xtensa: add alternative kernel memory layouts
MMUv3 is able to support low memory bigger than 128MB.
Implement 256MB and 512MB KSEG layouts:
- add Kconfig selector for KSEG layout;
- add KSEG base address, size and alignment definitions to
arch/xtensa/include/asm/kmem_layout.h;
- use new definitions in TLB initialization;
- add build time memory map consistency checks.
See Documentation/xtensa/mmu.txt for the details of new memory layouts.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
diff --git a/Documentation/xtensa/mmu.txt b/Documentation/xtensa/mmu.txt
index 0312fe6..867c0f8 100644
--- a/Documentation/xtensa/mmu.txt
+++ b/Documentation/xtensa/mmu.txt
@@ -62,3 +62,127 @@
6. The IO area covers the entire 256MB segment of parent-bus-address; the
"ranges" triplet length field is ignored
+
+
+MMUv3 address space layouts.
+============================
+
+Default MMUv2-compatible layout.
+
+ Symbol VADDR Size
++------------------+
+| Userspace | 0x00000000 TASK_SIZE
++------------------+ 0x40000000
++------------------+
+| Page table | 0x80000000
++------------------+ 0x80400000
++------------------+
+| KMAP area | PKMAP_BASE PTRS_PER_PTE *
+| | DCACHE_N_COLORS *
+| | PAGE_SIZE
+| | (4MB * DCACHE_N_COLORS)
++------------------+
+| Atomic KMAP area | FIXADDR_START KM_TYPE_NR *
+| | NR_CPUS *
+| | DCACHE_N_COLORS *
+| | PAGE_SIZE
++------------------+ FIXADDR_TOP 0xbffff000
++------------------+
+| VMALLOC area | VMALLOC_START 0xc0000000 128MB - 64KB
++------------------+ VMALLOC_END
+| Cache aliasing | TLBTEMP_BASE_1 0xc7ff0000 DCACHE_WAY_SIZE
+| remap area 1 |
++------------------+
+| Cache aliasing | TLBTEMP_BASE_2 DCACHE_WAY_SIZE
+| remap area 2 |
++------------------+
++------------------+
+| Cached KSEG | XCHAL_KSEG_CACHED_VADDR 0xd0000000 128MB
++------------------+
+| Uncached KSEG | XCHAL_KSEG_BYPASS_VADDR 0xd8000000 128MB
++------------------+
+| Cached KIO | XCHAL_KIO_CACHED_VADDR 0xe0000000 256MB
++------------------+
+| Uncached KIO | XCHAL_KIO_BYPASS_VADDR 0xf0000000 256MB
++------------------+
+
+
+256MB cached + 256MB uncached layout.
+
+ Symbol VADDR Size
++------------------+
+| Userspace | 0x00000000 TASK_SIZE
++------------------+ 0x40000000
++------------------+
+| Page table | 0x80000000
++------------------+ 0x80400000
++------------------+
+| KMAP area | PKMAP_BASE PTRS_PER_PTE *
+| | DCACHE_N_COLORS *
+| | PAGE_SIZE
+| | (4MB * DCACHE_N_COLORS)
++------------------+
+| Atomic KMAP area | FIXADDR_START KM_TYPE_NR *
+| | NR_CPUS *
+| | DCACHE_N_COLORS *
+| | PAGE_SIZE
++------------------+ FIXADDR_TOP 0x9ffff000
++------------------+
+| VMALLOC area | VMALLOC_START 0xa0000000 128MB - 64KB
++------------------+ VMALLOC_END
+| Cache aliasing | TLBTEMP_BASE_1 0xa7ff0000 DCACHE_WAY_SIZE
+| remap area 1 |
++------------------+
+| Cache aliasing | TLBTEMP_BASE_2 DCACHE_WAY_SIZE
+| remap area 2 |
++------------------+
++------------------+
+| Cached KSEG | XCHAL_KSEG_CACHED_VADDR 0xb0000000 256MB
++------------------+
+| Uncached KSEG | XCHAL_KSEG_BYPASS_VADDR 0xc0000000 256MB
++------------------+
++------------------+
+| Cached KIO | XCHAL_KIO_CACHED_VADDR 0xe0000000 256MB
++------------------+
+| Uncached KIO | XCHAL_KIO_BYPASS_VADDR 0xf0000000 256MB
++------------------+
+
+
+512MB cached + 512MB uncached layout.
