ARC: mm: PAE40 support
This is the first working implementation of 40-bit physical address
extension on ARCv2.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index fd9632f..2c2ac3f 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -453,6 +453,21 @@
kernel. Enable this to potentially allow access to rest of 2G and PAE
in future
+config ARC_HAS_PAE40
+ bool "Support for the 40-bit Physical Address Extension"
+ default n
+ depends on ISA_ARCV2
+ select HIGHMEM
+ help
+ Enable access to physical memory beyond 4G, only supported on
+ ARC cores with 40 bit Physical Addressing support
+
+config ARCH_PHYS_ADDR_T_64BIT
+ def_bool ARC_HAS_PAE40
+
+config ARCH_DMA_ADDR_T_64BIT
+ bool
+
config ARC_CURR_IN_REG
bool "Dedicate Register r25 for current_task pointer"
default y
diff --git a/arch/arc/include/asm/cache.h b/arch/arc/include/asm/cache.h
index e23ea6e..abf06e8 100644
--- a/arch/arc/include/asm/cache.h
+++ b/arch/arc/include/asm/cache.h
@@ -65,6 +65,7 @@
#if defined(CONFIG_ARC_MMU_V3) || defined(CONFIG_ARC_MMU_V4)
#define ARC_REG_IC_PTAG 0x1E
#endif
+#define ARC_REG_IC_PTAG_HI 0x1F
/* Bit val in IC_CTRL */
#define IC_CTRL_CACHE_DISABLE 0x1
@@ -77,6 +78,7 @@
#define ARC_REG_DC_FLSH 0x4B
#define ARC_REG_DC_FLDL 0x4C
#define ARC_REG_DC_PTAG 0x5C
+#define ARC_REG_DC_PTAG_HI 0x5F
/* Bit val in DC_CTRL */
#define DC_CTRL_INV_MODE_FLUSH 0x40
diff --git a/arch/arc/include/asm/mmu.h b/arch/arc/include/asm/mmu.h
index 0f9c3eb..b144d7c 100644
--- a/arch/arc/include/asm/mmu.h
+++ b/arch/arc/include/asm/mmu.h
@@ -24,6 +24,7 @@
#if (CONFIG_ARC_MMU_VER < 4)
#define ARC_REG_TLBPD0 0x405
#define ARC_REG_TLBPD1 0x406
+#define ARC_REG_TLBPD1HI 0 /* Dummy: allows code sharing with ARC700 */
#define ARC_REG_TLBINDEX 0x407
#define ARC_REG_TLBCOMMAND 0x408
#define ARC_REG_PID 0x409
@@ -31,6 +32,7 @@
#else
#define ARC_REG_TLBPD0 0x460
#define ARC_REG_TLBPD1 0x461
+#define ARC_REG_TLBPD1HI 0x463
#define ARC_REG_TLBINDEX 0x464
#define ARC_REG_TLBCOMMAND 0x465
#define ARC_REG_PID 0x468
@@ -83,6 +85,11 @@
extern char *arc_mmu_mumbojumbo(int cpu_id, char *buf, int len);
void read_decode_mmu_bcr(void);
+static inline int is_pae40_enabled(void)
+{
+ return IS_ENABLED(CONFIG_ARC_HAS_PAE40);
+}
+
#endif /* !__ASSEMBLY__ */
#endif
diff --git a/arch/arc/include/asm/page.h b/arch/arc/include/asm/page.h
index 3770683..429957f 100644
--- a/arch/arc/include/asm/page.h
+++ b/arch/arc/include/asm/page.h
@@ -56,7 +56,11 @@
#else /* !STRICT_MM_TYPECHECKS */
+#ifdef CONFIG_ARC_HAS_PAE40
+typedef unsigned long long pte_t;
+#else
typedef unsigned long pte_t;
+#endif
typedef unsigned long pgd_t;
typedef unsigned long pgprot_t;
diff --git a/arch/arc/include/asm/pgalloc.h b/arch/arc/include/asm/pgalloc.h
index 9149b5c..86ed671 100644
--- a/arch/arc/include/asm/pgalloc.h
+++ b/arch/arc/include/asm/pgalloc.h
@@ -49,7 +49,7 @@
static inline int __get_order_pgd(void)
{
- return get_order(PTRS_PER_PGD * 4);
+ return get_order(PTRS_PER_PGD * sizeof(pgd_t));
}
static inline pgd_t *pgd_alloc(struct mm_struct *mm)
@@ -87,7 +87,7 @@
static inline int __get_order_pte(void)
{
- return get_order(PTRS_PER_PTE * 4);
+ return get_order(PTRS_PER_PTE * sizeof(pte_t));
}
static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
@@ -110,7 +110,7 @@
pte_pg = (pgtable_t)__get_free_pages(GFP_KERNEL | __GFP_REPEAT, __get_order_pte());
if (!pte_pg)
return 0;
- memzero((void *)pte_pg, PTRS_PER_PTE * 4);
+ memzero((void *)pte_pg, PTRS_PER_PTE * sizeof(pte_t));
page = virt_to_page(pte_pg);
