F: drivers/acpi/
F: drivers/pnp/pnpacpi/
F: include/linux/acpi.h
+F: include/linux/fwnode.h
F: include/acpi/
F: Documentation/acpi/
F: Documentation/ABI/testing/sysfs-bus-acpi
F: drivers/pci/*/*/*acpi*
F: tools/power/acpi/
+ACPI APEI
+F: drivers/acpi/apei/
+
ACPI COMPONENT ARCHITECTURE (ACPICA)
F: arch/arm/mach-artpec
F: arch/arm/boot/dts/artpec6*
F: drivers/clk/axis
+F: drivers/crypto/axis
F: drivers/pinctrl/pinctrl-artpec*
F: Documentation/devicetree/bindings/pinctrl/axis,artpec6-pinctrl.txt
ARM/CORTINA SYSTEMS GEMINI ARM ARCHITECTURE
T: git git://github.com/ulli-kroll/linux.git
S: Maintained
+F: Documentation/devicetree/bindings/arm/gemini.txt
+F: Documentation/devicetree/bindings/pinctrl/cortina,gemini-pinctrl.txt
+F: Documentation/devicetree/bindings/rtc/faraday,ftrtc010.txt
F: arch/arm/mach-gemini/
+F: drivers/pinctrl/pinctrl-gemini.c
F: drivers/rtc/rtc-ftrtc010.c
ARM/CSR SIRFPRIMA2 MACHINE SUPPORT
S: Maintained
-F: drivers/phy/phy-mt65xx-usb3.c
+F: drivers/phy/mediatek/phy-mtk-tphy.c
ARM/MICREL KS8695 ARCHITECTURE
F: drivers/bus/uniphier-system-bus.c
F: drivers/clk/uniphier/
F: drivers/i2c/busses/i2c-uniphier*
+F: drivers/irqchip/irq-uniphier-aidet.c
F: drivers/pinctrl/uniphier/
F: drivers/reset/reset-uniphier.c
F: drivers/tty/serial/8250/8250_uniphier.c
S: Maintained
F: Documentation/ABI/testing/sysfs-class-net-batman-adv
F: Documentation/ABI/testing/sysfs-class-net-mesh
-F: Documentation/networking/batman-adv.txt
+F: Documentation/networking/batman-adv.rst
F: include/uapi/linux/batman_adv.h
F: net/batman-adv/
F: drivers/gpu/drm/qxl/
F: include/uapi/drm/qxl_drm.h
+DRM DRIVER FOR PERVASIVE DISPLAYS REPAPER PANELS
+S: Maintained
+F: drivers/gpu/drm/tinydrm/repaper.c
+F: Documentation/devicetree/bindings/display/repaper.txt
+
DRM DRIVER FOR RAGE 128 VIDEO CARDS
S: Orphan / Obsolete
F: drivers/gpu/drm/r128/
F: drivers/gpu/drm/sis/
F: include/uapi/drm/sis_drm.h
+DRM DRIVER FOR SITRONIX ST7586 PANELS
+S: Maintained
+F: drivers/gpu/drm/tinydrm/st7586.c
+F: Documentation/devicetree/bindings/display/st7586.txt
+
DRM DRIVER FOR TDFX VIDEO CARDS
S: Orphan / Obsolete
F: drivers/gpu/drm/tdfx/
F: include/drm/drm_panel.h
F: Documentation/devicetree/bindings/display/panel/
+DRM TINYDRM DRIVERS
+W: https://github.com/notro/tinydrm/wiki/Development
+T: git git://anongit.freedesktop.org/drm/drm-misc
+S: Maintained
+F: drivers/gpu/drm/tinydrm/
+F: include/drm/tinydrm/
+
DSBR100 USB FM RADIO DRIVER
F: include/linux/phy.h
F: include/linux/phy_fixed.h
F: include/linux/platform_data/mdio-gpio.h
+F: include/linux/platform_data/mdio-bcm-unimac.h
F: include/trace/events/mdio.h
F: include/uapi/linux/mdio.h
F: include/uapi/linux/mii.h
FPGA MANAGER FRAMEWORK
S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/atull/linux-fpga.git
+Q: http://patchwork.kernel.org/project/linux-fpga/list/
F: Documentation/fpga/
