From be0c37c985eddc46d0d67543898c086f60460e2e Mon Sep 17 00:00:00 2001
From: "Steven J. Hill" <Steven.Hill@imgtec.com>
Date: Thu, 26 Feb 2015 18:16:37 -0600
Subject: MIPS: Rearrange PTE bits into fixed positions.

This patch rearranges the PTE bits into fixed positions for R2
and later cores. In the past, the TLB handling code did runtime
checking of RI/XI and adjusted the shifts and rotates in order
to fit the largest PFN value into the PTE. The checking now
occurs when building the TLB handler, thus eliminating those
checks. These new arrangements also define the largest possible
PFN value that can fit in the PTE. HUGE page support is only
available for 64-bit cores. Layouts of the PTE bits are now:

   64-bit, R1 or earlier:     CCC D V G [S H] M A W R P
   32-bit, R1 or earler:      CCC D V G M A W R P
   64-bit, R2 or later:       CCC D V G RI/R XI [S H] M A W P
   32-bit, R2 or later:       CCC D V G RI/R XI M A W P

[ralf@linux-mips.org: Fix another build error *rant* *rant*]

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9353/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/mm/tlbex.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'arch/mips/mm/tlbex.c')

diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index d75ff73a2012..20d985901e44 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -231,14 +231,14 @@ static void output_pgtable_bits_defines(void)
 	pr_define("_PAGE_HUGE_SHIFT %d\n", _PAGE_HUGE_SHIFT);
 	pr_define("_PAGE_SPLITTING_SHIFT %d\n", _PAGE_SPLITTING_SHIFT);
 #endif
+#ifdef CONFIG_CPU_MIPSR2
 	if (cpu_has_rixi) {
 #ifdef _PAGE_NO_EXEC_SHIFT
 		pr_define("_PAGE_NO_EXEC_SHIFT %d\n", _PAGE_NO_EXEC_SHIFT);
-#endif
-#ifdef _PAGE_NO_READ_SHIFT
 		pr_define("_PAGE_NO_READ_SHIFT %d\n", _PAGE_NO_READ_SHIFT);
 #endif
 	}
+#endif
 	pr_define("_PAGE_GLOBAL_SHIFT %d\n", _PAGE_GLOBAL_SHIFT);
 	pr_define("_PAGE_VALID_SHIFT %d\n", _PAGE_VALID_SHIFT);
 	pr_define("_PAGE_DIRTY_SHIFT %d\n", _PAGE_DIRTY_SHIFT);
-- 
cgit v1.2.3


From c5b367835cfc7a8ef53b9670a409ffcc95194344 Mon Sep 17 00:00:00 2001
From: "Steven J. Hill" <Steven.Hill@imgtec.com>
Date: Thu, 26 Feb 2015 18:16:38 -0600
Subject: MIPS: Add support for XPA.

Add support for extended physical addressing (XPA) so that
32-bit platforms can access equal to or greater than 40 bits
of physical addresses.

NOTE:
      1) XPA and EVA are not the same and cannot be used
         simultaneously.
      2) If you configure your kernel for XPA, the PTEs
         and all address sizes become 64-bit.
      3) Your platform MUST have working HIGHMEM support.

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9355/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/Kconfig                    | 35 ++++++++++++++
 arch/mips/include/asm/cpu-features.h |  3 ++
 arch/mips/include/asm/cpu.h          |  1 +
 arch/mips/include/asm/pgtable-32.h   | 15 +++---
 arch/mips/include/asm/pgtable-bits.h | 13 +++++-
 arch/mips/include/asm/pgtable.h      | 36 ++++++---------
 arch/mips/kernel/cpu-probe.c         |  4 ++
 arch/mips/kernel/proc.c              |  1 +
 arch/mips/mm/init.c                  |  7 ++-
 arch/mips/mm/tlb-r4k.c               | 12 +++++
 arch/mips/mm/tlbex.c                 | 90 ++++++++++++++++++++++++++++++------
 11 files changed, 173 insertions(+), 44 deletions(-)

(limited to 'arch/mips/mm/tlbex.c')

