[commit] r967 - in trunk/openbios-devel: arch/ppc/qemu include/arch/ppc

[repository service]

Author: afaerber
Date: Mon Nov 22 21:00:13 2010
New Revision: 967
URL: http://tracker.coreboot.org/trac/openbios/changeset/967

Log:
ppc: SDR1 fixes

Clean up use of SDR1 fields.

IBM's "The Programming Environments for 32-Bit Microprocessors":
  The HTABMASK field in SDR1 contains a mask value that determines
  how many bits from the hash are used in the page table index. This mask
  must be of the form 0b00...011...1; that is, a string of 0 bits followed by
  a string of 1bits. The 1 bits determine how many additional bits (at least 10)
  from the hash are used in the index; HTABORG must have this same number of
  low-order bits equal to 0.

IBM's "The Programming Environments Manual for 64-bit Microprocessors" 3.0:
  The HTABSIZE field in SDR1 contains an integer value that determines
  how many bits from the hash are used in the page table index. This number
  must not exceed 28. HTABSIZE is used to generate a mask of the form
  0b00...011...1; that is, a string of 0 bits followed by a string of 1-bits.
  The 1-bits determine how many additional bits (beyond the minimum of 11)
  from the hash are used in the index. The HTABORG must have this same number
  of low-order bits equal to 0.

Adjust alignment mask and hash size for ppc64.

Note that the page table does not yet scale with the memory size, and
the secondary hash is not yet used.

v5:
* Move HTABORG mask to header.
* Keep is_ppc64() for now, suggested by Alex.
  Merge CONFIG_PPC_64BITSUPPORT handling here so that it behaves as intended,
  not recognizing a ppc64 CPU in pure 32-bit mode.
* Stub out hash_page_32() for ppc64 to avoid having to care about it for ppc64.
  hash_page_64() is less critical for pure ppc build since the code needs to be
  32-bit compatible anyway.

v4:
* Don't redefine hash_page_{32,64} but add TODO comments for renaming.
* Keep and simplify hash_page().

v3:
* Fix shifts. Thanks to Segher and Alex.
* Fix HTABSIZE for 32-bit ppc64: ((2 << 15) - 1) >> 16 happened to be 0,
  so that it worked as expected. Avoid underflow, spotted by Alex.
  Make this fix available for legacy 64-bit support as well.
* Drop get_hash_size(). It was only used in hash_page_32() and caused
  unnecessary conversions between HTABMASK and size.
* Introduce {mfsdr1,mtsdr1} as suggested by Alex.
  Note that this changes the volatility for hash_page_64().
* Conditionalize 64-bit support, drop 32-bit support for ppc64.
* Adjust hash size for ppc64.

v2:
* Use HTABSIZE for ppc64, fix HTABMASK usage for ppc.
  Error spotted by Segher.

Cc: Segher Boessenkool 
Signed-off-by: Andreas Färber 
Signed-off-by: Alexander Graf

Modified:
   trunk/openbios-devel/arch/ppc/qemu/ofmem.c
   trunk/openbios-devel/include/arch/ppc/processor.h

Modified: trunk/openbios-devel/arch/ppc/qemu/ofmem.c
==============================================================================
--- trunk/openbios-devel/arch/ppc/qemu/ofmem.c	Sun Nov 21 22:53:54 2010	(r966)
+++ trunk/openbios-devel/arch/ppc/qemu/ofmem.c	Mon Nov 22 21:00:13 2010	(r967)
@@ -48,7 +48,12 @@
 #define OF_CODE_START	0xfff00000UL
 #define IO_BASE			0x80000000

-#define HASH_SIZE		(2 << 15)
+#ifdef __powerpc64__
+#define HASH_BITS		18
+#else
+#define HASH_BITS		15
+#endif
+#define HASH_SIZE		(2 << HASH_BITS)
 #define OFMEM_SIZE		(2 * 1024 * 1024)

