kernel_optimize_test/include/linux/iova.h
Tomasz Nowicki 538d5b3332 iommu/iova: Make rcache flush optional on IOVA allocation failure
Since IOVA allocation failure is not unusual case we need to flush
CPUs' rcache in hope we will succeed in next round.

However, it is useful to decide whether we need rcache flush step because
of two reasons:
- Not scalability. On large system with ~100 CPUs iterating and flushing
  rcache for each CPU becomes serious bottleneck so we may want to defer it.
- free_cpu_cached_iovas() does not care about max PFN we are interested in.
  Thus we may flush our rcaches and still get no new IOVA like in the
  commonly used scenario:

    if (dma_limit > DMA_BIT_MASK(32) && dev_is_pci(dev))
        iova = alloc_iova_fast(iovad, iova_len, DMA_BIT_MASK(32) >> shift);

    if (!iova)
        iova = alloc_iova_fast(iovad, iova_len, dma_limit >> shift);

   1. First alloc_iova_fast() call is limited to DMA_BIT_MASK(32) to get
      PCI devices a SAC address
   2. alloc_iova() fails due to full 32-bit space
   3. rcaches contain PFNs out of 32-bit space so free_cpu_cached_iovas()
      throws entries away for nothing and alloc_iova() fails again
   4. Next alloc_iova_fast() call cannot take advantage of rcache since we
      have just defeated caches. In this case we pick the slowest option
      to proceed.

This patch reworks flushed_rcache local flag to be additional function
argument instead and control rcache flush step. Also, it updates all users
to do the flush as the last chance.

Signed-off-by: Tomasz Nowicki <Tomasz.Nowicki@caviumnetworks.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Nate Watterson <nwatters@codeaurora.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-10-12 14:18:02 +02:00

