Highmem was only supported on UML/i386. And the support has been
removed by commit a98a6d864d3b ("um: Remove broken highmem support").
Remove the leftovers and stop UML from trying to setup highmem when
the sum of physmem_size and iomem_size exceeds max_physmem.
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
---
arch/um/drivers/virtio_uml.c | 9 +--------
arch/um/include/shared/as-layout.h | 1 -
arch/um/include/shared/mem_user.h | 5 ++---
arch/um/kernel/mem.c | 3 ---
arch/um/kernel/physmem.c | 30 +++++++++++-------------------
arch/um/kernel/um_arch.c | 17 +++++++----------
6 files changed, 21 insertions(+), 44 deletions(-)
diff --git a/arch/um/drivers/virtio_uml.c b/arch/um/drivers/virtio_uml.c
index 2b6e701776b6..e7f5556e3c96 100644
--- a/arch/um/drivers/virtio_uml.c
+++ b/arch/um/drivers/virtio_uml.c
@@ -72,7 +72,7 @@ struct virtio_uml_vq_info {
bool suspended;
};
-extern unsigned long long physmem_size, highmem;
+extern unsigned long long physmem_size;
#define vu_err(vu_dev, ...) dev_err(&(vu_dev)->pdev->dev, ##__VA_ARGS__)
@@ -673,13 +673,6 @@ static int vhost_user_set_mem_table(struct virtio_uml_device *vu_dev)
if (rc < 0)
return rc;
- if (highmem) {
- msg.payload.mem_regions.num++;
- rc = vhost_user_init_mem_region(__pa(end_iomem), highmem,
- &fds[1], &msg.payload.mem_regions.regions[1]);
- if (rc < 0)
- return rc;
- }
return vhost_user_send(vu_dev, false, &msg, fds,
msg.payload.mem_regions.num);
diff --git a/arch/um/include/shared/as-layout.h b/arch/um/include/shared/as-layout.h
index 06292fca5a4d..61965a06c18a 100644
--- a/arch/um/include/shared/as-layout.h
+++ b/arch/um/include/shared/as-layout.h
@@ -41,7 +41,6 @@ extern unsigned long uml_physmem;
extern unsigned long uml_reserved;
extern unsigned long end_vm;
extern unsigned long start_vm;
-extern unsigned long long highmem;
extern unsigned long brk_start;
diff --git a/arch/um/include/shared/mem_user.h b/arch/um/include/shared/mem_user.h
index 11a723a58545..adfa08062f88 100644
--- a/arch/um/include/shared/mem_user.h
+++ b/arch/um/include/shared/mem_user.h
@@ -47,10 +47,9 @@ extern int iomem_size;
#define ROUND_4M(n) ((((unsigned long) (n)) + (1 << 22)) & ~((1 << 22) - 1))
extern unsigned long find_iomem(char *driver, unsigned long *len_out);
-extern void mem_total_pages(unsigned long physmem, unsigned long iomem,
- unsigned long highmem);
+extern void mem_total_pages(unsigned long physmem, unsigned long iomem);
extern void setup_physmem(unsigned long start, unsigned long usable,
- unsigned long len, unsigned long long highmem);
+ unsigned long len);
extern void map_memory(unsigned long virt, unsigned long phys,
unsigned long len, int r, int w, int x);
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index a5b4fe2ad931..5026668dc054 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -6,7 +6,6 @@
#include <linux/stddef.h>
#include <linux/module.h>
#include <linux/memblock.h>
-#include <linux/highmem.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/slab.h>
@@ -51,8 +50,6 @@ EXPORT_SYMBOL(empty_zero_page);
pgd_t swapper_pg_dir[PTRS_PER_PGD];
/* Initialized at boot time, and readonly after that */
-unsigned long long highmem;
-EXPORT_SYMBOL(highmem);
int kmalloc_ok = 0;
/* Used during early boot */
diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
index fb2adfb49945..cc5238c1bf1e 100644
--- a/arch/um/kernel/physmem.c
+++ b/arch/um/kernel/physmem.c
@@ -24,17 +24,14 @@ EXPORT_SYMBOL(high_physmem);
extern unsigned long long physmem_size;
-void __init mem_total_pages(unsigned long physmem, unsigned long iomem,
- unsigned long highmem)
+void __init mem_total_pages(unsigned long physmem, unsigned long iomem)
{
- unsigned long phys_pages, highmem_pages;
- unsigned long iomem_pages, total_pages;
+ unsigned long phys_pages, iomem_pages, total_pages;
- phys_pages = physmem >> PAGE_SHIFT;
- iomem_pages = iomem >> PAGE_SHIFT;
- highmem_pages = highmem >> PAGE_SHIFT;
+ phys_pages = physmem >> PAGE_SHIFT;
+ iomem_pages = iomem >> PAGE_SHIFT;
- total_pages = phys_pages + iomem_pages + highmem_pages;
+ total_pages = phys_pages + iomem_pages;
max_mapnr = total_pages;
}
@@ -64,13 +61,12 @@ void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
* @reserve_end: end address of the physical kernel memory.
