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ANDROID: arm64/mm: Add command line option to make ZONE_DMA32 empty

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ZONE_DMA32 is enabled by default, yet it is not
needed for all devices, nor is it desirable to have if not needed. For
instance, if a partner in GKI 1.0 did not use ZONE_DMA32, memory can
be lower for ZONE_NORMAL relative to older targets, such that memory
would run out more quickly in ZONE_NORMAL leading kswapd to be invoked
unnecessarily.

Correspondingly, provide a means of making ZONE_DMA32 empty via the
kernel command line when it is compiled in via CONFIG_ZONE_DMA32.

P.S. The following two patches are squashed into this one,
1. bf96382 ("ANDROID: dma-direct: Make DMA32 disablement work for CONFIG_NUMA")
2. 135406c ("ANDROID: dma-direct: Document disable_dma32")

Additionally, for kernels 6.6+, ensure that arm64_dma_phys_limit
is set correctly by letting it be set to the highest possible
physical address when disable_dma32 is present on the kernel
command line.

This allows SWIOTLB allocations to be satisfied from anywhere within
the physical memory space, as opposed to restricting these
allocations to the lower 32-bit addressable physical memory space.
It is important that SWIOTLB allocations use the correct addressing
limits, as SWIOTLB buffers can now be allocated at runtime--not just
boot. Using the correct addressing limits can help increase the amount
of memory available for SWIOTLB allocations, increasing the likelihood
of success.

This also aligns the behavior of disable_dma32 to what would happen if
CONFIG_ZONE_DMA32 were disabled.

