[PATCH] ppc32: Support 36-bit physical addressing on e500 (fwd)

From: Kumar Gala
Date: Thu Apr 07 2005 - 16:24:08 EST

Oops, forget to CC the lists on this one.

- kumar

---------- Forwarded message ----------
Date: Thu, 7 Apr 2005 16:20:43 -0500 (CDT)
From: Kumar Gala <galak@xxxxxxxxxxxxx>
To: Andrew Morton <akpm@xxxxxxxx>
Subject: [PATCH] ppc32: Support 36-bit physical addressing on e500

Andrew,

To add support for 36-bit physical addressing on e500 the following
changes have been made. The changes are generalized to support any
physical address size larger than 32-bits:

* Allow FSL Book-E parts to use a 64-bit PTE, it is 44-bits of pfn,
20-bits of flags.

* Introduced new CPU feature (CPU_FTR_BIG_PHYS) to allow runtime
handling of updating hardware register (SPRN_MAS7) which holds the upper
32-bits of physical address that will be written into the TLB. This is
useful since not all e500 cores support 36-bit physical addressing.

* Currently have a pass through implementation of fixup_bigphys_addr

* Moved _PAGE_DIRTY in the 64-bit PTE case to free room for three
additional storage attributes that may exist in future FSL Book-E cores
and updated fault handler to copy these bits into the hardware TLBs.

Signed-off-by: Kumar Gala <kumar.gala@xxxxxxxxxxxxx>

---

diff -Nru a/arch/ppc/Kconfig b/arch/ppc/Kconfig
--- a/arch/ppc/Kconfig 2005-04-07 16:19:41 -05:00
+++ b/arch/ppc/Kconfig 2005-04-07 16:19:41 -05:00
@@ -98,13 +98,19 @@

config PTE_64BIT
bool
- depends on 44x
- default y
+ depends on 44x || E500
+ default y if 44x
+ default y if E500 && PHYS_64BIT

config PHYS_64BIT
- bool
- depends on 44x
- default y
+ bool 'Large physical address support' if E500
+ depends on 44x || E500
+ default y if 44x
+ ---help---
+ This option enables kernel support for larger than 32-bit physical
+ addresses. This features is not be available on all e500 cores.
+
+ If in doubt, say N here.

config ALTIVEC
bool "AltiVec Support"
diff -Nru a/arch/ppc/kernel/head_fsl_booke.S b/arch/ppc/kernel/head_fsl_booke.S
--- a/arch/ppc/kernel/head_fsl_booke.S 2005-04-07 16:19:41 -05:00
+++ b/arch/ppc/kernel/head_fsl_booke.S 2005-04-07 16:19:41 -05:00
@@ -347,6 +347,38 @@
mtspr SPRN_SRR1,r3
rfi /* change context and jump to start_kernel */

+/* Macros to hide the PTE size differences
+ *
+ * FIND_PTE -- walks the page tables given EA & pgdir pointer
+ * r10 -- EA of fault
+ * r11 -- PGDIR pointer
+ * r12 -- free
+ * label 2: is the bailout case
+ *
+ * if we find the pte (fall through):
+ * r11 is low pte word
+ * r12 is pointer to the pte
+ */
+#ifdef CONFIG_PTE_64BIT
+#define PTE_FLAGS_OFFSET 4
+#define FIND_PTE \
+ rlwinm r12, r10, 13, 19, 29; /* Compute pgdir/pmd offset */ \
+ lwzx r11, r12, r11; /* Get pgd/pmd entry */ \
+ rlwinm. r12, r11, 0, 0, 20; /* Extract pt base address */ \
+ beq 2f; /* Bail if no table */ \
+ rlwimi r12, r10, 23, 20, 28; /* Compute pte address */ \
+ lwz r11, 4(r12); /* Get pte entry */
+#else
+#define PTE_FLAGS_OFFSET 0
+#define FIND_PTE \
+ rlwimi r11, r10, 12, 20, 29; /* Create L1 (pgdir/pmd) address */ \
+ lwz r11, 0(r11); /* Get L1 entry */ \
+ rlwinm. r12, r11, 0, 0, 19; /* Extract L2 (pte) base address */ \
+ beq 2f; /* Bail if no table */ \
+ rlwimi r12, r10, 22, 20, 29; /* Compute PTE address */ \
+ lwz r11, 0(r12); /* Get Linux PTE */
+#endif
+
/*
* Interrupt vector entry code
*
@@ -405,13 +437,7 @@
mfspr r11,SPRN_SPRG3
lwz r11,PGDIR(r11)
4:
- rlwimi r11, r10, 12, 20, 29 /* Create L1 (pgdir/pmd) address */
- lwz r11, 0(r11) /* Get L1 entry */
- rlwinm. r12, r11, 0, 0, 19 /* Extract L2 (pte) base address */
- beq 2f /* Bail if no table */
-
- rlwimi r12, r10, 22, 20, 29 /* Compute PTE address */
- lwz r11, 0(r12) /* Get Linux PTE */
+ FIND_PTE

