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From:   Mike Rapoport <rppt@linux.vnet.ibm.com>
To:     Richard Henderson <rth@twiddle.net>,
        Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc:     Michal Hocko <mhocko@kernel.org>,
        linux-alpha <linux-alpha@vger.kernel.org>,
        linux-mm <linux-mm@kvack.org>,
        lkml <linux-kernel@vger.kernel.org>,
        Mike Rapoport <rppt@linux.vnet.ibm.com>
Subject: [PATCH v2] alpha: switch to NO_BOOTMEM
Date:   Sat, 30 Jun 2018 18:13:30 +0300
Message-Id: <1530371610-22174-1-git-send-email-rppt@linux.vnet.ibm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Replace bootmem allocator with memblock and enable use of NO_BOOTMEM like
on most other architectures.

Alpha gets the description of the physical memory from the firmware as an
array of memory clusters. Each cluster that is not reserved by the firmware
is added to memblock.memory.

Once the memblock.memory is set up, we reserve the kernel and initrd pages
with memblock reserve.

Since we don't need the bootmem bitmap anymore, the code that finds an
appropriate place is removed.

The conversion does not take care of NUMA support which is marked broken
for more than 10 years now.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
---
v2: describe the conversion as per Michal's request

Tested with qemu-system-alpha. I've added some tweaks to sys_dp264 to force
memory split for testing with CONFIG_DISCONTIGMEM=y

The allyesconfig build requires update to DEFERRED_STRUCT_PAGE_INIT
dependencies [1] which is already in -mm tree.

[1] https://lkml.org/lkml/2018/6/29/353

 arch/alpha/Kconfig                |   2 +
 arch/alpha/kernel/core_irongate.c |   4 +-
 arch/alpha/kernel/setup.c         |  98 ++++-----------------------------
 arch/alpha/mm/numa.c              | 113 +++++---------------------------------
 4 files changed, 29 insertions(+), 188 deletions(-)

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 04a4a138ed13..040692a8d433 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -30,6 +30,8 @@ config ALPHA
 	select ODD_RT_SIGACTION
 	select OLD_SIGSUSPEND
 	select CPU_NO_EFFICIENT_FFS if !ALPHA_EV67
+	select HAVE_MEMBLOCK
+	select NO_BOOTMEM
 	help
 	  The Alpha is a 64-bit general-purpose processor designed and
 	  marketed by the Digital Equipment Corporation of blessed memory,
diff --git a/arch/alpha/kernel/core_irongate.c b/arch/alpha/kernel/core_irongate.c
index aec757250e07..f70986683fc6 100644
--- a/arch/alpha/kernel/core_irongate.c
+++ b/arch/alpha/kernel/core_irongate.c
@@ -21,6 +21,7 @@
 #include <linux/init.h>
 #include <linux/initrd.h>
 #include <linux/bootmem.h>
+#include <linux/memblock.h>
 
 #include <asm/ptrace.h>
 #include <asm/cacheflush.h>
@@ -241,8 +242,7 @@ albacore_init_arch(void)
 				       size / 1024);
 		}
 #endif
-		reserve_bootmem_node(NODE_DATA(0), pci_mem, memtop -
-				pci_mem, BOOTMEM_DEFAULT);
+		memblock_reserve(pci_mem, memtop - pci_mem);
 		printk("irongate_init_arch: temporarily reserving "
 			"region %08lx-%08lx for PCI\n", pci_mem, memtop - 1);
 	}
diff --git a/arch/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c
index 5576f7646fb6..4f0d94471bc9 100644
--- a/arch/alpha/kernel/setup.c
+++ b/arch/alpha/kernel/setup.c
@@ -30,6 +30,7 @@
 #include <linux/ioport.h>
 #include <linux/platform_device.h>
 #include <linux/bootmem.h>
+#include <linux/memblock.h>
 #include <linux/pci.h>
 #include <linux/seq_file.h>
 #include <linux/root_dev.h>
@@ -312,9 +313,7 @@ setup_memory(void *kernel_end)
 {
 	struct memclust_struct * cluster;
 	struct memdesc_struct * memdesc;
-	unsigned long start_kernel_pfn, end_kernel_pfn;
-	unsigned long bootmap_size, bootmap_pages, bootmap_start;
-	unsigned long start, end;
+	unsigned long kernel_size;
 	unsigned long i;
 
