There are 2 distinct cases in which a kernel for a MIPS32 CPU
(CONFIG_CPU_MIPS32=y) may use 64 bit physical addresses
(CONFIG_PHYS_ADDR_T_64BIT=y):
- 36 bit physical addressing as used by RMI Alchemy & Netlogic XLP/XLR
CPUs.
- MIPS32r5 eXtended Physical Addressing (XPA).
These 2 cases are distinct in that they require different behaviour from
the kernel - the EntryLo registers have different formats. Until Linux
v4.1 we only supported the first case, with code conditional upon the 2
aforementioned Kconfig variables being set. Commit c5b367835cfc ("MIPS:
Add support for XPA.") added support for the second case, but did so by
modifying the code that existed for the first case rather than treating
the 2 cases as distinct. Since the EntryLo registers have different
formats this breaks the 36 bit Alchemy/XLP/XLR case. Fix this by
splitting the 2 cases, with XPA cases now being conditional upon
CONFIG_XPA and the non-XPA case matching the code as it existed prior to
commit c5b367835cfc ("MIPS: Add support for XPA.").
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
Reported-by: Manuel Lauss <manuel.lauss@xxxxxxxxx>
Tested-by: Manuel Lauss <manuel.lauss@xxxxxxxxx>
Fixes: c5b367835cfc ("MIPS: Add support for XPA.")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.1+
---
Changes in v2:
- Catch some extra pte_low manipulations (thanks James!).
arch/mips/include/asm/pgtable-32.h | 27 +++++++++++++++--
arch/mips/include/asm/pgtable-bits.h | 29 +++++++++++++++---
arch/mips/include/asm/pgtable.h | 57 +++++++++++++++++++++++++++++++-----
arch/mips/mm/init.c | 4 ++-
arch/mips/mm/tlbex.c | 35 ++++++++++++++--------
5 files changed, 125 insertions(+), 27 deletions(-)
diff --git a/arch/mips/include/asm/pgtable-32.h b/arch/mips/include/asm/pgtable-32.h
index 181bd8e..d21f3da 100644
--- a/arch/mips/include/asm/pgtable-32.h
+++ b/arch/mips/include/asm/pgtable-32.h
@@ -103,7 +103,7 @@ static inline void pmd_clear(pmd_t *pmdp)
pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
}
-#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
+#if defined(CONFIG_XPA)
#define pte_pfn(x) (((unsigned long)((x).pte_high >> _PFN_SHIFT)) | (unsigned long)((x).pte_low << _PAGE_PRESENT_SHIFT))
static inline pte_t
@@ -118,6 +118,20 @@ pfn_pte(unsigned long pfn, pgprot_t prot)
return pte;
}
+#elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
+
+#define pte_pfn(x) ((unsigned long)((x).pte_high >> 6))
+
+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);
+
+ return pte;
+}
+
#else
#ifdef CONFIG_CPU_VR41XX
@@ -166,7 +180,7 @@ pfn_pte(unsigned long pfn, pgprot_t prot)
#else
-#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
+#if defined(CONFIG_XPA)
/* Swap entries must have VALID and GLOBAL bits cleared. */
#define __swp_type(x) (((x).val >> 4) & 0x1f)
@@ -175,6 +189,15 @@ pfn_pte(unsigned long pfn, pgprot_t prot)
#define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_high })
#define __swp_entry_to_pte(x) ((pte_t) { 0, (x).val })
+#elif 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 __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_high })
+#define __swp_entry_to_pte(x) ((pte_t) { 0, (x).val })
+
#else
/*
* Constraints:
diff --git a/arch/mips/include/asm/pgtable-bits.h b/arch/mips/include/asm/pgtable-bits.h
index 5bc663d..58e8bf8 100644
--- a/arch/mips/include/asm/pgtable-bits.h
+++ b/arch/mips/include/asm/pgtable-bits.h
@@ -32,11 +32,11 @@
* unpredictable things. The code (when it is written) to deal with
* this problem will be in the update_mmu_cache() code for the r4k.
*/
-#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
+#if defined(CONFIG_XPA)
/*
- * Page table bit offsets used for 64 bit physical addressing on MIPS32,
- * for example with Alchemy, Netlogic XLP/XLR or XPA.
+ * Page table bit offsets used for 64 bit physical addressing on
+ * MIPS32r5 with XPA.