F: Documentation/devicetree/bindings/fpga/
F: drivers/fpga/
F: drivers/net/ethernet/hisilicon/
F: Documentation/devicetree/bindings/net/hisilicon*.txt
+HISILICON NETWORK SUBSYSTEM 3 DRIVER (HNS3)
+W: http://www.hisilicon.com
+S: Maintained
+F: drivers/net/ethernet/hisilicon/hns3/
+
HISILICON ROCE DRIVER
S: Maintained
F: drivers/input/touchscreen/htcpen.c
+HUAWEI ETHERNET DRIVER
+S: Supported
+F: Documentation/networking/hinic.txt
+F: drivers/net/ethernet/huawei/hinic/
+
HUGETLB FILESYSTEM
S: Maintained
S: Maintained
+F: Documentation/networking/netvsc.txt
F: arch/x86/include/asm/mshyperv.h
+ F: arch/x86/include/asm/trace/hyperv.h
F: arch/x86/include/uapi/asm/hyperv.h
F: arch/x86/kernel/cpu/mshyperv.c
F: arch/x86/hyperv
F: drivers/scsi/storvsc_drv.c
F: drivers/uio/uio_hv_generic.c
F: drivers/video/fbdev/hyperv_fb.c
+F: net/vmw_vsock/hyperv_transport.c
F: include/linux/hyperv.h
+ F: include/uapi/linux/hyperv.h
F: tools/hv/
F: Documentation/ABI/stable/sysfs-bus-vmbus
F: drivers/scsi/isci/
INTEL DRM DRIVERS (excluding Poulsbo, Moorestown and derivative chipsets)
W: https://01.org/linuxgraphics/
B: https://01.org/linuxgraphics/documentation/how-report-bugs
S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/sameo/irda-2.6.git
F: Documentation/networking/irda.txt
-F: drivers/net/irda/
-F: include/net/irda/
-F: net/irda/
+F: drivers/staging/irda/
IRQ DOMAINS (IRQ NUMBER MAPPING LIBRARY)
S: Maintained
F: drivers/media/dvb-frontends/lgdt3305.*
-LGUEST
-W: http://lguest.ozlabs.org/
-S: Odd Fixes
-F: arch/x86/include/asm/lguest*.h
-F: arch/x86/lguest/
-F: drivers/lguest/
-F: include/linux/lguest*.h
-F: tools/lguest/
-
LIBATA PATA ARASAN COMPACT FLASH CONTROLLER
MEDIATEK ETHERNET DRIVER
S: Maintained
F: drivers/net/ethernet/mediatek/
S: Maintained
F: drivers/char/hw_random/mtk-rng.c
+MEDIATEK USB3 DRD IP DRIVER
+S: Maintained
+F: drivers/usb/mtu3/
+
MEGACHIPS STDPXXXX-GE-B850V3-FW LVDS/DP++ BRIDGES
S: Supported
-F: kernel/membarrier.c
+F: kernel/sched/membarrier.c
F: include/uapi/linux/membarrier.h
MEMORY MANAGEMENT
F: drivers/dma/at_hdmac_regs.h
F: include/linux/platform_data/dma-atmel.h
+MICROCHIP / ATMEL ECC DRIVER
+S: Maintained
+F: drivers/crypto/atmel-ecc.*
+
MICROCHIP / ATMEL ISC DRIVER
S: Maintained
F: drivers/nvmem/
F: Documentation/devicetree/bindings/nvmem/
+F: Documentation/ABI/stable/sysfs-bus-nvmem
F: include/linux/nvmem-consumer.h
F: include/linux/nvmem-provider.h
S: Supported
F: arch/x86/kernel/cpu/intel_rdt*
-F: arch/x86/include/asm/intel_rdt*
+F: arch/x86/include/asm/intel_rdt_sched.h
F: Documentation/x86/intel_rdt*
READ-COPY UPDATE (RCU)
S: Maintained
F: drivers/thunderbolt/
+THUNDERX GPIO DRIVER
+S: Maintained
+F: drivers/gpio/gpio-thunderx.c
+
TI AM437X VPFE DRIVER
obj-$(CONFIG_XEN) += xen/
# Hyper-V paravirtualization support
- obj-$(CONFIG_HYPERVISOR_GUEST) += hyperv/