* @len: Length of total physical memory that should be mapped/made
* available, in bytes.
- * @highmem: Number of highmem bytes that should be mapped/made available.
*
- * Creates an unlinked temporary file of size (len + highmem) and memory maps
+ * Creates an unlinked temporary file of size (len) and memory maps
* it on the last executable image address (uml_reserved).
*
* The offset is needed as the length of the total physical memory
- * (len + highmem) includes the size of the memory used be the executable image,
+ * (len) includes the size of the memory used be the executable image,
* but the mapped-to address is the last address of the executable image
* (uml_reserved == end address of executable image).
*
@@ -78,19 +74,19 @@ void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
* of all user space processes/kernel tasks.
*/
void __init setup_physmem(unsigned long start, unsigned long reserve_end,
- unsigned long len, unsigned long long highmem)
+ unsigned long len)
{
unsigned long reserve = reserve_end - start;
long map_size = len - reserve;
int err;
- if(map_size <= 0) {
+ if (map_size <= 0) {
os_warn("Too few physical memory! Needed=%lu, given=%lu\n",
reserve, len);
exit(1);
}
- physmem_fd = create_mem_file(len + highmem);
+ physmem_fd = create_mem_file(len);
err = os_map_memory((void *) reserve_end, physmem_fd, reserve,
map_size, 1, 1, 1);
@@ -109,7 +105,7 @@ void __init setup_physmem(unsigned long start, unsigned long reserve_end,
os_write_file(physmem_fd, __syscall_stub_start, PAGE_SIZE);
os_fsync_file(physmem_fd);
- memblock_add(__pa(start), len + highmem);
+ memblock_add(__pa(start), len);
memblock_reserve(__pa(start), reserve);
min_low_pfn = PFN_UP(__pa(reserve_end));
@@ -137,10 +133,6 @@ int phys_mapping(unsigned long phys, unsigned long long *offset_out)
region = region->next;
}
}
- else if (phys < __pa(end_iomem) + highmem) {
- fd = physmem_fd;
- *offset_out = phys - iomem_size;
- }
return fd;
}
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 8e594cda6d77..8f86aa468b50 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -366,18 +366,15 @@ int __init linux_main(int argc, char **argv)
setup_machinename(init_utsname()->machine);
- highmem = 0;
+ physmem_size = (physmem_size + PAGE_SIZE - 1) & PAGE_MASK;
iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
+
max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC;
- /*
- * Zones have to begin on a 1 << MAX_PAGE_ORDER page boundary,
- * so this makes sure that's true for highmem
- */
- max_physmem &= ~((1 << (PAGE_SHIFT + MAX_PAGE_ORDER)) - 1);
if (physmem_size + iomem_size > max_physmem) {
- highmem = physmem_size + iomem_size - max_physmem;
- physmem_size -= highmem;
+ physmem_size = max_physmem - iomem_size;
+ os_info("Physical memory size shrunk to %llu bytes\n",
+ physmem_size);
}
high_physmem = uml_physmem + physmem_size;
@@ -413,8 +410,8 @@ void __init setup_arch(char **cmdline_p)
u8 rng_seed[32];
stack_protections((unsigned long) &init_thread_info);
- setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
- mem_total_pages(physmem_size, iomem_size, highmem);
+ setup_physmem(uml_physmem, uml_reserved, physmem_size);
+ mem_total_pages(physmem_size, iomem_size);
uml_dtb_init();
read_initrd();
--
2.34.1Hi,
does that mean we can also drop the 3-level page table support on i386?
