[PATCH 08/25] lmb: Remove rmo_size, burry it in arch/powerpc where it belongs

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

The RMA (RMO is a misnomer) is a concept specific to ppc64 (in fact
server ppc64 though I hijack it on embedded ppc64 for similar purposes)
and represents the area of memory that can be accessed in real mode
(aka with MMU off), or on embedded, from the exception vectors (which
is bolted in the TLB) which pretty much boils down to the same thing.

We take that out of the generic LMB data structure and move it into
arch/powerpc where it belongs, renaming it to "RMA" while at it.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/include/asm/mmu.h  |   12 ++++++++++++
 arch/powerpc/kernel/head_40x.S  |    6 +-----
 arch/powerpc/kernel/paca.c      |    2 +-
 arch/powerpc/kernel/prom.c      |   29 ++++++++---------------------
 arch/powerpc/kernel/rtas.c      |    2 +-
 arch/powerpc/kernel/setup_64.c  |    2 +-
 arch/powerpc/mm/40x_mmu.c       |   14 +++++++++++++-
 arch/powerpc/mm/44x_mmu.c       |   14 ++++++++++++++
 arch/powerpc/mm/fsl_booke_mmu.c |    9 +++++++++
 arch/powerpc/mm/hash_utils_64.c |   22 +++++++++++++++++++++-
 arch/powerpc/mm/init_32.c       |   14 ++++++++++++++
 arch/powerpc/mm/init_64.c       |    1 +
 arch/powerpc/mm/ppc_mmu_32.c    |   15 +++++++++++++++
 arch/powerpc/mm/tlb_nohash.c    |   14 ++++++++++++++
 include/linux/lmb.h             |    1 -
 lib/lmb.c                       |    8 --------
 16 files changed, 125 insertions(+), 40 deletions(-)

diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index 7ebf42e..bc68624 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -2,6 +2,8 @@
 #define _ASM_POWERPC_MMU_H_
 #ifdef __KERNEL__
 
+#include <linux/types.h>
+
 #include <asm/asm-compat.h>
 #include <asm/feature-fixups.h>
 
@@ -82,6 +84,16 @@ extern unsigned int __start___mmu_ftr_fixup, __stop___mmu_ftr_fixup;
 extern void early_init_mmu(void);
 extern void early_init_mmu_secondary(void);
 
+extern void setup_initial_memory_limit(phys_addr_t first_lmb_base,
+				       phys_addr_t first_lmb_size);
+
+#ifdef CONFIG_PPC64
+/* This is our real memory area size on ppc64 server, on embedded, we
+ * make it match the size our of bolted TLB area
+ */
+extern u64 ppc64_rma_size;
+#endif /* CONFIG_PPC64 */
+
 #endif /* !__ASSEMBLY__ */
 
 /* The kernel use the constants below to index in the page sizes array.
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index a90625f..8278e8b 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -923,11 +923,7 @@ initial_mmu:
 	mtspr	SPRN_PID,r0
 	sync
 
-	/* Configure and load two entries into TLB slots 62 and 63.
-	 * In case we are pinning TLBs, these are reserved in by the
-	 * other TLB functions.  If not reserving, then it doesn't
-	 * matter where they are loaded.
-	 */
+	/* Configure and load one entry into TLB slots 63 */
 	clrrwi	r4,r4,10		/* Mask off the real page number */
 	ori	r4,r4,(TLB_WR | TLB_EX)	/* Set the write and execute bits */
 
diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index 0c40c6f..717185b 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -115,7 +115,7 @@ void __init allocate_pacas(void)
 	 * the first segment. On iSeries they must be within the area mapped
 	 * by the HV, which is HvPagesToMap * HVPAGESIZE bytes.
 	 */
-	limit = min(0x10000000ULL, lmb.rmo_size);
+	limit = min(0x10000000ULL, ppc64_rma_size);
 	if (firmware_has_feature(FW_FEATURE_ISERIES))
 		limit = min(limit, HvPagesToMap * HVPAGESIZE);
 