+ obj-$(subst m,y,$(CONFIG_HYPERV)) += hyperv/
-# lguest paravirtualization support
-obj-$(CONFIG_LGUEST_GUEST) += lguest/
-
obj-y += realmode/
obj-y += kernel/
obj-y += mm/
#include <linux/types.h>
#include <linux/atomic.h>
+ #include <linux/nmi.h>
+ #include <asm/io.h>
#include <asm/hyperv.h>
/*
u32 features;
u32 misc_features;
u32 hints;
+ u32 max_vp_index;
+ u32 max_lp_index;
};
extern struct ms_hyperv_info ms_hyperv;
#if IS_ENABLED(CONFIG_HYPERV)
extern struct clocksource *hyperv_cs;
+ extern void *hv_hypercall_pg;
+
+ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
+ {
+ u64 input_address = input ? virt_to_phys(input) : 0;
+ u64 output_address = output ? virt_to_phys(output) : 0;
+ u64 hv_status;
+ register void *__sp asm(_ASM_SP);
+
+ #ifdef CONFIG_X86_64
+ if (!hv_hypercall_pg)
+ return U64_MAX;
+
+ __asm__ __volatile__("mov %4, %%r8\n"
+ "call *%5"
+ : "=a" (hv_status), "+r" (__sp),
+ "+c" (control), "+d" (input_address)
+ : "r" (output_address), "m" (hv_hypercall_pg)
+ : "cc", "memory", "r8", "r9", "r10", "r11");
+ #else
+ u32 input_address_hi = upper_32_bits(input_address);
+ u32 input_address_lo = lower_32_bits(input_address);
+ u32 output_address_hi = upper_32_bits(output_address);
+ u32 output_address_lo = lower_32_bits(output_address);
+
+ if (!hv_hypercall_pg)
+ return U64_MAX;
+
+ __asm__ __volatile__("call *%7"
+ : "=A" (hv_status),
+ "+c" (input_address_lo), "+r" (__sp)
+ : "A" (control),
+ "b" (input_address_hi),
+ "D"(output_address_hi), "S"(output_address_lo),
+ "m" (hv_hypercall_pg)
+ : "cc", "memory");
+ #endif /* !x86_64 */
+ return hv_status;
+ }
+
+ #define HV_HYPERCALL_RESULT_MASK GENMASK_ULL(15, 0)
+ #define HV_HYPERCALL_FAST_BIT BIT(16)
+ #define HV_HYPERCALL_VARHEAD_OFFSET 17
+ #define HV_HYPERCALL_REP_COMP_OFFSET 32
+ #define HV_HYPERCALL_REP_COMP_MASK GENMASK_ULL(43, 32)
+ #define HV_HYPERCALL_REP_START_OFFSET 48
+ #define HV_HYPERCALL_REP_START_MASK GENMASK_ULL(59, 48)
+
+ /* Fast hypercall with 8 bytes of input and no output */
+ static inline u64 hv_do_fast_hypercall8(u16 code, u64 input1)
+ {
+ u64 hv_status, control = (u64)code | HV_HYPERCALL_FAST_BIT;
+ register void *__sp asm(_ASM_SP);
+
+ #ifdef CONFIG_X86_64
+ {
+ __asm__ __volatile__("call *%4"
+ : "=a" (hv_status), "+r" (__sp),
+ "+c" (control), "+d" (input1)
+ : "m" (hv_hypercall_pg)
+ : "cc", "r8", "r9", "r10", "r11");
+ }
+ #else
+ {
+ u32 input1_hi = upper_32_bits(input1);
+ u32 input1_lo = lower_32_bits(input1);
+
+ __asm__ __volatile__ ("call *%5"
+ : "=A"(hv_status),
+ "+c"(input1_lo),
+ "+r"(__sp)
+ : "A" (control),
+ "b" (input1_hi),
+ "m" (hv_hypercall_pg)
+ : "cc", "edi", "esi");
+ }
+ #endif
+ return hv_status;
+ }
+
+ /*
+ * Rep hypercalls. Callers of this functions are supposed to ensure that
+ * rep_count and varhead_size comply with Hyper-V hypercall definition.