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index c7a16904cd03..69a3b0fab926 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -377,6 +377,7 @@ config MIPS_MALTA
 	select SYS_HAS_CPU_MIPS32_R1
 	select SYS_HAS_CPU_MIPS32_R2
 	select SYS_HAS_CPU_MIPS32_R3_5
+	select SYS_HAS_CPU_MIPS32_R5
 	select SYS_HAS_CPU_MIPS32_R6
 	select SYS_HAS_CPU_MIPS64_R1
 	select SYS_HAS_CPU_MIPS64_R2
@@ -386,6 +387,7 @@ config MIPS_MALTA
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
+	select SYS_SUPPORTS_HIGHMEM
 	select SYS_SUPPORTS_LITTLE_ENDIAN
 	select SYS_SUPPORTS_MICROMIPS
 	select SYS_SUPPORTS_MIPS_CMP
@@ -1596,6 +1598,33 @@ config CPU_MIPS32_3_5_EVA
 	  One of its primary benefits is an increase in the maximum size
 	  of lowmem (up to 3GB). If unsure, say 'N' here.
 
+config CPU_MIPS32_R5_FEATURES
+	bool "MIPS32 Release 5 Features"
+	depends on SYS_HAS_CPU_MIPS32_R5
+	depends on CPU_MIPS32_R2
+	help
+	  Choose this option to build a kernel for release 2 or later of the
+	  MIPS32 architecture including features from release 5 such as
+	  support for Extended Physical Addressing (XPA).
+
+config CPU_MIPS32_R5_XPA
+	bool "Extended Physical Addressing (XPA)"
+	depends on CPU_MIPS32_R5_FEATURES
+	depends on !EVA
+	depends on !PAGE_SIZE_4KB
+	depends on SYS_SUPPORTS_HIGHMEM
+	select XPA
+	select HIGHMEM
+	select ARCH_PHYS_ADDR_T_64BIT
+	default n
+	help
+	  Choose this option if you want to enable the Extended Physical
+	  Addressing (XPA) on your MIPS32 core (such as P5600 series). The
+	  benefit is to increase physical addressing equal to or greater
+	  than 40 bits. Note that this has the side effect of turning on
+	  64-bit addressing which in turn makes the PTEs 64-bit in size.
+	  If unsure, say 'N' here.
+
 if CPU_LOONGSON2F
 config CPU_NOP_WORKAROUNDS
 	bool
@@ -1699,6 +1728,9 @@ config SYS_HAS_CPU_MIPS32_R2
 config SYS_HAS_CPU_MIPS32_R3_5
 	bool
 
+config SYS_HAS_CPU_MIPS32_R5
+	bool
+
 config SYS_HAS_CPU_MIPS32_R6
 	bool
 
@@ -1836,6 +1868,9 @@ config CPU_MIPSR6
 config EVA
 	bool
 
+config XPA
+	bool
+
 config SYS_SUPPORTS_32BIT_KERNEL
 	bool
 config SYS_SUPPORTS_64BIT_KERNEL
diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index 0d8208de9a3f..a324751b02ff 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -139,6 +139,9 @@
 # endif
 #endif
 
+#ifndef cpu_has_xpa
+#define cpu_has_xpa		(cpu_data[0].options & MIPS_CPU_XPA)
+#endif
 #ifndef cpu_has_vtag_icache
 #define cpu_has_vtag_icache	(cpu_data[0].icache.flags & MIPS_CACHE_VTAG)
 #endif
diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index 15687234d70a..e492c740bb94 100644
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -377,6 +377,7 @@ enum cpu_type_enum {
 #define MIPS_CPU_MAAR		0x400000000ull /* MAAR(I) registers are present */
 #define MIPS_CPU_FRE		0x800000000ull /* FRE & UFE bits implemented */
 #define MIPS_CPU_RW_LLB		0x1000000000ull /* LLADDR/LLB writes are allowed */
+#define MIPS_CPU_XPA		0x2000000000ull /* CPU supports Extended Physical Addressing */
 
 /*
  * CPU ASE encodings
diff --git a/arch/mips/include/asm/pgtable-32.h b/arch/mips/include/asm/pgtable-32.h
index a6be006b6f75..7d56686c0e62 100644
--- a/arch/mips/include/asm/pgtable-32.h
+++ b/arch/mips/include/asm/pgtable-32.h
@@ -105,13 +105,16 @@ static inline void pmd_clear(pmd_t *pmdp)
 
