# HG changeset patch
# User yamahata@xxxxxxxxxxxxx
# Date 1159863943 -32400
# Node ID 8a8af531c68b130e2f7d58c8bb0880fa3b4db6c7
# Parent  6e7b70b0d937e5ef7d4ba10f8a7257f87416847d
p2m exposure. linux side part.
This patch introduce compile time option XEN_IA64_EXPOSE_P2M
to enable this feature and boot option xen_ia64_p2m_expose to
disable the functionality.
This patch also introduce XEN_IA64_EXPOSE_P2M_USE_DTR to map p2m table
with dtr and boot option xen_ia64_p2m_expose_use_dtr to disable it.
PATCHNAME: p2m_exposure_linux_side

Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>

diff -r 6e7b70b0d937 -r 8a8af531c68b linux-2.6-xen-sparse/arch/ia64/Kconfig
--- a/linux-2.6-xen-sparse/arch/ia64/Kconfig	Tue Oct 03 14:48:06 2006 +0900
+++ b/linux-2.6-xen-sparse/arch/ia64/Kconfig	Tue Oct 03 17:25:43 2006 +0900
@@ -63,6 +63,20 @@ config XEN_IA64_VDSO_PARAVIRT
 	default y
 	help
 	  vDSO paravirtualization
+
+config XEN_IA64_EXPOSE_P2M
+	bool "Xen/IA64 exposure p2m table"
+	depends on XEN
+	default y
+	help
+	  expose p2m from xen
+
+config XEN_IA64_EXPOSE_P2M_USE_DTR
+	bool "Xen/IA64 map p2m table with dtr"
+	depends on XEN_IA64_EXPOSE_P2M
+	default y
+	help
+	  use dtr to map the exposed p2m table
 
 config SCHED_NO_NO_OMIT_FRAME_POINTER
 	bool
diff -r 6e7b70b0d937 -r 8a8af531c68b linux-2.6-xen-sparse/arch/ia64/kernel/setup.c
--- a/linux-2.6-xen-sparse/arch/ia64/kernel/setup.c	Tue Oct 03 14:48:06 2006 +0900
+++ b/linux-2.6-xen-sparse/arch/ia64/kernel/setup.c	Tue Oct 03 17:25:43 2006 +0900
@@ -955,6 +955,7 @@ cpu_init (void)
 	/* Need to be moved into platform_cpu_init later */
 	if (is_running_on_xen()) {
 		extern void xen_smp_intr_init(void);
+		p2m_expose_dtr_init();
 		xen_smp_intr_init();
 	}
 #endif
diff -r 6e7b70b0d937 -r 8a8af531c68b linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c
--- a/linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c	Tue Oct 03 14:48:06 2006 +0900
+++ b/linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c	Tue Oct 03 17:25:43 2006 +0900
@@ -448,6 +448,10 @@ out:
 	       privcmd_resource_min, privcmd_resource_max, 
 	       (privcmd_resource_max - privcmd_resource_min) >> 20);
 	BUG_ON(privcmd_resource_min >= privcmd_resource_max);
+
+	// XXX this should be somewhere appropriate
+	(void)p2m_expose_init();
+
 	return 0;
 }
 late_initcall(xen_ia64_privcmd_init);
@@ -753,3 +757,249 @@ time_resume(void)
 	/* Just trigger a tick.  */
 	ia64_cpu_local_tick();
 }
+
+///////////////////////////////////////////////////////////////////////////
+// expose p2m table
+#ifdef CONFIG_XEN_IA64_EXPOSE_P2M
+#include <asm/uaccess.h>
+
+int p2m_initialized __read_mostly = 0;
+
+unsigned long p2m_min_low_pfn __read_mostly;
+unsigned long p2m_max_low_pfn __read_mostly;
+unsigned long p2m_convert_min_pfn __read_mostly;
+unsigned long p2m_convert_max_pfn __read_mostly;
+