if (!pgtable_page_ctor(page)) {
__free_page(page);
diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h
index bd771351..57af2f0 100644
--- a/arch/arc/include/asm/pgtable.h
+++ b/arch/arc/include/asm/pgtable.h
@@ -134,7 +134,12 @@
/* Masks for actual TLB "PD"s */
#define PTE_BITS_IN_PD0 (_PAGE_GLOBAL | _PAGE_PRESENT | _PAGE_HW_SZ)
#define PTE_BITS_RWX (_PAGE_EXECUTE | _PAGE_WRITE | _PAGE_READ)
+
+#ifdef CONFIG_ARC_HAS_PAE40
+#define PTE_BITS_NON_RWX_IN_PD1 (0xff00000000 | PAGE_MASK | _PAGE_CACHEABLE)
+#else
#define PTE_BITS_NON_RWX_IN_PD1 (PAGE_MASK | _PAGE_CACHEABLE)
+#endif
/**************************************************************************
* Mapping of vm_flags (Generic VM) to PTE flags (arch specific)
@@ -272,7 +277,8 @@
#define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot)
#define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT)
-#define pfn_pte(pfn, prot) (__pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot)))
+#define pfn_pte(pfn, prot) (__pte(((pte_t)(pfn) << PAGE_SHIFT) | \
+ pgprot_val(prot)))
#define __pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
/*
diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index 91e28d7..ff7ff6c 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -253,6 +253,10 @@
}
}
+/*
+ * For ARC700 MMUv3 I-cache and D-cache flushes
+ * Also reused for HS38 aliasing I-cache configuration
+ */
static inline
void __cache_line_loop_v3(phys_addr_t paddr, unsigned long vaddr,
unsigned long sz, const int op)
@@ -289,6 +293,16 @@
if (full_page)
write_aux_reg(aux_tag, paddr);
+ /*
+ * This is technically for MMU v4, using the MMU v3 programming model
+ * Special work for HS38 aliasing I-cache configuratino with PAE40
+ * - upper 8 bits of paddr need to be written into PTAG_HI
+ * - (and needs to be written before the lower 32 bits)
+ * Note that PTAG_HI is hoisted outside the line loop
+ */
+ if (is_pae40_enabled() && op == OP_INV_IC)
+ write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
+
while (num_lines-- > 0) {
if (!full_page) {
write_aux_reg(aux_tag, paddr);
@@ -301,11 +315,17 @@
}
/*
- * In HS38x (MMU v4), although icache is VIPT, only paddr is needed for cache
- * maintenance ops (in IVIL reg), as long as icache doesn't alias.
+ * In HS38x (MMU v4), I-cache is VIPT (can alias), D-cache is PIPT
+ * Here's how cache ops are implemented
*
- * For Aliasing icache, vaddr is also needed (in IVIL), while paddr is
- * specified in PTAG (similar to MMU v3)
+ * - D-cache: only paddr needed (in DC_IVDL/DC_FLDL)
+ * - I-cache Non Aliasing: Despite VIPT, only paddr needed (in IC_IVIL)
+ * - I-cache Aliasing: Both vaddr and paddr needed (in IC_IVIL, IC_PTAG
+ * respectively, similar to MMU v3 programming model, hence
+ * __cache_line_loop_v3() is used)
+ *
+ * If PAE40 is enabled, independent of aliasing considerations, the higher bits
+ * needs to be written into PTAG_HI
*/
static inline
void __cache_line_loop_v4(phys_addr_t paddr, unsigned long vaddr,
@@ -335,6 +355,22 @@
num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
+ /*
+ * For HS38 PAE40 configuration
+ * - upper 8 bits of paddr need to be written into PTAG_HI
+ * - (and needs to be written before the lower 32 bits)
+ */
+ if (is_pae40_enabled()) {
+ if (cacheop == OP_INV_IC)
+ /*
+ * Non aliasing I-cache in HS38,
+ * aliasing I-cache handled in __cache_line_loop_v3()
+ */
+ write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
+ else
+ write_aux_reg(ARC_REG_DC_PTAG_HI, (u64)paddr >> 32);
