From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f46.google.com ([209.85.220.46]:34381 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752626AbcDTEZb (ORCPT ); Wed, 20 Apr 2016 00:25:31 -0400 Received: by mail-pa0-f46.google.com with SMTP id r5so12274331pag.1 for ; Tue, 19 Apr 2016 21:25:30 -0700 (PDT) Subject: Re: [PATCH v8 38/45] powerpc/powernv: Functions to get/set PCI slot status To: Gavin Shan References: <1455680668-23298-1-git-send-email-gwshan@linux.vnet.ibm.com> <1455680668-23298-39-git-send-email-gwshan@linux.vnet.ibm.com> <5715FCD6.90703@ozlabs.ru> <20160420023607.GA3199@gwshan> Cc: linuxppc-dev@lists.ozlabs.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, benh@kernel.crashing.org, mpe@ellerman.id.au, dja@axtens.net, bhelgaas@google.com, robherring2@gmail.com, grant.likely@linaro.org From: Alexey Kardashevskiy Message-ID: <571704B1.7070109@ozlabs.ru> Date: Wed, 20 Apr 2016 14:25:21 +1000 MIME-Version: 1.0 In-Reply-To: <20160420023607.GA3199@gwshan> Content-Type: text/plain; charset=koi8-r; format=flowed Sender: linux-pci-owner@vger.kernel.org List-ID: On 04/20/2016 12:36 PM, Gavin Shan wrote: > On Tue, Apr 19, 2016 at 07:39:34PM +1000, Alexey Kardashevskiy wrote: >> On 02/17/2016 02:44 PM, Gavin Shan wrote: >>> This exports 4 functins, which base on the corresponding OPAL >> >> >> s/functins/functions/ >> > > Thanks. > >>> APIs to get/set PCI slot status. Those functions are going to >>> be used by PowerNV PCI hotplug driver: >>> >>> pnv_pci_get_device_tree() opal_get_device_tree() >>> pnv_pci_get_presence_state() opal_pci_get_presence_state() >>> pnv_pci_get_power_state() opal_pci_get_power_state() >>> pnv_pci_set_power_state() opal_pci_set_power_state() >>> >>> Besides, the patch also exports pnv_pci_hotplug_notifier_{register, >>> unregister}() to allow registration and unregistration of PCI hotplug >>> notifier, which will be used to receive PCI hotplug message from >>> skiboot firmware in PowerNV PCI hotplug driver. >>> >>> Signed-off-by: Gavin Shan >>> --- >>> arch/powerpc/include/asm/opal-api.h | 17 ++++++- >>> arch/powerpc/include/asm/opal.h | 4 ++ >>> arch/powerpc/include/asm/pnv-pci.h | 7 +++ >>> arch/powerpc/platforms/powernv/opal-wrappers.S | 4 ++ >>> arch/powerpc/platforms/powernv/pci.c | 66 ++++++++++++++++++++++++++ >>> 5 files changed, 97 insertions(+), 1 deletion(-) >>> >>> diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h >>> index f8faaae..a6af338 100644 >>> --- a/arch/powerpc/include/asm/opal-api.h >>> +++ b/arch/powerpc/include/asm/opal-api.h >>> @@ -158,7 +158,11 @@ >>> #define OPAL_LEDS_SET_INDICATOR 115 >>> #define OPAL_CEC_REBOOT2 116 >>> #define OPAL_CONSOLE_FLUSH 117 >>> -#define OPAL_LAST 117 >>> +#define OPAL_GET_DEVICE_TREE 118 >>> +#define OPAL_PCI_GET_PRESENCE_STATE 119 >>> +#define OPAL_PCI_GET_POWER_STATE 120 >>> +#define OPAL_PCI_SET_POWER_STATE 121 >>> +#define OPAL_LAST 121 >>> >>> /* Device tree flags */ >>> >>> @@ -344,6 +348,16 @@ enum OpalPciResetState { >>> OPAL_ASSERT_RESET = 1 >>> }; >>> >>> +enum OpalPciSlotPresentenceState { >>> + OPAL_PCI_SLOT_EMPTY = 0, >>> + OPAL_PCI_SLOT_PRESENT = 