*/
enum pgtable_bits {
/* Used by TLB hardware (placed in EntryLo*) */
@@ -59,6 +59,27 @@ enum pgtable_bits {
*/
#define _PFNX_MASK 0xffffff
+#elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
+
+/*
+ * Page table bit offsets used for 36 bit physical addressing on MIPS32,
+ * for example with Alchemy or Netlogic XLP/XLR.
+ */
+enum pgtable_bits {
+ /* Used by TLB hardware (placed in EntryLo*) */
+ _PAGE_GLOBAL_SHIFT,
+ _PAGE_VALID_SHIFT,
+ _PAGE_DIRTY_SHIFT,
+ _CACHE_SHIFT,
+
+ /* Used only by software (masked out before writing EntryLo*) */
+ _PAGE_PRESENT_SHIFT = _CACHE_SHIFT + 3,
+ _PAGE_NO_READ_SHIFT,
+ _PAGE_WRITE_SHIFT,
+ _PAGE_ACCESSED_SHIFT,
+ _PAGE_MODIFIED_SHIFT,
+};
+
#elif defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
/* Page table bits used for r3k systems */
@@ -116,7 +137,7 @@ enum pgtable_bits {
#endif
/* Used by TLB hardware (placed in EntryLo*) */
-#if (defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32))
+#if defined(CONFIG_XPA)
# define _PAGE_NO_EXEC (1 << _PAGE_NO_EXEC_SHIFT)
#elif defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6)
# define _PAGE_NO_EXEC (cpu_has_rixi ? (1 << _PAGE_NO_EXEC_SHIFT) : 0)
diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index 1459ee9..3822d7d 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -130,7 +130,12 @@ do { \
#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
-#define pte_none(pte) (!(((pte).pte_high) & ~_PAGE_GLOBAL))
+#ifdef CONFIG_XPA
+# define pte_none(pte) (!(((pte).pte_high) & ~_PAGE_GLOBAL))
+#else
+# define pte_none(pte) (!(((pte).pte_low | (pte).pte_high) & ~_PAGE_GLOBAL))
+#endif
+
#define pte_present(pte) ((pte).pte_low & _PAGE_PRESENT)
static inline void set_pte(pte_t *ptep, pte_t pte)
@@ -139,14 +144,21 @@ static inline void set_pte(pte_t *ptep, pte_t pte)
smp_wmb();
ptep->pte_low = pte.pte_low;
+#ifdef CONFIG_XPA
if (pte.pte_high & _PAGE_GLOBAL) {
+#else
+ if (pte.pte_low & _PAGE_GLOBAL) {
+#endif
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))
+ if (pte_none(*buddy)) {
+ if (!config_enabled(CONFIG_XPA))
+ buddy->pte_low |= _PAGE_GLOBAL;
buddy->pte_high |= _PAGE_GLOBAL;
+ }
}
}
#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
@@ -157,8 +169,13 @@ 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_high & _PAGE_GLOBAL)
- null.pte_high = _PAGE_GLOBAL;
+ if (config_enabled(CONFIG_XPA)) {
+ if (ptep_buddy(ptep)->pte_high & _PAGE_GLOBAL)
+ null.pte_high = _PAGE_GLOBAL;
+ } else {
+ if (ptep_buddy(ptep)->pte_low & _PAGE_GLOBAL)
+ null.pte_low = null.pte_high = _PAGE_GLOBAL;
+ }
set_pte_at(mm, addr, ptep, null);
htw_start();
@@ -271,6 +288,8 @@ 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;
+ if (!config_enabled(CONFIG_XPA))
+ pte.pte_low &= ~_PAGE_SILENT_WRITE;
pte.pte_high &= ~_PAGE_SILENT_WRITE;
return pte;
}
@@ -278,6 +297,8 @@ static inline pte_t pte_wrprotect(pte_t pte)
static inline pte_t pte_mkclean(pte_t pte)
{
pte.pte_low &= ~_PAGE_MODIFIED;
+ if (!config_enabled(CONFIG_XPA))
+ pte.pte_low &= ~_PAGE_SILENT_WRITE;
pte.pte_high &= ~_PAGE_SILENT_WRITE;
return pte;
}
@@ -285,6 +306,8 @@ static inline pte_t pte_mkclean(pte_t pte)
static inline pte_t pte_mkold(pte_t pte)
{
pte.pte_low &= ~_PAGE_ACCESSED;
+ if (!config_enabled(CONFIG_XPA))
+ pte.pte_low &= ~_PAGE_SILENT_READ;
pte.pte_high &= ~_PAGE_SILENT_READ;
return pte;
}
@@ -292,24 +315,33 @@ 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)
+ if (pte.pte_low & _PAGE_MODIFIED) {
+ if (!config_enabled(CONFIG_XPA))
