Re: [PATCH v4 3/5] memblock: add memblock_cap_memory_ranges for multiple ranges

2019-04-15 Thread Chen Zhou
Hi Mike,

On 2019/4/16 3:09, Mike Rapoport wrote:
> Hi,
> 
> On Mon, Apr 15, 2019 at 06:57:23PM +0800, Chen Zhou wrote:
>> The memblock_cap_memory_range() removes all the memory except the
>> range passed to it. Extend this function to receive memblock_type
>> with the regions that should be kept.
>>
>> Enable this function in arm64 for reservation of multiple regions
>> for the crash kernel.
>>
>> Signed-off-by: Chen Zhou 
>> Signed-off-by: Mike Rapoport 
> 
> I didn't work on this version, please drop the signed-off.

Sorry about this. I should ask you firstly before doing it this way. I will 
drop it.

remove_size);
>> +}
>> +
>> +memblock_remove_range(&memblock.reserved,
>> +regs[nr - 1].base + regs[nr - 1].size, PHYS_ADDR_MAX);
>> +}
>> +
> 
> I've double-checked and I see no problem with using
> for_each_mem_range_rev() iterators for removing some ranges. And with them
> this functions becomes much clearer and more efficient.
> 
> Can you please check if the below patch works for you?
> 
>>From e25e6c9cd94a01abac124deacc66e5d258fdbf7c Mon Sep 17 00:00:00 2001
> From: Mike Rapoport 
> Date: Wed, 10 Apr 2019 16:02:32 +0300
> Subject: [PATCH] memblock: extend memblock_cap_memory_range to multiple ranges
> 
> The memblock_cap_memory_range() removes all the memory except the range
> passed to it. Extend this function to receive an array of memblock_regions
> that should be kept. This allows switching to simple iteration over
> memblock arrays with 'for_each_mem_range_rev' to remove the unneeded memory.
> 
> Enable use of this function in arm64 for reservation of multiple regions for
> the crash kernel.
> 
> Signed-off-by: Mike Rapoport 
> ---
>  arch/arm64/mm/init.c | 34 --
>  include/linux/memblock.h |  2 +-
>  mm/memblock.c| 44 
>  3 files changed, 45 insertions(+), 35 deletions(-)
> 
> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> index 6bc1350..8665d29 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -64,6 +64,10 @@ EXPORT_SYMBOL(memstart_addr);
>  phys_addr_t arm64_dma_phys_limit __ro_after_init;
>  
>  #ifdef CONFIG_KEXEC_CORE
> +
> +/* at most two crash kernel regions, low_region and high_region */
> +#define CRASH_MAX_USABLE_RANGES  2
> +
>  /*
>   * reserve_crashkernel() - reserves memory for crash kernel
>   *
> @@ -280,9 +284,9 @@ early_param("mem", early_mem);
>  static int __init early_init_dt_scan_usablemem(unsigned long node,
>   const char *uname, int depth, void *data)
>  {
> - struct memblock_region *usablemem = data;
> - const __be32 *reg;
> - int len;
> + struct memblock_type *usablemem = data;
> + const __be32 *reg, *endp;
> + int len, nr = 0;
>  
>   if (depth != 1 || strcmp(uname, "chosen") != 0)
>   return 0;
> @@ -291,22 +295,32 @@ static int __init early_init_dt_scan_usablemem(unsigned 
> long node,
>   if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells)))
>   return 1;
>  
> - usablemem->base = dt_mem_next_cell(dt_root_addr_cells, ®);
> - usablemem->size = dt_mem_next_cell(dt_root_size_cells, ®);
> + endp = reg + (len / sizeof(__be32));
> + while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
> + unsigned long base = dt_mem_next_cell(dt_root_addr_cells, ®);
> + unsigned long size = dt_mem_next_cell(dt_root_size_cells, ®);
>  
> + if (memblock_add_range(usablemem, base, size, NUMA_NO_NODE,
> +MEMBLOCK_NONE))
> + return 0;
> + if (++nr >= CRASH_MAX_USABLE_RANGES)
> + break;
> + }
>   return 1;
>  }
>  
>  static void __init fdt_enforce_memory_region(void)
>  {
> - struct memblock_region reg = {
> - .size = 0,
> + struct memblock_region usable_regions[CRASH_MAX_USABLE_RANGES];
> + struct memblock_type usablemem = {
> + .max = CRASH_MAX_USABLE_RANGES,
> + .regions = usable_regions,
>   };
>  
> - of_scan_flat_dt(early_init_dt_scan_usablemem, ®);
> + of_scan_flat_dt(early_init_dt_scan_usablemem, &usablemem);
>  
> - if (reg.size)
> - memblock_cap_memory_range(reg.base, reg.size);
> + if (usablemem.cnt)
> + memblock_cap_memory_ranges(usablemem.regions, usablemem.cnt);
>  }
>  
>  void __init arm64_memblock_init(void)
> diff --git a/include/linux/memblock.h b/include/linux/memblock.h
> index 294d5d8..f5c029b 100644
> --- a/include/linux/memblock.h
> +++ b/include/linux/memblock.h
> @@ -404,7 +404,7 @@ phys_addr_t memblock_mem_size(unsigned long limit_pfn);
>  phys_addr_t memblock_start_of_DRAM(void);
>  phys_addr_t memblock_end_of_DRAM(void);
>  void memblock_enforce_memory_limit(phys_addr_t memory_limit);
> -void memblock_cap_memory_range(phys_addr_t base, phys_addr_t size);
> +void membl