271 lines
6.9 KiB
C

/*
* Copyright (c) 2006, Intel Corporation.
*
* This file is released under the GPLv2.
*
* Copyright (C) 2006-2008 Intel Corporation
* Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
*
*/
#ifndef _IOVA_H_
#define _IOVA_H_
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/rbtree.h>
#include <linux/atomic.h>
#include <linux/dma-mapping.h>
/* iova structure */
struct iova {
struct rb_node node;
unsigned long pfn_hi; /* Highest allocated pfn */
unsigned long pfn_lo; /* Lowest allocated pfn */
};
struct iova_magazine;
struct iova_cpu_rcache;
#define IOVA_RANGE_CACHE_MAX_SIZE 6 /* log of max cached IOVA range size (in pages) */
#define MAX_GLOBAL_MAGS 32 /* magazines per bin */
struct iova_rcache {
spinlock_t lock;
unsigned long depot_size;
struct iova_magazine *depot[MAX_GLOBAL_MAGS];
struct iova_cpu_rcache __percpu *cpu_rcaches;
};
struct iova_domain;
/* Call-Back from IOVA code into IOMMU drivers */
typedef void (* iova_flush_cb)(struct iova_domain *domain);
/* Destructor for per-entry data */
typedef void (* iova_entry_dtor)(unsigned long data);
/* Number of entries per Flush Queue */
#define IOVA_FQ_SIZE 256
/* Timeout (in ms) after which entries are flushed from the Flush-Queue */
#define IOVA_FQ_TIMEOUT 10
/* Flush Queue entry for defered flushing */
struct iova_fq_entry {
unsigned long iova_pfn;
unsigned long pages;
unsigned long data;
u64 counter; /* Flush counter when this entrie was added */
};
/* Per-CPU Flush Queue structure */
struct iova_fq {
struct iova_fq_entry entries[IOVA_FQ_SIZE];
unsigned head, tail;
spinlock_t lock;
};
/* holds all the iova translations for a domain */
struct iova_domain {
spinlock_t iova_rbtree_lock; /* Lock to protect update of rbtree */
struct rb_root rbroot; /* iova domain rbtree root */
struct rb_node *cached_node; /* Save last alloced node */
struct rb_node *cached32_node; /* Save last 32-bit alloced node */
unsigned long granule; /* pfn granularity for this domain */
unsigned long start_pfn; /* Lower limit for this domain */
unsigned long dma_32bit_pfn;
struct iova anchor; /* rbtree lookup anchor */
struct iova_rcache rcaches[IOVA_RANGE_CACHE_MAX_SIZE]; /* IOVA range caches */
iova_flush_cb flush_cb; /* Call-Back function to flush IOMMU
TLBs */
iova_entry_dtor entry_dtor; /* IOMMU driver specific destructor for
iova entry */
struct iova_fq __percpu *fq; /* Flush Queue */
atomic64_t fq_flush_start_cnt; /* Number of TLB flushes that
have been started */
atomic64_t fq_flush_finish_cnt; /* Number of TLB flushes that
have been finished */
struct timer_list fq_timer; /* Timer to regularily empty the
flush-queues */
atomic_t fq_timer_on; /* 1 when timer is active, 0
when not */
};
static inline unsigned long iova_size(struct iova *iova)
{
return iova->pfn_hi - iova->pfn_lo + 1;
}
static inline unsigned long iova_shift(struct iova_domain *iovad)
{
return __ffs(iovad->granule);
}
static inline unsigned long iova_mask(struct iova_domain *iovad)
{
return iovad->granule - 1;
}
static inline size_t iova_offset(struct iova_domain *iovad, dma_addr_t iova)
{
return iova & iova_mask(iovad);
}
static inline size_t iova_align(struct iova_domain *iovad, size_t size)
{
return ALIGN(size, iovad->granule);
}
static inline dma_addr_t iova_dma_addr(struct iova_domain *iovad, struct iova *iova)
{
return (dma_addr_t)iova->pfn_lo << iova_shift(iovad);
}
static inline unsigned long iova_pfn(struct iova_domain *iovad, dma_addr_t iova)
{
return iova >> iova_shift(iovad);
}
#if IS_ENABLED(CONFIG_IOMMU_IOVA)
int iova_cache_get(void);
void iova_cache_put(void);
struct iova *alloc_iova_mem(void);
void free_iova_mem(struct iova *iova);
void free_iova(struct iova_domain *iovad, unsigned long pfn);
void __free_iova(struct iova_domain *iovad, struct iova *iova);
struct iova *alloc_iova(struct iova_domain *iovad, unsigned long size,
unsigned long limit_pfn,
bool size_aligned);
void free_iova_fast(struct iova_domain *iovad, unsigned long pfn,
unsigned long size);
void queue_iova(struct iova_domain *iovad,
unsigned long pfn, unsigned long pages,
unsigned long data);
unsigned long alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
unsigned long limit_pfn, bool flush_rcache);
struct iova *reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo,
unsigned long pfn_hi);
void copy_reserved_iova(struct iova_domain *from, struct iova_domain *to);
void init_iova_domain(struct iova_domain *iovad, unsigned long granule,
unsigned long start_pfn);
int init_iova_flush_queue(struct iova_domain *iovad,
iova_flush_cb flush_cb, iova_entry_dtor entry_dtor);
struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn);
void put_iova_domain(struct iova_domain *iovad);
struct iova *split_and_remove_iova(struct iova_domain *iovad,
struct iova *iova, unsigned long pfn_lo, unsigned long pfn_hi);
void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad);
#else
static inline int iova_cache_get(void)
{
return -ENOTSUPP;
}
static inline void iova_cache_put(void)
{
}
static inline struct iova *alloc_iova_mem(void)
{
return NULL;
}
static inline void free_iova_mem(struct iova *iova)
{
}
static inline void free_iova(struct iova_domain *iovad, unsigned long pfn)
{
}
static inline void __free_iova(struct iova_domain *iovad, struct iova *iova)
{
}
static inline struct iova *alloc_iova(struct iova_domain *iovad,
unsigned long size,
unsigned long limit_pfn,
bool size_aligned)
{
return NULL;
}
static inline void free_iova_fast(struct iova_domain *iovad,
unsigned long pfn,
unsigned long size)
{
}
static inline void queue_iova(struct iova_domain *iovad,
unsigned long pfn, unsigned long pages,
unsigned long data)
{
}
static inline unsigned long alloc_iova_fast(struct iova_domain *iovad,
unsigned long size,
unsigned long limit_pfn,
bool flush_rcache)
{
return 0;
}
static inline struct iova *reserve_iova(struct iova_domain *iovad,
unsigned long pfn_lo,
unsigned long pfn_hi)
{
return NULL;
}
static inline void copy_reserved_iova(struct iova_domain *from,
struct iova_domain *to)
{
}
static inline void init_iova_domain(struct iova_domain *iovad,
unsigned long granule,
unsigned long start_pfn)
{
}
static inline int init_iova_flush_queue(struct iova_domain *iovad,
iova_flush_cb flush_cb,
iova_entry_dtor entry_dtor)
{
return -ENODEV;
}
static inline struct iova *find_iova(struct iova_domain *iovad,
unsigned long pfn)
{
return NULL;
}
static inline void put_iova_domain(struct iova_domain *iovad)
{
}
static inline struct iova *split_and_remove_iova(struct iova_domain *iovad,
struct iova *iova,
unsigned long pfn_lo,
unsigned long pfn_hi)
{
return NULL;
}
static inline void free_cpu_cached_iovas(unsigned int cpu,
struct iova_domain *iovad)
{
}
#endif
#endif