+ */
+ static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
+ void *input, void *output)
+ {
+ u64 control = code;
+ u64 status;
+ u16 rep_comp;
+
+ control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
+ control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
+
+ do {
+ status = hv_do_hypercall(control, input, output);
+ if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS)
+ return status;
+
+ /* Bits 32-43 of status have 'Reps completed' data. */
+ rep_comp = (status & HV_HYPERCALL_REP_COMP_MASK) >>
+ HV_HYPERCALL_REP_COMP_OFFSET;
+
+ control &= ~HV_HYPERCALL_REP_START_MASK;
+ control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
+
+ touch_nmi_watchdog();
+ } while (rep_comp < rep_count);
+
+ return status;
+ }
+
+ /*
+ * Hypervisor's notion of virtual processor ID is different from
+ * Linux' notion of CPU ID. This information can only be retrieved
+ * in the context of the calling CPU. Setup a map for easy access
+ * to this information.
+ */
+ extern u32 *hv_vp_index;
+
+ /**
+ * hv_cpu_number_to_vp_number() - Map CPU to VP.
+ * @cpu_number: CPU number in Linux terms
+ *
+ * This function returns the mapping between the Linux processor
+ * number and the hypervisor's virtual processor number, useful
+ * in making hypercalls and such that talk about specific
+ * processors.
+ *
+ * Return: Virtual processor number in Hyper-V terms
+ */
+ static inline int hv_cpu_number_to_vp_number(int cpu_number)
+ {
+ return hv_vp_index[cpu_number];
+ }
void hyperv_init(void);
+ void hyperv_setup_mmu_ops(void);
+ void hyper_alloc_mmu(void);
void hyperv_report_panic(struct pt_regs *regs);
bool hv_is_hypercall_page_setup(void);
void hyperv_cleanup(void);
- #endif
+ #else /* CONFIG_HYPERV */
+ static inline void hyperv_init(void) {}
+ static inline bool hv_is_hypercall_page_setup(void) { return false; }
+ static inline void hyperv_cleanup(void) {}
+ static inline void hyperv_setup_mmu_ops(void) {}
+ #endif /* CONFIG_HYPERV */
+
#ifdef CONFIG_HYPERV_TSCPAGE
struct ms_hyperv_tsc_page *hv_get_tsc_page(void);
static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
void hv_setup_vmbus_irq(void (*handler)(void))
{
vmbus_handler = handler;
- /*
- * Setup the IDT for hypervisor callback. Prevent reallocation
- * at module reload.
- */
- if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
- alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
- hyperv_callback_vector);
+ /* Setup the IDT for hypervisor callback */
+ alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector);
}
void hv_remove_vmbus_irq(void)
ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES);
ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
- pr_info("HyperV: features 0x%x, hints 0x%x\n",
+ pr_info("Hyper-V: features 0x%x, hints 0x%x\n",
ms_hyperv.features, ms_hyperv.hints);
+ ms_hyperv.max_vp_index = cpuid_eax(HVCPUID_IMPLEMENTATION_LIMITS);
+ ms_hyperv.max_lp_index = cpuid_ebx(HVCPUID_IMPLEMENTATION_LIMITS);
+
+ pr_debug("Hyper-V: max %u virtual processors, %u logical processors\n",
+ ms_hyperv.max_vp_index, ms_hyperv.max_lp_index);
+
/*
* Extract host information.
*/
rdmsrl(HV_X64_MSR_APIC_FREQUENCY, hv_lapic_frequency);
hv_lapic_frequency = div_u64(hv_lapic_frequency, HZ);
lapic_timer_frequency = hv_lapic_frequency;
- pr_info("HyperV: LAPIC Timer Frequency: %#x\n",
+ pr_info("Hyper-V: LAPIC Timer Frequency: %#x\n",
lapic_timer_frequency);
}
* Setup the hook to get control post apic initialization.
*/
x86_platform.apic_post_init = hyperv_init;
+ hyperv_setup_mmu_ops();
#endif
}
const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
- .name = "Microsoft HyperV",
+ .name = "Microsoft Hyper-V",
.detect = ms_hyperv_platform,
.init_platform = ms_hyperv_init_platform,
};
/* Make sure this is a new offer */
mutex_lock(&vmbus_connection.channel_mutex);
+ /*
+ * Now that we have acquired the channel_mutex,
+ * we can release the potentially racing rescind thread.
