linux/arch/x86/include/asm/amd_nb.h
Aravind Gopalakrishnan 1b4574292e x86/gart: Check for GART support before accessing GART registers
GART registers are not present in newer AMD processors (Fam15h, Model
10h and later). So, avoid accessing those in PCI config space by
returning early in early_gart_iommu_check() and gart_iommu_hole_init()
if GART is not available.

Current code doesn't break on existing processors but there are some
side effects:

We get bogus AGP aperture messages which are simply noise on
GART-less processors:

  AGP: Node 0: aperture [bus addr 0x00000000-0x01ffffff] (32MB)
  AGP: Your BIOS doesn't leave aperture memory hole
  AGP: Please enable the IOMMU option in the BIOS setup
  AGP: This costs you 64MB of RAM
  AGP: Mapping aperture over RAM [mem 0xd4000000-0xd7ffffff]

We can avoid calling allocate_aperture() and would not have to
wastefully reserve 64MB of RAM with memblock_reserve(). Also, we can
avoid having to loop through all PCI buses and devices twice, searching
for a non-existent AGP bridge if we bail out early.

Refactor the family check used in amd_nb.c into an inline function so we
can use it here as well as in amd_nb.c

Fix some typos while at it.

Tested the patch on Fam10h and Fam15h Model 00h-fh and this code runs
fine. On Fam15h Model 60h-6fh and on Fam16h, we bail early as they don't
have GART.

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Joerg Rodel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1428443197-3834-1-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-06 11:15:53 +02:00

122 lines
2.6 KiB
C

#ifndef _ASM_X86_AMD_NB_H
#define _ASM_X86_AMD_NB_H
#include <linux/ioport.h>
#include <linux/pci.h>
struct amd_nb_bus_dev_range {
u8 bus;
u8 dev_base;
u8 dev_limit;
};
extern const struct pci_device_id amd_nb_misc_ids[];
extern const struct amd_nb_bus_dev_range amd_nb_bus_dev_ranges[];
extern bool early_is_amd_nb(u32 value);
extern struct resource *amd_get_mmconfig_range(struct resource *res);
extern int amd_cache_northbridges(void);
extern void amd_flush_garts(void);
extern int amd_numa_init(void);
extern int amd_get_subcaches(int);
extern int amd_set_subcaches(int, unsigned long);
struct amd_l3_cache {
unsigned indices;
u8 subcaches[4];
};
struct threshold_block {
unsigned int block;
unsigned int bank;
unsigned int cpu;
u32 address;
u16 interrupt_enable;
bool interrupt_capable;
u16 threshold_limit;
struct kobject kobj;
struct list_head miscj;
};
struct threshold_bank {
struct kobject *kobj;
struct threshold_block *blocks;
/* initialized to the number of CPUs on the node sharing this bank */
atomic_t cpus;
};
struct amd_northbridge {
struct pci_dev *misc;
struct pci_dev *link;
struct amd_l3_cache l3_cache;
struct threshold_bank *bank4;
};
struct amd_northbridge_info {
u16 num;
u64 flags;
struct amd_northbridge *nb;
};
extern struct amd_northbridge_info amd_northbridges;
#define AMD_NB_GART BIT(0)
#define AMD_NB_L3_INDEX_DISABLE BIT(1)
#define AMD_NB_L3_PARTITIONING BIT(2)
#ifdef CONFIG_AMD_NB
static inline u16 amd_nb_num(void)
{
return amd_northbridges.num;
}
static inline bool amd_nb_has_feature(unsigned feature)
{
return ((amd_northbridges.flags & feature) == feature);
}
static inline struct amd_northbridge *node_to_amd_nb(int node)
{
return (node < amd_northbridges.num) ? &amd_northbridges.nb[node] : NULL;
}
static inline u16 amd_get_node_id(struct pci_dev *pdev)
{
struct pci_dev *misc;
int i;
for (i = 0; i != amd_nb_num(); i++) {
misc = node_to_amd_nb(i)->misc;
if (pci_domain_nr(misc->bus) == pci_domain_nr(pdev->bus) &&
PCI_SLOT(misc->devfn) == PCI_SLOT(pdev->devfn))
return i;
}
WARN(1, "Unable to find AMD Northbridge id for %s\n", pci_name(pdev));
return 0;
}
static inline bool amd_gart_present(void)
{
/* GART present only on Fam15h, upto model 0fh */
if (boot_cpu_data.x86 == 0xf || boot_cpu_data.x86 == 0x10 ||
(boot_cpu_data.x86 == 0x15 && boot_cpu_data.x86_model < 0x10))
return true;
return false;
}
#else
#define amd_nb_num(x) 0
#define amd_nb_has_feature(x) false
#define node_to_amd_nb(x) NULL
#define amd_gart_present(x) false
#endif
#endif /* _ASM_X86_AMD_NB_H */