On 6/10/22 17:17, Serge Semin wrote: > There are systems with no BIOS or comprehensive embedded firmware which > could be able to properly initialize the SATA AHCI controller > platform-specific capabilities. In that case a good alternative to having > a clever bootloader is to create a device tree node with the properties > well describing all the AHCI-related platform specifics. All the settings > which are normally detected and marked as available in the HBA and its > ports capabilities fields [1] could be defined in the platform DTB by > means of a set of the dedicated properties. Such approach perfectly fits > to the DTB-philosophy - to provide hardware/platform description. > > So here we suggest to extend the SATA AHCI device tree bindings with two > additional DT-properties: > 1) "hba-cap" - HBA platform generic capabilities like: > - SSS - Staggered Spin-up support. > - SMPS - Mechanical Presence Switch support. > 2) "hba-port-cap" - HBA platform port capabilities like: > - HPCP - Hot Plug Capable Port. > - MPSP - Mechanical Presence Switch Attached to Port. > - CPD - Cold Presence Detection. > - ESP - External SATA Port. > - FBSCP - FIS-based Switching Capable Port. > All of these capabilities require to have a corresponding hardware > configuration. Thus it's ok to have them defined in DTB. > > Even though the driver currently takes into account the state of the ESP > and FBSCP flags state only, there is nothing wrong with having all of them > supported by the generic AHCI library in order to have a complete OF-based > platform-capabilities initialization procedure. These properties will be > parsed in the ahci_platform_get_resources() method and their values will > be stored in the saved_* fields of the ahci_host_priv structure, which in > its turn then will be used to restore the H.CAP, H.PI and P#.CMD > capability fields on device init and after HBA reset. > > Please note this modification concerns the HW-init HBA and its ports flags > only, which are by specification [1] are supposed to be initialized by the > BIOS/platform firmware/expansion ROM and which are normally declared in > the one-time-writable-after-reset register fields. Even though these flags > aren't supposed to be cleared after HBA reset some AHCI instances may > violate that rule so we still need to perform the fields resetting after > each reset. Luckily the corresponding functionality has already been > partly implemented in the framework of the ahci_save_initial_config() and > ahci_restore_initial_config() methods. > > [1] Serial ATA AHCI 1.3.1 Specification, p. 103 > > Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx> > > --- > > Changelog v4: > - Convert the boolean properties to the bitfield DT-properties. (@Rob) > --- > drivers/ata/ahci.h | 1 + > drivers/ata/libahci.c | 51 ++++++++++++++++++++++++++++------ > drivers/ata/libahci_platform.c | 41 +++++++++++++++++++++++++-- > 3 files changed, 82 insertions(+), 11 deletions(-) > > diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h > index 8b9826533ae5..0de221055961 100644 > --- a/drivers/ata/ahci.h > +++ b/drivers/ata/ahci.h > @@ -337,6 +337,7 @@ struct ahci_host_priv { > u32 saved_cap; /* saved initial cap */ > u32 saved_cap2; /* saved initial cap2 */ > u32 saved_port_map; /* saved initial port_map */ > + u32 saved_port_cap[AHCI_MAX_PORTS]; /* saved port_cap */ > u32 em_loc; /* enclosure management location */ > u32 em_buf_sz; /* EM buffer size in byte */ > u32 em_msg_type; /* EM message type */ > diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c > index 1ffaa5f5f21a..954386a2b500 100644 > --- a/drivers/ata/libahci.c > +++ b/drivers/ata/libahci.c > @@ -16,6 +16,7 @@ > * http://www.intel.com/technology/serialata/pdf/rev1_1.pdf > */ > > +#include <linux/bitops.h> > #include <linux/kernel.h> > #include <linux/gfp.h> > #include <linux/module.h> > @@ -443,16 +444,28 @@ static ssize_t ahci_show_em_supported(struct device *dev, > void ahci_save_initial_config(struct device *dev, struct ahci_host_priv *hpriv) > { > void __iomem *mmio = hpriv->mmio; > - u32 cap, cap2, vers, port_map; > + void __iomem *port_mmio; > + unsigned long port_map; > + u32 cap, cap2, vers; > int i; > > /* make sure AHCI mode is enabled before accessing CAP */ > ahci_enable_ahci(mmio); > > - /* Values prefixed with saved_ are written back to host after > - * reset. Values without are used for driver operation. > + /* > + * Values prefixed with saved_ are written back to the HBA and ports > + * registers after reset. Values without are used for driver operation. > + */ > + > + /* > + * Override HW-init HBA capability fields with the platform-specific > + * values. The rest of the HBA capabilities are defined as Read-only > + * and can't be modified in CSR anyway. > */ > - hpriv->saved_cap = cap = readl(mmio + HOST_CAP); > + cap = readl(mmio + HOST_CAP); > + if (hpriv->saved_cap) > + cap = (cap & ~(HOST_CAP_SSS | HOST_CAP_MPS)) | hpriv->saved_cap; > + hpriv->saved_cap = cap; > > /* CAP2 register is only defined for AHCI 1.2 and later */ > vers = readl(mmio + HOST_VERSION); > @@ -519,7 +532,7 @@ void