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authorMichael Kelley <mikelley@microsoft.com>2021-07-14 21:34:45 +0300
committerWei Liu <wei.liu@kernel.org>2021-07-15 15:59:45 +0300
commitafca4d95dd7d7936d46a0ff02169cc40f534a6a3 (patch)
treed37090124c331cf23e25ae78bb9750dd5579f361 /drivers/hv/hv_common.c
parentc445535c3efbfb8cb42d098e624d46ab149664b7 (diff)
downloadlinux-afca4d95dd7d7936d46a0ff02169cc40f534a6a3.tar.xz
Drivers: hv: Make portions of Hyper-V init code be arch neutral
The code to allocate and initialize the hv_vp_index array is architecture neutral. Similarly, the code to allocate and populate the hypercall input and output arg pages is architecture neutral. Move both sets of code out from arch/x86 and into utility functions in drivers/hv/hv_common.c that can be shared by Hyper-V initialization on ARM64. No functional changes. However, the allocation of the hypercall input and output arg pages is done differently so that the size is always the Hyper-V page size, even if not the same as the guest page size (such as with ARM64's 64K page size). Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1626287687-2045-2-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'drivers/hv/hv_common.c')
-rw-r--r--drivers/hv/hv_common.c138
1 files changed, 138 insertions, 0 deletions
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index 7f42da98d377..e836002bc0ce 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -15,9 +15,147 @@
#include <linux/types.h>
#include <linux/export.h>
#include <linux/bitfield.h>
+#include <linux/cpumask.h>
+#include <linux/slab.h>
#include <asm/hyperv-tlfs.h>
#include <asm/mshyperv.h>
+/*
+ * hv_root_partition and ms_hyperv are defined here with other Hyper-V
+ * specific globals so they are shared across all architectures and are
+ * built only when CONFIG_HYPERV is defined. But on x86,
+ * ms_hyperv_init_platform() is built even when CONFIG_HYPERV is not
+ * defined, and it uses these two variables. So mark them as __weak
+ * here, allowing for an overriding definition in the module containing
+ * ms_hyperv_init_platform().
+ */
+bool __weak hv_root_partition;
+EXPORT_SYMBOL_GPL(hv_root_partition);
+
+struct ms_hyperv_info __weak ms_hyperv;
+EXPORT_SYMBOL_GPL(ms_hyperv);
+
+u32 *hv_vp_index;
+EXPORT_SYMBOL_GPL(hv_vp_index);
+
+u32 hv_max_vp_index;
+EXPORT_SYMBOL_GPL(hv_max_vp_index);
+
+void __percpu **hyperv_pcpu_input_arg;
+EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg);
+
+void __percpu **hyperv_pcpu_output_arg;
+EXPORT_SYMBOL_GPL(hyperv_pcpu_output_arg);
+
+/*
+ * Hyper-V specific initialization and shutdown code that is
+ * common across all architectures. Called from architecture
+ * specific initialization functions.
+ */
+
+void __init hv_common_free(void)
+{
+ kfree(hv_vp_index);
+ hv_vp_index = NULL;
+
+ free_percpu(hyperv_pcpu_output_arg);
+ hyperv_pcpu_output_arg = NULL;
+
+ free_percpu(hyperv_pcpu_input_arg);
+ hyperv_pcpu_input_arg = NULL;
+}
+
+int __init hv_common_init(void)
+{
+ int i;
+
+ /*
+ * Allocate the per-CPU state for the hypercall input arg.
+ * If this allocation fails, we will not be able to setup
+ * (per-CPU) hypercall input page and thus this failure is
+ * fatal on Hyper-V.
+ */
+ hyperv_pcpu_input_arg = alloc_percpu(void *);
+ BUG_ON(!hyperv_pcpu_input_arg);
+
+ /* Allocate the per-CPU state for output arg for root */
+ if (hv_root_partition) {
+ hyperv_pcpu_output_arg = alloc_percpu(void *);
+ BUG_ON(!hyperv_pcpu_output_arg);
+ }
+
+ hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index),
+ GFP_KERNEL);
+ if (!hv_vp_index) {
+ hv_common_free();
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < num_possible_cpus(); i++)
+ hv_vp_index[i] = VP_INVAL;
+
+ return 0;
+}
+
+/*
+ * Hyper-V specific initialization and die code for
+ * individual CPUs that is common across all architectures.
+ * Called by the CPU hotplug mechanism.
+ */
+
+int hv_common_cpu_init(unsigned int cpu)
+{
+ void **inputarg, **outputarg;
+ u64 msr_vp_index;
+ gfp_t flags;
+ int pgcount = hv_root_partition ? 2 : 1;
+
+ /* hv_cpu_init() can be called with IRQs disabled from hv_resume() */
+ flags = irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL;
+
+ inputarg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
+ *inputarg = kmalloc(pgcount * HV_HYP_PAGE_SIZE, flags);
+ if (!(*inputarg))
+ return -ENOMEM;
+
+ if (hv_root_partition) {
+ outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
+ *outputarg = (char *)(*inputarg) + HV_HYP_PAGE_SIZE;
+ }
+
+ msr_vp_index = hv_get_register(HV_REGISTER_VP_INDEX);
+
+ hv_vp_index[cpu] = msr_vp_index;
+
+ if (msr_vp_index > hv_max_vp_index)
+ hv_max_vp_index = msr_vp_index;
+
+ return 0;
+}
+
+int hv_common_cpu_die(unsigned int cpu)
+{
+ unsigned long flags;
+ void **inputarg, **outputarg;
+ void *mem;
+
+ local_irq_save(flags);
+
+ inputarg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
+ mem = *inputarg;
+ *inputarg = NULL;
+
+ if (hv_root_partition) {
+ outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
+ *outputarg = NULL;
+ }
+
+ local_irq_restore(flags);
+
+ kfree(mem);
+
+ return 0;
+}
/* Bit mask of the extended capability to query: see HV_EXT_CAPABILITY_xxx */
bool hv_query_ext_cap(u64 cap_query)