+
+ Symbol VADDR Size
++------------------+
+| Userspace | 0x00000000 TASK_SIZE
++------------------+ 0x40000000
++------------------+
+| Page table | 0x80000000
++------------------+ 0x80400000
++------------------+
+| KMAP area | PKMAP_BASE PTRS_PER_PTE *
+| | DCACHE_N_COLORS *
+| | PAGE_SIZE
+| | (4MB * DCACHE_N_COLORS)
++------------------+
+| Atomic KMAP area | FIXADDR_START KM_TYPE_NR *
+| | NR_CPUS *
+| | DCACHE_N_COLORS *
+| | PAGE_SIZE
++------------------+ FIXADDR_TOP 0x8ffff000
++------------------+
+| VMALLOC area | VMALLOC_START 0x90000000 128MB - 64KB
++------------------+ VMALLOC_END
+| Cache aliasing | TLBTEMP_BASE_1 0x97ff0000 DCACHE_WAY_SIZE
+| remap area 1 |
++------------------+
+| Cache aliasing | TLBTEMP_BASE_2 DCACHE_WAY_SIZE
+| remap area 2 |
++------------------+
++------------------+
+| Cached KSEG | XCHAL_KSEG_CACHED_VADDR 0xa0000000 512MB
++------------------+
+| Uncached KSEG | XCHAL_KSEG_BYPASS_VADDR 0xc0000000 512MB
++------------------+
+| Cached KIO | XCHAL_KIO_CACHED_VADDR 0xe0000000 256MB
++------------------+
+| Uncached KIO | XCHAL_KIO_BYPASS_VADDR 0xf0000000 256MB
++------------------+
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 64336f6..c17496b 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -236,6 +236,50 @@
If in doubt, say Y.
+config KSEG_PADDR
+ hex "Physical address of the KSEG mapping"
+ depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX && MMU
+ default 0x00000000
+ help
+ This is the physical address where KSEG is mapped. Please refer to
+ the chosen KSEG layout help for the required address alignment.
+ Unpacked kernel image (including vectors) must be located completely
+ within KSEG.
+ Physical memory below this address is not available to linux.
+
+ If unsure, leave the default value here.
+
+choice
+ prompt "KSEG layout"
+ depends on MMU
+ default XTENSA_KSEG_MMU_V2
+
+config XTENSA_KSEG_MMU_V2
+ bool "MMUv2: 128MB cached + 128MB uncached"
+ help
+ MMUv2 compatible kernel memory map: TLB way 5 maps 128MB starting
+ at KSEG_PADDR to 0xd0000000 with cache and to 0xd8000000
+ without cache.
+ KSEG_PADDR must be aligned to 128MB.
+
+config XTENSA_KSEG_256M
+ bool "256MB cached + 256MB uncached"
+ depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
+ help
+ TLB way 6 maps 256MB starting at KSEG_PADDR to 0xb0000000
+ with cache and to 0xc0000000 without cache.
+ KSEG_PADDR must be aligned to 256MB.
+
+config XTENSA_KSEG_512M
+ bool "512MB cached + 512MB uncached"
+ depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
+ help
+ TLB way 6 maps 512MB starting at KSEG_PADDR to 0xa0000000
+ with cache and to 0xc0000000 without cache.
+ KSEG_PADDR must be aligned to 256MB.
+
+endchoice
+
config HIGHMEM
bool "High Memory Support"
depends on MMU
diff --git a/arch/xtensa/include/asm/fixmap.h b/arch/xtensa/include/asm/fixmap.h
index 62b507d..0d30403 100644
--- a/arch/xtensa/include/asm/fixmap.h
+++ b/arch/xtensa/include/asm/fixmap.h
@@ -59,6 +59,11 @@
*/
static __always_inline unsigned long fix_to_virt(const unsigned int idx)
{
+ /* Check if this memory layout is broken because fixmap overlaps page
+ * table.
+ */
+ BUILD_BUG_ON(FIXADDR_START <
+ XCHAL_PAGE_TABLE_VADDR + XCHAL_PAGE_TABLE_SIZE);
BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
return __fix_to_virt(idx);
}
diff --git a/arch/xtensa/include/asm/highmem.h b/arch/xtensa/include/asm/highmem.h
index 01cef6b..6e070db 100644
--- a/arch/xtensa/include/asm/highmem.h
+++ b/arch/xtensa/include/asm/highmem.h
@@ -68,6 +68,11 @@
static inline void *kmap(struct page *page)
{
+ /* Check if this memory layout is broken because PKMAP overlaps
+ * page table.
