[PATCH 09/11] x86/snp: create snp_x86_shutdown()

[Tycho Andersen]

From: "Tycho Andersen (AMD)" <tycho@xxxxxxxxxx>

After SNP_SHUTDOWN, two architecture-level things should be done:

1. clear the RMP table
2. disable MFDM to prevent the FW_WARN in k8_check_syscfg_dram_mod_en() in
   the event of a kexec

Create and export to the CCP driver a function that does them.

Signed-off-by: Tycho Andersen (AMD) <tycho@xxxxxxxxxx>
---
 arch/x86/include/asm/sev.h | 2 ++
 arch/x86/virt/svm/sev.c    | 7 +++++++
 2 files changed, 9 insertions(+)

diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index 0bcd89d4fe90..36d2b1ea19c0 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -662,6 +662,7 @@ static inline void snp_leak_pages(u64 pfn, unsigned int pages)
 	__snp_leak_pages(pfn, pages, true);
 }
 void snp_prepare_for_snp_init(void);
+void snp_x86_shutdown(void);
 #else
 static inline bool snp_probe_rmptable_info(void) { return false; }
 static inline int snp_rmptable_init(void) { return -ENOSYS; }
@@ -679,6 +680,7 @@ static inline void snp_leak_pages(u64 pfn, unsigned int npages) {}
 static inline void kdump_sev_callback(void) { }
 static inline void snp_fixup_e820_tables(void) {}
 static inline void snp_prepare_for_snp_init(void) {}
+static inline void snp_x86_shutdown(void) {}
 #endif
 
 #endif
diff --git a/arch/x86/virt/svm/sev.c b/arch/x86/virt/svm/sev.c
index cf984b8f4493..0524fc77b44d 100644
--- a/arch/x86/virt/svm/sev.c
+++ b/arch/x86/virt/svm/sev.c
@@ -544,6 +544,13 @@ void snp_prepare_for_snp_init(void)
 }
 EXPORT_SYMBOL_FOR_MODULES(snp_prepare_for_snp_init, "ccp");
 
+void snp_x86_shutdown(void)
+{
+	snp_clear_rmp();
+	on_each_cpu(mfd_reconfigure, 0, 1);
+}
+EXPORT_SYMBOL_FOR_MODULES(snp_x86_shutdown, "ccp");
+
 /*
  * Do the necessary preparations which are verified by the firmware as
  * described in the SNP_INIT_EX firmware command description in the SNP
-- 
2.53.0