 	/* Find free clusters, and init and free the bootmem accordingly.  */
@@ -322,6 +321,8 @@ setup_memory(void *kernel_end)
 	  (hwrpb->mddt_offset + (unsigned long) hwrpb);
 
 	for_each_mem_cluster(memdesc, cluster, i) {
+		unsigned long end;
+
 		printk("memcluster %lu, usage %01lx, start %8lu, end %8lu\n",
 		       i, cluster->usage, cluster->start_pfn,
 		       cluster->start_pfn + cluster->numpages);
@@ -335,6 +336,9 @@ setup_memory(void *kernel_end)
 		end = cluster->start_pfn + cluster->numpages;
 		if (end > max_low_pfn)
 			max_low_pfn = end;
+
+		memblock_add(PFN_PHYS(cluster->start_pfn),
+			     cluster->numpages << PAGE_SHIFT);
 	}
 
 	/*
@@ -363,87 +367,9 @@ setup_memory(void *kernel_end)
 		max_low_pfn = mem_size_limit;
 	}
 
-	/* Find the bounds of kernel memory.  */
-	start_kernel_pfn = PFN_DOWN(KERNEL_START_PHYS);
-	end_kernel_pfn = PFN_UP(virt_to_phys(kernel_end));
-	bootmap_start = -1;
-
- try_again:
-	if (max_low_pfn <= end_kernel_pfn)
-		panic("not enough memory to boot");
-
-	/* We need to know how many physically contiguous pages
-	   we'll need for the bootmap.  */
-	bootmap_pages = bootmem_bootmap_pages(max_low_pfn);
-
-	/* Now find a good region where to allocate the bootmap.  */
-	for_each_mem_cluster(memdesc, cluster, i) {
-		if (cluster->usage & 3)
-			continue;
-
-		start = cluster->start_pfn;
-		end = start + cluster->numpages;
-		if (start >= max_low_pfn)
-			continue;
-		if (end > max_low_pfn)
-			end = max_low_pfn;
-		if (start < start_kernel_pfn) {
-			if (end > end_kernel_pfn
-			    && end - end_kernel_pfn >= bootmap_pages) {
-				bootmap_start = end_kernel_pfn;
-				break;
-			} else if (end > start_kernel_pfn)
-				end = start_kernel_pfn;
-		} else if (start < end_kernel_pfn)
-			start = end_kernel_pfn;
-		if (end - start >= bootmap_pages) {
-			bootmap_start = start;
-			break;
-		}
-	}
-
-	if (bootmap_start == ~0UL) {
-		max_low_pfn >>= 1;
-		goto try_again;
-	}
-
-	/* Allocate the bootmap and mark the whole MM as reserved.  */
-	bootmap_size = init_bootmem(bootmap_start, max_low_pfn);
-
-	/* Mark the free regions.  */
-	for_each_mem_cluster(memdesc, cluster, i) {
-		if (cluster->usage & 3)
-			continue;
-
-		start = cluster->start_pfn;
-		end = cluster->start_pfn + cluster->numpages;
-		if (start >= max_low_pfn)
-			continue;
-		if (end > max_low_pfn)
-			end = max_low_pfn;
-		if (start < start_kernel_pfn) {
-			if (end > end_kernel_pfn) {
-				free_bootmem(PFN_PHYS(start),
-					     (PFN_PHYS(start_kernel_pfn)
-					      - PFN_PHYS(start)));
-				printk("freeing pages %ld:%ld\n",
-				       start, start_kernel_pfn);
-				start = end_kernel_pfn;
-			} else if (end > start_kernel_pfn)
-				end = start_kernel_pfn;
-		} else if (start < end_kernel_pfn)
-			start = end_kernel_pfn;
-		if (start >= end)
-			continue;
-
-		free_bootmem(PFN_PHYS(start), PFN_PHYS(end) - PFN_PHYS(start));
-		printk("freeing pages %ld:%ld\n", start, end);
-	}
-
-	/* Reserve the bootmap memory.  */
-	reserve_bootmem(PFN_PHYS(bootmap_start), bootmap_size,
-			BOOTMEM_DEFAULT);
-	printk("reserving pages %ld:%ld\n", bootmap_start, bootmap_start+PFN_UP(bootmap_size));
+	/* Reserve the kernel memory. */
+	kernel_size = virt_to_phys(kernel_end) - KERNEL_START_PHYS;
+	memblock_reserve(KERNEL_START_PHYS, kernel_size);
 