+ */
+ BUILD_BUG_ON(PKMAP_BASE <
+ XCHAL_PAGE_TABLE_VADDR + XCHAL_PAGE_TABLE_SIZE);
BUG_ON(in_interrupt());
if (!PageHighMem(page))
return page_address(page);
diff --git a/arch/xtensa/include/asm/initialize_mmu.h b/arch/xtensa/include/asm/initialize_mmu.h
index 7a1e075..46d4bef 100644
--- a/arch/xtensa/include/asm/initialize_mmu.h
+++ b/arch/xtensa/include/asm/initialize_mmu.h
@@ -116,22 +116,35 @@
add a5, a5, a4
bne a5, a2, 3b
- /* Step 4: Setup MMU with the old V2 mappings. */
+ /* Step 4: Setup MMU with the requested static mappings. */
+
movi a6, 0x01000000
wsr a6, ITLBCFG
wsr a6, DTLBCFG
isync
- movi a5, 0xd0000005
- movi a4, CA_WRITEBACK
+ movi a5, XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_TLB_WAY
+ movi a4, XCHAL_KSEG_PADDR + CA_WRITEBACK
wdtlb a4, a5
witlb a4, a5
- movi a5, 0xd8000005
- movi a4, CA_BYPASS
+ movi a5, XCHAL_KSEG_BYPASS_VADDR + XCHAL_KSEG_TLB_WAY
+ movi a4, XCHAL_KSEG_PADDR + CA_BYPASS
wdtlb a4, a5
witlb a4, a5
+#ifdef CONFIG_XTENSA_KSEG_512M
+ movi a5, XCHAL_KSEG_CACHED_VADDR + 0x10000000 + XCHAL_KSEG_TLB_WAY
+ movi a4, XCHAL_KSEG_PADDR + 0x10000000 + CA_WRITEBACK
+ wdtlb a4, a5
+ witlb a4, a5
+
+ movi a5, XCHAL_KSEG_BYPASS_VADDR + 0x10000000 + XCHAL_KSEG_TLB_WAY
+ movi a4, XCHAL_KSEG_PADDR + 0x10000000 + CA_BYPASS
+ wdtlb a4, a5
+ witlb a4, a5
+#endif
+
movi a5, XCHAL_KIO_CACHED_VADDR + 6
movi a4, XCHAL_KIO_DEFAULT_PADDR + CA_WRITEBACK
wdtlb a4, a5
diff --git a/arch/xtensa/include/asm/kmem_layout.h b/arch/xtensa/include/asm/kmem_layout.h
index 4eb43b6..bfce7ee 100644
--- a/arch/xtensa/include/asm/kmem_layout.h
+++ b/arch/xtensa/include/asm/kmem_layout.h
@@ -13,13 +13,59 @@
#include <asm/types.h>
+#ifdef CONFIG_MMU
+
/*
* Fixed TLB translations in the processor.