+ */
+ atomic_dec(&vmbus_connection.offer_in_progress);
+
list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
if (!uuid_le_cmp(channel->offermsg.offer.if_type,
newchannel->offermsg.offer.if_type) &&
channel->num_sc++;
spin_unlock_irqrestore(&channel->lock, flags);
} else {
- atomic_dec(&vmbus_connection.offer_in_progress);
goto err_free_chan;
}
}
if (!fnew) {
if (channel->sc_creation_callback != NULL)
channel->sc_creation_callback(newchannel);
- atomic_dec(&vmbus_connection.offer_in_progress);
return;
}
goto err_deq_chan;
}
- atomic_dec(&vmbus_connection.offer_in_progress);
+ newchannel->probe_done = true;
return;
err_deq_chan:
*/
channel->numa_node = 0;
channel->target_cpu = 0;
- channel->target_vp = hv_context.vp_index[0];
+ channel->target_vp = hv_cpu_number_to_vp_number(0);
return;
}
}
channel->target_cpu = cur_cpu;
- channel->target_vp = hv_context.vp_index[cur_cpu];
+ channel->target_vp = hv_cpu_number_to_vp_number(cur_cpu);
}
static void vmbus_wait_for_unload(void)
/*
* Setup state for signalling the host.
*/
- newchannel->sig_event = (struct hv_input_signal_event *)
- (ALIGN((unsigned long)
- &newchannel->sig_buf,
- HV_HYPERCALL_PARAM_ALIGN));
-
- newchannel->sig_event->connectionid.asu32 = 0;
- newchannel->sig_event->connectionid.u.id = VMBUS_EVENT_CONNECTION_ID;
- newchannel->sig_event->flag_number = 0;
- newchannel->sig_event->rsvdz = 0;
+ newchannel->sig_event = VMBUS_EVENT_CONNECTION_ID;
if (vmbus_proto_version != VERSION_WS2008) {
newchannel->is_dedicated_interrupt =
(offer->is_dedicated_interrupt != 0);
- newchannel->sig_event->connectionid.u.id =
- offer->connection_id;
+ newchannel->sig_event = offer->connection_id;
}
memcpy(&newchannel->offermsg, offer,
channel->rescind = true;
spin_unlock_irqrestore(&channel->lock, flags);
+ /*
+ * Now that we have posted the rescind state, perform
+ * rescind related cleanup.
+ */
vmbus_rescind_cleanup(channel);
+ /*
+ * Now wait for offer handling to complete.
+ */
+ while (READ_ONCE(channel->probe_done) == false) {
+ /*
+ * We wait here until any channel offer is currently
+ * being processed.
+ */
+ msleep(1);
+ }
+
+ /*
+ * At this point, the rescind handling can proceed safely.
+ */
+
if (channel->device_obj) {
if (channel->chn_rescind_callback) {
channel->chn_rescind_callback(channel);
return outgoing_channel;
}
- cur_cpu = hv_context.vp_index[get_cpu()];
- put_cpu();
+ cur_cpu = hv_cpu_number_to_vp_number(smp_processor_id());
list_for_each_safe(cur, tmp, &primary->sc_list) {
cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
if (cur_channel->state != CHANNEL_OPENED_STATE)
if (channel->offermsg.child_relid != relid)
continue;
+ if (channel->rescind)
+ continue;
+
switch (channel->callback_mode) {
case HV_CALL_ISR:
vmbus_channel_isr(channel);
}
EXPORT_SYMBOL_GPL(vmbus_free_mmio);
- /**
- * vmbus_cpu_number_to_vp_number() - Map CPU to VP.
- * @cpu_number: CPU number in Linux terms
- *
- * This function returns the mapping between the Linux processor
- * number and the hypervisor's virtual processor number, useful
- * in making hypercalls and such that talk about specific
- * processors.
- *
- * Return: Virtual processor number in Hyper-V terms
- */
- int vmbus_cpu_number_to_vp_number(int cpu_number)
- {
- return hv_context.vp_index[cpu_number];
- }
- EXPORT_SYMBOL_GPL(vmbus_cpu_number_to_vp_number);
-
static int vmbus_acpi_add(struct acpi_device *device)
{
acpi_status result;
spinlock_t ring_lock;
u32 ring_datasize; /* < ring_size */
- u32 ring_data_startoffset;
- u32 priv_write_index;
u32 priv_read_index;
- u32 cached_read_index;
};
/*
return write;
}
-static inline u32 hv_get_cached_bytes_to_write(
- const struct hv_ring_buffer_info *rbi)
-{
- u32 read_loc, write_loc, dsize, write;
-
- dsize = rbi->ring_datasize;
- read_loc = rbi->cached_read_index;
- write_loc = rbi->ring_buffer->write_index;
-
- write = write_loc >= read_loc ? dsize - (write_loc - read_loc) :
- read_loc - write_loc;
- return write;
-}
/*
* VMBUS version is 32 bit entity broken up into
* two 16 bit quantities: major_number. minor_number.