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index b8428d3..7bec9ac 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -66,6 +66,7 @@
 int __initdata iommu_is_off;
 int __initdata iommu_force_on;
 unsigned long tce_alloc_start, tce_alloc_end;
+u64 ppc64_rma_size;
 #endif
 
 static int __init early_parse_mem(char *p)
@@ -492,7 +493,7 @@ static int __init early_init_dt_scan_memory_ppc(unsigned long node,
 
 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 {
-#if defined(CONFIG_PPC64)
+#ifdef CONFIG_PPC64
 	if (iommu_is_off) {
 		if (base >= 0x80000000ul)
 			return;
@@ -501,9 +502,13 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 	}
 #endif
 
-	lmb_add(base, size);
-
+	/* First LMB added, do some special initializations */
+	if (memstart_addr == ~(phys_addr_t)0)
+		setup_initial_memory_limit(base, size);
 	memstart_addr = min((u64)memstart_addr, base);
+
+	/* Add the chunk to the LMB list */
+	lmb_add(base, size);
 }
 
 u64 __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
@@ -655,22 +660,6 @@ static void __init phyp_dump_reserve_mem(void)
 static inline void __init phyp_dump_reserve_mem(void) {}
 #endif /* CONFIG_PHYP_DUMP  && CONFIG_PPC_RTAS */
 
-static void set_boot_memory_limit(void)
-{	
-#ifdef CONFIG_PPC32
-	/* 601 can only access 16MB at the moment */
-	if (PVR_VER(mfspr(SPRN_PVR)) == 1)
-		lmb_set_current_limit(0x01000000);
-	/* 8xx can only access 8MB at the moment */
-	else if (PVR_VER(mfspr(SPRN_PVR)) == 0x50)
-		lmb_set_current_limit(0x00800000);
-	else
-		lmb_set_current_limit(0x10000000);
-#else
-	lmb_set_current_limit(lmb.rmo_size);
-#endif
-}
-
 void __init early_init_devtree(void *params)
 {
 	phys_addr_t limit;
@@ -734,8 +723,6 @@ void __init early_init_devtree(void *params)
 
 	DBG("Phys. mem: %llx\n", lmb_phys_mem_size());
 
-	set_boot_memory_limit();
-
 	/* We may need to relocate the flat tree, do it now.
 	 * FIXME .. and the initrd too? */
 	move_device_tree();
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 0e1ec6f..fbe8fe7 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -934,7 +934,7 @@ void __init rtas_initialize(void)
 	 */
 #ifdef CONFIG_PPC64
 	if (machine_is(pseries) && firmware_has_feature(FW_FEATURE_LPAR)) {
-		rtas_region = min(lmb.rmo_size, RTAS_INSTANTIATE_MAX);
+		rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX);
 		ibm_suspend_me_token = rtas_token("ibm,suspend-me");
 	}
 #endif
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 9143891..9690d74 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -482,7 +482,7 @@ static void __init emergency_stack_init(void)
 	 * bringup, we need to get at them in real mode. This means they
 	 * must also be within the RMO region.
 	 */
-	limit = min(0x10000000ULL, lmb.rmo_size);
+	limit = min(0x10000000ULL, ppc64_rma_size);
 
 	for_each_possible_cpu(i) {
 		unsigned long sp;
diff --git a/arch/powerpc/mm/40x_mmu.c b/arch/powerpc/mm/40x_mmu.c
index 809f655..475932f 100644
--- a/arch/powerpc/mm/40x_mmu.c
+++ b/arch/powerpc/mm/40x_mmu.c
@@ -141,7 +141,19 @@ unsigned long __init mmu_mapin_ram(unsigned long top)
 	 * coverage with normal-sized pages (or other reasons) do not
 	 * attempt to allocate outside the allowed range.
 	 */
-	lmb_set_current_limit(memstart_addr + mapped);
+	lmb_set_current_limit(mapped);
 
 	return mapped;
 }
+
+void setup_initial_memory_limit(phys_addr_t first_lmb_base,
+				phys_addr_t first_lmb_size)
+{
+	/* We don't currently support the first LMB not mapping 0
+	 * physical on those processors
+	 */
+	BUG_ON(first_lmb_base != 0);
+
+	/* 40x can only access 16MB at the moment (see head_40x.S) */
+	lmb_set_current_limit(min_t(u64, first_lmb_size, 0x00800000));
+}
diff --git a/arch/powerpc/mm/44x_mmu.c b/arch/powerpc/mm/44x_mmu.c
index d8c6efb..a2d3aa9 100644
--- a/arch/powerpc/mm/44x_mmu.c
+++ b/arch/powerpc/mm/44x_mmu.c
@@ -24,6 +24,8 @@
  */
 