+ pte.pte_low |= _PAGE_SILENT_WRITE;
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)
+ if (pte.pte_low & _PAGE_WRITE) {
+ if (!config_enabled(CONFIG_XPA))
+ pte.pte_low |= _PAGE_SILENT_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_NO_READ))
+ if (!(pte.pte_low & _PAGE_NO_READ)) {
+ if (!config_enabled(CONFIG_XPA))
+ pte.pte_low |= _PAGE_SILENT_READ;
pte.pte_high |= _PAGE_SILENT_READ;
+ }
return pte;
}
#else
@@ -407,7 +439,7 @@ static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
*/
#define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot))
-#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
+#if defined(CONFIG_XPA)
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
pte.pte_low &= (_PAGE_MODIFIED | _PAGE_ACCESSED | _PFNX_MASK);
@@ -416,6 +448,15 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
pte.pte_high |= pgprot_val(newprot) & ~_PFN_MASK;
return pte;
}
+#elif 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_high &= (_PFN_MASK | _CACHE_MASK);
+ pte.pte_low |= pgprot_val(newprot);
+ pte.pte_high |= pgprot_val(newprot) & ~(_PFN_MASK | _CACHE_MASK);
+ return pte;
+}
#else
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 7e5fa09..0e57893 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -98,8 +98,10 @@ static void *__kmap_pgprot(struct page *page, unsigned long addr, pgprot_t prot)
idx += in_interrupt() ? FIX_N_COLOURS : 0;
vaddr = __fix_to_virt(FIX_CMAP_END - idx);
pte = mk_pte(page, prot);
-#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
+#if defined(CONFIG_XPA)
entrylo = pte_to_entrylo(pte.pte_high);
+#elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
+ entrylo = pte.pte_high;
#else
entrylo = pte_to_entrylo(pte_val(pte));
#endif
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 7e3272f..ceaee32 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -1003,25 +1003,21 @@ static void build_get_ptep(u32 **p, unsigned int tmp, unsigned int ptr)
static void build_update_entries(u32 **p, unsigned int tmp, unsigned int ptep)
{
- /*
- * 64bit address support (36bit on a 32bit CPU) in a 32bit
- * Kernel is a special case. Only a few CPUs use it.
- */
- if (config_enabled(CONFIG_PHYS_ADDR_T_64BIT) && !cpu_has_64bits) {
+ if (config_enabled(CONFIG_XPA)) {
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 */
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_lw(p, ptep, pte_off_odd, ptep); /* odd pte */
+ UASM_i_ROTR(p, ptep, ptep, ilog2(_PAGE_GLOBAL));
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);
@@ -1030,7 +1026,22 @@ static void build_update_entries(u32 **p, unsigned int tmp, unsigned int ptep)
uasm_i_and(p, ptep, scratch, ptep);
uasm_i_mthc0(p, tmp, C0_ENTRYLO0);
uasm_i_mthc0(p, ptep, C0_ENTRYLO1);
-#endif
+ return;
+ }
+
+ /*
+ * 64bit address support (36bit on a 32bit CPU) in a 32bit
+ * Kernel is a special case. Only a few CPUs use it.
+ */
+ if (config_enabled(CONFIG_PHYS_ADDR_T_64BIT) && !cpu_has_64bits) {
+ int pte_off_even = sizeof(pte_t) / 2;
+ int pte_off_odd = pte_off_even + sizeof(pte_t);
+
+ uasm_i_lw(p, tmp, pte_off_even, ptep); /* even pte */
+ UASM_i_MTC0(p, tmp, C0_ENTRYLO0);
+
+ uasm_i_lw(p, ptep, pte_off_odd, ptep); /* odd pte */
+ UASM_i_MTC0(p, ptep, C0_ENTRYLO1);
return;
}
@@ -1524,7 +1535,7 @@ 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);
- if (!cpu_has_64bits) {
+ if (config_enabled(CONFIG_XPA) && !cpu_has_64bits) {
const int scratch = 1; /* Our extra working register */
uasm_i_lui(p, scratch, (mode >> 16));
--
2.8.0