} u;
};
- /* Definition of the hv_signal_event hypercall input structure. */
- struct hv_input_signal_event {
- union hv_connection_id connectionid;
- u16 flag_number;
- u16 rsvdz;
- };
-
- struct hv_input_signal_event_buffer {
- u64 align8;
- struct hv_input_signal_event event;
- };
-
enum hv_numa_policy {
HV_BALANCED = 0,
HV_LOCALIZED,
} callback_mode;
bool is_dedicated_interrupt;
- struct hv_input_signal_event_buffer sig_buf;
- struct hv_input_signal_event *sig_event;
+ u64 sig_event;
/*
* Starting with win8, this field will be used to specify
*/
enum hv_numa_policy affinity_policy;
+ bool probe_done;
+
};
static inline bool is_hvsock_channel(const struct vmbus_channel *c)
enum vmbus_packet_type type,
u32 flags);
-extern int vmbus_sendpacket_ctl(struct vmbus_channel *channel,
- void *buffer,
- u32 bufferLen,
- u64 requestid,
- enum vmbus_packet_type type,
- u32 flags);
-
extern int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
struct hv_page_buffer pagebuffers[],
u32 pagecount,
u32 bufferlen,
u64 requestid);
-extern int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
- struct hv_page_buffer pagebuffers[],
- u32 pagecount,
- void *buffer,
- u32 bufferlen,
- u64 requestid,
- u32 flags);
-
-extern int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
- struct hv_multipage_buffer *mpb,
- void *buffer,
- u32 bufferlen,
- u64 requestid);
-
extern int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
struct vmbus_packet_mpb_array *mpb,
u32 desc_size,
resource_size_t size, resource_size_t align,
bool fb_overlap_ok);
void vmbus_free_mmio(resource_size_t start, resource_size_t size);
- int vmbus_cpu_number_to_vp_number(int cpu_number);
- u64 hv_do_hypercall(u64 control, void *input, void *output);
/*
* GUID definitions of various offer types - services offered to the guest.
return ring_info->ring_buffer->buffer;
}
-/*
- * To optimize the flow management on the send-side,
- * when the sender is blocked because of lack of
- * sufficient space in the ring buffer, potential the
- * consumer of the ring buffer can signal the producer.
- * This is controlled by the following parameters:
- *
- * 1. pending_send_sz: This is the size in bytes that the
- * producer is trying to send.
- * 2. The feature bit feat_pending_send_sz set to indicate if
- * the consumer of the ring will signal when the ring
- * state transitions from being full to a state where
- * there is room for the producer to send the pending packet.
- */
-
-static inline void hv_signal_on_read(struct vmbus_channel *channel)
-{
- u32 cur_write_sz, cached_write_sz;
- u32 pending_sz;
- struct hv_ring_buffer_info *rbi = &channel->inbound;
-
- /*
- * Issue a full memory barrier before making the signaling decision.
- * Here is the reason for having this barrier:
- * If the reading of the pend_sz (in this function)
- * were to be reordered and read before we commit the new read
- * index (in the calling function) we could
- * have a problem. If the host were to set the pending_sz after we
- * have sampled pending_sz and go to sleep before we commit the
- * read index, we could miss sending the interrupt. Issue a full
- * memory barrier to address this.
- */
- virt_mb();
-
- pending_sz = READ_ONCE(rbi->ring_buffer->pending_send_sz);
- /* If the other end is not blocked on write don't bother. */
- if (pending_sz == 0)
- return;
-
- cur_write_sz = hv_get_bytes_to_write(rbi);
-
- if (cur_write_sz < pending_sz)
- return;
-
- cached_write_sz = hv_get_cached_bytes_to_write(rbi);
- if (cached_write_sz < pending_sz)
- vmbus_setevent(channel);
-}
-
/*
* Mask off host interrupt callback notifications
*/
projects / linux.git / commitdiff