 #ifdef CONFIG_BLK_DEV_INITRD
 	initrd_start = INITRD_START;
@@ -459,8 +385,8 @@ setup_memory(void *kernel_end)
 				       initrd_end,
 				       phys_to_virt(PFN_PHYS(max_low_pfn)));
 		} else {
-			reserve_bootmem(virt_to_phys((void *)initrd_start),
-					INITRD_SIZE, BOOTMEM_DEFAULT);
+			memblock_reserve(virt_to_phys((void *)initrd_start),
+					INITRD_SIZE);
 		}
 	}
 #endif /* CONFIG_BLK_DEV_INITRD */
diff --git a/arch/alpha/mm/numa.c b/arch/alpha/mm/numa.c
index a9e86475f169..26cd925d19b1 100644
--- a/arch/alpha/mm/numa.c
+++ b/arch/alpha/mm/numa.c
@@ -11,6 +11,7 @@
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/bootmem.h>
+#include <linux/memblock.h>
 #include <linux/swap.h>
 #include <linux/initrd.h>
 #include <linux/pfn.h>
@@ -59,12 +60,10 @@ setup_memory_node(int nid, void *kernel_end)
 	struct memclust_struct * cluster;
 	struct memdesc_struct * memdesc;
 	unsigned long start_kernel_pfn, end_kernel_pfn;
-	unsigned long bootmap_size, bootmap_pages, bootmap_start;
 	unsigned long start, end;
 	unsigned long node_pfn_start, node_pfn_end;
 	unsigned long node_min_pfn, node_max_pfn;
 	int i;
-	unsigned long node_datasz = PFN_UP(sizeof(pg_data_t));
 	int show_init = 0;
 
 	/* Find the bounds of current node */
@@ -134,24 +133,14 @@ setup_memory_node(int nid, void *kernel_end)
 	/* Cute trick to make sure our local node data is on local memory */
 	node_data[nid] = (pg_data_t *)(__va(node_min_pfn << PAGE_SHIFT));
 #endif
-	/* Quasi-mark the pg_data_t as in-use */
-	node_min_pfn += node_datasz;
-	if (node_min_pfn >= node_max_pfn) {
-		printk(" not enough mem to reserve NODE_DATA");
-		return;
-	}
-	NODE_DATA(nid)->bdata = &bootmem_node_data[nid];
-
 	printk(" Detected node memory:   start %8lu, end %8lu\n",
 	       node_min_pfn, node_max_pfn);
 
 	DBGDCONT(" DISCONTIG: node_data[%d]   is at 0x%p\n", nid, NODE_DATA(nid));
-	DBGDCONT(" DISCONTIG: NODE_DATA(%d)->bdata is at 0x%p\n", nid, NODE_DATA(nid)->bdata);
 
 	/* Find the bounds of kernel memory.  */
 	start_kernel_pfn = PFN_DOWN(KERNEL_START_PHYS);
 	end_kernel_pfn = PFN_UP(virt_to_phys(kernel_end));
-	bootmap_start = -1;
 
 	if (!nid && (node_max_pfn < end_kernel_pfn || node_min_pfn > start_kernel_pfn))
 		panic("kernel loaded out of ram");
@@ -161,89 +150,11 @@ setup_memory_node(int nid, void *kernel_end)
 	   has much larger alignment than 8Mb, so it's safe. */
 	node_min_pfn &= ~((1UL << (MAX_ORDER-1))-1);
 
-	/* We need to know how many physically contiguous pages
-	   we'll need for the bootmap.  */
-	bootmap_pages = bootmem_bootmap_pages(node_max_pfn-node_min_pfn);
-
-	/* Now find a good region where to allocate the bootmap.  */
-	for_each_mem_cluster(memdesc, cluster, i) {
-		if (cluster->usage & 3)
-			continue;
-
-		start = cluster->start_pfn;
-		end = start + cluster->numpages;
-
-		if (start >= node_max_pfn || end <= node_min_pfn)
-			continue;
-
-		if (end > node_max_pfn)
-			end = node_max_pfn;
-		if (start < node_min_pfn)
-			start = node_min_pfn;
-
-		if (start < start_kernel_pfn) {
-			if (end > end_kernel_pfn
-			    && end - end_kernel_pfn >= bootmap_pages) {
-				bootmap_start = end_kernel_pfn;
-				break;
-			} else if (end > start_kernel_pfn)
-				end = start_kernel_pfn;
-		} else if (start < end_kernel_pfn)
-			start = end_kernel_pfn;
-		if (end - start >= bootmap_pages) {
-			bootmap_start = start;
-			break;
-		}
-	}
-
-	if (bootmap_start == -1)
-		panic("couldn't find a contiguous place for the bootmap");
-
-	/* Allocate the bootmap and mark the whole MM as reserved.  */
-	bootmap_size = init_bootmem_node(NODE_DATA(nid), bootmap_start,
-					 node_min_pfn, node_max_pfn);
-	DBGDCONT(" bootmap_start %lu, bootmap_size %lu, bootmap_pages %lu\n",
-		 bootmap_start, bootmap_size, bootmap_pages);
+	memblock_add(PFN_PHYS(node_min_pfn),
+		     (node_max_pfn - node_min_pfn) << PAGE_SHIFT);
 
