hvc_xen: support PV on HVM consoles (eb5ef071) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/tty/hvc/hvc_xen.c

+68 −16

Original line number	Diff line number	Diff line
		@@ -24,9 +24,12 @@
		#include <linux/init.h>
		#include <linux/types.h>

		#include <asm/io.h>
		#include <asm/xen/hypervisor.h>

		#include <xen/xen.h>
		#include <xen/interface/xen.h>
		#include <xen/hvm.h>
		#include <xen/page.h>
		#include <xen/events.h>
		#include <xen/interface/io/console.h>
		@@ -42,9 +45,13 @@ static int xencons_irq;
		/* ------------------------------------------------------------------ */

		static unsigned long console_pfn = ~0ul;
		static unsigned int console_evtchn = ~0ul;
		static struct xencons_interface *xencons_if = NULL;

		static inline struct xencons_interface *xencons_interface(void)
		{
		if (xencons_if != NULL)
		return xencons_if;
		if (console_pfn == ~0ul)
		return mfn_to_virt(xen_start_info->console.domU.mfn);
		else
		@@ -54,7 +61,10 @@ static inline struct xencons_interface *xencons_interface(void)
		static inline void notify_daemon(void)
		{
		/* Use evtchn: this is called early, before irq is set up. */
		if (console_evtchn == ~0ul)
		notify_remote_via_evtchn(xen_start_info->console.domU.evtchn);
		else
		notify_remote_via_evtchn(console_evtchn);
		}

		static int __write_console(const char *data, int len)
		@@ -157,28 +167,63 @@ static struct hv_ops dom0_hvc_ops = {
		.notifier_hangup = notifier_hangup_irq,
		};

		static int xen_hvm_console_init(void)
		{
		int r;
		uint64_t v = 0;
		unsigned long mfn;

		if (!xen_hvm_domain())
		return -ENODEV;

		if (xencons_if != NULL)
		return -EBUSY;

		r = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v);
		if (r < 0)
		return -ENODEV;
		console_evtchn = v;
		hvm_get_parameter(HVM_PARAM_CONSOLE_PFN, &v);
		if (r < 0)
		return -ENODEV;
		mfn = v;
		xencons_if = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE);
		if (xencons_if == NULL)
		return -ENODEV;

		return 0;
		}

		static int __init xen_hvc_init(void)
		{
		struct hvc_struct *hp;
		struct hv_ops *ops;
		int r;

		if (!xen_pv_domain())
		if (!xen_domain())
		return -ENODEV;

		if (xen_initial_domain()) {
		ops = &dom0_hvc_ops;
		xencons_irq = bind_virq_to_irq(VIRQ_CONSOLE, 0);
		} else {
		ops = &domU_hvc_ops;
		if (xen_pv_domain()) {
		if (!xen_start_info->console.domU.evtchn)
		return -ENODEV;

		ops = &domU_hvc_ops;
		xencons_irq = bind_evtchn_to_irq(xen_start_info->console.domU.evtchn);
		console_pfn = mfn_to_pfn(xen_start_info->console.domU.mfn);
		console_evtchn = xen_start_info->console.domU.evtchn;
		} else {
		r = xen_hvm_console_init();
		if (r < 0)
		return r;
		}
		xencons_irq = bind_evtchn_to_irq(console_evtchn);
		if (xencons_irq < 0)
		xencons_irq = 0; /* NO_IRQ */
		else
		irq_set_noprobe(xencons_irq);
		}

		hp = hvc_alloc(HVC_COOKIE, xencons_irq, ops, 256);
		if (IS_ERR(hp))
		@@ -186,15 +231,13 @@ static int __init xen_hvc_init(void)

		hvc = hp;

		console_pfn = mfn_to_pfn(xen_start_info->console.domU.mfn);

		return 0;
		}

		void xen_console_resume(void)
		{
		if (xencons_irq)
		rebind_evtchn_irq(xen_start_info->console.domU.evtchn, xencons_irq);
		rebind_evtchn_irq(console_evtchn, xencons_irq);
		}

		static void __exit xen_hvc_fini(void)
		@@ -205,16 +248,22 @@ static void __exit xen_hvc_fini(void)

		static int xen_cons_init(void)
		{
		struct hv_ops *ops;
		const struct hv_ops *ops;

		if (!xen_pv_domain())
		if (!xen_domain())
		return 0;

		if (xen_initial_domain())
		ops = &dom0_hvc_ops;
		else
		else {
		ops = &domU_hvc_ops;

		if (xen_pv_domain())
		console_evtchn = xen_start_info->console.domU.evtchn;
		else
		xen_hvm_console_init();
		}

		hvc_instantiate(HVC_COOKIE, 0, ops);
		return 0;
		}
		@@ -230,6 +279,9 @@ static void xenboot_write_console(struct console console, const char string,
		unsigned int linelen, off = 0;
		const char *pos;

		if (!xen_pv_domain())
		return;

		dom0_write_console(0, string, len);

		if (xen_initial_domain())

include/xen/interface/hvm/params.h

+5 −1

Original line number	Diff line number	Diff line
		@@ -90,6 +90,10 @@
		/* Boolean: Enable aligning all periodic vpts to reduce interrupts */
		#define HVM_PARAM_VPT_ALIGN 16

		#define HVM_NR_PARAMS 17
		/* Console debug shared memory ring and event channel */
		#define HVM_PARAM_CONSOLE_PFN 17
		#define HVM_PARAM_CONSOLE_EVTCHN 18

		#define HVM_NR_PARAMS 19

		#endif /* __XEN_PUBLIC_HVM_PARAMS_H__ */