+static struct resource p2m_resource = {
+	.name    = "Xen p2m table",
+	.flags   = IORESOURCE_MEM,
+};
+static unsigned long p2m_assign_start_pfn __read_mostly;
+static unsigned long p2m_assign_end_pfn __read_mostly;
+volatile const pte_t* p2m_pte __read_mostly;
+
+#define GRNULE_PFN	PTRS_PER_PTE
+static unsigned long p2m_granule_pfn __read_mostly = GRNULE_PFN;
+
+#define ROUNDDOWN(x, y)	((x) & ~((y) - 1))
+#define ROUNDUP(x, y)	(((x) + (y) - 1) & ~((y) - 1))
+
+#define P2M_PREFIX	"Xen p2m: "
+
+static int xen_ia64_p2m_expose __read_mostly = 1;
+module_param(xen_ia64_p2m_expose, int, 0);
+MODULE_PARM_DESC(xen_ia64_p2m_expose,
+		 "enable/disable xen/ia64 p2m exposure optimization\n");
+
+#ifdef CONFIG_XEN_IA64_EXPOSE_P2M_USE_DTR
+static int xen_ia64_p2m_expose_use_dtr __read_mostly = 1;
+module_param(xen_ia64_p2m_expose_use_dtr, int, 0);
+MODULE_PARM_DESC(xen_ia64_p2m_expose_use_dtr,
+		 "use/unuse dtr to map exposed p2m table\n");
+
+static const int p2m_page_shifts[] = {
+	_PAGE_SIZE_4K,
+	_PAGE_SIZE_8K,
+	_PAGE_SIZE_16K,
+	_PAGE_SIZE_64K,
+	_PAGE_SIZE_256K,
+	_PAGE_SIZE_1M,
+	_PAGE_SIZE_4M,
+	_PAGE_SIZE_16M,
+	_PAGE_SIZE_64M,
+	_PAGE_SIZE_256M,
+};
+
+struct p2m_itr_arg {
+	unsigned long vaddr;
+	unsigned long pteval;
+	unsigned long log_page_size;
+};
+static struct p2m_itr_arg p2m_itr_arg __read_mostly;
+
+#define IA64_TR_P2M_TABLE	3
+static void
+p2m_itr(void* info)
+{
+	struct p2m_itr_arg* arg = (struct p2m_itr_arg*)info;
+	ia64_itr(0x2, IA64_TR_P2M_TABLE,
+		 arg->vaddr, arg->pteval, arg->log_page_size);
+	ia64_srlz_d();
+}
+
+void
+p2m_expose_dtr_init(void)
+{
+	if (!(p2m_initialized && xen_ia64_p2m_expose_use_dtr))
+		return;
+
+	p2m_itr(&p2m_itr_arg);
+}
+#endif
+
+int
+p2m_expose_init(void)
+{
+	unsigned long num_pfn;
+	unsigned long size = 0;
+	unsigned long p2m_size = 0;
+	unsigned long align = ~0UL;
+	int error;
+#ifdef CONFIG_XEN_IA64_EXPOSE_P2M_USE_DTR
+	int i;
+	unsigned long page_size;
+	unsigned long log_page_size = 0;
+#endif
+
+	if (!xen_ia64_p2m_expose)
+		return -ENOSYS;
+	if (p2m_initialized)
+		return 0;
+
+#ifdef CONFIG_DISCONTIGMEM
+	p2m_min_low_pfn = min_low_pfn;
+	p2m_max_low_pfn = max_low_pfn;
+#else
+	p2m_min_low_pfn = 0;
+	p2m_max_low_pfn = max_pfn;
+#endif
+
+#ifdef CONFIG_XEN_IA64_EXPOSE_P2M_USE_DTR
+	if (xen_ia64_p2m_expose_use_dtr) {
+		unsigned long granule_pfn = 0;
+		p2m_size = p2m_max_low_pfn - p2m_min_low_pfn;
+		for (i = 0;
+		     i < sizeof(p2m_page_shifts)/sizeof(p2m_page_shifts[0]);
+		     i++) {
+			log_page_size = p2m_page_shifts[i];
+			page_size = 1UL << log_page_size;
+			if (page_size < p2m_size)
+				continue;
+
+			granule_pfn = max(page_size >> PAGE_SHIFT,
+					  p2m_granule_pfn);
+			p2m_convert_min_pfn = ROUNDDOWN(p2m_min_low_pfn,
+							granule_pfn);
+			p2m_convert_max_pfn = ROUNDUP(p2m_max_low_pfn,
+						      granule_pfn);
+			num_pfn = p2m_convert_max_pfn - p2m_convert_min_pfn;