 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
 #define pte_page(x)		pfn_to_page(pte_pfn(x))
-#define pte_pfn(x)		((unsigned long)((x).pte_high >> 6))
+#define pte_pfn(x)		(((unsigned long)((x).pte_high >> _PFN_SHIFT)) | (unsigned long)((x).pte_low << _PAGE_PRESENT_SHIFT))
 static inline pte_t
 pfn_pte(unsigned long pfn, pgprot_t prot)
 {
 	pte_t pte;
-	pte.pte_high = (pfn << 6) | (pgprot_val(prot) & 0x3f);
-	pte.pte_low = pgprot_val(prot);
+
+	pte.pte_low = (pfn >> _PAGE_PRESENT_SHIFT) |
+				(pgprot_val(prot) & ~_PFNX_MASK);
+	pte.pte_high = (pfn << _PFN_SHIFT) |
+				(pgprot_val(prot) & ~_PFN_MASK);
 	return pte;
 }
 
@@ -166,9 +169,9 @@ pfn_pte(unsigned long pfn, pgprot_t prot)
 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
 
 /* Swap entries must have VALID and GLOBAL bits cleared. */
-#define __swp_type(x)			(((x).val >> 2) & 0x1f)
-#define __swp_offset(x)			 ((x).val >> 7)
-#define __swp_entry(type,offset)	((swp_entry_t)	{ ((type) << 2) | ((offset) << 7) })
+#define __swp_type(x)			(((x).val >> 4) & 0x1f)
+#define __swp_offset(x)			 ((x).val >> 9)
+#define __swp_entry(type,offset)	((swp_entry_t)  { ((type) << 4) | ((offset) << 9) })
 #define __pte_to_swp_entry(pte)		((swp_entry_t) { (pte).pte_high })
 #define __swp_entry_to_pte(x)		((pte_t) { 0, (x).val })
 
diff --git a/arch/mips/include/asm/pgtable-bits.h b/arch/mips/include/asm/pgtable-bits.h
index 8e432a8ec4fe..18ae5ddef118 100644
--- a/arch/mips/include/asm/pgtable-bits.h
+++ b/arch/mips/include/asm/pgtable-bits.h
@@ -37,7 +37,11 @@
 /*
  * The following bits are implemented by the TLB hardware
  */
-#define _PAGE_GLOBAL_SHIFT	0
+#define _PAGE_NO_EXEC_SHIFT	0
+#define _PAGE_NO_EXEC		(1 << _PAGE_NO_EXEC_SHIFT)
+#define _PAGE_NO_READ_SHIFT	(_PAGE_NO_EXEC_SHIFT + 1)
+#define _PAGE_NO_READ		(1 << _PAGE_NO_READ_SHIFT)
+#define _PAGE_GLOBAL_SHIFT	(_PAGE_NO_READ_SHIFT + 1)
 #define _PAGE_GLOBAL		(1 << _PAGE_GLOBAL_SHIFT)
 #define _PAGE_VALID_SHIFT	(_PAGE_GLOBAL_SHIFT + 1)
 #define _PAGE_VALID		(1 << _PAGE_VALID_SHIFT)
@@ -49,7 +53,7 @@
 /*
  * The following bits are implemented in software
  */
-#define _PAGE_PRESENT_SHIFT	(_CACHE_SHIFT + 3)
+#define _PAGE_PRESENT_SHIFT	(24)
 #define _PAGE_PRESENT		(1 << _PAGE_PRESENT_SHIFT)
 #define _PAGE_READ_SHIFT	(_PAGE_PRESENT_SHIFT + 1)
 #define _PAGE_READ		(1 << _PAGE_READ_SHIFT)
@@ -62,6 +66,11 @@
 
 #define _PFN_SHIFT		(PAGE_SHIFT - 12 + _CACHE_SHIFT + 3)
 
+/*
+ * Bits for extended EntryLo0/EntryLo1 registers
+ */
+#define _PFNX_MASK		0xffffff
+
 #elif defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
 
 /*
diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index e1fec0237ce2..bffd46ca3694 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -133,7 +133,7 @@ extern void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
 
 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
 
-#define pte_none(pte)		(!(((pte).pte_low | (pte).pte_high) & ~_PAGE_GLOBAL))
+#define pte_none(pte)		(!(((pte).pte_high) & ~_PAGE_GLOBAL))
 #define pte_present(pte)	((pte).pte_low & _PAGE_PRESENT)
 
 static inline void set_pte(pte_t *ptep, pte_t pte)
@@ -142,16 +142,14 @@ static inline void set_pte(pte_t *ptep, pte_t pte)
 	smp_wmb();
 	ptep->pte_low = pte.pte_low;
 