*/
+#define XCHAL_PAGE_TABLE_VADDR __XTENSA_UL_CONST(0x80000000)
+#define XCHAL_PAGE_TABLE_SIZE __XTENSA_UL_CONST(0x00400000)
+
+#if defined(CONFIG_XTENSA_KSEG_MMU_V2)
+
#define XCHAL_KSEG_CACHED_VADDR __XTENSA_UL_CONST(0xd0000000)
#define XCHAL_KSEG_BYPASS_VADDR __XTENSA_UL_CONST(0xd8000000)
#define XCHAL_KSEG_SIZE __XTENSA_UL_CONST(0x08000000)
+#define XCHAL_KSEG_ALIGNMENT __XTENSA_UL_CONST(0x08000000)
+#define XCHAL_KSEG_TLB_WAY 5
+
+#elif defined(CONFIG_XTENSA_KSEG_256M)
+
+#define XCHAL_KSEG_CACHED_VADDR __XTENSA_UL_CONST(0xb0000000)
+#define XCHAL_KSEG_BYPASS_VADDR __XTENSA_UL_CONST(0xc0000000)
+#define XCHAL_KSEG_SIZE __XTENSA_UL_CONST(0x10000000)
+#define XCHAL_KSEG_ALIGNMENT __XTENSA_UL_CONST(0x10000000)
+#define XCHAL_KSEG_TLB_WAY 6
+
+#elif defined(CONFIG_XTENSA_KSEG_512M)
+
+#define XCHAL_KSEG_CACHED_VADDR __XTENSA_UL_CONST(0xa0000000)
+#define XCHAL_KSEG_BYPASS_VADDR __XTENSA_UL_CONST(0xc0000000)
+#define XCHAL_KSEG_SIZE __XTENSA_UL_CONST(0x20000000)
+#define XCHAL_KSEG_ALIGNMENT __XTENSA_UL_CONST(0x10000000)
+#define XCHAL_KSEG_TLB_WAY 6
+
+#else
+#error Unsupported KSEG configuration
+#endif
+
+#ifdef CONFIG_KSEG_PADDR
+#define XCHAL_KSEG_PADDR __XTENSA_UL_CONST(CONFIG_KSEG_PADDR)
+#else
#define XCHAL_KSEG_PADDR __XTENSA_UL_CONST(0x00000000)
+#endif
+
+#if XCHAL_KSEG_PADDR & (XCHAL_KSEG_ALIGNMENT - 1)
+#error XCHAL_KSEG_PADDR is not properly aligned to XCHAL_KSEG_ALIGNMENT
+#endif
+
+#else
+
+#define XCHAL_KSEG_CACHED_VADDR __XTENSA_UL_CONST(0xd0000000)
+#define XCHAL_KSEG_BYPASS_VADDR __XTENSA_UL_CONST(0xd8000000)
+#define XCHAL_KSEG_SIZE __XTENSA_UL_CONST(0x08000000)
+
+#endif
#endif
diff --git a/arch/xtensa/include/asm/page.h b/arch/xtensa/include/asm/page.h
index fd12a19..8a02438 100644
--- a/arch/xtensa/include/asm/page.h
+++ b/arch/xtensa/include/asm/page.h
@@ -27,10 +27,12 @@
#ifdef CONFIG_MMU
#define PAGE_OFFSET XCHAL_KSEG_CACHED_VADDR
-#define MAX_MEM_PFN XCHAL_KSEG_SIZE
+#define MAX_LOW_PFN (PHYS_PFN(XCHAL_KSEG_PADDR) + \
+ PHYS_PFN(XCHAL_KSEG_SIZE))
#else
#define PAGE_OFFSET __XTENSA_UL_CONST(0)
-#define MAX_MEM_PFN (PLATFORM_DEFAULT_MEM_START + PLATFORM_DEFAULT_MEM_SIZE)
+#define MAX_LOW_PFN (PHYS_PFN(PLATFORM_DEFAULT_MEM_START) + \
+ PHYS_PFN(PLATFORM_DEFAULT_MEM_SIZE))
#endif
#define PGTABLE_START 0x80000000
diff --git a/arch/xtensa/include/uapi/asm/types.h b/arch/xtensa/include/uapi/asm/types.h
index 87ec7ae..2efc9215 100644
--- a/arch/xtensa/include/uapi/asm/types.h
+++ b/arch/xtensa/include/uapi/asm/types.h
@@ -18,7 +18,8 @@
# define __XTENSA_UL_CONST(x) x
#else
# define __XTENSA_UL(x) ((unsigned long)(x))
-# define __XTENSA_UL_CONST(x) x##UL
+# define ___XTENSA_UL_CONST(x) x##UL
+# define __XTENSA_UL_CONST(x) ___XTENSA_UL_CONST(x)
#endif
#ifndef __ASSEMBLY__
diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
index 4d7142b..302fa72 100644
--- a/arch/xtensa/mm/init.c
+++ b/arch/xtensa/mm/init.c
@@ -266,8 +266,7 @@
if (min_low_pfn > max_pfn)
panic("No memory found!\n");
- max_low_pfn = max_pfn < MAX_MEM_PFN >> PAGE_SHIFT ?
- max_pfn : MAX_MEM_PFN >> PAGE_SHIFT;
+ max_low_pfn = min(max_pfn, MAX_LOW_PFN);
/* Find an area to use for the bootmem bitmap. */