+			size = num_pfn << PAGE_SHIFT;
+			p2m_size = num_pfn / PTRS_PER_PTE;
+			p2m_size = ROUNDUP(p2m_size,
+					   granule_pfn << PAGE_SHIFT);
+			if (p2m_size == page_size)
+				break;
+		}
+		if (p2m_size != page_size) {
+			printk(KERN_ERR "p2m_size != page_size\n");
+			return -EINVAL;
+		}
+		align = max(privcmd_resource_align, granule_pfn << PAGE_SHIFT);
+	} else
+#endif
+	{
+		BUG_ON(p2m_granule_pfn & (p2m_granule_pfn - 1));
+		p2m_convert_min_pfn = ROUNDDOWN(p2m_min_low_pfn,
+						p2m_granule_pfn);
+		p2m_convert_max_pfn = ROUNDUP(p2m_max_low_pfn,
+					      p2m_granule_pfn);
+		num_pfn = p2m_convert_max_pfn - p2m_convert_min_pfn;
+		size = num_pfn << PAGE_SHIFT;
+		p2m_size = num_pfn / PTRS_PER_PTE;
+		p2m_size = ROUNDUP(p2m_size, p2m_granule_pfn << PAGE_SHIFT);
+		align = max(privcmd_resource_align,
+			    p2m_granule_pfn << PAGE_SHIFT);
+	}
+	
+	// use privcmd region
+	error = allocate_resource(&iomem_resource, &p2m_resource, p2m_size,
+				  privcmd_resource_min, privcmd_resource_max,
+				  align, NULL, NULL);
+	if (error) {
+		printk(KERN_ERR P2M_PREFIX
+		       "can't allocate region for p2m exposure "
+		       "[0x%016lx, 0x%016lx) 0x%016lx\n",
+		       p2m_convert_min_pfn, p2m_convert_max_pfn,
+		       p2m_size);
+		return error;
+	}
+
+	p2m_assign_start_pfn = p2m_resource.start >> PAGE_SHIFT;
+	p2m_assign_end_pfn = p2m_resource.end >> PAGE_SHIFT;
+	
+	error = HYPERVISOR_expose_p2m(p2m_convert_min_pfn,
+				      p2m_assign_start_pfn,
+				      size, p2m_granule_pfn);
+	if (error) {
+		printk(KERN_ERR P2M_PREFIX "failed expose p2m hypercall\n");
+		printk(KERN_ERR P2M_PREFIX "conv 0x%016lx assign 0x%016lx "
+		       "size 0x%016lx granule 0x%016lx\n",
+		       p2m_convert_min_pfn, p2m_assign_start_pfn,
+		       size, p2m_granule_pfn);;
+		release_resource(&p2m_resource);
+		return error;
+	}
+	p2m_pte = (volatile const pte_t*)pfn_to_kaddr(p2m_assign_start_pfn);
+#ifdef CONFIG_XEN_IA64_EXPOSE_P2M_USE_DTR
+	if (xen_ia64_p2m_expose_use_dtr) {
+		p2m_itr_arg.vaddr = (unsigned long)__va(p2m_assign_start_pfn << PAGE_SHIFT);
+		p2m_itr_arg.pteval = pte_val(pfn_pte(p2m_assign_start_pfn, PAGE_KERNEL));
+		p2m_itr_arg.log_page_size = log_page_size;
+		smp_mb();
+		smp_call_function(&p2m_itr, &p2m_itr_arg, 1, 1);
+		p2m_itr(&p2m_itr_arg);
+	}
+#endif	
+	smp_mb();
+	p2m_initialized = 1;
+	printk(P2M_PREFIX "assign p2m table of [0x%016lx, 0x%016lx)\n",
+	       p2m_convert_min_pfn << PAGE_SHIFT,
+	       p2m_convert_max_pfn << PAGE_SHIFT);
+	printk(P2M_PREFIX "to [0x%016lx, 0x%016lx) (%ld KBytes)\n",
+	       p2m_assign_start_pfn << PAGE_SHIFT,
+	       p2m_assign_end_pfn << PAGE_SHIFT,
+	       p2m_size / 1024);
+	return 0;
+}
+
+#ifdef notyet
+void
+p2m_expose_cleanup(void)
+{
+	BUG_ON(!p2m_initialized);
+	release_resrouce(&p2m_resource);
+}
+#endif
+
+//XXX inlinize?
