From: Sergiu Moga <sergiu.moga@protonmail.com>
Date: Sun, 21 May 2023 13:25:14 +0000 (+0300)
Subject: plat/kvm/arm: Enable fetching of the `PSCI` method through `ACPI`
X-Git-Tag: RELEASE-0.14.0~45
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=b0aee57ae9ad1503ee7faa58cd5d53d1d168c072;p=unikraft%2Funikraft.git

plat/kvm/arm: Enable fetching of the `PSCI` method through `ACPI`

Add the alternative of fetching the `PSCI` method from `ACPI`'s
`FADT`'s `ARM Boot Flags` field.

Signed-off-by: Sergiu Moga <sergiu.moga@protonmail.com>
Reviewed-by: Razvan Virtan <virtanrazvan@gmail.com>
Reviewed-by: Michalis Pappas <michalis@unikraft.io>
Approved-by: Razvan Deaconescu <razvand@unikraft.io>
Tested-by: Unikraft CI <monkey@unikraft.io>
GitHub-Closes: #912
---

diff --git a/plat/kvm/arm/setup.c b/plat/kvm/arm/setup.c
index 4975fdc4a..c6af9fd59 100644
--- a/plat/kvm/arm/setup.c
+++ b/plat/kvm/arm/setup.c
@@ -48,28 +48,50 @@
 
 smccc_conduit_fn_t smccc_psci_call;
 
-static void _dtb_get_psci_method(void *fdt)
+#ifdef CONFIG_UKPLAT_ACPI
+static int get_psci_method(struct ukplat_bootinfo *bi __unused)
+{
+	struct acpi_fadt *acpi_fadt = acpi_get_fadt();
+
+	if (unlikely(!acpi_fadt))
+		return -ENOTSUP;
+
+	if (unlikely(!(acpi_fadt->arm_bflags & ACPI_FADT_ARM_BFLAGS_PSCI)))
+		return -ENOTSUP;
+
+	if (acpi_fadt->arm_bflags & ACPI_FADT_ARM_BFLAGS_PSCI_HVC)
+		smccc_psci_call = smccc_hvc;
+	else
+		smccc_psci_call = smccc_smc;
+
+	return 0;
+}
+#else
+static int get_psci_method(struct ukplat_bootinfo *bi)
 {
-	int fdtpsci, len;
 	const char *fdtmethod;
+	int fdtpsci, len;
+	void *fdt;
+
+	fdt = (void *)bi->dtb;
+	UK_ASSERT(bi->dtb);
 
 	/*
 	 * We just support PSCI-0.2 and PSCI-1.0, the PSCI-0.1 would not
 	 * be supported.
 	 */
-	fdtpsci = fdt_node_offset_by_compatible(fdt, -1,
-						"arm,psci-1.0");
-	if (fdtpsci < 0)
-		fdtpsci = fdt_node_offset_by_compatible(fdt,
-							-1, "arm,psci-0.2");
+	fdtpsci = fdt_node_offset_by_compatible(fdt, -1, "arm,psci-1.0");
+	if (unlikely(fdtpsci < 0))
+		fdtpsci = fdt_node_offset_by_compatible(fdt, -1,
+							"arm,psci-0.2");
 
-	if (fdtpsci < 0) {
+	if (unlikely(fdtpsci < 0)) {
 		uk_pr_info("No PSCI conduit found in DTB\n");
 		goto enomethod;
 	}
 
 	fdtmethod = fdt_getprop(fdt, fdtpsci, "method", &len);
-	if (!fdtmethod || (len <= 0)) {
+	if (unlikely(!fdtmethod || len <= 0)) {
 		uk_pr_info("No PSCI method found\n");
 		goto enomethod;
 	}
@@ -79,17 +101,20 @@ static void _dtb_get_psci_method(void *fdt)
 	else if (!strcmp(fdtmethod, "smc"))
 		smccc_psci_call = smccc_smc;
 	else {
-		uk_pr_info("Invalid PSCI conduit method: %s\n",
-			   fdtmethod);
+		uk_pr_info("Invalid PSCI conduit method: %s\n", fdtmethod);
 		goto enomethod;
 	}
 	uk_pr_info("PSCI method: %s\n", fdtmethod);
-	return;
+
+	return 0;
 
 enomethod:
 	uk_pr_info("Support PSCI from PSCI-0.2\n");
 	smccc_psci_call = NULL;
+
+	return -ENOENT;
 }
+#endif
 
 static char *cmdline;
 static __sz cmdline_len;
@@ -153,8 +178,6 @@ void __no_pauth _ukplat_entry(struct ukplat_bootinfo *bi)
 		UK_CRASH("Boot stack alloc failed\n");
 	bstack = (void *)((__uptr)bstack + __STACK_SIZE);
 
-	/* Get PSCI method from DTB */
-	_dtb_get_psci_method(fdt);
 
 	/* Initialize paging */
 	rc = ukplat_mem_init();
@@ -204,6 +227,10 @@ void __no_pauth _ukplat_entry(struct ukplat_bootinfo *bi)
 		UK_CRASH("SMP initialization failed: %d.\n", rc);
 #endif /* CONFIG_HAVE_SMP */
 
+	rc = get_psci_method(bi);
+	if (unlikely(rc < 0))
+		UK_CRASH("Failed to get PSCI method: %d.\n", rc);
+
 	/*
 	 * Switch away from the bootstrap stack as early as possible.
 	 */