powerpc/47x: allow kernel to be loaded in higher physical memory
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: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c15f2e6..f8e578b 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -842,7 +842,7 @@
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_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_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_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 5e12b74..f8e971b 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -93,6 +93,30 @@
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@ha
+ la r3,kernstart_addr@l(r3)
+
+ lis r4,KERNELBASE@h
+ ori r4,r4,KERNELBASE@l
+ lis r5,PAGE_OFFSET@h
+ ori r5,r5,PAGE_OFFSET@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 @@
lis r3,PAGE_OFFSET@h
ori r3,r3,PAGE_OFFSET@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 @@
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 @@
/* 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 @@
lis r4,interrupt_base@h /* IVPR only uses the high 16-bits */
mtspr SPRN_IVPR,r4
- addis r22,r22,KERNELBASE@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@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 @@
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 @@
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 @@
* 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);