/* Are _PAGE_USER & _PAGE_RW set & _PAGE_HWWRITE not? */
andi. r13, r11, _PAGE_RW|_PAGE_USER|_PAGE_HWWRITE
@@ -420,14 +446,12 @@

/* Update 'changed'. */
ori r11, r11, _PAGE_DIRTY|_PAGE_ACCESSED|_PAGE_HWWRITE
- stw r11, 0(r12) /* Update Linux page table */
+ stw r11, PTE_FLAGS_OFFSET(r12) /* Update Linux page table */

/* MAS2 not updated as the entry does exist in the tlb, this
fault taken to detect state transition (eg: COW -> DIRTY)
*/
- lis r12, MAS3_RPN@h
- ori r12, r12, _PAGE_HWEXEC | MAS3_RPN@l
- and r11, r11, r12
+ andi. r11, r11, _PAGE_HWEXEC
rlwimi r11, r11, 31, 27, 27 /* SX <- _PAGE_HWEXEC */
ori r11, r11, (MAS3_UW|MAS3_SW|MAS3_UR|MAS3_SR)@l /* set static perms */

@@ -439,7 +463,10 @@
/* find the TLB index that caused the fault. It has to be here. */
tlbsx 0, r10

- mtspr SPRN_MAS3,r11
+ /* only update the perm bits, assume the RPN is fine */
+ mfspr r12, SPRN_MAS3
+ rlwimi r12, r11, 0, 20, 31
+ mtspr SPRN_MAS3,r12
tlbwe

/* Done...restore registers and get out of here. */
@@ -530,18 +557,15 @@
lwz r11,PGDIR(r11)

4:
- rlwimi r11, r10, 12, 20, 29 /* Create L1 (pgdir/pmd) address */
- lwz r11, 0(r11) /* Get L1 entry */
- rlwinm. r12, r11, 0, 0, 19 /* Extract L2 (pte) base address */
- beq 2f /* Bail if no table */
-
- rlwimi r12, r10, 22, 20, 29 /* Compute PTE address */
- lwz r11, 0(r12) /* Get Linux PTE */
- andi. r13, r11, _PAGE_PRESENT
- beq 2f
-
+ FIND_PTE
+ andi. r13, r11, _PAGE_PRESENT /* Is the page present? */
+ beq 2f /* Bail if not present */
+
+#ifdef CONFIG_PTE_64BIT
+ lwz r13, 0(r12)
+#endif
ori r11, r11, _PAGE_ACCESSED
- stw r11, 0(r12)
+ stw r11, PTE_FLAGS_OFFSET(r12)

/* Jump to common tlb load */
b finish_tlb_load
@@ -594,18 +618,15 @@
lwz r11,PGDIR(r11)

4:
- rlwimi r11, r10, 12, 20, 29 /* Create L1 (pgdir/pmd) address */
- lwz r11, 0(r11) /* Get L1 entry */
- rlwinm. r12, r11, 0, 0, 19 /* Extract L2 (pte) base address */
- beq 2f /* Bail if no table */
-
- rlwimi r12, r10, 22, 20, 29 /* Compute PTE address */
- lwz r11, 0(r12) /* Get Linux PTE */
- andi. r13, r11, _PAGE_PRESENT
- beq 2f
-
+ FIND_PTE
+ andi. r13, r11, _PAGE_PRESENT /* Is the page present? */
+ beq 2f /* Bail if not present */
+
+#ifdef CONFIG_PTE_64BIT
+ lwz r13, 0(r12)
+#endif
ori r11, r11, _PAGE_ACCESSED
- stw r11, 0(r12)
+ stw r11, PTE_FLAGS_OFFSET(r12)