Re: [PATCH v4 3/5] memblock: add memblock_cap_memory_ranges for multiple ranges

2019-04-15 Thread Mike Rapoport
Hi,

On Mon, Apr 15, 2019 at 06:57:23PM +0800, Chen Zhou wrote:
> The memblock_cap_memory_range() removes all the memory except the
> range passed to it. Extend this function to receive memblock_type
> with the regions that should be kept.
> 
> Enable this function in arm64 for reservation of multiple regions
> for the crash kernel.
> 
> Signed-off-by: Chen Zhou 
> Signed-off-by: Mike Rapoport 

I didn't work on this version, please drop the signed-off.

> ---
>  include/linux/memblock.h |  1 +
>  mm/memblock.c| 45 +
>  2 files changed, 46 insertions(+)
> 
> diff --git a/include/linux/memblock.h b/include/linux/memblock.h
> index 47e3c06..180877c 100644
> --- a/include/linux/memblock.h
> +++ b/include/linux/memblock.h
> @@ -446,6 +446,7 @@ phys_addr_t memblock_start_of_DRAM(void);
>  phys_addr_t memblock_end_of_DRAM(void);
>  void memblock_enforce_memory_limit(phys_addr_t memory_limit);
>  void memblock_cap_memory_range(phys_addr_t base, phys_addr_t size);
> +void memblock_cap_memory_ranges(struct memblock_type *regions_to_keep);
>  void memblock_mem_limit_remove_map(phys_addr_t limit);
>  bool memblock_is_memory(phys_addr_t addr);
>  bool memblock_is_map_memory(phys_addr_t addr);
> diff --git a/mm/memblock.c b/mm/memblock.c
> index f315eca..9661807 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -1697,6 +1697,51 @@ void __init memblock_cap_memory_range(phys_addr_t 
> base, phys_addr_t size)
>   base + size, PHYS_ADDR_MAX);
>  }
>  
> +void __init memblock_cap_memory_ranges(struct memblock_type *regions_to_keep)
> +{
> + int start_rgn[INIT_MEMBLOCK_REGIONS], end_rgn[INIT_MEMBLOCK_REGIONS];
> + int i, j, ret, nr = 0;
> + struct memblock_region *regs = regions_to_keep->regions;
> +
> + for (i = 0; i < regions_to_keep->cnt; i++) {
> + ret = memblock_isolate_range(&memblock.memory, regs[i].base,
> + regs[i].size, &start_rgn[i], &end_rgn[i]);
> + if (ret)
> + break;
> + nr++;
> + }
> + if (!nr)
> + return;
> +
> + /* remove all the MAP regions */
> + for (i = memblock.memory.cnt - 1; i >= end_rgn[nr - 1]; i--)
> + if (!memblock_is_nomap(&memblock.memory.regions[i]))
> + memblock_remove_region(&memblock.memory, i);
> +
> + for (i = nr - 1; i > 0; i--)
> + for (j = start_rgn[i] - 1; j >= end_rgn[i - 1]; j--)
> + if (!memblock_is_nomap(&memblock.memory.regions[j]))
> + memblock_remove_region(&memblock.memory, j);
> +
> + for (i = start_rgn[0] - 1; i >= 0; i--)
> + if (!memblock_is_nomap(&memblock.memory.regions[i]))
> + memblock_remove_region(&memblock.memory, i);
> +
> + /* truncate the reserved regions */
> + memblock_remove_range(&memblock.reserved, 0, regs[0].base);
> +
> + for (i = nr - 1; i > 0; i--) {
> + phys_addr_t remove_base = regs[i - 1].base + regs[i - 1].size;
> + phys_addr_t remove_size = regs[i].base - remove_base;
> +
> + memblock_remove_range(&memblock.reserved, remove_base,
> + remove_size);
> + }
> +
> + memblock_remove_range(&memblock.reserved,
> + regs[nr - 1].base + regs[nr - 1].size, PHYS_ADDR_MAX);
> +}
> +

I've double-checked and I see no problem with using
for_each_mem_range_rev() iterators for removing some ranges. And with them
this functions becomes much clearer and more efficient.

Can you please check if the below patch works for you?

