Merge tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "This is a bit late, partly due to me travelling, and partly due to a
  power outage knocking out some of my test systems *while* I was
  travelling.

   - Initial support for running on a system with an Ultravisor, which
     is software that runs below the hypervisor and protects guests
     against some attacks by the hypervisor.

   - Support for building the kernel to run as a "Secure Virtual
     Machine", ie. as a guest capable of running on a system with an
     Ultravisor.

   - Some changes to our DMA code on bare metal, to allow devices with
     medium sized DMA masks (> 32 && < 59 bits) to use more than 2GB of
     DMA space.

   - Support for firmware assisted crash dumps on bare metal (powernv).

   - Two series fixing bugs in and refactoring our PCI EEH code.

   - A large series refactoring our exception entry code to use gas
     macros, both to make it more readable and also enable some future
     optimisations.

  As well as many cleanups and other minor features & fixups.

  Thanks to: Adam Zerella, Alexey Kardashevskiy, Alistair Popple, Andrew
  Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anshuman Khandual,
  Balbir Singh, Benjamin Herrenschmidt, Cédric Le Goater, Christophe
  JAILLET, Christophe Leroy, Christopher M. Riedl, Christoph Hellwig,
  Claudio Carvalho, Daniel Axtens, David Gibson, David Hildenbrand,
  Desnes A. Nunes do Rosario, Ganesh Goudar, Gautham R. Shenoy, Greg
  Kurz, Guerney Hunt, Gustavo Romero, Halil Pasic, Hari Bathini, Joakim
  Tjernlund, Jonathan Neuschafer, Jordan Niethe, Leonardo Bras, Lianbo
  Jiang, Madhavan Srinivasan, Mahesh Salgaonkar, Mahesh Salgaonkar,
  Masahiro Yamada, Maxiwell S. Garcia, Michael Anderson, Nathan
  Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver
  O'Halloran, Qian Cai, Ram Pai, Ravi Bangoria, Reza Arbab, Ryan Grimm,
  Sam Bobroff, Santosh Sivaraj, Segher Boessenkool, Sukadev Bhattiprolu,
  Thiago Bauermann, Thiago Jung Bauermann, Thomas Gleixner, Tom
  Lendacky, Vasant Hegde"

* tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (264 commits)
  powerpc/mm/mce: Keep irqs disabled during lockless page table walk
  powerpc: Use ftrace_graph_ret_addr() when unwinding
  powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
  ftrace: Look up the address of return_to_handler() using helpers
  powerpc: dump kernel log before carrying out fadump or kdump
  docs: powerpc: Add missing documentation reference
  powerpc/xmon: Fix output of XIVE IPI
  powerpc/xmon: Improve output of XIVE interrupts
  powerpc/mm/radix: remove useless kernel messages
  powerpc/fadump: support holes in kernel boot memory area
  powerpc/fadump: remove RMA_START and RMA_END macros
  powerpc/fadump: update documentation about option to release opalcore
  powerpc/fadump: consider f/w load area
  powerpc/opalcore: provide an option to invalidate /sys/firmware/opal/core file
  powerpc/opalcore: export /sys/firmware/opal/core for analysing opal crashes
  powerpc/fadump: update documentation about CONFIG_PRESERVE_FA_DUMP
  powerpc/fadump: add support to preserve crash data on FADUMP disabled kernel
  powerpc/fadump: improve how crashed kernel's memory is reserved
  powerpc/fadump: consider reserved ranges while releasing memory
  powerpc/fadump: make crash memory ranges array allocation generic
  ...

1 files changed, 97 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 514707ef6779..a4e7762dd286 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -40,6 +40,7 @@
 #include <asm/sections.h>
 #include <asm/machdep.h>
 #include <asm/asm-prototypes.h>
+#include <asm/ultravisor-api.h>
 
 #include <linux/linux_logo.h>
 
@@ -94,7 +95,7 @@ static int of_workarounds __prombss;
 #define PROM_BUG() do {						\
         prom_printf("kernel BUG at %s line 0x%x!\n",		\
 		    __FILE__, __LINE__);			\
-        __asm__ __volatile__(".long " BUG_ILLEGAL_INSTR);	\
+	__builtin_trap();					\
 } while (0)
 
 #ifdef DEBUG_PROM
@@ -171,6 +172,10 @@ static bool __prombss prom_radix_disable;
 static bool __prombss prom_xive_disable;
 #endif
 