-	/* Mark the free regions.  */
-	for_each_mem_cluster(memdesc, cluster, i) {
-		if (cluster->usage & 3)
-			continue;
-
-		start = cluster->start_pfn;
-		end = cluster->start_pfn + cluster->numpages;
-
-		if (start >= node_max_pfn || end <= node_min_pfn)
-			continue;
-
-		if (end > node_max_pfn)
-			end = node_max_pfn;
-		if (start < node_min_pfn)
-			start = node_min_pfn;
-
-		if (start < start_kernel_pfn) {
-			if (end > end_kernel_pfn) {
-				free_bootmem_node(NODE_DATA(nid), PFN_PHYS(start),
-					     (PFN_PHYS(start_kernel_pfn)
-					      - PFN_PHYS(start)));
-				printk(" freeing pages %ld:%ld\n",
-				       start, start_kernel_pfn);
-				start = end_kernel_pfn;
-			} else if (end > start_kernel_pfn)
-				end = start_kernel_pfn;
-		} else if (start < end_kernel_pfn)
-			start = end_kernel_pfn;
-		if (start >= end)
-			continue;
-
-		free_bootmem_node(NODE_DATA(nid), PFN_PHYS(start), PFN_PHYS(end) - PFN_PHYS(start));
-		printk(" freeing pages %ld:%ld\n", start, end);
-	}
-
-	/* Reserve the bootmap memory.  */
-	reserve_bootmem_node(NODE_DATA(nid), PFN_PHYS(bootmap_start),
-			bootmap_size, BOOTMEM_DEFAULT);
-	printk(" reserving pages %ld:%ld\n", bootmap_start, bootmap_start+PFN_UP(bootmap_size));
+	NODE_DATA(nid)->node_start_pfn = node_min_pfn;
+	NODE_DATA(nid)->node_present_pages = node_max_pfn - node_min_pfn;
 
 	node_set_online(nid);
 }
@@ -251,6 +162,7 @@ setup_memory_node(int nid, void *kernel_end)
 void __init
 setup_memory(void *kernel_end)
 {
+	unsigned long kernel_size;
 	int nid;
 
 	show_mem_layout();
@@ -262,6 +174,9 @@ setup_memory(void *kernel_end)
 	for (nid = 0; nid < MAX_NUMNODES; nid++)
 		setup_memory_node(nid, kernel_end);
 
+	kernel_size = virt_to_phys(kernel_end) - KERNEL_START_PHYS;
+	memblock_reserve(KERNEL_START_PHYS, kernel_size);
+
 #ifdef CONFIG_BLK_DEV_INITRD
 	initrd_start = INITRD_START;
 	if (initrd_start) {
@@ -279,9 +194,8 @@ setup_memory(void *kernel_end)
 				       phys_to_virt(PFN_PHYS(max_low_pfn)));
 		} else {
 			nid = kvaddr_to_nid(initrd_start);
-			reserve_bootmem_node(NODE_DATA(nid),
-					     virt_to_phys((void *)initrd_start),
-					     INITRD_SIZE, BOOTMEM_DEFAULT);
+			memblock_reserve(virt_to_phys((void *)initrd_start),
+					 INITRD_SIZE);
 		}
 	}
 #endif /* CONFIG_BLK_DEV_INITRD */
@@ -303,9 +217,8 @@ void __init paging_init(void)
 	dma_local_pfn = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
 
 	for_each_online_node(nid) {
-		bootmem_data_t *bdata = &bootmem_node_data[nid];
-		unsigned long start_pfn = bdata->node_min_pfn;
-		unsigned long end_pfn = bdata->node_low_pfn;
+		unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
+		unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_present_pages;
 
 		if (dma_local_pfn >= end_pfn - start_pfn)
 			zones_size[ZONE_DMA] = end_pfn - start_pfn;
-- 
2.7.4