Bug: 199917449
Bug: 268587627
Bug: 296282294
Bug: 372371001
Change-Id: I70ec76914b92e518d61a61072f0b3cb41cb28646
Signed-off-by: Chris Goldsworthy <quic_cgoldswo@quicinc.com>
Signed-off-by: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com>
Signed-off-by: Chinwen Chang <chinwen.chang@mediatek.com>
[isaacmanjarres: Updated commit message to note that this
version of the patch treats arm64_phys_dma_limit differently
than the original version of the patch.]
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>
Signed-off-by: Chinwen Chang <chinwen.chang@mediatek.com>
This commit is contained in:
Chris Goldsworthy
2021-10-05 23:02:29 -07:00
committed by Suren Baghdasaryan
parent 1c7700028e
commit a1dfc257ae
6 changed files with 81 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files
Documentation/admin-guide/kernel-parameters.txt
+4
View File
@@ -1133,6 +1133,10 @@
can be useful when debugging issues that require an SLB
miss to occur.
disable_dma32= [KNL]
Dynamically disable ZONE_DMA32 on kernels compiled with
CONFIG_ZONE_DMA32=y.
disable= [IPV6]
See Documentation/networking/ipv6.rst.
arch/arm64/mm/init.c
+23 -3
View File
@@ -66,6 +66,12 @@ EXPORT_SYMBOL(memstart_addr);
*/
phys_addr_t __ro_after_init arm64_dma_phys_limit;
/*
* Provide a run-time mean of disabling ZONE_DMA32 if it is enabled via
* CONFIG_ZONE_DMA32.
*/
static bool disable_dma32 __ro_after_init;
/*
* To make optimal use of block mappings when laying out the linear
* mapping, round down the base of physical memory to a size that can
@@ -144,9 +150,11 @@ static void __init zone_sizes_init(void)
max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit);
#endif
#ifdef CONFIG_ZONE_DMA32
max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
if (!arm64_dma_phys_limit)
arm64_dma_phys_limit = dma32_phys_limit;
if (!disable_dma32) {
max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
if (!arm64_dma_phys_limit)
arm64_dma_phys_limit = dma32_phys_limit;
}
#endif
if (!arm64_dma_phys_limit)
arm64_dma_phys_limit = PHYS_MASK + 1;
@@ -155,6 +163,18 @@ static void __init zone_sizes_init(void)
free_area_init(max_zone_pfns);
}
static int __init early_disable_dma32(char *buf)
{
if (!buf)
return -EINVAL;
if (!strcmp(buf, "on"))
disable_dma32 = true;
return 0;
}
early_param("disable_dma32", early_disable_dma32);
int pfn_is_map_memory(unsigned long pfn)
{
phys_addr_t addr = PFN_PHYS(pfn);
arch/x86/mm/init.c
+19 -1
View File
@@ -113,6 +113,12 @@ static unsigned long min_pfn_mapped;
static bool __initdata can_use_brk_pgt = true;
/*
* Provide a run-time mean of disabling ZONE_DMA32 if it is enabled via
* CONFIG_ZONE_DMA32.
*/
static bool disable_dma32 __ro_after_init;
/*
* Pages returned are already directly mapped.
*
@@ -997,7 +1003,7 @@ void __init zone_sizes_init(void)
max_zone_pfns[ZONE_DMA] = min(MAX_DMA_PFN, max_low_pfn);
#endif
#ifdef CONFIG_ZONE_DMA32
max_zone_pfns[ZONE_DMA32] = min(MAX_DMA32_PFN, max_low_pfn);
max_zone_pfns[ZONE_DMA32] = disable_dma32 ? 0 : min(MAX_DMA32_PFN, max_low_pfn);
#endif
max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
#ifdef CONFIG_HIGHMEM
@@ -1007,6 +1013,18 @@ void __init zone_sizes_init(void)
free_area_init(max_zone_pfns);
}
static int __init early_disable_dma32(char *buf)
{
if (!buf)
return -EINVAL;
if (!strcmp(buf, "on"))
disable_dma32 = true;
return 0;
}
early_param("disable_dma32", early_disable_dma32);
__visible DEFINE_PER_CPU_ALIGNED(struct tlb_state, cpu_tlbstate) = {
.loaded_mm = &init_mm,
.next_asid = 1,
include/linux/dma-direct.h
+27
View File
@@ -23,6 +23,33 @@ struct bus_dma_region {
u64 size;
};
static inline bool zone_dma32_is_empty(int node)
{
#ifdef CONFIG_ZONE_DMA32
pg_data_t *pgdat = NODE_DATA(node);
return zone_is_empty(&pgdat->node_zones[ZONE_DMA32]);
#else
return true;
#endif
}
static inline bool zone_dma32_are_empty(void)
{
#ifdef CONFIG_NUMA
int node;
for_each_node(node)
if (!zone_dma32_is_empty(node))
return false;
#else
if (!zone_dma32_is_empty(numa_node_id()))
return false;
#endif
return true;
}
static inline dma_addr_t translate_phys_to_dma(struct device *dev,
phys_addr_t paddr)
{
kernel/dma/direct.c
+4 -2
View File
@@ -61,7 +61,8 @@ static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 *phys_limit)
*phys_limit = dma_to_phys(dev, dma_limit);
if (*phys_limit <= zone_dma_limit)
return GFP_DMA;
if (*phys_limit <= DMA_BIT_MASK(32))
if (*phys_limit <= DMA_BIT_MASK(32) &&
!zone_dma32_are_empty())
return GFP_DMA32;
return 0;
}
@@ -145,7 +146,8 @@ again:
if (IS_ENABLED(CONFIG_ZONE_DMA32) &&
phys_limit < DMA_BIT_MASK(64) &&
!(gfp & (GFP_DMA32 | GFP_DMA))) {
!(gfp & (GFP_DMA32 | GFP_DMA)) &&
!zone_dma32_are_empty()) {
gfp |= GFP_DMA32;
goto again;
}
kernel/dma/pool.c
+4 -4
View File
@@ -71,7 +71,7 @@ static bool cma_in_zone(gfp_t gfp)
end = cma_get_base(cma) + size - 1;
if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA))
return end <= zone_dma_limit;
if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32) && !zone_dma32_are_empty())
return end <= max(DMA_BIT_MASK(32), zone_dma_limit);
return true;
}
@@ -153,7 +153,7 @@ static void atomic_pool_work_fn(struct work_struct *work)
if (IS_ENABLED(CONFIG_ZONE_DMA))
atomic_pool_resize(atomic_pool_dma,
GFP_KERNEL | GFP_DMA);
if (IS_ENABLED(CONFIG_ZONE_DMA32))
if (IS_ENABLED(CONFIG_ZONE_DMA32) && !zone_dma32_are_empty())
atomic_pool_resize(atomic_pool_dma32,
GFP_KERNEL | GFP_DMA32);
atomic_pool_resize(atomic_pool_kernel, GFP_KERNEL);
@@ -209,7 +209,7 @@ static int __init dma_atomic_pool_init(void)
if (!atomic_pool_dma)
ret = -ENOMEM;
}
if (IS_ENABLED(CONFIG_ZONE_DMA32)) {
if (IS_ENABLED(CONFIG_ZONE_DMA32) && !zone_dma32_are_empty()) {
atomic_pool_dma32 = __dma_atomic_pool_init(atomic_pool_size,
GFP_KERNEL | GFP_DMA32);
if (!atomic_pool_dma32)
@@ -224,7 +224,7 @@ postcore_initcall(dma_atomic_pool_init);
static inline struct gen_pool *dma_guess_pool(struct gen_pool *prev, gfp_t gfp)
{
if (prev == NULL) {
if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32) && !zone_dma32_are_empty())
return atomic_pool_dma32;
if (atomic_pool_dma && (gfp & GFP_DMA))
return atomic_pool_dma;