#define	SEGR_USER		BIT(2)
@@ -57,21 +62,7 @@
 static inline unsigned long
 get_hash_base( void )
 {
-	unsigned long sdr1;
-
-	asm volatile("mfsdr1 %0" : "=r" (sdr1) );
-
-	return (sdr1 & 0xffff0000);
-}
-
-static inline unsigned long
-get_hash_size( void )
-{
-	unsigned long sdr1;
-
-	asm volatile("mfsdr1 %0" : "=r" (sdr1) );
-
-	return ((sdr1 << 16) | 0x0000ffff) + 1;
+    return (mfsdr1() & SDR1_HTABORG_MASK);
 }

static inline unsigned long
@@ -242,7 +233,7 @@
    vsid = (ea >> 28) + SEGR_BASE;
    vsid_sh = 7;
    vsid_mask = 0x00003FFFFFFFFF80ULL;
-	asm ( "mfsdr1 %0" : "=r" (sdr) );
+	sdr = mfsdr1();
    sdr_sh = 18;
    sdr_mask = 0x3FF80;
    page_mask = 0x0FFFFFFF; // XXX correct?
@@ -297,6 +288,7 @@
 static void
 hash_page_32( ucell ea, ucell phys, ucell mode )
 {
+#ifndef __powerpc64__
    static int next_grab_slot=0;
    unsigned long *upte, cmp, hash1;
    int i, vsid, found;
@@ -307,7 +299,7 @@

hash1 = vsid;
    hash1 ^= (ea >> 12) & 0xffff;
-	hash1 &= (get_hash_size() - 1) >> 6;
+	hash1 &= (((mfsdr1() & 0x1ff) << 16) | 0xffff) >> 6;

pp = (mPTE_t*)(get_hash_base() + (hash1 << 6));
    upte = (unsigned long*)pp;
@@ -332,14 +324,22 @@
    upte[i*2+1] = (phys & ~0xfff) | mode;

asm volatile( "tlbie %0"  :: "r"(ea) );
+#endif
 }

static int is_ppc64(void)
 {
+#ifdef __powerpc64__
+	return 1;
+#elif defined(CONFIG_PPC_64BITSUPPORT)
    unsigned int pvr = mfpvr();
    return ((pvr >= 0x330000) && (pvr < 0x70330000));
+#else
+	return 0;
+#endif
 }

+/* XXX Remove these ugly constructs when legacy 64-bit support is dropped. */
 static void hash_page( unsigned long ea, unsigned long phys, ucell mode )
 {
    if ( is_ppc64() )
@@ -385,20 +385,21 @@
 setup_mmu( unsigned long ramsize )
 {
    ofmem_t *ofmem;
-	unsigned long sdr1;
 #ifndef __powerpc64__
    unsigned long sr_base;
 #endif
    unsigned long hash_base;
-	unsigned long hash_mask = 0xfff00000; /* alignment for ppc64 */
+	unsigned long hash_mask = ~0x000fffffUL; /* alignment for ppc64 */
    int i;

/* SDR1: Storage Description Register 1 */

hash_base = (ramsize - 0x00100000 - HASH_SIZE) & hash_mask;
    memset((void *)hash_base, 0, HASH_SIZE);
-	sdr1 = hash_base | ((HASH_SIZE-1) >> 16);
-	asm volatile("mtsdr1 %0" :: "r" (sdr1) );
+	if (is_ppc64())
+		mtsdr1(hash_base | MAX(HASH_BITS - 18, 0));
+	else
+		mtsdr1(hash_base | ((HASH_SIZE - 1) >> 16));

#ifdef __powerpc64__

Modified: trunk/openbios-devel/include/arch/ppc/processor.h
==============================================================================
--- trunk/openbios-devel/include/arch/ppc/processor.h	Sun Nov 21 22:53:54 2010	(r966)
+++ trunk/openbios-devel/include/arch/ppc/processor.h	Mon Nov 22 21:00:13 2010	(r967)
@@ -425,6 +425,24 @@
 #endif
 }

+#ifdef __powerpc64__
+#define SDR1_HTABORG_MASK 0x3FFFFFFFFFFC0000UL
+#else
+#define SDR1_HTABORG_MASK 0xffff0000
+#endif
+
+static inline unsigned long mfsdr1(void)
+{
+    unsigned long sdr1;
+    asm volatile("mfsdr1 %0" : "=r" (sdr1));
+    return sdr1;
+}
+
+static inline void mtsdr1(unsigned long sdr1)
+{
+    asm volatile("mtsdr1 %0" :: "r" (sdr1));
+}
+
 static inline unsigned int mfpvr(void)
 {
     unsigned int pvr;