 #include <linux/init.h>
+#include <linux/lmb.h>
+
 #include <asm/mmu.h>
 #include <asm/system.h>
 #include <asm/page.h>
@@ -213,6 +215,18 @@ unsigned long __init mmu_mapin_ram(unsigned long top)
 	return total_lowmem;
 }
 
+void setup_initial_memory_limit(phys_addr_t first_lmb_base,
+				phys_addr_t first_lmb_size)
+{
+	/* We don't currently support the first LMB not mapping 0
+	 * physical on those processors
+	 */
+	BUG_ON(first_lmb_base != 0);
+
+	/* 44x has a 256M TLB entry pinned at boot */
+	lmb_set_current_limit(min_t(u64, first_lmb_size, PPC_PIN_SIZE));
+}
+
 #ifdef CONFIG_SMP
 void __cpuinit mmu_init_secondary(int cpu)
 {
diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c
index 038cb29..e652560 100644
--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -234,3 +234,12 @@ void __init adjust_total_lowmem(void)
 
 	lmb_set_current_limit(memstart_addr + __max_low_memory);
 }
+
+void setup_initial_memory_limit(phys_addr_t first_lmb_base,
+				phys_addr_t first_lmb_size)
+{
+	phys_addr_t limit = first_lmb_base + first_lmb_size;
+
+	/* 64M mapped initially according to head_fsl_booke.S */
+	lmb_set_current_limit(min_t(u64, limit, 0x04000000));
+}
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index ae7a8f1..2b748c5 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -649,7 +649,7 @@ static void __init htab_initialize(void)
 #ifdef CONFIG_DEBUG_PAGEALLOC
 	linear_map_hash_count = lmb_end_of_DRAM() >> PAGE_SHIFT;
 	linear_map_hash_slots = __va(lmb_alloc_base(linear_map_hash_count,
-						    1, lmb.rmo_size));
+						    1, ppc64_rma_size));
 	memset(linear_map_hash_slots, 0, linear_map_hash_count);
 #endif /* CONFIG_DEBUG_PAGEALLOC */
 
@@ -1221,3 +1221,23 @@ void kernel_map_pages(struct page *page, int numpages, int enable)
 	local_irq_restore(flags);
 }
 #endif /* CONFIG_DEBUG_PAGEALLOC */
+
+void setup_initial_memory_limit(phys_addr_t first_lmb_base,
+				phys_addr_t first_lmb_size)
+{
+	/* We don't currently support the first LMB not mapping 0
+	 * physical on those processors
+	 */
+	BUG_ON(first_lmb_base != 0);
+
+	/* On LPAR systems, the first entry is our RMA region,
+	 * non-LPAR 64-bit hash MMU systems don't have a limitation
+	 * on real mode access, but using the first entry works well
+	 * enough. We also clamp it to 1G to avoid some funky things
+	 * such as RTAS bugs etc...
+	 */
+	ppc64_rma_size = min_t(u64, first_lmb_size, 0x40000000);
+
+	/* Finally limit subsequent allocations */ 
+	lmb_set_current_limit(ppc64_rma_size);		
+}
diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c
index 62d2242..218869a 100644
--- a/arch/powerpc/mm/init_32.c
+++ b/arch/powerpc/mm/init_32.c
@@ -237,3 +237,17 @@ void free_initrd_mem(unsigned long start, unsigned long end)
 }
 #endif
 