+#ifdef CONFIG_PPC_SVM
+static bool __prombss prom_svm_enable;
+#endif
+
 struct platform_support {
 	bool hash_mmu;
 	bool radix_mmu;
@@ -812,6 +817,17 @@ static void __init early_cmdline_parse(void)
 		prom_debug("XIVE disabled from cmdline\n");
 	}
 #endif /* CONFIG_PPC_PSERIES */
+
+#ifdef CONFIG_PPC_SVM
+	opt = prom_strstr(prom_cmd_line, "svm=");
+	if (opt) {
+		bool val;
+
+		opt += sizeof("svm=") - 1;
+		if (!prom_strtobool(opt, &val))
+			prom_svm_enable = val;
+	}
+#endif /* CONFIG_PPC_SVM */
 }
 
 #ifdef CONFIG_PPC_PSERIES
@@ -1712,6 +1728,43 @@ static void __init prom_close_stdin(void)
 	}
 }
 
+#ifdef CONFIG_PPC_SVM
+static int prom_rtas_hcall(uint64_t args)
+{
+	register uint64_t arg1 asm("r3") = H_RTAS;
+	register uint64_t arg2 asm("r4") = args;
+
+	asm volatile("sc 1\n" : "=r" (arg1) :
+			"r" (arg1),
+			"r" (arg2) :);
+	return arg1;
+}
+
+static struct rtas_args __prombss os_term_args;
+
+static void __init prom_rtas_os_term(char *str)
+{
+	phandle rtas_node;
+	__be32 val;
+	u32 token;
+
+	prom_debug("%s: start...\n", __func__);
+	rtas_node = call_prom("finddevice", 1, 1, ADDR("/rtas"));
+	prom_debug("rtas_node: %x\n", rtas_node);
+	if (!PHANDLE_VALID(rtas_node))
+		return;
+
+	val = 0;
+	prom_getprop(rtas_node, "ibm,os-term", &val, sizeof(val));
+	token = be32_to_cpu(val);
+	prom_debug("ibm,os-term: %x\n", token);
+	if (token == 0)
+		prom_panic("Could not get token for ibm,os-term\n");
+	os_term_args.token = cpu_to_be32(token);
+	prom_rtas_hcall((uint64_t)&os_term_args);
+}
+#endif /* CONFIG_PPC_SVM */
+
 /*
  * Allocate room for and instantiate RTAS
  */
@@ -3168,6 +3221,46 @@ static void unreloc_toc(void)
 #endif
 #endif
 
+#ifdef CONFIG_PPC_SVM
+/*
+ * Perform the Enter Secure Mode ultracall.
+ */
+static int enter_secure_mode(unsigned long kbase, unsigned long fdt)
+{
+	register unsigned long r3 asm("r3") = UV_ESM;
+	register unsigned long r4 asm("r4") = kbase;
+	register unsigned long r5 asm("r5") = fdt;
+
+	asm volatile("sc 2" : "+r"(r3) : "r"(r4), "r"(r5));
+
+	return r3;
+}
+
+/*
+ * Call the Ultravisor to transfer us to secure memory if we have an ESM blob.
+ */
+static void setup_secure_guest(unsigned long kbase, unsigned long fdt)
+{
+	int ret;
+
+	if (!prom_svm_enable)
+		return;
+
+	/* Switch to secure mode. */
+	prom_printf("Switching to secure mode.\n");
+
+	ret = enter_secure_mode(kbase, fdt);
+	if (ret != U_SUCCESS) {
+		prom_printf("Returned %d from switching to secure mode.\n", ret);
+		prom_rtas_os_term("Switch to secure mode failed.\n");
+	}
+}
+#else
+static void setup_secure_guest(unsigned long kbase, unsigned long fdt)
+{
+}
+#endif /* CONFIG_PPC_SVM */
+
 /*
  * We enter here early on, when the Open Firmware prom is still
  * handling exceptions and the MMU hash table for us.
@@ -3366,6 +3459,9 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
 	unreloc_toc();
 #endif
 
+	/* Move to secure memory if we're supposed to be secure guests. */
+	setup_secure_guest(kbase, hdr);
+
 	__start(hdr, kbase, 0, 0, 0, 0, 0);
 
 	return 0;