-	if (pte.pte_low & _PAGE_GLOBAL) {
+	if (pte.pte_high & _PAGE_GLOBAL) {
 		pte_t *buddy = ptep_buddy(ptep);
 		/*
 		 * Make sure the buddy is global too (if it's !none,
 		 * it better already be global)
 		 */
-		if (pte_none(*buddy)) {
-			buddy->pte_low	|= _PAGE_GLOBAL;
+		if (pte_none(*buddy))
 			buddy->pte_high |= _PAGE_GLOBAL;
-		}
 	}
 }
 
@@ -161,8 +159,8 @@ static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *pt
 
 	htw_stop();
 	/* Preserve global status for the pair */
-	if (ptep_buddy(ptep)->pte_low & _PAGE_GLOBAL)
-		null.pte_low = null.pte_high = _PAGE_GLOBAL;
+	if (ptep_buddy(ptep)->pte_high & _PAGE_GLOBAL)
+		null.pte_high = _PAGE_GLOBAL;
 
 	set_pte_at(mm, addr, ptep, null);
 	htw_start();
@@ -242,21 +240,21 @@ static inline int pte_young(pte_t pte)	{ return pte.pte_low & _PAGE_ACCESSED; }
 
 static inline pte_t pte_wrprotect(pte_t pte)
 {
-	pte.pte_low  &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
+	pte.pte_low  &= ~_PAGE_WRITE;
 	pte.pte_high &= ~_PAGE_SILENT_WRITE;
 	return pte;
 }
 
 static inline pte_t pte_mkclean(pte_t pte)
 {
-	pte.pte_low  &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
+	pte.pte_low  &= ~_PAGE_MODIFIED;
 	pte.pte_high &= ~_PAGE_SILENT_WRITE;
 	return pte;
 }
 
 static inline pte_t pte_mkold(pte_t pte)
 {
-	pte.pte_low  &= ~(_PAGE_ACCESSED | _PAGE_SILENT_READ);
+	pte.pte_low  &= ~_PAGE_ACCESSED;
 	pte.pte_high &= ~_PAGE_SILENT_READ;
 	return pte;
 }
@@ -264,30 +262,24 @@ static inline pte_t pte_mkold(pte_t pte)
 static inline pte_t pte_mkwrite(pte_t pte)
 {
 	pte.pte_low |= _PAGE_WRITE;
-	if (pte.pte_low & _PAGE_MODIFIED) {
-		pte.pte_low  |= _PAGE_SILENT_WRITE;
+	if (pte.pte_low & _PAGE_MODIFIED)
 		pte.pte_high |= _PAGE_SILENT_WRITE;
-	}
 	return pte;
 }
 
 static inline pte_t pte_mkdirty(pte_t pte)
 {
 	pte.pte_low |= _PAGE_MODIFIED;
-	if (pte.pte_low & _PAGE_WRITE) {
-		pte.pte_low  |= _PAGE_SILENT_WRITE;
+	if (pte.pte_low & _PAGE_WRITE)
 		pte.pte_high |= _PAGE_SILENT_WRITE;
-	}
 	return pte;
 }
 
 static inline pte_t pte_mkyoung(pte_t pte)
 {
 	pte.pte_low |= _PAGE_ACCESSED;
-	if (pte.pte_low & _PAGE_READ) {
-		pte.pte_low  |= _PAGE_SILENT_READ;
+	if (pte.pte_low & _PAGE_READ)
 		pte.pte_high |= _PAGE_SILENT_READ;
-	}
 	return pte;
 }
 #else
@@ -391,10 +383,10 @@ static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
-	pte.pte_low  &= _PAGE_CHG_MASK;
+	pte.pte_low  &= (_PAGE_MODIFIED | _PAGE_ACCESSED | _PFNX_MASK);
 	pte.pte_high &= (_PFN_MASK | _CACHE_MASK);
-	pte.pte_low  |= pgprot_val(newprot);
-	pte.pte_high |= pgprot_val(newprot) & ~(_PFN_MASK | _CACHE_MASK);
+	pte.pte_low  |= pgprot_val(newprot) & ~_PFNX_MASK;
+	pte.pte_high |= pgprot_val(newprot) & ~_PFN_MASK;
 	return pte;
 }
 #else
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 48dfb9de853d..ac96817d1f99 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -516,6 +516,10 @@ static inline unsigned int decode_config5(struct cpuinfo_mips *c)
 		c->options |= MIPS_CPU_MAAR;
 	if (config5 & MIPS_CONF5_LLB)
 		c->options |= MIPS_CPU_RW_LLB;
+#ifdef CONFIG_XPA
+	if (config5 & MIPS_CONF5_MVH)
+		c->options |= MIPS_CPU_XPA;
+#endif
 
