0 files changed, 0 insertions, 0 deletions

// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2010-2012 Broadcom. All rights reserved. * Copyright (c) 2013 Lubomir Rintel */ #include <linux/hw_random.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of_address.h> #include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/printk.h> #include <linux/clk.h> #define RNG_CTRL 0x0 #define RNG_STATUS 0x4 #define RNG_DATA 0x8 #define RNG_INT_MASK 0x10 /* enable rng */ #define RNG_RBGEN 0x1 /* the initial numbers generated are "less random" so will be discarded */ #define RNG_WARMUP_COUNT 0x40000 #define RNG_INT_OFF 0x1 struct bcm2835_rng_priv { struct hwrng rng; void __iomem *base; bool mask_interrupts; struct clk *clk; }; static inline struct bcm2835_rng_priv *to_rng_priv(struct hwrng *rng) { return container_of(rng, struct bcm2835_rng_priv, rng); } static inline u32 rng_readl(struct bcm2835_rng_priv *priv, u32 offset) { /* MIPS chips strapped for BE will automagically configure the * peripheral registers for CPU-native byte order. */ if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) return __raw_readl(priv->base + offset); else return readl(priv->base + offset); } static inline void rng_writel(struct bcm2835_rng_priv *priv, u32 val, u32 offset) { if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) __raw_writel(val, priv->base + offset); else writel(val, priv->base + offset); } static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) { struct bcm2835_rng_priv *priv = to_rng_priv(rng); u32 max_words = max / sizeof(u32); u32 num_words, count; while ((rng_readl(priv, RNG_STATUS) >> 24) == 0) { if (!wait) return 0; cpu_relax(); } num_words = rng_readl(priv, RNG_STATUS) >> 24; if (num_words > max_words) num_words = max_words; for (count = 0; count < num_words; count++) ((u32 *)buf)[count] = rng_readl(priv, RNG_DATA); return num_words * sizeof(u32); } static int bcm2835_rng_init(struct hwrng *rng) { struct bcm2835_rng_priv *priv = to_rng_priv(rng); int ret = 0; u32 val; if (!IS_ERR(priv->clk)) { ret = clk_prepare_enable(priv->clk); if (ret) return ret; } if (priv->mask_interrupts) { /* mask the interrupt */ val = rng_readl(priv, RNG_INT_MASK); val |= RNG_INT_OFF; rng_writel(priv, val, RNG_INT_MASK); } /* set warm-up count & enable */ rng_writel(priv, RNG_WARMUP_COUNT, RNG_STATUS); rng_writel(priv, RNG_RBGEN, RNG_CTRL); return ret; } static void bcm2835_rng_cleanup(struct hwrng *rng) { struct bcm2835_rng_priv *priv = to_rng_priv(rng); /* disable rng hardware */ rng_writel(priv, 0, RNG_CTRL); if (!IS_ERR(priv->clk)) clk_disable_unprepare(priv->clk); } struct bcm2835_rng_of_data { bool mask_interrupts; }; static const struct bcm2835_rng_of_data nsp_rng_of_data = { .mask_interrupts = true, }; static const struct of_device_id bcm2835_rng_of_match[] = { { .compatible = "brcm,bcm2835-rng"}, { .compatible = "brcm,bcm-nsp-rng", .data = &nsp_rng_of_data }, { .compatible = "brcm,bcm5301x-rng", .data = &nsp_rng_of_data }, { .compatible = "brcm,bcm6368-rng"}, {}, }; static int bcm2835_rng_probe(struct platform_device *pdev) { const struct bcm2835_rng_of_data *of_data; struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; const struct of_device_id *rng_id; struct bcm2835_rng_priv *priv; struct resource *r; int err; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; platform_set_drvdata(pdev, priv); r = platform_get_resource(pdev, IORESOURCE_MEM, 0); /* map peripheral */ priv->base = devm_ioremap_resource(dev, r); if (IS_ERR(priv->base)) return PTR_ERR(priv->base); /* Clock is optional on most platforms */ priv->clk = devm_clk_get(dev, NULL); if (IS_ERR(priv->clk) && PTR_ERR(priv->clk) == -EPROBE_DEFER) return -EPROBE_DEFER; priv->rng.name = pdev->name; priv->rng.init = bcm2835_rng_init; priv->rng.read = bcm2835_rng_read; priv->rng.cleanup = bcm2835_rng_cleanup; rng_id = of_match_node(bcm2835_rng_of_match, np); if (!rng_id) return -EINVAL; /* Check for rng init function, execute it */ of_data = rng_id->data; if (of_data) priv->mask_interrupts = of_data->mask_interrupts; /* register driver */ err = devm_hwrng_register(dev, &priv->rng); if (err) dev_err(dev, "hwrng registration failed\n"); else dev_info(dev, "hwrng registered\n"); return err; } MODULE_DEVICE_TABLE(of, bcm2835_rng_of_match); static struct platform_device_id bcm2835_rng_devtype[] = { { .name = "bcm2835-rng" }, { .name = "bcm63xx-rng" }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(platform, bcm2835_rng_devtype); static struct platform_driver bcm2835_rng_driver = { .driver = { .name = "bcm2835-rng", .of_match_table = bcm2835_rng_of_match, }, .probe = bcm2835_rng_probe, .id_table = bcm2835_rng_devtype, }; module_platform_driver(bcm2835_rng_driver); MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>"); MODULE_DESCRIPTION("BCM2835 Random Number Generator (RNG) driver"); MODULE_LICENSE("GPL v2");


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