Subject: Re: [PATCH v8 38/45] powerpc/powernv: Functions to get/set PCI slot status

From: Gavin Shan <[email-masked]>
Date: Wed, 20 Apr 2016 12:36:07 +1000

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 <[email-masked]>
>>---
>>  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 <linux/pci.h>
>>  #include <misc/cxl-base.h>
>>
>>+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.

>Anyway, looks correct.
>
>
>Reviewed-by: Alexey Kardashevskiy <[email-masked]>
>
>
>
>
>>+	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
>