# HG changeset patch
# User yamahata@xxxxxxxxxxxxx
# Date 1155119075 -32400
# Node ID dc37e8c2b96afe282d95a7263fb64ede040b28df
# Parent  5e2fec53ecc5c62acb0e2b083464b527d77b9bcf
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.
PATCHNAME: fix_p2m_exposure_linux_side

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

diff -r 5e2fec53ecc5 -r dc37e8c2b96a linux-2.6-xen-sparse/arch/ia64/Kconfig
--- a/linux-2.6-xen-sparse/arch/ia64/Kconfig	Wed Aug 09 19:23:11 2006 +0900
+++ b/linux-2.6-xen-sparse/arch/ia64/Kconfig	Wed Aug 09 19:24:35 2006 +0900
@@ -63,6 +63,13 @@ config XEN_IA64_VDSO_PARAVIRT
 	default y
 	help
 	  vDSO paravirtualization
+
+config XEN_IA64_EXPOSE_P2M
+	bool
+	depends on XEN
+	default y
+	help
+	  expose p2m from xen
 
 config SCHED_NO_NO_OMIT_FRAME_POINTER
 	bool
diff -r 5e2fec53ecc5 -r dc37e8c2b96a linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c
--- a/linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c	Wed Aug 09 19:23:11 2006 +0900
+++ b/linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c	Wed Aug 09 19:24:35 2006 +0900
@@ -503,6 +503,12 @@ 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
+#ifdef CONFIG_XEN_IA64_EXPOSE_P2M
+	(void)p2m_expose_init();
+#endif
+
 	return 0;
 }
 late_initcall(xen_ia64_privcmd_init);
@@ -808,3 +814,141 @@ 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;
+static unsigned long p2m_assign_start_pfn __read_mostly;
+static unsigned long p2m_assign_end_pfn __read_mostly;
+volatile const pte_t* p2m_pte;
+
+#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 = 1;
+module_param(xen_ia64_p2m_expose, int, 0);
+MODULE_DESCRIPTION("enable/disable xen/ia64 p2m exposure optimization");
+
+int
+p2m_expose_init(void)
+{
+	unsigned long size;
+	int error;
+
+	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
+
+	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);
+	size = (p2m_convert_max_pfn - p2m_convert_min_pfn) << PAGE_SHIFT;
+	
+	// use privcmd region
+	p2m_resource.name = "Xen p2m table";
+	error = allocate_resource(&iomem_resource, &p2m_resource, size,
+				  privcmd_resource_min, privcmd_resource_max,
+				  max(privcmd_resource_align,
+				      p2m_granule_pfn << PAGE_SHIFT),
+				  NULL, NULL);
+	if (error) {
+		printk(KERN_ERR P2M_PREFIX
+		       "can't allocate region for p2m exposure "
+		       "[0x%016lx, 0x%016lx]\n",
+		       p2m_convert_min_pfn, p2m_convert_max_pfn);
+		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);
+	
+	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]\n",
+	       p2m_assign_start_pfn << PAGE_SHIFT,
+	       p2m_assign_end_pfn << PAGE_SHIFT);
+	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(p2m_initialized);
+EXPORT_SYMBOL(p2m_min_low_pfn);
+EXPORT_SYMBOL(p2m_max_low_pfn);
+EXPORT_SYMBOL(p2m_convert_min_pfn);
+EXPORT_SYMBOL(p2m_convert_max_pfn);
+EXPORT_SYMBOL(p2m_pte);
+EXPORT_SYMBOL(p2m_expose_init);
+EXPORT_SYMBOL(p2m_phystomach);
+#endif
diff -r 5e2fec53ecc5 -r dc37e8c2b96a linux-2.6-xen-sparse/include/asm-ia64/hypercall.h
--- a/linux-2.6-xen-sparse/include/asm-ia64/hypercall.h	Wed Aug 09 19:23:11 2006 +0900
+++ b/linux-2.6-xen-sparse/include/asm-ia64/hypercall.h	Wed Aug 09 19:24:35 2006 +0900
@@ -490,6 +490,33 @@ 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 _hypercall_imm4(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 5e2fec53ecc5 -r dc37e8c2b96a linux-2.6-xen-sparse/include/asm-ia64/hypervisor.h
--- a/linux-2.6-xen-sparse/include/asm-ia64/hypervisor.h	Wed Aug 09 19:23:11 2006 +0900
+++ b/linux-2.6-xen-sparse/include/asm-ia64/hypervisor.h	Wed Aug 09 19:24:35 2006 +0900
@@ -168,6 +168,17 @@ xen_destroy_contiguous_region(unsigned l
 		__xen_destroy_contiguous_region(vstart, order);
 }
 
+#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); 
+#endif
+
 // for netfront.c, netback.c
 #define MULTI_UVMFLAGS_INDEX 0 //XXX any value
 
diff -r 5e2fec53ecc5 -r dc37e8c2b96a linux-2.6-xen-sparse/include/asm-ia64/page.h
--- a/linux-2.6-xen-sparse/include/asm-ia64/page.h	Wed Aug 09 19:23:11 2006 +0900
+++ b/linux-2.6-xen-sparse/include/asm-ia64/page.h	Wed Aug 09 19:24:35 2006 +0900
@@ -271,6 +271,13 @@ pfn_to_mfn_for_dma(unsigned long pfn)
 pfn_to_mfn_for_dma(unsigned long pfn)
 {
 	unsigned long mfn;
+#ifdef CONFIG_XEN_IA64_EXPOSE_P2M
+	// avoid include hell.
+	extern int p2m_initialized;
+	unsigned long p2m_phystomach(unsigned long gpfn); 
+	if (p2m_initialized)
+		return p2m_phystomach(pfn);
+#endif
 	mfn = HYPERVISOR_phystomach(pfn);
 	BUG_ON(mfn == 0); // XXX
 	BUG_ON(mfn == INVALID_P2M_ENTRY); // XXX