ahci_save_initial_config(struct device *dev, struct ahci_host_priv *hpriv) > /* Override the HBA ports mapping if the platform needs it */ > port_map = readl(mmio + HOST_PORTS_IMPL); > if (hpriv->saved_port_map && port_map != hpriv->saved_port_map) { > - dev_info(dev, "forcing port_map 0x%x -> 0x%x\n", > + dev_info(dev, "forcing port_map 0x%lx -> 0x%x\n", This change is not necessary. > port_map, hpriv->saved_port_map); > port_map = hpriv->saved_port_map; > } else { > @@ -527,7 +540,7 @@ void ahci_save_initial_config(struct device *dev, struct ahci_host_priv *hpriv) > } > > if (hpriv->mask_port_map) { > - dev_warn(dev, "masking port_map 0x%x -> 0x%x\n", > + dev_warn(dev, "masking port_map 0x%lx -> 0x%lx\n", Same. > port_map, > port_map & hpriv->mask_port_map); > port_map &= hpriv->mask_port_map; > @@ -546,7 +559,7 @@ void ahci_save_initial_config(struct device *dev, struct ahci_host_priv *hpriv) > */ > if (map_ports > ahci_nr_ports(cap)) { > dev_warn(dev, > - "implemented port map (0x%x) contains more ports than nr_ports (%u), using nr_ports\n", > + "implemented port map (0x%lx) contains more ports than nr_ports (%u), using nr_ports\n", Same. > port_map, ahci_nr_ports(cap)); > port_map = 0; > } > @@ -555,12 +568,26 @@ void ahci_save_initial_config(struct device *dev, struct ahci_host_priv *hpriv) > /* fabricate port_map from cap.nr_ports for < AHCI 1.3 */ > if (!port_map && vers < 0x10300) { > port_map = (1 << ahci_nr_ports(cap)) - 1; > - dev_warn(dev, "forcing PORTS_IMPL to 0x%x\n", port_map); > + dev_warn(dev, "forcing PORTS_IMPL to 0x%lx\n", port_map); And again not needed. > > /* write the fixed up value to the PI register */ > hpriv->saved_port_map = port_map; > } > > + /* > + * Preserve the ports capabilities defined by the platform. Note there > + * is no need in storing the rest of the P#.CMD fields since they are > + * volatile. > + */ > + for_each_set_bit(i, &port_map, AHCI_MAX_PORTS) { > + if (hpriv->saved_port_cap[i]) > + continue; > + > + port_mmio = __ahci_port_base(hpriv, i); > + hpriv->saved_port_cap[i] = > + readl(port_mmio + PORT_CMD) & PORT_CMD_CAP; > + } > + > /* record values to use during operation */ > hpriv->cap = cap; > hpriv->cap2 = cap2; > @@ -590,13 +617,21 @@ EXPORT_SYMBOL_GPL(ahci_save_initial_config); > static void ahci_restore_initial_config(struct ata_host *host) > { > struct ahci_host_priv *hpriv = host->private_data; > + unsigned long port_map = hpriv->port_map; > void __iomem *mmio = hpriv->mmio; > + void __iomem *port_mmio; > + int i; > > writel(hpriv->saved_cap, mmio + HOST_CAP); > if (hpriv->saved_cap2) > writel(hpriv->saved_cap2, mmio + HOST_CAP2); > writel(hpriv->saved_port_map, mmio + HOST_PORTS_IMPL); > (void) readl(mmio + HOST_PORTS_IMPL); /* flush */ > + > + for_each_set_bit(i, &port_map, AHCI_MAX_PORTS) { > + port_mmio = __ahci_port_base(hpriv, i); > + writel(hpriv->saved_port_cap[i], port_mmio + PORT_CMD); > + } > } > > static unsigned ahci_scr_offset(struct ata_port *ap, unsigned int sc_reg) > diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c > index efe640603f3f..8b542a8bc487 100644 > --- a/drivers/ata/libahci_platform.c > +++ b/drivers/ata/libahci_platform.c > @@ -23,6 +23,7 @@ > #include <linux/pm_runtime.h> > #include <linux/of_platform.h> > #include <linux/reset.h> > + white line change. > #include "ahci.h" > > static void ahci_host_stop(struct ata_host *host); > @@ -383,6 +384,34 @@ static int ahci_platform_get_regulator(struct ahci_host_priv *hpriv, u32 port, > return rc; > } > > +static int ahci_platform_get_firmware(struct ahci_host_priv *hpriv, > + struct device *dev) > +{ > + struct device_node *child; > + u32 port; > + > + if (!of_property_read_u32(dev->of_node, "hba-cap", &hpriv->saved_cap)) > + hpriv->saved_cap &= (HOST_CAP_SSS | HOST_CAP_MPS); > + > + of_property_read_u32(dev->of_node, > + "ports-implemented", &hpriv->saved_port_map); > + > + for_each_child_of_node(dev->of_node, child) { > + if (!of_device_is_available(child)) > + continue; > + > + if (of_property_read_u32(child, "reg", &port)) { > + of_node_put(child); > + return -EINVAL; > + } > + > + if (!of_property_read_u32(child, "hba-port-cap", &hpriv->saved_port_cap[port])) > + hpriv->saved_port_cap[port] &= PORT_CMD_CAP; > + } > + > + return 0; > +} > + > /** > * ahci_platform_get_resources - Get platform resources > * @pdev: platform device to get resources for > @@ -523,9 +552,6 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev, > goto err_out; > } > > - of_property_read_u32(dev->of_node, > - "ports-implemented", &hpriv->saved_port_map); > - > if (child_nodes) { > for_each_child_of_node(dev->of_node, child) { > u32 port; > @@ -590,6 +616,15 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev, > if (rc == -EPROBE_DEFER) > goto err_out; > } > + > + /* > + * Retrieve firmware-specific flags which then will be used to set > + * the HW-init fields of HBA and its ports > + */ > + rc = ahci_platform_get_firmware(hpriv, dev); > + if (rc) > + goto err_out; > + > pm_runtime_enable(dev); > pm_runtime_get_sync(dev); > hpriv->got_runtime_pm = true; -- Damien Le Moal Western Digital Research