diff options
| -rw-r--r-- | arch/powerpc/sysdev/fsl_soc.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/fsl_soc.c b/arch/powerpc/sysdev/fsl_soc.c index c93848c..c374b37 100644 --- a/arch/powerpc/sysdev/fsl_soc.c +++ b/arch/powerpc/sysdev/fsl_soc.c @@ -23,6 +23,7 @@ #include <linux/device.h> #include <linux/platform_device.h> #include <linux/of.h> +#include <linux/of_address.h> #include <linux/of_platform.h> #include <linux/phy.h> #include <linux/phy_fixed.h> @@ -326,3 +327,44 @@ void fsl_hv_halt(void) fh_partition_stop(-1); } #endif + +#ifdef CONFIG_KVM +static const struct of_device_id cpc_matches[] = { + { .compatible = "fsl,b4860-l3-cache-controller" }, + { .compatible = "fsl,t2080-l3-cache-controller" }, + { .compatible = "fsl,t4240-l3-cache-controller" }, + {} +}; + +static int __init cpc_disable_sole_data(void) +{ + struct device_node *node; + u32 __iomem *regs; + int i; + + for_each_matching_node(node, cpc_matches) { + i = 0; + + for (;;) { + regs = of_iomap(node, i++); + if (!regs) + break; + + /* + * Set undocumented bit to disable CPC sole data + * mode, making it safe to use the LRAT with KVM + * guests, which could otherwise hang the host (under + * certain usage patterns) by accessing memory with + * the M bit unset. The guest still needs to set the + * M bit to operate properly, but this removes a DoS + * vector. + */ + setbits32(regs + 0xf00 / 4, 0x4000); + iounmap(regs); + } + } + + return 0; +} +arch_initcall(cpc_disable_sole_data); +#endif |