1 >>> +}; >>> + >>> +enum OpalPciSlotPowerState { >>> + OPAL_PCI_SLOT_POWER_OFF = 0, >>> + OPAL_PCI_SLOT_POWER_ON = 1 >>> +}; >>> + >>> enum OpalSlotLedType { >>> OPAL_SLOT_LED_TYPE_ID = 0, /* IDENTIFY LED */ >>> OPAL_SLOT_LED_TYPE_FAULT = 1, /* FAULT LED */ >>> @@ -378,6 +392,7 @@ enum opal_msg_type { >>> OPAL_MSG_DPO, >>> OPAL_MSG_PRD, >>> OPAL_MSG_OCC, >>> + OPAL_MSG_PCI_HOTPLUG, >>> OPAL_MSG_TYPE_MAX, >>> }; >>> >>> diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h >>> index 9e0039f..899bcb941 100644 >>> --- a/arch/powerpc/include/asm/opal.h >>> +++ b/arch/powerpc/include/asm/opal.h >>> @@ -209,6 +209,10 @@ int64_t opal_flash_write(uint64_t id, uint64_t offset, uint64_t buf, >>> uint64_t size, uint64_t token); >>> int64_t opal_flash_erase(uint64_t id, uint64_t offset, uint64_t size, >>> uint64_t token); >>> +int64_t opal_get_device_tree(uint32_t phandle, uint64_t buf, uint64_t len); >>> +int64_t opal_pci_get_presence_state(uint64_t id, uint8_t *state); >>> +int64_t opal_pci_get_power_state(uint64_t id, uint8_t *state); >>> +int64_t opal_pci_set_power_state(uint64_t id, uint8_t state); >>> >>> /* Internal functions */ >>> extern int early_init_dt_scan_opal(unsigned long node, const char *uname, >>> diff --git a/arch/powerpc/include/asm/pnv-pci.h b/arch/powerpc/include/asm/pnv-pci.h >>> index 6f77f71..d9d095b 100644 >>> --- a/arch/powerpc/include/asm/pnv-pci.h >>> +++ b/arch/powerpc/include/asm/pnv-pci.h >>> @@ -13,6 +13,13 @@ >>> #include >>> #include >>> >>> +extern int pnv_pci_get_device_tree(uint32_t phandle, void *buf, uint64_t len); >>> +extern int pnv_pci_get_presence_state(uint64_t id, uint8_t *state); >>> +extern int pnv_pci_get_power_state(uint64_t id, uint8_t *state); >>> +extern int pnv_pci_set_power_state(uint64_t id, uint8_t state); >>> +extern int pnv_pci_hotplug_notifier_register(struct notifier_block *nb); >>> +extern int pnv_pci_hotplug_notifier_unregister(struct notifier_block *nb); >>> + >>> int pnv_phb_to_cxl_mode(struct pci_dev *dev, uint64_t mode); >>> int pnv_cxl_ioda_msi_setup(struct pci_dev *dev, unsigned int hwirq, >>> unsigned int virq); >>> diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S >>> index e45b88a..3ea1a855 100644 >>> --- a/arch/powerpc/platforms/powernv/opal-wrappers.S >>> +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S >>> @@ -302,3 +302,7 @@ OPAL_CALL(opal_prd_msg, OPAL_PRD_MSG); >>> OPAL_CALL(opal_leds_get_ind, OPAL_LEDS_GET_INDICATOR); >>> OPAL_CALL(opal_leds_set_ind, OPAL_LEDS_SET_INDICATOR); >>> OPAL_CALL(opal_console_flush, OPAL_CONSOLE_FLUSH); >>> +OPAL_CALL(opal_get_device_tree, OPAL_GET_DEVICE_TREE); >>> +OPAL_CALL(opal_pci_get_presence_state, OPAL_PCI_GET_PRESENCE_STATE); >>> +OPAL_CALL(opal_pci_get_power_state, OPAL_PCI_GET_POWER_STATE); >>> +OPAL_CALL(opal_pci_set_power_state, OPAL_PCI_SET_POWER_STATE); >>> diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c >>> index a458703..206385f 100644 >>> --- a/arch/powerpc/platforms/powernv/pci.c >>> +++ b/arch/powerpc/platforms/powernv/pci.c >>> @@ -63,6 +63,72 @@ int pnv_pci_poll(uint64_t id, int64_t rval, uint8_t *state) >>> return (rval == OPAL_SUCCESS) ? 