It seems like the two level page table is entirely sufficient on a
system without high memory (i.e. only 32bit physical addresses).
When I took a look at it for the 4-level page table support on 64 bit I
got a bit confused. But I had not realized that highmem support had
been removed.
Benjamin
On Fri, 2024-09-13 at 22:21 +0800, Tiwei Bie wrote:
> Highmem was only supported on UML/i386. And the support has been
> removed by commit a98a6d864d3b ("um: Remove broken highmem support").
> Remove the leftovers and stop UML from trying to setup highmem when
> the sum of physmem_size and iomem_size exceeds max_physmem.
>
> Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
> ---
> arch/um/drivers/virtio_uml.c | 9 +--------
> arch/um/include/shared/as-layout.h | 1 -
> arch/um/include/shared/mem_user.h | 5 ++---
> arch/um/kernel/mem.c | 3 ---
> arch/um/kernel/physmem.c | 30 +++++++++++-----------------
> --
> arch/um/kernel/um_arch.c | 17 +++++++----------
> 6 files changed, 21 insertions(+), 44 deletions(-)
>
> diff --git a/arch/um/drivers/virtio_uml.c
> b/arch/um/drivers/virtio_uml.c
> index 2b6e701776b6..e7f5556e3c96 100644
> --- a/arch/um/drivers/virtio_uml.c
> +++ b/arch/um/drivers/virtio_uml.c
> @@ -72,7 +72,7 @@ struct virtio_uml_vq_info {
> bool suspended;
> };
>
> -extern unsigned long long physmem_size, highmem;
> +extern unsigned long long physmem_size;
>
> #define vu_err(vu_dev, ...) dev_err(&(vu_dev)->pdev->dev,
> ##__VA_ARGS__)
>
> @@ -673,13 +673,6 @@ static int vhost_user_set_mem_table(struct
> virtio_uml_device *vu_dev)
>
> if (rc < 0)
> return rc;
> - if (highmem) {
> - msg.payload.mem_regions.num++;
> - rc = vhost_user_init_mem_region(__pa(end_iomem),
> highmem,
> - &fds[1],
> &msg.payload.mem_regions.regions[1]);
> - if (rc < 0)
> - return rc;
> - }
>
> return vhost_user_send(vu_dev, false, &msg, fds,
> msg.payload.mem_regions.num);
> diff --git a/arch/um/include/shared/as-layout.h
> b/arch/um/include/shared/as-layout.h
> index 06292fca5a4d..61965a06c18a 100644
> --- a/arch/um/include/shared/as-layout.h
> +++ b/arch/um/include/shared/as-layout.h
> @@ -41,7 +41,6 @@ extern unsigned long uml_physmem;
> extern unsigned long uml_reserved;
> extern unsigned long end_vm;
> extern unsigned long start_vm;
> -extern unsigned long long highmem;
>
> extern unsigned long brk_start;
>
> diff --git a/arch/um/include/shared/mem_user.h
> b/arch/um/include/shared/mem_user.h
> index 11a723a58545..adfa08062f88 100644
> --- a/arch/um/include/shared/mem_user.h
> +++ b/arch/um/include/shared/mem_user.h
> @@ -47,10 +47,9 @@ extern int iomem_size;
> #define ROUND_4M(n) ((((unsigned long) (n)) + (1 << 22)) & ~((1 <<
> 22) - 1))
>
> extern unsigned long find_iomem(char *driver, unsigned long
> *len_out);
> -extern void mem_total_pages(unsigned long physmem, unsigned long
> iomem,
> - unsigned long highmem);
> +extern void mem_total_pages(unsigned long physmem, unsigned long
> iomem);
> extern void setup_physmem(unsigned long start, unsigned long usable,
> - unsigned long len, unsigned long long
> highmem);
> + unsigned long len);
> extern void map_memory(unsigned long virt, unsigned long phys,
> unsigned long len, int r, int w, int x);
>
> diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
> index a5b4fe2ad931..5026668dc054 100644
> --- a/arch/um/kernel/mem.c
> +++ b/arch/um/kernel/mem.c
> @@ -6,7 +6,6 @@
> #include <linux/stddef.h>
> #include <linux/module.h>
> #include <linux/memblock.h>
