pci: recheck pci nvram hacks on fast-reboot

Sometimes it's useful to fiddle with some of the PCI NVRAM options that
we have. Currently this is mostly for enabling and disabling pci-tracing
mode, but having a common place for this stuff is a good idea.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>

core/fast-reboot.c

@@ -433,6 +433,9 @@ void __noreturn fast_reboot_entry(void)
 		psi_irq_reset();
 	}
 
+	/* update pci nvram settings */
+	pci_nvram_init();
+
 	/* Remove all PCI devices */
 	if (pci_reset()) {
 		prlog(PR_NOTICE, "RESET: Fast reboot failed to reset PCI\n");

core/init.c

@@ -48,6 +48,7 @@
 
 enum proc_gen proc_gen;
 unsigned int pcie_max_link_speed;
+bool pci_tracing;
 bool verbose_eeh;
 extern const char version[];
 
@@ -844,7 +845,7 @@ static void per_thread_sanity_checks(void)
 	assert(cpu->state != cpu_state_no_cpu);
 }
 
-static void pci_nvram_init(void)
+void pci_nvram_init(void)
 {
 	const char *nvram_speed;
 
@@ -860,6 +861,8 @@ static void pci_nvram_init(void)
 		prlog(PR_NOTICE, "PHB: NVRAM set max link speed to GEN%i\n",
 		      pcie_max_link_speed);
 	}
+
+	pci_tracing = nvram_query_eq_safe("pci-tracing", "true");
 }
 
 static uint32_t mem_csum(void *_p, void *_e)

hw/phb4.c

@@ -138,7 +138,6 @@ static void phb4_init_hw(struct phb4 *p);
 
 #define PHB4_CAN_STORE_EOI(p) XIVE_STORE_EOI_ENABLED
 
-static bool pci_tracing;
 static bool pci_eeh_mmio;
 static bool pci_retry_all;
 static int rx_err_max = PHB4_RX_ERR_MAX;
@@ -5946,7 +5945,6 @@ void probe_phb4(void)
 	struct dt_node *np;
 	const char *s;
 
-	pci_tracing = nvram_query_eq_safe("pci-tracing", "true");
 	pci_eeh_mmio = !nvram_query_eq_dangerous("pci-eeh-mmio", "disabled");
 	pci_retry_all = nvram_query_eq_dangerous("pci-retry-all", "true");
 	s = nvram_query_dangerous("phb-rx-err-max");

include/pci.h

@@ -356,8 +356,11 @@ enum phb_type {
 	phb_type_npu_v3,
 };
 
-
+/* Generic PCI NVRAM flags */
 extern bool verbose_eeh;
+extern bool pci_tracing;
+
+void pci_nvram_init(void);
 
 struct phb {
 	struct dt_node		*dt_node;