+ }
+
while (num_lines-- > 0) {
write_aux_reg(aux_cmd, paddr);
paddr += L1_CACHE_BYTES;
diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c
index b5f28dc..0ee7398 100644
--- a/arch/arc/mm/tlb.c
+++ b/arch/arc/mm/tlb.c
@@ -109,6 +109,10 @@
static inline void __tlb_entry_erase(void)
{
write_aux_reg(ARC_REG_TLBPD1, 0);
+
+ if (is_pae40_enabled())
+ write_aux_reg(ARC_REG_TLBPD1HI, 0);
+
write_aux_reg(ARC_REG_TLBPD0, 0);
write_aux_reg(ARC_REG_TLBCOMMAND, TLBWrite);
}
@@ -182,7 +186,7 @@
}
-static void tlb_entry_insert(unsigned int pd0, unsigned int pd1)
+static void tlb_entry_insert(unsigned int pd0, pte_t pd1)
{
unsigned int idx;
@@ -225,10 +229,14 @@
write_aux_reg(ARC_REG_TLBCOMMAND, TLBDeleteEntry);
}
-static void tlb_entry_insert(unsigned int pd0, unsigned int pd1)
+static void tlb_entry_insert(unsigned int pd0, pte_t pd1)
{
write_aux_reg(ARC_REG_TLBPD0, pd0);
write_aux_reg(ARC_REG_TLBPD1, pd1);
+
+ if (is_pae40_enabled())
+ write_aux_reg(ARC_REG_TLBPD1HI, (u64)pd1 >> 32);
+
write_aux_reg(ARC_REG_TLBCOMMAND, TLBInsertEntry);
}
@@ -249,6 +257,10 @@
/* Load PD0 and PD1 with template for a Blank Entry */
write_aux_reg(ARC_REG_TLBPD1, 0);
+
+ if (is_pae40_enabled())
+ write_aux_reg(ARC_REG_TLBPD1HI, 0);
+
write_aux_reg(ARC_REG_TLBPD0, 0);
for (entry = 0; entry < num_tlb; entry++) {
@@ -503,7 +515,8 @@
{
unsigned long flags;
unsigned int asid_or_sasid, rwx;
- unsigned long pd0, pd1;
+ unsigned long pd0;
+ pte_t pd1;
/*
* create_tlb() assumes that current->mm == vma->mm, since
@@ -785,10 +798,11 @@
IS_USED_CFG(CONFIG_TRANSPARENT_HUGEPAGE));
n += scnprintf(buf + n, len - n,
- "MMU [v%x]\t: %dK PAGE, %sJTLB %d (%dx%d), uDTLB %d, uITLB %d\n",
+ "MMU [v%x]\t: %dk PAGE, %sJTLB %d (%dx%d), uDTLB %d, uITLB %d %s%s\n",
p_mmu->ver, p_mmu->pg_sz_k, super_pg,
p_mmu->sets * p_mmu->ways, p_mmu->sets, p_mmu->ways,
- p_mmu->u_dtlb, p_mmu->u_itlb);
+ p_mmu->u_dtlb, p_mmu->u_itlb,
+ IS_AVAIL2(p_mmu->pae, "PAE40 ", CONFIG_ARC_HAS_PAE40));
return buf;
}
@@ -821,6 +835,9 @@
panic("MMU Super pg size != Linux HPAGE_PMD_SIZE (%luM)\n",
(unsigned long)TO_MB(HPAGE_PMD_SIZE));
+ if (IS_ENABLED(CONFIG_ARC_HAS_PAE40) && !mmu->pae)
+ panic("Hardware doesn't support PAE40\n");
+
/* Enable the MMU */
write_aux_reg(ARC_REG_PID, MMU_ENABLE);
diff --git a/arch/arc/mm/tlbex.S b/arch/arc/mm/tlbex.S
index 8d1b819..63860ad 100644
--- a/arch/arc/mm/tlbex.S
+++ b/arch/arc/mm/tlbex.S
@@ -223,12 +223,16 @@
; (2) y = x & (PTRS_PER_PTE - 1) -> to get index
; (3) z = (pgtbl + y * 4)
+#ifdef CONFIG_ARC_HAS_PAE40
+#define PTE_SIZE_LOG 3 /* 8 == 2 ^ 3 */
+#else
#define PTE_SIZE_LOG 2 /* 4 == 2 ^ 2 */
+#endif
; multiply in step (3) above avoided by shifting lesser in step (1)
lsr r0, r2, ( PAGE_SHIFT - PTE_SIZE_LOG )
and r0, r0, ( (PTRS_PER_PTE - 1) << PTE_SIZE_LOG )
- ld.aw r0, [r1, r0] ; r0: PTE
+ ld.aw r0, [r1, r0] ; r0: PTE (lower word only for PAE40)
; r1: PTE ptr
2:
@@ -247,6 +251,7 @@
;-----------------------------------------------------------------
; Convert Linux PTE entry into TLB entry
; A one-word PTE entry is programmed as two-word TLB Entry [PD0:PD1] in mmu
+; (for PAE40, two-words PTE, while three-word TLB Entry [PD0:PD1:PD1HI])
; IN: r0 = PTE, r1 = ptr to PTE
.macro CONV_PTE_TO_TLB
@@ -259,6 +264,10 @@
or r3, r3, r2
sr r3, [ARC_REG_TLBPD1] ; paddr[31..13] | Kr Kw Kx Ur Uw Ux | C
+#ifdef CONFIG_ARC_HAS_PAE40
+ ld r3, [r1, 4] ; paddr[39..32]
+ sr r3, [ARC_REG_TLBPD1HI]
+#endif
and r2, r0, PTE_BITS_IN_PD0 ; Extract other PTE flags: (V)alid, (G)lb