> -#include <linux/highmem.h>
> #include <linux/mm.h>
> #include <linux/swap.h>
> #include <linux/slab.h>
> @@ -51,8 +50,6 @@ EXPORT_SYMBOL(empty_zero_page);
> pgd_t swapper_pg_dir[PTRS_PER_PGD];
>
> /* Initialized at boot time, and readonly after that */
> -unsigned long long highmem;
> -EXPORT_SYMBOL(highmem);
> int kmalloc_ok = 0;
>
> /* Used during early boot */
> diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
> index fb2adfb49945..cc5238c1bf1e 100644
> --- a/arch/um/kernel/physmem.c
> +++ b/arch/um/kernel/physmem.c
> @@ -24,17 +24,14 @@ EXPORT_SYMBOL(high_physmem);
>
> extern unsigned long long physmem_size;
>
> -void __init mem_total_pages(unsigned long physmem, unsigned long
> iomem,
> - unsigned long highmem)
> +void __init mem_total_pages(unsigned long physmem, unsigned long
> iomem)
> {
> - unsigned long phys_pages, highmem_pages;
> - unsigned long iomem_pages, total_pages;
> + unsigned long phys_pages, iomem_pages, total_pages;
>
> - phys_pages = physmem >> PAGE_SHIFT;
> - iomem_pages = iomem >> PAGE_SHIFT;
> - highmem_pages = highmem >> PAGE_SHIFT;
> + phys_pages = physmem >> PAGE_SHIFT;
> + iomem_pages = iomem >> PAGE_SHIFT;
>
> - total_pages = phys_pages + iomem_pages + highmem_pages;
> + total_pages = phys_pages + iomem_pages;
>
> max_mapnr = total_pages;
> }
> @@ -64,13 +61,12 @@ void map_memory(unsigned long virt, unsigned long
> phys, unsigned long len,
> * @reserve_end: end address of the physical kernel memory.
> * @len: Length of total physical memory that should be
> mapped/made
> * available, in bytes.
> - * @highmem: Number of highmem bytes that should be mapped/made
> available.
> *
> - * Creates an unlinked temporary file of size (len + highmem) and
> memory maps
> + * Creates an unlinked temporary file of size (len) and memory maps
> * it on the last executable image address (uml_reserved).
> *
> * The offset is needed as the length of the total physical memory
> - * (len + highmem) includes the size of the memory used be the
> executable image,
> + * (len) includes the size of the memory used be the executable
> image,
> * but the mapped-to address is the last address of the executable
> image
> * (uml_reserved == end address of executable image).
> *
> @@ -78,19 +74,19 @@ void map_memory(unsigned long virt, unsigned long
> phys, unsigned long len,
> * of all user space processes/kernel tasks.
> */
> void __init setup_physmem(unsigned long start, unsigned long
> reserve_end,
> - unsigned long len, unsigned long long
> highmem)
> + unsigned long len)
> {
> unsigned long reserve = reserve_end - start;
> long map_size = len - reserve;
> int err;
>
> - if(map_size <= 0) {
> + if (map_size <= 0) {
> os_warn("Too few physical memory! Needed=%lu,
> given=%lu\n",
> reserve, len);
> exit(1);
> }
>
> - physmem_fd = create_mem_file(len + highmem);
> + physmem_fd = create_mem_file(len);
>
> err = os_map_memory((void *) reserve_end, physmem_fd,
> reserve,
> map_size, 1, 1, 1);
> @@ -109,7 +105,7 @@ void __init setup_physmem(unsigned long start,
> unsigned long reserve_end,
> os_write_file(physmem_fd, __syscall_stub_start, PAGE_SIZE);
> os_fsync_file(physmem_fd);
>
> - memblock_add(__pa(start), len + highmem);
> + memblock_add(__pa(start), len);
> memblock_reserve(__pa(start), reserve);
>
> min_low_pfn = PFN_UP(__pa(reserve_end));
> @@ -137,10 +133,6 @@ int phys_mapping(unsigned long phys, unsigned
> long long *offset_out)
> region = region->next;
> }
