[PATCH v3 3/6] powerpc/47x: allow kernel to be loaded in higher physical memory
Dave Kleikamp
shaggy at linux.vnet.ibm.com
Thu Feb 10 10:08:10 EST 2011
The 44x code (which is shared by 47x) assumes the available physical memory
begins at 0x00000000. This is not necessarily the case in an AMP
environment.
Support CONFIG_RELOCATABLE for 476 in order to allow the kernel to be
loaded into a higher memory range.
Signed-off-by: Dave Kleikamp <shaggy at linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Cc: Josh Boyer <jwboyer at linux.vnet.ibm.com>
Cc: linuxppc-dev at lists.ozlabs.org
---
arch/powerpc/Kconfig | 2 +-
arch/powerpc/configs/44x/iss476-smp_defconfig | 6 ++--
arch/powerpc/kernel/head_44x.S | 42 ++++++++++++++++++++-----
arch/powerpc/mm/44x_mmu.c | 13 ++++++--
4 files changed, 48 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 7d69e9b..fa41026 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -827,7 +827,7 @@ config LOWMEM_CAM_NUM
config RELOCATABLE
bool "Build a relocatable kernel (EXPERIMENTAL)"
- depends on EXPERIMENTAL && ADVANCED_OPTIONS && FLATMEM && FSL_BOOKE
+ depends on EXPERIMENTAL && ADVANCED_OPTIONS && FLATMEM && (FSL_BOOKE || PPC_47x)
help
This builds a kernel image that is capable of running at the
location the kernel is loaded at (some alignment restrictions may
diff --git a/arch/powerpc/configs/44x/iss476-smp_defconfig b/arch/powerpc/configs/44x/iss476-smp_defconfig
index 92f863a..a6eb6ad 100644
--- a/arch/powerpc/configs/44x/iss476-smp_defconfig
+++ b/arch/powerpc/configs/44x/iss476-smp_defconfig
@@ -3,8 +3,8 @@ CONFIG_SMP=y
CONFIG_EXPERIMENTAL=y
CONFIG_SYSVIPC=y
CONFIG_POSIX_MQUEUE=y
+CONFIG_SPARSE_IRQ=y
CONFIG_LOG_BUF_SHIFT=14
-CONFIG_SYSFS_DEPRECATED_V2=y
CONFIG_BLK_DEV_INITRD=y
# CONFIG_CC_OPTIMIZE_FOR_SIZE is not set
CONFIG_EXPERT=y
@@ -21,10 +21,11 @@ CONFIG_ISS4xx=y
CONFIG_HZ_100=y
CONFIG_MATH_EMULATION=y
CONFIG_IRQ_ALL_CPUS=y
-CONFIG_SPARSE_IRQ=y
CONFIG_CMDLINE_BOOL=y
CONFIG_CMDLINE="root=/dev/issblk0"
# CONFIG_PCI is not set
+CONFIG_ADVANCED_OPTIONS=y
+CONFIG_RELOCATABLE=y
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
@@ -67,7 +68,6 @@ CONFIG_EXT3_FS=y
# CONFIG_EXT3_DEFAULTS_TO_ORDERED is not set
CONFIG_EXT3_FS_POSIX_ACL=y
CONFIG_EXT3_FS_SECURITY=y
-CONFIG_INOTIFY=y
CONFIG_PROC_KCORE=y
CONFIG_TMPFS=y
CONFIG_CRAMFS=y
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index cbb3436..1da9b7e 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -93,6 +93,30 @@ _ENTRY(_start);
bl early_init
+#ifdef CONFIG_RELOCATABLE
+ /*
+ * r25 will contain RPN/ERPN for the start address of memory
+ *
+ * Add the difference between KERNELBASE and PAGE_OFFSET to the
+ * start of physical memory to get kernstart_addr.
+ */
+ lis r3,kernstart_addr at ha
+ la r3,kernstart_addr at l(r3)
+
+ lis r4,KERNELBASE at h
+ ori r4,r4,KERNELBASE at l
+ lis r5,PAGE_OFFSET at h
+ ori r5,r5,PAGE_OFFSET at l
+ subf r4,r5,r4
+
+ rlwinm r6,r25,0,28,31 /* ERPN */
+ rlwinm r7,r25,0,0,3 /* RPN - assuming 256 MB page size */
+ add r7,r7,r4
+
+ stw r6,0(r3)
+ stw r7,4(r3)
+#endif
+
/*
* Decide what sort of machine this is and initialize the MMU.