0 : -EIO; >>> } >>> >>> +int pnv_pci_get_device_tree(uint32_t phandle, void *buf, uint64_t len) >>> +{ >>> + int64_t rc; >>> + >>> + if (!opal_check_token(OPAL_GET_DEVICE_TREE)) >>> + return -ENXIO; >>> + >>> + rc = opal_get_device_tree(phandle, (uint64_t)buf, len); >>> + if (rc != OPAL_SUCCESS) >>> + return -EIO; >>> + >>> + return 0; >>> +} >>> +EXPORT_SYMBOL_GPL(pnv_pci_get_device_tree); >>> + >>> +int pnv_pci_get_presence_state(uint64_t id, uint8_t *state) >>> +{ >>> + int64_t rc; >>> + >>> + if (!opal_check_token(OPAL_PCI_GET_PRESENCE_STATE)) >>> + return -ENXIO; >>> + >>> + rc = opal_pci_get_presence_state(id, state); >>> + if (rc != OPAL_SUCCESS) >>> + return -EIO; >>> + >>> + return 0; >>> +} >>> +EXPORT_SYMBOL_GPL(pnv_pci_get_presence_state); >>> + >>> +int pnv_pci_get_power_state(uint64_t id, uint8_t *state) >>> +{ >>> + int64_t rc; >>> + >>> + if (!opal_check_token(OPAL_PCI_GET_POWER_STATE)) >>> + return -ENXIO; >>> + >>> + rc = opal_pci_get_power_state(id, state); >> >> >> Out of curiosity - if rc==OPAL_SUCCESS, @state should already contain the >> correct state and you do not have to call pnv_pci_poll() (which will call >> opal_pci_poll() immediately), is that correct? >> > > It's not correct. opal_pci_get_power_state() to starts a state machine > in the OPAL firmware and pnv_pci_poll() keeps pushing the state machine > moving forward. opal_pci_get_power_state() and pnv_pci_poll() both read the state, they do not push it (as they are not xxx_set or xxx_put or xxx_push) and there is no delay between these calls, does the state change so fast? In practice, can this happen? 1. opal_pci_get_power_state() returns OPAL_SUCCESS and some state A; 2. pnv_pci_poll() called right-after-that-with-zero-delay (pnv_pci_poll() does not do loop if OPAL_SUCCESS) return a different state B. Or these helpers return different types of states (unlikely though)? It is not a concern but may help to understand all this OPAL polling magic. > >> Anyway, looks correct. >> >> >> Reviewed-by: Alexey Kardashevskiy >> >> >> >> >>> + return pnv_pci_poll(id, rc, state); >>> +} >>> +EXPORT_SYMBOL_GPL(pnv_pci_get_power_state); >>> + >>> +int pnv_pci_set_power_state(uint64_t id, uint8_t state) >>> +{ >>> + int64_t rc; >>> + >>> + if (!opal_check_token(OPAL_PCI_SET_POWER_STATE)) >>> + return -ENXIO; >>> + >>> + rc = opal_pci_set_power_state(id, state); >>> + return pnv_pci_poll(id, rc, NULL); >>> +} >>> +EXPORT_SYMBOL_GPL(pnv_pci_set_power_state); >>> + >>> +int pnv_pci_hotplug_notifier_register(struct notifier_block *nb) >>> +{ >>> + return opal_message_notifier_register(OPAL_MSG_PCI_HOTPLUG, nb); >>> +} >>> +EXPORT_SYMBOL_GPL(pnv_pci_hotplug_notifier_register); >>> + >>> +int pnv_pci_hotplug_notifier_unregister(struct notifier_block *nb) >>> +{ >>> + return opal_message_notifier_unregister(OPAL_MSG_PCI_HOTPLUG, nb); >>> +} >>> +EXPORT_SYMBOL_GPL(pnv_pci_hotplug_notifier_unregister); >>> + >>> #ifdef CONFIG_PCI_MSI >>> int pnv_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type) >>> { >>> >> >> >> -- >> Alexey >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Alexey