> }
> - else if (phys < __pa(end_iomem) + highmem) {
> - fd = physmem_fd;
> - *offset_out = phys - iomem_size;
> - }
>
> return fd;
> }
> diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
> index 8e594cda6d77..8f86aa468b50 100644
> --- a/arch/um/kernel/um_arch.c
> +++ b/arch/um/kernel/um_arch.c
> @@ -366,18 +366,15 @@ int __init linux_main(int argc, char **argv)
>
> setup_machinename(init_utsname()->machine);
>
> - highmem = 0;
> + physmem_size = (physmem_size + PAGE_SIZE - 1) & PAGE_MASK;
> iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
> +
> max_physmem = TASK_SIZE - uml_physmem - iomem_size -
> MIN_VMALLOC;
>
> - /*
> - * Zones have to begin on a 1 << MAX_PAGE_ORDER page
> boundary,
> - * so this makes sure that's true for highmem
> - */
> - max_physmem &= ~((1 << (PAGE_SHIFT + MAX_PAGE_ORDER)) - 1);
> if (physmem_size + iomem_size > max_physmem) {
> - highmem = physmem_size + iomem_size - max_physmem;
> - physmem_size -= highmem;
> + physmem_size = max_physmem - iomem_size;
> + os_info("Physical memory size shrunk to %llu
> bytes\n",
> + physmem_size);
> }
>
> high_physmem = uml_physmem + physmem_size;
> @@ -413,8 +410,8 @@ void __init setup_arch(char **cmdline_p)
> u8 rng_seed[32];
>
> stack_protections((unsigned long) &init_thread_info);
> - setup_physmem(uml_physmem, uml_reserved, physmem_size,
> highmem);
> - mem_total_pages(physmem_size, iomem_size, highmem);
> + setup_physmem(uml_physmem, uml_reserved, physmem_size);
> + mem_total_pages(physmem_size, iomem_size);
> uml_dtb_init();
> read_initrd();
>
On 2024/9/16 00:55, Benjamin Berg wrote:
> Hi,
>
> does that mean we can also drop the 3-level page table support on i386?
> It seems like the two level page table is entirely sufficient on a
> system without high memory (i.e. only 32bit physical addresses).
Good point. I think so too.
Regards,
Tiwei
>
> When I took a look at it for the 4-level page table support on 64 bit I
> got a bit confused. But I had not realized that highmem support had
> been removed.
>
> Benjamin
>
> On Fri, 2024-09-13 at 22:21 +0800, Tiwei Bie wrote:
>> Highmem was only supported on UML/i386. And the support has been
>> removed by commit a98a6d864d3b ("um: Remove broken highmem support").
>> Remove the leftovers and stop UML from trying to setup highmem when
>> the sum of physmem_size and iomem_size exceeds max_physmem.
>>
>> Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
>> ---
>> arch/um/drivers/virtio_uml.c | 9 +--------
>> arch/um/include/shared/as-layout.h | 1 -
>> arch/um/include/shared/mem_user.h | 5 ++---
>> arch/um/kernel/mem.c | 3 ---
>> arch/um/kernel/physmem.c | 30 +++++++++++-----------------
>> --
>> arch/um/kernel/um_arch.c | 17 +++++++----------
>> 6 files changed, 21 insertions(+), 44 deletions(-)
>>
>> diff --git a/arch/um/drivers/virtio_uml.c
>> b/arch/um/drivers/virtio_uml.c
>> index 2b6e701776b6..e7f5556e3c96 100644
>> --- a/arch/um/drivers/virtio_uml.c
>> +++ b/arch/um/drivers/virtio_uml.c
>> @@ -72,7 +72,7 @@ struct virtio_uml_vq_info {
>> bool suspended;
>> };
>>
>> -extern unsigned long long physmem_size, highmem;
>> +extern unsigned long long physmem_size;
>>
>> #define vu_err(vu_dev, ...) dev_err(&(vu_dev)->pdev->dev,
>> ##__VA_ARGS__)
>>
>> @@ -673,13 +673,6 @@ static int vhost_user_set_mem_table(struct
>> virtio_uml_device *vu_dev)
>>
>> if (rc < 0)
>> return rc;
>> - if (highmem) {
>> - msg.payload.mem_regions.num++;
>> - rc = vhost_user_init_mem_region(__pa(end_iomem),