+
+#ifdef CONFIG_8xx /* No 8xx specific .c file to put that in ... */ 
+void setup_initial_memory_limit(phys_addr_t first_lmb_base,
+				phys_addr_t first_lmb_size)
+{
+	/* We don't currently support the first LMB not mapping 0
+	 * physical on those processors
+	 */
+	BUG_ON(first_lmb_base != 0);
+
+	/* 8xx can only access 8MB at the moment */
+	lmb_set_current_limit(min_t(u64, first_lmb_size, 0x00800000));
+}
+#endif /* CONFIG_8xx */
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index e267f22..433922a 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c
@@ -328,3 +328,4 @@ int __meminit vmemmap_populate(struct page *start_page,
 	return 0;
 }
 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
+
diff --git a/arch/powerpc/mm/ppc_mmu_32.c b/arch/powerpc/mm/ppc_mmu_32.c
index fe6af92..ad8a36c 100644
--- a/arch/powerpc/mm/ppc_mmu_32.c
+++ b/arch/powerpc/mm/ppc_mmu_32.c
@@ -271,3 +271,18 @@ void __init MMU_init_hw(void)
 
 	if ( ppc_md.progress ) ppc_md.progress("hash:done", 0x205);
 }
+
+void setup_initial_memory_limit(phys_addr_t first_lmb_base,
+				phys_addr_t first_lmb_size)
+{
+	/* We don't currently support the first LMB not mapping 0
+	 * physical on those processors
+	 */
+	BUG_ON(first_lmb_base != 0);
+
+	/* 601 can only access 16MB at the moment */
+	if (PVR_VER(mfspr(SPRN_PVR)) == 1)
+		lmb_set_current_limit(min_t(u64, first_lmb_size, 0x01000000));
+	else /* Anything else has 256M mapped */
+		lmb_set_current_limit(min_t(u64, first_lmb_size, 0x10000000));
+}
diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c
index 4a09475..a771e62 100644
--- a/arch/powerpc/mm/tlb_nohash.c
+++ b/arch/powerpc/mm/tlb_nohash.c
@@ -446,4 +446,18 @@ void __cpuinit early_init_mmu_secondary(void)
 	__early_init_mmu(0);
 }
 
+void setup_initial_memory_limit(phys_addr_t first_lmb_base,
+				phys_addr_t first_lmb_size)
+{
+	/* On Embedded 64-bit, we adjust the RMA size to match
+	 * the bolted TLB entry. We know for now that only 1G
+	 * entries are supported though that may eventually
+	 * change. We crop it to the size of the first LMB to
+	 * avoid going over total available memory just in case...
+	 */
+	ppc64_rma_size = min_t(u64, first_lmb_size, 0x40000000);
+
+	/* Finally limit subsequent allocations */ 
+	lmb_set_current_limit(ppc64_lmb_base + ppc64_rma_size);
+}
 #endif /* CONFIG_PPC64 */
diff --git a/include/linux/lmb.h b/include/linux/lmb.h
index 3b950c3..6912ae2 100644
--- a/include/linux/lmb.h
+++ b/include/linux/lmb.h
@@ -33,7 +33,6 @@ struct lmb_type {
 
 struct lmb {
 	unsigned long debug;
-	u64 rmo_size;
 	u64 current_limit;
 	struct lmb_type memory;
 	struct lmb_type reserved;
diff --git a/lib/lmb.c b/lib/lmb.c
index 34a558c..e7a7842 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -49,7 +49,6 @@ void lmb_dump_all(void)
 		return;
 
 	pr_info("LMB configuration:\n");
-	pr_info(" rmo_size    = 0x%llx\n", (unsigned long long)lmb.rmo_size);
 	pr_info(" memory.size = 0x%llx\n", (unsigned long long)lmb.memory.size);
 
 	lmb_dump(&lmb.memory, "memory");
@@ -195,10 +194,6 @@ static long lmb_add_region(struct lmb_type *type, u64 base, u64 size)
 
 long lmb_add(u64 base, u64 size)
 {
-	/* On pSeries LPAR systems, the first LMB is our RMO region. */
-	if (base == 0)
-		lmb.rmo_size = size;
-
 	return lmb_add_region(&lmb.memory, base, size);
 
 }
@@ -459,9 +454,6 @@ void __init lmb_enforce_memory_limit(u64 memory_limit)
 		break;
 	}
 
-	if (lmb.memory.regions[0].size < lmb.rmo_size)
-		lmb.rmo_size = lmb.memory.regions[0].size;
-
 	memory_limit = lmb_end_of_DRAM();
 
 	/* And truncate any reserves above the limit also. */
-- 
1.6.3.3

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