powerpc/powernv: Introduce FW_FEATURE_ULTRAVISOR

In PEF enabled systems, some of the resources which were previously
hypervisor privileged are now ultravisor privileged and controlled by
the ultravisor firmware.

This adds FW_FEATURE_ULTRAVISOR to indicate if PEF is enabled.

The host kernel can use FW_FEATURE_ULTRAVISOR, for instance, to skip
accessing resources (e.g. PTCR and LDBAR) in case PEF is enabled.

Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
[ andmike: Device node name to "ibm,ultravisor" ]
Signed-off-by: Michael Anderson <andmike@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190822034838.27876-4-cclaudio@linux.ibm.com

diff --git a/arch/powerpc/include/asm/firmware.h b/arch/powerpc/include/asm/firmware.h
index faeca8b..b3e214a 100644 (file)
--- a/arch/powerpc/include/asm/firmware.h
+++ b/arch/powerpc/include/asm/firmware.h
@@ -50,6 +50,7 @@
 #define FW_FEATURE_DRC_INFO    ASM_CONST(0x0000000800000000)
 #define FW_FEATURE_BLOCK_REMOVE ASM_CONST(0x0000001000000000)
 #define FW_FEATURE_PAPR_SCM    ASM_CONST(0x0000002000000000)
+#define FW_FEATURE_ULTRAVISOR  ASM_CONST(0x0000004000000000)
 
 #ifndef __ASSEMBLY__
 
@@ -68,9 +69,9 @@ enum {
                FW_FEATURE_TYPE1_AFFINITY | FW_FEATURE_PRRN |
                FW_FEATURE_HPT_RESIZE | FW_FEATURE_DRMEM_V2 |
                FW_FEATURE_DRC_INFO | FW_FEATURE_BLOCK_REMOVE |
-               FW_FEATURE_PAPR_SCM,
+               FW_FEATURE_PAPR_SCM | FW_FEATURE_ULTRAVISOR,
        FW_FEATURE_PSERIES_ALWAYS = 0,
-       FW_FEATURE_POWERNV_POSSIBLE = FW_FEATURE_OPAL,
+       FW_FEATURE_POWERNV_POSSIBLE = FW_FEATURE_OPAL | FW_FEATURE_ULTRAVISOR,
        FW_FEATURE_POWERNV_ALWAYS = 0,
        FW_FEATURE_PS3_POSSIBLE = FW_FEATURE_LPAR | FW_FEATURE_PS3_LV1,
        FW_FEATURE_PS3_ALWAYS = FW_FEATURE_LPAR | FW_FEATURE_PS3_LV1,

diff --git a/arch/powerpc/include/asm/ultravisor.h b/arch/powerpc/include/asm/ultravisor.h
new file mode 100644 (file)
index 0000000..dc6e1ea
--- /dev/null
+++ b/arch/powerpc/include/asm/ultravisor.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Ultravisor definitions
+ *
+ * Copyright 2019, IBM Corporation.
+ *
+ */
+#ifndef _ASM_POWERPC_ULTRAVISOR_H
+#define _ASM_POWERPC_ULTRAVISOR_H
+
+int early_init_dt_scan_ultravisor(unsigned long node, const char *uname,
+                                 int depth, void *data);
+
+#endif /* _ASM_POWERPC_ULTRAVISOR_H */

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 7159e79..5828f1c 100644 (file)
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -55,6 +55,7 @@
 #include <asm/firmware.h>
 #include <asm/dt_cpu_ftrs.h>
 #include <asm/drmem.h>
+#include <asm/ultravisor.h>
 
 #include <mm/mmu_decl.h>
 
@@ -702,6 +703,9 @@ void __init early_init_devtree(void *params)
 #ifdef CONFIG_PPC_POWERNV
        /* Some machines might need OPAL info for debugging, grab it now. */
        of_scan_flat_dt(early_init_dt_scan_opal, NULL);
+
+       /* Scan tree for ultravisor feature */
+       of_scan_flat_dt(early_init_dt_scan_ultravisor, NULL);
 #endif
 
 #ifdef CONFIG_FA_DUMP

diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
index da2e99e..2c27c8a 100644 (file)
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -4,6 +4,7 @@ obj-y                   += idle.o opal-rtc.o opal-nvram.o opal-lpc.o opal-flash.o
 obj-y                  += rng.o opal-elog.o opal-dump.o opal-sysparam.o opal-sensor.o
 obj-y                  += opal-msglog.o opal-hmi.o opal-power.o opal-irqchip.o
 obj-y                  += opal-kmsg.o opal-powercap.o opal-psr.o opal-sensor-groups.o
+obj-y                  += ultravisor.o
 
 obj-$(CONFIG_SMP)      += smp.o subcore.o subcore-asm.o
 obj-$(CONFIG_PCI)      += pci.o pci-ioda.o npu-dma.o pci-ioda-tce.o

diff --git a/arch/powerpc/platforms/powernv/ultravisor.c b/arch/powerpc/platforms/powernv/ultravisor.c
new file mode 100644 (file)
index 0000000..02ac57b
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/ultravisor.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Ultravisor high level interfaces
+ *
+ * Copyright 2019, IBM Corporation.
+ *
+ */
+#include <linux/init.h>
+#include <linux/printk.h>
+#include <linux/of_fdt.h>
+
+#include <asm/ultravisor.h>
+#include <asm/firmware.h>
+
+int __init early_init_dt_scan_ultravisor(unsigned long node, const char *uname,
+                                        int depth, void *data)
+{
+       if (!of_flat_dt_is_compatible(node, "ibm,ultravisor"))
+               return 0;
+
+       powerpc_firmware_features |= FW_FEATURE_ULTRAVISOR;
+       pr_debug("Ultravisor detected!\n");
+       return 1;
+}