 	return config5 & MIPS_CONF_M;
 }
diff --git a/arch/mips/kernel/proc.c b/arch/mips/kernel/proc.c
index 130af7d26a9c..298b2b773d12 100644
--- a/arch/mips/kernel/proc.c
+++ b/arch/mips/kernel/proc.c
@@ -120,6 +120,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 	if (cpu_has_msa)	seq_printf(m, "%s", " msa");
 	if (cpu_has_eva)	seq_printf(m, "%s", " eva");
 	if (cpu_has_htw)	seq_printf(m, "%s", " htw");
+	if (cpu_has_xpa)	seq_printf(m, "%s", " xpa");
 	seq_printf(m, "\n");
 
 	if (cpu_has_mmips) {
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 448cde372af0..faa5c9822ecc 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -96,7 +96,7 @@ static void *__kmap_pgprot(struct page *page, unsigned long addr, pgprot_t prot)
 	vaddr = __fix_to_virt(FIX_CMAP_END - idx);
 	pte = mk_pte(page, prot);
 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
-	entrylo = pte.pte_high;
+	entrylo = pte_to_entrylo(pte.pte_high);
 #else
 	entrylo = pte_to_entrylo(pte_val(pte));
 #endif
@@ -106,6 +106,11 @@ static void *__kmap_pgprot(struct page *page, unsigned long addr, pgprot_t prot)
 	write_c0_entryhi(vaddr & (PAGE_MASK << 1));
 	write_c0_entrylo0(entrylo);
 	write_c0_entrylo1(entrylo);
+#ifdef CONFIG_XPA
+	entrylo = (pte.pte_low & _PFNX_MASK);
+	writex_c0_entrylo0(entrylo);
+	writex_c0_entrylo1(entrylo);
+#endif
 	tlbidx = read_c0_wired();
 	write_c0_wired(tlbidx + 1);
 	write_c0_index(tlbidx);
diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
index b2afa49beab0..c2500f4cb1d1 100644
--- a/arch/mips/mm/tlb-r4k.c
+++ b/arch/mips/mm/tlb-r4k.c
@@ -333,9 +333,17 @@ void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
 		ptep = pte_offset_map(pmdp, address);
 
 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
+#ifdef CONFIG_XPA
+		write_c0_entrylo0(pte_to_entrylo(ptep->pte_high));
+		writex_c0_entrylo0(ptep->pte_low & _PFNX_MASK);
+		ptep++;
+		write_c0_entrylo1(pte_to_entrylo(ptep->pte_high));
+		writex_c0_entrylo1(ptep->pte_low & _PFNX_MASK);
+#else
 		write_c0_entrylo0(ptep->pte_high);
 		ptep++;
 		write_c0_entrylo1(ptep->pte_high);
+#endif
 #else
 		write_c0_entrylo0(pte_to_entrylo(pte_val(*ptep++)));
 		write_c0_entrylo1(pte_to_entrylo(pte_val(*ptep)));
@@ -355,6 +363,9 @@ void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
 void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
 		     unsigned long entryhi, unsigned long pagemask)
 {
+#ifdef CONFIG_XPA
+	panic("Broken for XPA kernels");
+#else
 	unsigned long flags;
 	unsigned long wired;
 	unsigned long old_pagemask;
@@ -383,6 +394,7 @@ void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
 	write_c0_pagemask(old_pagemask);
 	local_flush_tlb_all();
 	local_irq_restore(flags);
+#endif
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 20d985901e44..7709920e0cef 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -35,6 +35,17 @@
 #include <asm/uasm.h>
 #include <asm/setup.h>
 
+static int __cpuinitdata mips_xpa_disabled;
+
+static int __init xpa_disable(char *s)
+{
+	mips_xpa_disabled = 1;
+
+	return 1;
+}
+
+__setup("noxpa", xpa_disable);
+
 /*
  * TLB load/store/modify handlers.
  *
@@ -1027,12 +1038,27 @@ static void build_update_entries(u32 **p, unsigned int tmp, unsigned int ptep)
 	} else {
 		int pte_off_even = sizeof(pte_t) / 2;
 		int pte_off_odd = pte_off_even + sizeof(pte_t);
+#ifdef CONFIG_XPA
+		const int scratch = 1; /* Our extra working register */
 