+unsigned long
+p2m_phystomach(unsigned long gpfn)
+{
+	volatile const pte_t* pte;
+	unsigned long mfn;
+	unsigned long pteval;
+	
+	if (!p2m_initialized ||
+	    gpfn < p2m_min_low_pfn || gpfn > p2m_max_low_pfn
+	    /* || !pfn_valid(gpfn) */)
+		return INVALID_MFN;
+	pte = p2m_pte + (gpfn - p2m_convert_min_pfn);
+
+	mfn = INVALID_MFN;
+	if (likely(__get_user(pteval, (unsigned long __user *)pte) == 0) &&
+	    likely(pte_present(__pte(pteval))) &&
+	    likely(pte_pfn(__pte(pteval)) != (INVALID_MFN >> PAGE_SHIFT)))
+		mfn = (pteval & _PFN_MASK) >> PAGE_SHIFT;
+
+	return mfn;
+}
+
+EXPORT_SYMBOL_GPL(p2m_initialized);
+EXPORT_SYMBOL_GPL(p2m_min_low_pfn);
+EXPORT_SYMBOL_GPL(p2m_max_low_pfn);
+EXPORT_SYMBOL_GPL(p2m_convert_min_pfn);
+EXPORT_SYMBOL_GPL(p2m_convert_max_pfn);
+EXPORT_SYMBOL_GPL(p2m_pte);
+EXPORT_SYMBOL_GPL(p2m_expose_init);
+EXPORT_SYMBOL_GPL(p2m_phystomach);
+#endif
diff -r 6e7b70b0d937 -r 8a8af531c68b linux-2.6-xen-sparse/include/asm-ia64/hypercall.h
--- a/linux-2.6-xen-sparse/include/asm-ia64/hypercall.h	Tue Oct 03 14:48:06 2006 +0900
+++ b/linux-2.6-xen-sparse/include/asm-ia64/hypercall.h	Tue Oct 03 17:25:43 2006 +0900
@@ -377,6 +377,33 @@ HYPERVISOR_add_physmap(unsigned long gpf
 	}
 	return ret;
 }
+
+#ifdef CONFIG_XEN_IA64_EXPOSE_P2M
+static inline unsigned long
+__HYPERVISOR_expose_p2m(unsigned long conv_start_gpfn,
+			unsigned long assign_start_gpfn,
+			unsigned long expose_size, unsigned long granule_pfn)
+{
+	return _hypercall5(unsigned long, ia64_dom0vp_op,
+			   IA64_DOM0VP_expose_p2m,
+			   conv_start_gpfn, assign_start_gpfn,
+			   expose_size, granule_pfn);
+}
+
+static inline unsigned long
+HYPERVISOR_expose_p2m(unsigned long conv_start_gpfn,
+		      unsigned long assign_start_gpfn,
+		      unsigned long expose_size, unsigned long granule_pfn)
+{
+	unsigned long ret = 0;
+	if (is_running_on_xen()) {
+		ret = __HYPERVISOR_expose_p2m(conv_start_gpfn,
+					      assign_start_gpfn,
+					      expose_size, granule_pfn);
+	}
+	return ret;
+}
+#endif
 
 // for balloon driver
 #define HYPERVISOR_update_va_mapping(va, new_val, flags) (0)
diff -r 6e7b70b0d937 -r 8a8af531c68b linux-2.6-xen-sparse/include/asm-ia64/maddr.h
--- a/linux-2.6-xen-sparse/include/asm-ia64/maddr.h	Tue Oct 03 14:48:06 2006 +0900
+++ b/linux-2.6-xen-sparse/include/asm-ia64/maddr.h	Tue Oct 03 17:25:43 2006 +0900
@@ -10,11 +10,34 @@
 
 #define INVALID_P2M_ENTRY       (~0UL)
 
+#ifdef CONFIG_XEN_IA64_EXPOSE_P2M
+extern int p2m_initialized;
+extern unsigned long p2m_min_low_pfn;
+extern unsigned long p2m_max_low_pfn;
+extern unsigned long p2m_convert_min_pfn;
+extern unsigned long p2m_convert_max_pfn;
+extern volatile const pte_t* p2m_pte;
+int p2m_expose_init(void);
+unsigned long p2m_phystomach(unsigned long gpfn);
+#else
+#define p2m_expose_init()	(0)
+#define p2m_initialized		(0)
+#define p2m_phystomach(gpfn)	INVALID_MFN
+#endif
+#ifdef CONFIG_XEN_IA64_EXPOSE_P2M_USE_DTR
+void p2m_expose_dtr_init(void);
+#else
+#define p2m_expose_dtr_init()	do { } while (0)
+#endif
+
+
 /* XXX xen page size != page size */
 static inline unsigned long
 pfn_to_mfn_for_dma(unsigned long pfn)
 {
 	unsigned long mfn;
+	if (p2m_initialized)
+		return p2m_phystomach(pfn);
 	mfn = HYPERVISOR_phystomach(pfn);
 	BUG_ON(mfn == 0); // XXX
 	BUG_ON(mfn == INVALID_P2M_ENTRY); // XXX