*/
@@ -1001,9 +1025,6 @@ clear_utlb_entry:
lis r3,PAGE_OFFSET at h
ori r3,r3,PAGE_OFFSET at l
- /* Kernel is at the base of RAM */
- li r4, 0 /* Load the kernel physical address */
-
/* Load the kernel PID = 0 */
li r0,0
mtspr SPRN_PID,r0
@@ -1013,9 +1034,8 @@ clear_utlb_entry:
clrrwi r3,r3,12 /* Mask off the effective page number */
ori r3,r3,PPC47x_TLB0_VALID | PPC47x_TLB0_256M
- /* Word 1 */
- clrrwi r4,r4,12 /* Mask off the real page number */
- /* ERPN is 0 for first 4GB page */
+ /* Word 1 - use r25. RPN is the same as the original entry */
+
/* Word 2 */
li r5,0
ori r5,r5,PPC47x_TLB2_S_RWX
@@ -1026,7 +1046,7 @@ clear_utlb_entry:
/* We write to way 0 and bolted 0 */
lis r0,0x8800
tlbwe r3,r0,0
- tlbwe r4,r0,1
+ tlbwe r25,r0,1
tlbwe r5,r0,2
/*
@@ -1124,7 +1144,13 @@ head_start_common:
lis r4,interrupt_base at h /* IVPR only uses the high 16-bits */
mtspr SPRN_IVPR,r4
- addis r22,r22,KERNELBASE at h
+ /*
+ * If the kernel was loaded at a non-zero 256 MB page, we need to
+ * mask off the most significant 4 bits to get the relative address
+ * from the start of physical memory
+ */
+ rlwinm r22,r22,0,4,31
+ addis r22,r22,PAGE_OFFSET at h
mtlr r22
isync
blr
diff --git a/arch/powerpc/mm/44x_mmu.c b/arch/powerpc/mm/44x_mmu.c
index 024acab..f60e006 100644
--- a/arch/powerpc/mm/44x_mmu.c
+++ b/arch/powerpc/mm/44x_mmu.c
@@ -186,10 +186,11 @@ void __init MMU_init_hw(void)
unsigned long __init mmu_mapin_ram(unsigned long top)
{
unsigned long addr;
+ unsigned long memstart = memstart_addr & ~(PPC_PIN_SIZE - 1);
/* Pin in enough TLBs to cover any lowmem not covered by the
* initial 256M mapping established in head_44x.S */
- for (addr = PPC_PIN_SIZE; addr < lowmem_end_addr;
+ for (addr = memstart + PPC_PIN_SIZE; addr < lowmem_end_addr;
addr += PPC_PIN_SIZE) {
if (mmu_has_feature(MMU_FTR_TYPE_47x))
ppc47x_pin_tlb(addr + PAGE_OFFSET, addr);
@@ -218,19 +219,25 @@ unsigned long __init mmu_mapin_ram(unsigned long top)
void setup_initial_memory_limit(phys_addr_t first_memblock_base,
phys_addr_t first_memblock_size)
{
+ u64 size;
+
+#ifndef CONFIG_RELOCATABLE
/* We don't currently support the first MEMBLOCK not mapping 0
* physical on those processors
*/
BUG_ON(first_memblock_base != 0);
+#endif
/* 44x has a 256M TLB entry pinned at boot */
- memblock_set_current_limit(min_t(u64, first_memblock_size, PPC_PIN_SIZE));
+ size = (min_t(u64, first_memblock_size, PPC_PIN_SIZE));
+ memblock_set_current_limit(first_memblock_base + size);
}
#ifdef CONFIG_SMP
void __cpuinit mmu_init_secondary(int cpu)
{
unsigned long addr;
+ unsigned long memstart = memstart_addr & ~(PPC_PIN_SIZE - 1);
/* Pin in enough TLBs to cover any lowmem not covered by the
* initial 256M mapping established in head_44x.S
@@ -241,7 +248,7 @@ void __cpuinit mmu_init_secondary(int cpu)
* stack. current (r2) isn't initialized, smp_processor_id()
* will not work, current thread info isn't accessible, ...
*/
- for (addr = PPC_PIN_SIZE; addr < lowmem_end_addr;
+ for (addr = memstart + PPC_PIN_SIZE; addr < lowmem_end_addr;
addr += PPC_PIN_SIZE) {
if (mmu_has_feature(MMU_FTR_TYPE_47x))
ppc47x_pin_tlb(addr + PAGE_OFFSET, addr);
--
1.7.3.4
More information about the Linuxppc-dev
mailing list