>From e25e6c9cd94a01abac124deacc66e5d258fdbf7c Mon Sep 17 00:00:00 2001
From: Mike Rapoport 
Date: Wed, 10 Apr 2019 16:02:32 +0300
Subject: [PATCH] memblock: extend memblock_cap_memory_range to multiple ranges

The memblock_cap_memory_range() removes all the memory except the range
passed to it. Extend this function to receive an array of memblock_regions
that should be kept. This allows switching to simple iteration over
memblock arrays with 'for_each_mem_range_rev' to remove the unneeded memory.

Enable use of this function in arm64 for reservation of multiple regions for
the crash kernel.

Signed-off-by: Mike Rapoport 
---
 arch/arm64/mm/init.c | 34 --
 include/linux/memblock.h |  2 +-
 mm/memblock.c| 44 
 3 files changed, 45 insertions(+), 35 deletions(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 6bc1350..8665d29 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -64,6 +64,10 @@ EXPORT_SYMBOL(memstart_addr);
 phys_addr_t arm64_dma_phys_limit __ro_after_init;
 
 #ifdef CONFIG_KEXEC_CORE
+
+/* at most two crash kernel regions, low_region and high_region */
+#define CRASH_MAX_USABLE_RANGES2
+
 /*
  * reserve_crashkernel() - reserves memory for crash kernel
  *
@@ -280,9 +284,9 

[PATCH v4 3/5] memblock: add memblock_cap_memory_ranges for multiple ranges

2019-04-15 Thread Chen Zhou
The memblock_cap_memory_range() removes all the memory except the
range passed to it. Extend this function to receive memblock_type
with the regions that should be kept.

Enable this function in arm64 for reservation of multiple regions
for the crash kernel.

Signed-off-by: Chen Zhou 
Signed-off-by: Mike Rapoport 
---
 include/linux/memblock.h |  1 +
 mm/memblock.c| 45 +
 2 files changed, 46 insertions(+)

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 47e3c06..180877c 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -446,6 +446,7 @@ phys_addr_t memblock_start_of_DRAM(void);
 phys_addr_t memblock_end_of_DRAM(void);
 void memblock_enforce_memory_limit(phys_addr_t memory_limit);
 void memblock_cap_memory_range(phys_addr_t base, phys_addr_t size);
+void memblock_cap_memory_ranges(struct memblock_type *regions_to_keep);
 void memblock_mem_limit_remove_map(phys_addr_t limit);
 bool memblock_is_memory(phys_addr_t addr);
 bool memblock_is_map_memory(phys_addr_t addr);
diff --git a/mm/memblock.c b/mm/memblock.c
index f315eca..9661807 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -1697,6 +1697,51 @@ void __init memblock_cap_memory_range(phys_addr_t base, 
phys_addr_t size)
base + size, PHYS_ADDR_MAX);
 }
 
+void __init memblock_cap_memory_ranges(struct memblock_type *regions_to_keep)
+{
+   int start_rgn[INIT_MEMBLOCK_REGIONS], end_rgn[INIT_MEMBLOCK_REGIONS];
+   int i, j, ret, nr = 0;
+   struct memblock_region *regs = regions_to_keep->regions;
+
+   for (i = 0; i < regions_to_keep->cnt; i++) {
+   ret = memblock_isolate_range(&memblock.memory, regs[i].base,
+   regs[i].size, &start_rgn[i], &end_rgn[i]);
+   if (ret)
+   break;
+   nr++;
+   }
+   if (!nr)
+   return;
+
+   /* remove all the MAP regions */
+   for (i = memblock.memory.cnt - 1; i >= end_rgn[nr - 1]; i--)
+   if (!memblock_is_nomap(&memblock.memory.regions[i]))
+   memblock_remove_region(&memblock.memory, i);
+
+   for (i = nr - 1; i > 0; i--)
+   for (j = start_rgn[i] - 1; j >= end_rgn[i - 1]; j--)
+   if (!memblock_is_nomap(&memblock.memory.regions[j]))
+   memblock_remove_region(&memblock.memory, j);
+
+   for (i = start_rgn[0] - 1; i >= 0; i--)
+   if (!memblock_is_nomap(&memblock.memory.regions[i]))
+   memblock_remove_region(&memblock.memory, i);
+
+   /* truncate the reserved regions */
+   memblock_remove_range(&memblock.reserved, 0, regs[0].base);
+
+   for (i = nr - 1; i > 0; i--) {
+   phys_addr_t remove_base = regs[i - 1].base + regs[i - 1].size;
+   phys_addr_t remove_size = regs[i].base - remove_base;
+
+   memblock_remove_range(&memblock.reserved, remove_base,
+   remove_size);
+   }
+
+   memblock_remove_range(&memblock.reserved,
+   regs[nr - 1].base + regs[nr - 1].size, PHYS_ADDR_MAX);
+}
+
 void __init memblock_mem_limit_remove_map(phys_addr_t limit)
 {
phys_addr_t max_addr;
-- 
2.7.4


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