[PARISC] Make sure use of RFI conforms to PA 2.0 and 1.1 arch docs

2.6.12-rc4-pa3 : first pass at making sure use of RFI conforms to
PA 2.0 arch pages F-4 and F-5, PA 1.1 Arch page 3-19 and 3-20.

The discussion revolves around all the rules for clearing PSW Q-bit.
The hard part is meeting all the rules for "relied upon translation".

.align directive is used to guarantee the critical sequence ends more than
8 instructions (32 bytes) from the end of page.

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

3 files changed, 54 insertions, 31 deletions

diff --git a/include/asm-parisc/assembly.h b/include/asm-parisc/assembly.h
index 30b0234..b24a99e 100644
--- a/include/asm-parisc/assembly.h
+++ b/include/asm-parisc/assembly.h
@@ -450,5 +450,30 @@
 	REST_CR	(%cr22, PT_PSW	(\regs))
 	.endm
 
+
+	/* First step to create a "relied upon translation"
+	 * See PA 2.0 Arch. page F-4 and F-5.
+	 *
+	 * The ssm was originally necessary due to a "PCxT bug".
+	 * But someone decided it needed to be added to the architecture
+	 * and this "feature" went into rev3 of PA-RISC 1.1 Arch Manual.
+	 * It's been carried forward into PA 2.0 Arch as well. :^(
+	 *
+	 * "ssm 0,%r0" is a NOP with side effects (prefetch barrier).
+	 * rsm/ssm prevents the ifetch unit from speculatively fetching
+	 * instructions past this line in the code stream.
+	 * PA 2.0 processor will single step all insn in the same QUAD (4 insn).
+	 */
+	.macro	pcxt_ssm_bug
+	rsm	PSW_SM_I,%r0
+	nop	/* 1 */
+	nop	/* 2 */
+	nop	/* 3 */
+	nop	/* 4 */
+	nop	/* 5 */
+	nop	/* 6 */
+	nop	/* 7 */
+	.endm
+
 #endif /* __ASSEMBLY__ */
 #endif
diff --git a/include/asm-parisc/psw.h b/include/asm-parisc/psw.h
index 5132302..4334d6c 100644
--- a/include/asm-parisc/psw.h
+++ b/include/asm-parisc/psw.h
@@ -1,4 +1,7 @@
 #ifndef _PARISC_PSW_H
+
+#include <linux/config.h>
+
 #define	PSW_I	0x00000001
 #define	PSW_D	0x00000002
 #define	PSW_P	0x00000004
@@ -9,6 +12,16 @@
 #define	PSW_G	0x00000040	/* PA1.x only */
 #define PSW_O	0x00000080	/* PA2.0 only */
 
+/* ssm/rsm instructions number PSW_W and PSW_E differently */
+#define PSW_SM_I	PSW_I	/* Enable External Interrupts */
+#define PSW_SM_D	PSW_D
+#define PSW_SM_P	PSW_P
+#define PSW_SM_Q	PSW_Q	/* Enable Interrupt State Collection */
+#define PSW_SM_R	PSW_R	/* Enable Recover Counter Trap */
+#define PSW_SM_W	0x200	/* PA2.0 only : Enable Wide Mode */
+
+#define PSW_SM_QUIET	PSW_SM_R+PSW_SM_Q+PSW_SM_P+PSW_SM_D+PSW_SM_I
+
 #define PSW_CB	0x0000ff00
 
 #define	PSW_M	0x00010000
@@ -30,33 +43,21 @@
 #define	PSW_Z	0x40000000	/* PA1.x only */
 #define	PSW_Y	0x80000000	/* PA1.x only */
 
-#ifdef __LP64__
-#define PSW_HI_CB 0x000000ff    /* PA2.0 only */
+#ifdef CONFIG_64BIT
+#  define PSW_HI_CB 0x000000ff    /* PA2.0 only */
 #endif
 
-/* PSW bits to be used with ssm/rsm */
-#define PSW_SM_I        0x1
-#define PSW_SM_D        0x2
-#define PSW_SM_P        0x4
-#define PSW_SM_Q        0x8
-#define PSW_SM_R        0x10
-#define PSW_SM_F        0x20
-#define PSW_SM_G        0x40
-#define PSW_SM_O        0x80
-#define PSW_SM_E        0x100
-#define PSW_SM_W        0x200
-
-#ifdef __LP64__
-#  define USER_PSW      (PSW_C | PSW_Q | PSW_P | PSW_D | PSW_I)
-#  define KERNEL_PSW    (PSW_W | PSW_C | PSW_Q | PSW_P | PSW_D)
-#  define REAL_MODE_PSW (PSW_W | PSW_Q)
-#  define USER_PSW_MASK (PSW_W | PSW_T | PSW_N | PSW_X | PSW_B | PSW_V | PSW_CB)
-#  define USER_PSW_HI_MASK (PSW_HI_CB)
-#else
-#  define USER_PSW      (PSW_C | PSW_Q | PSW_P | PSW_D | PSW_I)
-#  define KERNEL_PSW    (PSW_C | PSW_Q | PSW_P | PSW_D)
-#  define REAL_MODE_PSW (PSW_Q)
-#  define USER_PSW_MASK (PSW_T | PSW_N | PSW_X | PSW_B | PSW_V | PSW_CB)
+#ifdef CONFIG_64BIT
+#  define USER_PSW_HI_MASK	PSW_HI_CB
+#  define WIDE_PSW		PSW_W
+#else 
+#  define WIDE_PSW		0
 #endif
 
+/* Used when setting up for rfi */
+#define KERNEL_PSW    (WIDE_PSW | PSW_C | PSW_Q | PSW_P | PSW_D)
+#define REAL_MODE_PSW (WIDE_PSW | PSW_Q)
+#define USER_PSW_MASK (WIDE_PSW | PSW_T | PSW_N | PSW_X | PSW_B | PSW_V | PSW_CB)
+#define USER_PSW      (PSW_C | PSW_Q | PSW_P | PSW_D | PSW_I)
+
 #endif
diff --git a/include/asm-parisc/tlbflush.h b/include/asm-parisc/tlbflush.h
index eb27b78..efbb2d8 100644
--- a/include/asm-parisc/tlbflush.h
+++ b/include/asm-parisc/tlbflush.h
@@ -64,29 +64,26 @@ static inline void flush_tlb_range(struct vm_area_struct *vma,
 {
 	unsigned long npages;
 
-	
 	npages = ((end - (start & PAGE_MASK)) + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
-	if (npages >= 512)  /* XXX arbitrary, should be tuned */
+	if (npages >= 512)  /* 2MB of space: arbitrary, should be tuned */
 		flush_tlb_all();
 	else {
 
 		mtsp(vma->vm_mm->context,1);
+		purge_tlb_start();
 		if (split_tlb) {
-			purge_tlb_start();
 			while (npages--) {
 				pdtlb(start);
 				pitlb(start);
 				start += PAGE_SIZE;
 			}
-			purge_tlb_end();
 		} else {
-			purge_tlb_start();
 			while (npages--) {
 				pdtlb(start);
 				start += PAGE_SIZE;
 			}
-			purge_tlb_end();
 		}
+		purge_tlb_end();
 	}
 }