-		/* The pte entries are pre-shifted */
-		uasm_i_lw(p, tmp, pte_off_even, ptep); /* get even pte */
-		UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */
-		uasm_i_lw(p, ptep, pte_off_odd, ptep); /* get odd pte */
-		UASM_i_MTC0(p, ptep, C0_ENTRYLO1); /* load it */
+		uasm_i_addu(p, scratch, 0, ptep);
+#endif
+		uasm_i_lw(p, tmp, pte_off_even, ptep); /* even pte */
+		uasm_i_lw(p, ptep, pte_off_odd, ptep); /* odd pte */
+		UASM_i_ROTR(p, tmp, tmp, ilog2(_PAGE_GLOBAL));
+		UASM_i_ROTR(p, ptep, ptep, ilog2(_PAGE_GLOBAL));
+		UASM_i_MTC0(p, tmp, C0_ENTRYLO0);
+		UASM_i_MTC0(p, ptep, C0_ENTRYLO1);
+#ifdef CONFIG_XPA
+		uasm_i_lw(p, tmp, 0, scratch);
+		uasm_i_lw(p, ptep, sizeof(pte_t), scratch);
+		uasm_i_lui(p, scratch, 0xff);
+		uasm_i_ori(p, scratch, scratch, 0xffff);
+		uasm_i_and(p, tmp, scratch, tmp);
+		uasm_i_and(p, ptep, scratch, ptep);
+		uasm_i_mthc0(p, tmp, C0_ENTRYLO0);
+		uasm_i_mthc0(p, ptep, C0_ENTRYLO1);
+#endif
 	}
 #else
 	UASM_i_LW(p, tmp, 0, ptep); /* get even pte */
@@ -1533,8 +1559,14 @@ iPTE_SW(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr,
 {
 #ifdef CONFIG_PHYS_ADDR_T_64BIT
 	unsigned int hwmode = mode & (_PAGE_VALID | _PAGE_DIRTY);
-#endif
 
+	if (!cpu_has_64bits) {
+		const int scratch = 1; /* Our extra working register */
+
+		uasm_i_lui(p, scratch, (mode >> 16));
+		uasm_i_or(p, pte, pte, scratch);
+	} else
+#endif
 	uasm_i_ori(p, pte, pte, mode);
 #ifdef CONFIG_SMP
 # ifdef CONFIG_PHYS_ADDR_T_64BIT
@@ -1598,15 +1630,17 @@ build_pte_present(u32 **p, struct uasm_reloc **r,
 			uasm_il_bbit0(p, r, pte, ilog2(_PAGE_PRESENT), lid);
 			uasm_i_nop(p);
 		} else {
-			uasm_i_andi(p, t, pte, _PAGE_PRESENT);
+			uasm_i_srl(p, t, pte, _PAGE_PRESENT_SHIFT);
+			uasm_i_andi(p, t, t, 1);
 			uasm_il_beqz(p, r, t, lid);
 			if (pte == t)
 				/* You lose the SMP race :-(*/
 				iPTE_LW(p, pte, ptr);
 		}
 	} else {
-		uasm_i_andi(p, t, pte, _PAGE_PRESENT | _PAGE_READ);
-		uasm_i_xori(p, t, t, _PAGE_PRESENT | _PAGE_READ);
+		uasm_i_srl(p, t, pte, _PAGE_PRESENT_SHIFT);
+		uasm_i_andi(p, t, t, 3);
+		uasm_i_xori(p, t, t, 3);
 		uasm_il_bnez(p, r, t, lid);
 		if (pte == t)
 			/* You lose the SMP race :-(*/
@@ -1635,8 +1669,9 @@ build_pte_writable(u32 **p, struct uasm_reloc **r,
 {
 	int t = scratch >= 0 ? scratch : pte;
 