>> highmem,
>> - &fds[1],
>> &msg.payload.mem_regions.regions[1]);
>> - if (rc < 0)
>> - return rc;
>> - }
>>
>> return vhost_user_send(vu_dev, false, &msg, fds,
>> msg.payload.mem_regions.num);
>> diff --git a/arch/um/include/shared/as-layout.h
>> b/arch/um/include/shared/as-layout.h
>> index 06292fca5a4d..61965a06c18a 100644
>> --- a/arch/um/include/shared/as-layout.h
>> +++ b/arch/um/include/shared/as-layout.h
>> @@ -41,7 +41,6 @@ extern unsigned long uml_physmem;
>> extern unsigned long uml_reserved;
>> extern unsigned long end_vm;
>> extern unsigned long start_vm;
>> -extern unsigned long long highmem;
>>
>> extern unsigned long brk_start;
>>
>> diff --git a/arch/um/include/shared/mem_user.h
>> b/arch/um/include/shared/mem_user.h
>> index 11a723a58545..adfa08062f88 100644
>> --- a/arch/um/include/shared/mem_user.h
>> +++ b/arch/um/include/shared/mem_user.h
>> @@ -47,10 +47,9 @@ extern int iomem_size;
>> #define ROUND_4M(n) ((((unsigned long) (n)) + (1 << 22)) & ~((1 <<
>> 22) - 1))
>>
>> extern unsigned long find_iomem(char *driver, unsigned long
>> *len_out);
>> -extern void mem_total_pages(unsigned long physmem, unsigned long
>> iomem,
>> - unsigned long highmem);
>> +extern void mem_total_pages(unsigned long physmem, unsigned long
>> iomem);
>> extern void setup_physmem(unsigned long start, unsigned long usable,
>> - unsigned long len, unsigned long long
>> highmem);
>> + unsigned long len);
>> extern void map_memory(unsigned long virt, unsigned long phys,
>> unsigned long len, int r, int w, int x);
>>
>> diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
>> index a5b4fe2ad931..5026668dc054 100644
>> --- a/arch/um/kernel/mem.c
>> +++ b/arch/um/kernel/mem.c
>> @@ -6,7 +6,6 @@
>> #include <linux/stddef.h>
>> #include <linux/module.h>
>> #include <linux/memblock.h>
>> -#include <linux/highmem.h>
>> #include <linux/mm.h>
>> #include <linux/swap.h>
>> #include <linux/slab.h>
>> @@ -51,8 +50,6 @@ EXPORT_SYMBOL(empty_zero_page);
>> pgd_t swapper_pg_dir[PTRS_PER_PGD];
>>
>> /* Initialized at boot time, and readonly after that */
>> -unsigned long long highmem;
>> -EXPORT_SYMBOL(highmem);
>> int kmalloc_ok = 0;
>>
>> /* Used during early boot */
>> diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
>> index fb2adfb49945..cc5238c1bf1e 100644
>> --- a/arch/um/kernel/physmem.c
>> +++ b/arch/um/kernel/physmem.c
>> @@ -24,17 +24,14 @@ EXPORT_SYMBOL(high_physmem);
>>
>> extern unsigned long long physmem_size;
>>
>> -void __init mem_total_pages(unsigned long physmem, unsigned long
>> iomem,
>> - unsigned long highmem)
>> +void __init mem_total_pages(unsigned long physmem, unsigned long
>> iomem)
>> {
>> - unsigned long phys_pages, highmem_pages;
>> - unsigned long iomem_pages, total_pages;
>> + unsigned long phys_pages, iomem_pages, total_pages;
>>
>> - phys_pages = physmem >> PAGE_SHIFT;
>> - iomem_pages = iomem >> PAGE_SHIFT;
>> - highmem_pages = highmem >> PAGE_SHIFT;
>> + phys_pages = physmem >> PAGE_SHIFT;
>> + iomem_pages = iomem >> PAGE_SHIFT;
>>
>> - total_pages = phys_pages + iomem_pages + highmem_pages;
>> + total_pages = phys_pages + iomem_pages;
>>
>> max_mapnr = total_pages;
>> }
>> @@ -64,13 +61,12 @@ void map_memory(unsigned long virt, unsigned long
>> phys, unsigned long len,
>> * @reserve_end: end address of the physical kernel memory.
>> * @len: Length of total physical memory that should be
>> mapped/made
>> * available, in bytes.