/* Jump to common TLB load point */
b finish_tlb_load
@@ -690,27 +711,39 @@
*/

mfspr r12, SPRN_MAS2
+#ifdef CONFIG_PTE_64BIT
+ rlwimi r12, r11, 26, 24, 31 /* extract ...WIMGE from pte */
+#else
rlwimi r12, r11, 26, 27, 31 /* extract WIMGE from pte */
+#endif
mtspr SPRN_MAS2, r12

bge 5, 1f

- /* addr > TASK_SIZE */
- li r10, (MAS3_UX | MAS3_UW | MAS3_UR)
- andi. r13, r11, (_PAGE_USER | _PAGE_HWWRITE | _PAGE_HWEXEC)
- andi. r12, r11, _PAGE_USER /* Test for _PAGE_USER */
- iseleq r12, 0, r10
- and r10, r12, r13
- srwi r12, r10, 1
+ /* is user addr */
+ andi. r12, r11, (_PAGE_USER | _PAGE_HWWRITE | _PAGE_HWEXEC)
+ andi. r10, r11, _PAGE_USER /* Test for _PAGE_USER */
+ srwi r10, r12, 1
or r12, r12, r10 /* Copy user perms into supervisor */
+ iseleq r12, 0, r12
b 2f

- /* addr <= TASK_SIZE */
+ /* is kernel addr */
1: rlwinm r12, r11, 31, 29, 29 /* Extract _PAGE_HWWRITE into SW */
ori r12, r12, (MAS3_SX | MAS3_SR)

+#ifdef CONFIG_PTE_64BIT
+2: rlwimi r12, r13, 24, 0, 7 /* grab RPN[32:39] */
+ rlwimi r12, r11, 24, 8, 19 /* grab RPN[40:51] */
+ mtspr SPRN_MAS3, r12
+BEGIN_FTR_SECTION
+ srwi r10, r13, 8 /* grab RPN[8:31] */
+ mtspr SPRN_MAS7, r10
+END_FTR_SECTION_IFSET(CPU_FTR_BIG_PHYS)
+#else
2: rlwimi r11, r12, 0, 20, 31 /* Extract RPN from PTE and merge with perms */
mtspr SPRN_MAS3, r11
+#endif
tlbwe

/* Done...restore registers and get out of here. */
diff -Nru a/arch/ppc/syslib/ppc85xx_common.c b/arch/ppc/syslib/ppc85xx_common.c
--- a/arch/ppc/syslib/ppc85xx_common.c 2005-04-07 16:19:41 -05:00
+++ b/arch/ppc/syslib/ppc85xx_common.c 2005-04-07 16:19:41 -05:00
@@ -31,3 +31,11 @@
}

EXPORT_SYMBOL(get_ccsrbar);
+
+/* For now this is a pass through */
+phys_addr_t fixup_bigphys_addr(phys_addr_t addr, phys_addr_t size)
+{
+ return addr;
+};
+EXPORT_SYMBOL(fixup_bigphys_addr);
+
diff -Nru a/include/asm-ppc/cputable.h b/include/asm-ppc/cputable.h
--- a/include/asm-ppc/cputable.h 2005-04-07 16:19:41 -05:00
+++ b/include/asm-ppc/cputable.h 2005-04-07 16:19:41 -05:00
@@ -86,8 +86,9 @@
#define CPU_FTR_DUAL_PLL_750FX 0x00004000
#define CPU_FTR_NO_DPM 0x00008000
#define CPU_FTR_HAS_HIGH_BATS 0x00010000
-#define CPU_FTR_NEED_COHERENT 0x00020000
+#define CPU_FTR_NEED_COHERENT 0x00020000
#define CPU_FTR_NO_BTIC 0x00040000
+#define CPU_FTR_BIG_PHYS 0x00080000

#ifdef __ASSEMBLY__

diff -Nru a/include/asm-ppc/pgtable.h b/include/asm-ppc/pgtable.h
--- a/include/asm-ppc/pgtable.h 2005-04-07 16:19:41 -05:00
+++ b/include/asm-ppc/pgtable.h 2005-04-07 16:19:41 -05:00
@@ -225,8 +225,7 @@
/* ERPN in a PTE never gets cleared, ignore it */
#define _PTE_NONE_MASK 0xffffffff00000000ULL

