From dd05add7b2b6004c5fa3a1f276f56d8668f86b65 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sat, 26 Sep 2026 19:20:30 -0300 Subject: netfs: zero the tail of a short DIO/unbuffered read The buffered read collector zero-fills the tail of a short read that stops below the inode's i_size (netfs_clear_unread()), so a read that races an extending write still returns the expected number of bytes. The non-buffered collector path does no such thing: it just records how much was transferred. Add the same zero-fill for the non-buffered case, gated on NETFS_SREQ_CLEAR_TAIL: a subreq's source sets that flag when a short result from it is known to be safe to treat as a hole, as opposed to NETFS_SREQ_HIT_EOF, which means the read genuinely ran off the end of the file and should be reported short as-is. Only CLEAR_TAIL should zero-fill here; a real EOF must stay a real short read. No source currently sets CLEAR_TAIL on an unbuffered/DIO subrequest, so this is inert on its own -- a following change teaches cifs to set it in the one case that needs it. Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Reviewed-by: David Howells Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org --- drivers/mtd/maps/physmap-versatile.c | 242 +++++++++++++++++++++++++++++++++++ 1 file changed, 242 insertions(+) create mode 100644 drivers/mtd/maps/physmap-versatile.c (limited to 'drivers/mtd/maps/physmap-versatile.c') diff --git a/drivers/mtd/maps/physmap-versatile.c b/drivers/mtd/maps/physmap-versatile.c new file mode 100644 index 000000000..2e779111b --- /dev/null +++ b/drivers/mtd/maps/physmap-versatile.c @@ -0,0 +1,242 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Versatile OF physmap driver add-on + * + * Copyright (c) 2016, Linaro Limited + * Author: Linus Walleij + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "physmap-versatile.h" + +static struct regmap *syscon_regmap; + +enum versatile_flashprot { + INTEGRATOR_AP_FLASHPROT, + INTEGRATOR_CP_FLASHPROT, + VERSATILE_FLASHPROT, + REALVIEW_FLASHPROT, +}; + +static const struct of_device_id syscon_match[] = { + { + .compatible = "arm,integrator-ap-syscon", + .data = (void *)INTEGRATOR_AP_FLASHPROT, + }, + { + .compatible = "arm,integrator-cp-syscon", + .data = (void *)INTEGRATOR_CP_FLASHPROT, + }, + { + .compatible = "arm,core-module-versatile", + .data = (void *)VERSATILE_FLASHPROT, + }, + { + .compatible = "arm,realview-eb-syscon", + .data = (void *)REALVIEW_FLASHPROT, + }, + { + .compatible = "arm,realview-pb1176-syscon", + .data = (void *)REALVIEW_FLASHPROT, + }, + { + .compatible = "arm,realview-pb11mp-syscon", + .data = (void *)REALVIEW_FLASHPROT, + }, + { + .compatible = "arm,realview-pba8-syscon", + .data = (void *)REALVIEW_FLASHPROT, + }, + { + .compatible = "arm,realview-pbx-syscon", + .data = (void *)REALVIEW_FLASHPROT, + }, + {}, +}; + +/* + * Flash protection handling for the Integrator/AP + */ +#define INTEGRATOR_SC_CTRLS_OFFSET 0x08 +#define INTEGRATOR_SC_CTRLC_OFFSET 0x0C +#define INTEGRATOR_SC_CTRL_FLVPPEN BIT(1) +#define INTEGRATOR_SC_CTRL_FLWP BIT(2) + +#define INTEGRATOR_EBI_CSR1_OFFSET 0x04 +/* The manual says bit 2, the code says bit 3, trust the code */ +#define INTEGRATOR_EBI_WRITE_ENABLE BIT(3) +#define INTEGRATOR_EBI_LOCK_OFFSET 0x20 +#define INTEGRATOR_EBI_LOCK_VAL 0xA05F + +static const struct of_device_id ebi_match[] = { + { .compatible = "arm,external-bus-interface"}, + { }, +}; + +static int ap_flash_init(struct platform_device *pdev) +{ + struct device_node *ebi; + void __iomem *ebi_base; + u32 val; + int ret; + + /* Look up the EBI */ + ebi = of_find_matching_node(NULL, ebi_match); + if (!ebi) { + return -ENODEV; + } + ebi_base = of_iomap(ebi, 0); + of_node_put(ebi); + if (!ebi_base) + return -ENODEV; + + /* Clear VPP and write protection bits */ + ret = regmap_write(syscon_regmap, + INTEGRATOR_SC_CTRLC_OFFSET, + INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP); + if (ret) + dev_err(&pdev->dev, "error clearing Integrator VPP/WP\n"); + + /* Unlock the EBI */ + writel(INTEGRATOR_EBI_LOCK_VAL, ebi_base + INTEGRATOR_EBI_LOCK_OFFSET); + + /* Enable write cycles on the EBI, CSR1 (flash) */ + val = readl(ebi_base + INTEGRATOR_EBI_CSR1_OFFSET); + val |= INTEGRATOR_EBI_WRITE_ENABLE; + writel(val, ebi_base + INTEGRATOR_EBI_CSR1_OFFSET); + + /* Lock the EBI again */ + writel(0, ebi_base + INTEGRATOR_EBI_LOCK_OFFSET); + iounmap(ebi_base); + + return 0; +} + +static void ap_flash_set_vpp(struct map_info *map, int on) +{ + int ret; + + if (on) { + ret = regmap_write(syscon_regmap, + INTEGRATOR_SC_CTRLS_OFFSET, + INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP); + if (ret) + pr_err("error enabling AP VPP\n"); + } else { + ret = regmap_write(syscon_regmap, + INTEGRATOR_SC_CTRLC_OFFSET, + INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP); + if (ret) + pr_err("error disabling AP VPP\n"); + } +} + +/* + * Flash protection handling for the Integrator/CP + */ + +#define INTCP_FLASHPROG_OFFSET 0x04 +#define CINTEGRATOR_FLVPPEN BIT(0) +#define CINTEGRATOR_FLWREN BIT(1) +#define CINTEGRATOR_FLMASK BIT(0)|BIT(1) + +static void cp_flash_set_vpp(struct map_info *map, int on) +{ + int ret; + + if (on) { + ret = regmap_update_bits(syscon_regmap, + INTCP_FLASHPROG_OFFSET, + CINTEGRATOR_FLMASK, + CINTEGRATOR_FLVPPEN | CINTEGRATOR_FLWREN); + if (ret) + pr_err("error setting CP VPP\n"); + } else { + ret = regmap_update_bits(syscon_regmap, + INTCP_FLASHPROG_OFFSET, + CINTEGRATOR_FLMASK, + 0); + if (ret) + pr_err("error setting CP VPP\n"); + } +} + +/* + * Flash protection handling for the Versatiles and RealViews + */ + +#define VERSATILE_SYS_FLASH_OFFSET 0x4C + +static void versatile_flash_set_vpp(struct map_info *map, int on) +{ + int ret; + + ret = regmap_update_bits(syscon_regmap, VERSATILE_SYS_FLASH_OFFSET, + 0x01, !!on); + if (ret) + pr_err("error setting Versatile VPP\n"); +} + +int of_flash_probe_versatile(struct platform_device *pdev, + struct device_node *np, + struct map_info *map) +{ + struct device_node *sysnp; + const struct of_device_id *devid; + struct regmap *rmap; + static enum versatile_flashprot versatile_flashprot; + int ret; + + /* Not all flash chips use this protection line */ + if (!of_device_is_compatible(np, "arm,versatile-flash")) + return 0; + + /* For first chip probed, look up the syscon regmap */ + if (!syscon_regmap) { + sysnp = of_find_matching_node_and_match(NULL, + syscon_match, + &devid); + if (!sysnp) + return -ENODEV; + + versatile_flashprot = (uintptr_t)devid->data; + rmap = syscon_node_to_regmap(sysnp); + of_node_put(sysnp); + if (IS_ERR(rmap)) + return PTR_ERR(rmap); + + syscon_regmap = rmap; + } + + switch (versatile_flashprot) { + case INTEGRATOR_AP_FLASHPROT: + ret = ap_flash_init(pdev); + if (ret) + return ret; + map->set_vpp = ap_flash_set_vpp; + dev_info(&pdev->dev, "Integrator/AP flash protection\n"); + break; + case INTEGRATOR_CP_FLASHPROT: + map->set_vpp = cp_flash_set_vpp; + dev_info(&pdev->dev, "Integrator/CP flash protection\n"); + break; + case VERSATILE_FLASHPROT: + case REALVIEW_FLASHPROT: + map->set_vpp = versatile_flash_set_vpp; + dev_info(&pdev->dev, "versatile/realview flash protection\n"); + break; + default: + dev_info(&pdev->dev, "device marked as Versatile flash " + "but no system controller was found\n"); + break; + } + + return 0; +} -- cgit v1.3.1