>> - * @highmem: Number of highmem bytes that should be mapped/made
>> available.
>> *
>> - * Creates an unlinked temporary file of size (len + highmem) and
>> memory maps
>> + * Creates an unlinked temporary file of size (len) and memory maps
>> * it on the last executable image address (uml_reserved).
>> *
>> * The offset is needed as the length of the total physical memory
>> - * (len + highmem) includes the size of the memory used be the
>> executable image,
>> + * (len) includes the size of the memory used be the executable
>> image,
>> * but the mapped-to address is the last address of the executable
>> image
>> * (uml_reserved == end address of executable image).
>> *
>> @@ -78,19 +74,19 @@ void map_memory(unsigned long virt, unsigned long
>> phys, unsigned long len,
>> * of all user space processes/kernel tasks.
>> */
>> void __init setup_physmem(unsigned long start, unsigned long
>> reserve_end,
>> - unsigned long len, unsigned long long
>> highmem)
>> + unsigned long len)
>> {
>> unsigned long reserve = reserve_end - start;
>> long map_size = len - reserve;
>> int err;
>>
>> - if(map_size <= 0) {
>> + if (map_size <= 0) {
>> os_warn("Too few physical memory! Needed=%lu,
>> given=%lu\n",
>> reserve, len);
>> exit(1);
>> }
>>
>> - physmem_fd = create_mem_file(len + highmem);
>> + physmem_fd = create_mem_file(len);
>>
>> err = os_map_memory((void *) reserve_end, physmem_fd,
>> reserve,
>> map_size, 1, 1, 1);
>> @@ -109,7 +105,7 @@ void __init setup_physmem(unsigned long start,
>> unsigned long reserve_end,
>> os_write_file(physmem_fd, __syscall_stub_start, PAGE_SIZE);
>> os_fsync_file(physmem_fd);
>>
>> - memblock_add(__pa(start), len + highmem);
>> + memblock_add(__pa(start), len);
>> memblock_reserve(__pa(start), reserve);
>>
>> min_low_pfn = PFN_UP(__pa(reserve_end));
>> @@ -137,10 +133,6 @@ int phys_mapping(unsigned long phys, unsigned
>> long long *offset_out)
>> region = region->next;
>> }
>> }
>> - else if (phys < __pa(end_iomem) + highmem) {
>> - fd = physmem_fd;
>> - *offset_out = phys - iomem_size;
>> - }
>>
>> return fd;
>> }
>> diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
>> index 8e594cda6d77..8f86aa468b50 100644
>> --- a/arch/um/kernel/um_arch.c
>> +++ b/arch/um/kernel/um_arch.c
>> @@ -366,18 +366,15 @@ int __init linux_main(int argc, char **argv)
>>
>> setup_machinename(init_utsname()->machine);
>>
>> - highmem = 0;
>> + physmem_size = (physmem_size + PAGE_SIZE - 1) & PAGE_MASK;
>> iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
>> +
>> max_physmem = TASK_SIZE - uml_physmem - iomem_size -
>> MIN_VMALLOC;
>>
>> - /*
>> - * Zones have to begin on a 1 << MAX_PAGE_ORDER page
>> boundary,
>> - * so this makes sure that's true for highmem
>> - */
>> - max_physmem &= ~((1 << (PAGE_SHIFT + MAX_PAGE_ORDER)) - 1);
>> if (physmem_size + iomem_size > max_physmem) {
>> - highmem = physmem_size + iomem_size - max_physmem;
>> - physmem_size -= highmem;
>> + physmem_size = max_physmem - iomem_size;
>> + os_info("Physical memory size shrunk to %llu
>> bytes\n",
>> + physmem_size);
>> }
>>
>> high_physmem = uml_physmem + physmem_size;
>> @@ -413,8 +410,8 @@ void __init setup_arch(char **cmdline_p)
>> u8 rng_seed[32];
>>
>> stack_protections((unsigned long) &init_thread_info);
>> - setup_physmem(uml_physmem, uml_reserved, physmem_size,
>> highmem);
>> - mem_total_pages(physmem_size, iomem_size, highmem);
>> + setup_physmem(uml_physmem, uml_reserved, physmem_size);
>> + mem_total_pages(physmem_size, iomem_size);
>> uml_dtb_init();
>> read_initrd();
>>
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