svn commit: r312952 - in head/sys/i386: i386 include

[Jason A. Harmening]

Author: jah
Date: Sun Jan 29 16:54:55 2017
New Revision: 312952
URL: https://svnweb.freebsd.org/changeset/base/312952

Log:
  Implement get_pcpu() for i386 and use it to replace pcpu_find(curcpu)
  in the i386 pmap.
  
  The curcpu macro loads the per-cpu data pointer as its first step,
  so the remaining steps of pcpu_find(curcpu) are circular.
  
  get_pcpu() is already implemented for arm, arm64, and risc-v.
  My plan is to implement it for the remaining architectures and use
  it to replace several instances of pcpu_find(curcpu) in MI code.
  
  Reviewed by:	kib
  MFC after:	1 week
  Differential Revision:	https://reviews.freebsd.org/D9370

Modified:
  head/sys/i386/i386/pmap.c
  head/sys/i386/include/pcpu.h

Modified: head/sys/i386/i386/pmap.c
==============================================================================
--- head/sys/i386/i386/pmap.c	Sun Jan 29 14:29:02 2017	(r312951)
+++ head/sys/i386/i386/pmap.c	Sun Jan 29 16:54:55 2017	(r312952)
@@ -440,7 +440,7 @@ pmap_bootstrap(vm_paddr_t firstaddr)
 	 * CMAP1/CMAP2 are used for zeroing and copying pages.
 	 * CMAP3 is used for the boot-time memory test.
 	 */
-	pc = pcpu_find(curcpu);
+	pc = get_pcpu();
 	mtx_init(&pc->pc_cmap_lock, "SYSMAPS", NULL, MTX_DEF);
 	SYSMAP(caddr_t, pc->pc_cmap_pte1, pc->pc_cmap_addr1, 1)
 	SYSMAP(caddr_t, pc->pc_cmap_pte2, pc->pc_cmap_addr2, 1)
@@ -4206,7 +4206,7 @@ pmap_zero_page(vm_page_t m)
 	struct pcpu *pc;
 
 	sched_pin();
-	pc = pcpu_find(curcpu);
+	pc = get_pcpu();
 	cmap_pte2 = pc->pc_cmap_pte2;
 	mtx_lock(&pc->pc_cmap_lock);
 	if (*cmap_pte2)
@@ -4237,7 +4237,7 @@ pmap_zero_page_area(vm_page_t m, int off
 	struct pcpu *pc;
 
 	sched_pin();
-	pc = pcpu_find(curcpu);
+	pc = get_pcpu();
 	cmap_pte2 = pc->pc_cmap_pte2;
 	mtx_lock(&pc->pc_cmap_lock);
 	if (*cmap_pte2)
@@ -4264,7 +4264,7 @@ pmap_copy_page(vm_page_t src, vm_page_t 
 	struct pcpu *pc;
 
 	sched_pin();
-	pc = pcpu_find(curcpu);
+	pc = get_pcpu();
 	cmap_pte1 = pc->pc_cmap_pte1; 
 	cmap_pte2 = pc->pc_cmap_pte2;
 	mtx_lock(&pc->pc_cmap_lock);
@@ -4299,7 +4299,7 @@ pmap_copy_pages(vm_page_t ma[], vm_offse
 	int cnt;
 
 	sched_pin();
-	pc = pcpu_find(curcpu);
+	pc = get_pcpu();
 	cmap_pte1 = pc->pc_cmap_pte1; 
 	cmap_pte2 = pc->pc_cmap_pte2;
 	mtx_lock(&pc->pc_cmap_lock);
@@ -5288,7 +5288,7 @@ pmap_flush_page(vm_page_t m)
 	useclflushopt = (cpu_stdext_feature & CPUID_STDEXT_CLFLUSHOPT) != 0;
 	if (useclflushopt || (cpu_feature & CPUID_CLFSH) != 0) {
 		sched_pin();
-		pc = pcpu_find(curcpu);
+		pc = get_pcpu();
 		cmap_pte2 = pc->pc_cmap_pte2; 
 		mtx_lock(&pc->pc_cmap_lock);
 		if (*cmap_pte2)

Modified: head/sys/i386/include/pcpu.h
==============================================================================
--- head/sys/i386/include/pcpu.h	Sun Jan 29 14:29:02 2017	(r312951)
+++ head/sys/i386/include/pcpu.h	Sun Jan 29 16:54:55 2017	(r312952)
@@ -76,6 +76,7 @@
 
 extern struct pcpu *pcpup;
 
+#define	get_pcpu()		(pcpup)
 #define	PCPU_GET(member)	(pcpup->pc_ ## member)
 #define	PCPU_ADD(member, val)	(pcpup->pc_ ## member += (val))
 #define	PCPU_INC(member)	PCPU_ADD(member, 1)
@@ -196,6 +197,15 @@ extern struct pcpu *pcpup;
 	}								\
 } while (0)
 
+#define	get_pcpu() __extension__ ({					\
+	struct pcpu *__pc;						\
+									\
+	__asm __volatile("movl %%fs:%1,%0"				\
+	    : "=r" (__pc)						\
+	    : "m" (*(struct pcpu *)(__pcpu_offset(pc_prvspace))));	\
+	__pc;								\
+})
+
 #define	PCPU_GET(member)	__PCPU_GET(pc_ ## member)
 #define	PCPU_ADD(member, val)	__PCPU_ADD(pc_ ## member, val)
 #define	PCPU_INC(member)	__PCPU_INC(pc_ ## member)