-	uasm_i_andi(p, t, pte, _PAGE_PRESENT | _PAGE_WRITE);
-	uasm_i_xori(p, t, t, _PAGE_PRESENT | _PAGE_WRITE);
+	uasm_i_srl(p, t, pte, _PAGE_PRESENT_SHIFT);
+	uasm_i_andi(p, t, t, 5);
+	uasm_i_xori(p, t, t, 5);
 	uasm_il_bnez(p, r, t, lid);
 	if (pte == t)
 		/* You lose the SMP race :-(*/
@@ -1672,7 +1707,8 @@ build_pte_modifiable(u32 **p, struct uasm_reloc **r,
 		uasm_i_nop(p);
 	} else {
 		int t = scratch >= 0 ? scratch : pte;
-		uasm_i_andi(p, t, pte, _PAGE_WRITE);
+		uasm_i_srl(p, t, pte, _PAGE_WRITE_SHIFT);
+		uasm_i_andi(p, t, t, 1);
 		uasm_il_beqz(p, r, t, lid);
 		if (pte == t)
 			/* You lose the SMP race :-(*/
@@ -2285,6 +2321,11 @@ static void config_htw_params(void)
 
 	pwsize = ilog2(PTRS_PER_PGD) << MIPS_PWSIZE_GDW_SHIFT;
 	pwsize |= ilog2(PTRS_PER_PTE) << MIPS_PWSIZE_PTW_SHIFT;
+
+	/* If XPA has been enabled, PTEs are 64-bit in size. */
+	if (read_c0_pagegrain() & PG_ELPA)
+		pwsize |= 1;
+
 	write_c0_pwsize(pwsize);
 
 	/* Make sure everything is set before we enable the HTW */
@@ -2298,6 +2339,28 @@ static void config_htw_params(void)
 	print_htw_config();
 }
 
+static void config_xpa_params(void)
+{
+#ifdef CONFIG_XPA
+	unsigned int pagegrain;
+
+	if (mips_xpa_disabled) {
+		pr_info("Extended Physical Addressing (XPA) disabled\n");
+		return;
+	}
+
+	pagegrain = read_c0_pagegrain();
+	write_c0_pagegrain(pagegrain | PG_ELPA);
+	back_to_back_c0_hazard();
+	pagegrain = read_c0_pagegrain();
+
+	if (pagegrain & PG_ELPA)
+		pr_info("Extended Physical Addressing (XPA) enabled\n");
+	else
+		panic("Extended Physical Addressing (XPA) disabled");
+#endif
+}
+
 void build_tlb_refill_handler(void)
 {
 	/*
@@ -2362,8 +2425,9 @@ void build_tlb_refill_handler(void)
 		}
 		if (cpu_has_local_ebase)
 			build_r4000_tlb_refill_handler();
+		if (cpu_has_xpa)
+			config_xpa_params();
 		if (cpu_has_htw)
 			config_htw_params();
-
 	}
 }
-- 
cgit v1.2.3


From 9eaffa84a8a46adab065c983401fc9d5949c958f Mon Sep 17 00:00:00 2001
From: Ralf Baechle <ralf@linux-mips.org>
Date: Wed, 25 Mar 2015 13:18:27 +0100
Subject: Revert "MIPS: Avoid pipeline stalls on some MIPS32R2 cores."

For a discussion, see http://patchwork.linux-mips.org/patch/9539/.

This reverts commit 625c0a21700bdb90844d926a1508a17a77e369c9.
---
 arch/mips/mm/tlbex.c | 21 ++-------------------
 1 file changed, 2 insertions(+), 19 deletions(-)

(limited to 'arch/mips/mm/tlbex.c')

diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 7709920e0cef..971b1ee51234 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -512,26 +512,9 @@ static void build_tlb_write_entry(u32 **p, struct uasm_label **l,
 	case tlb_indexed: tlbw = uasm_i_tlbwi; break;
 	}
 
-	if (cpu_has_mips_r2_exec_hazard) {
-		/*
-		 * The architecture spec says an ehb is required here,
-		 * but a number of cores do not have the hazard and
-		 * using an ehb causes an expensive pipeline stall.
-		 */
-		switch (current_cpu_type()) {
-		case CPU_M14KC:
-		case CPU_74K:
-		case CPU_1074K:
-		case CPU_PROAPTIV:
-		case CPU_P5600:
-		case CPU_M5150:
-		case CPU_QEMU_GENERIC:
-			break;
-
-		default:
+	if (cpu_has_mips_r2_r6) {
+		if (cpu_has_mips_r2_exec_hazard)
 			uasm_i_ehb(p);
-			break;
-		}
 		tlbw(p);
 		return;
 	}
-- 
cgit v1.2.3