-#elif defined(CONFIG_E500)
-
+#elif defined(CONFIG_FSL_BOOKE)
/*
MMU Assist Register 3:

@@ -240,21 +239,29 @@
entries use the top 29 bits.
*/

-/* Definitions for e500 core */
-#define _PAGE_PRESENT 0x001 /* S: PTE contains a translation */
-#define _PAGE_USER 0x002 /* S: User page (maps to UR) */
-#define _PAGE_FILE 0x002 /* S: when !present: nonlinear file mapping */
-#define _PAGE_ACCESSED 0x004 /* S: Page referenced */
-#define _PAGE_HWWRITE 0x008 /* H: Dirty & RW, set in exception */
-#define _PAGE_RW 0x010 /* S: Write permission */
-#define _PAGE_HWEXEC 0x020 /* H: UX permission */
-
-#define _PAGE_ENDIAN 0x040 /* H: E bit */
-#define _PAGE_GUARDED 0x080 /* H: G bit */
-#define _PAGE_COHERENT 0x100 /* H: M bit */
-#define _PAGE_NO_CACHE 0x200 /* H: I bit */
-#define _PAGE_WRITETHRU 0x400 /* H: W bit */
-#define _PAGE_DIRTY 0x800 /* S: Page dirty */
+/* Definitions for FSL Book-E Cores */
+#define _PAGE_PRESENT 0x00001 /* S: PTE contains a translation */
+#define _PAGE_USER 0x00002 /* S: User page (maps to UR) */
+#define _PAGE_FILE 0x00002 /* S: when !present: nonlinear file mapping */
+#define _PAGE_ACCESSED 0x00004 /* S: Page referenced */
+#define _PAGE_HWWRITE 0x00008 /* H: Dirty & RW, set in exception */
+#define _PAGE_RW 0x00010 /* S: Write permission */
+#define _PAGE_HWEXEC 0x00020 /* H: UX permission */
+
+#define _PAGE_ENDIAN 0x00040 /* H: E bit */
+#define _PAGE_GUARDED 0x00080 /* H: G bit */
+#define _PAGE_COHERENT 0x00100 /* H: M bit */
+#define _PAGE_NO_CACHE 0x00200 /* H: I bit */
+#define _PAGE_WRITETHRU 0x00400 /* H: W bit */
+
+#ifdef CONFIG_PTE_64BIT
+#define _PAGE_DIRTY 0x08000 /* S: Page dirty */
+
+/* ERPN in a PTE never gets cleared, ignore it */
+#define _PTE_NONE_MASK 0xffffffffffff0000ULL
+#else
+#define _PAGE_DIRTY 0x00800 /* S: Page dirty */
+#endif

#define _PMD_PRESENT 0
#define _PMD_PRESENT_MASK (PAGE_MASK)
@@ -433,7 +440,11 @@

/* in some case we want to additionaly adjust where the pfn is in the pte to
* allow room for more flags */
+#if defined(CONFIG_FSL_BOOKE) && defined(CONFIG_PTE_64BIT)
+#define PFN_SHIFT_OFFSET (PAGE_SHIFT + 8)
+#else
#define PFN_SHIFT_OFFSET (PAGE_SHIFT)
+#endif

#define pte_pfn(x) (pte_val(x) >> PFN_SHIFT_OFFSET)
#define pte_page(x) pfn_to_page(pte_pfn(x))
diff -Nru a/include/asm-ppc/reg_booke.h b/include/asm-ppc/reg_booke.h
--- a/include/asm-ppc/reg_booke.h 2005-04-07 16:19:41 -05:00
+++ b/include/asm-ppc/reg_booke.h 2005-04-07 16:19:41 -05:00
@@ -172,6 +172,7 @@
#define SPRN_MAS4 0x274 /* MMU Assist Register 4 */
#define SPRN_MAS5 0x275 /* MMU Assist Register 5 */
#define SPRN_MAS6 0x276 /* MMU Assist Register 6 */
+#define SPRN_MAS7 0x3b0 /* MMU Assist Register 7 */
#define SPRN_PID1 0x279 /* Process ID Register 1 */
#define SPRN_PID2 0x27A /* Process ID Register 2 */
#define SPRN_TLB0CFG 0x2B0 /* TLB 0 Config Register */

-
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