aboutsummaryrefslogtreecommitdiff
path: root/drivers/mtd/chips/cfi_util.c
diff options
context:
space:
mode:
authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /drivers/mtd/chips/cfi_util.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'drivers/mtd/chips/cfi_util.c')
-rw-r--r--drivers/mtd/chips/cfi_util.c445
1 files changed, 445 insertions, 0 deletions
diff --git a/drivers/mtd/chips/cfi_util.c b/drivers/mtd/chips/cfi_util.c
new file mode 100644
index 000000000..6a6a2a21d
--- /dev/null
+++ b/drivers/mtd/chips/cfi_util.c
@@ -0,0 +1,445 @@
+/*
+ * Common Flash Interface support:
+ * Generic utility functions not dependent on command set
+ *
+ * Copyright (C) 2002 Red Hat
+ * Copyright (C) 2003 STMicroelectronics Limited
+ *
+ * This code is covered by the GPL.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <asm/io.h>
+#include <asm/byteorder.h>
+
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/mtd/xip.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/cfi.h>
+
+void cfi_udelay(int us)
+{
+ if (us >= 1000) {
+ msleep(DIV_ROUND_UP(us, 1000));
+ } else {
+ udelay(us);
+ cond_resched();
+ }
+}
+EXPORT_SYMBOL(cfi_udelay);
+
+/*
+ * Returns the command address according to the given geometry.
+ */
+uint32_t cfi_build_cmd_addr(uint32_t cmd_ofs,
+ struct map_info *map, struct cfi_private *cfi)
+{
+ unsigned bankwidth = map_bankwidth(map);
+ unsigned interleave = cfi_interleave(cfi);
+ unsigned type = cfi->device_type;
+ uint32_t addr;
+
+ addr = (cmd_ofs * type) * interleave;
+
+ /* Modify the unlock address if we are in compatibility mode.
+ * For 16bit devices on 8 bit busses
+ * and 32bit devices on 16 bit busses
+ * set the low bit of the alternating bit sequence of the address.
+ */
+ if (((type * interleave) > bankwidth) && ((cmd_ofs & 0xff) == 0xaa))
+ addr |= (type >> 1)*interleave;
+
+ return addr;
+}
+EXPORT_SYMBOL(cfi_build_cmd_addr);
+
+/*
+ * Transforms the CFI command for the given geometry (bus width & interleave).
+ * It looks too long to be inline, but in the common case it should almost all
+ * get optimised away.
+ */
+map_word cfi_build_cmd(u_long cmd, struct map_info *map, struct cfi_private *cfi)
+{
+ map_word val = { {0} };
+ int wordwidth, words_per_bus, chip_mode, chips_per_word;
+ unsigned long onecmd;
+ int i;
+
+ /* We do it this way to give the compiler a fighting chance
+ of optimising away all the crap for 'bankwidth' larger than
+ an unsigned long, in the common case where that support is
+ disabled */
+ if (map_bankwidth_is_large(map)) {
+ wordwidth = sizeof(unsigned long);
+ words_per_bus = (map_bankwidth(map)) / wordwidth; // i.e. normally 1
+ } else {
+ wordwidth = map_bankwidth(map);
+ words_per_bus = 1;
+ }
+
+ chip_mode = map_bankwidth(map) / cfi_interleave(cfi);
+ chips_per_word = wordwidth * cfi_interleave(cfi) / map_bankwidth(map);
+
+ /* First, determine what the bit-pattern should be for a single
+ device, according to chip mode and endianness... */
+ switch (chip_mode) {
+ default: BUG();
+ case 1:
+ onecmd = cmd;
+ break;
+ case 2:
+ onecmd = cpu_to_cfi16(map, cmd);
+ break;
+ case 4:
+ onecmd = cpu_to_cfi32(map, cmd);
+ break;
+ }
+
+ /* Now replicate it across the size of an unsigned long, or
+ just to the bus width as appropriate */
+ switch (chips_per_word) {
+ default: BUG();
+#if BITS_PER_LONG >= 64
+ case 8:
+ onecmd |= (onecmd << (chip_mode * 32));
+ fallthrough;
+#endif
+ case 4:
+ onecmd |= (onecmd << (chip_mode * 16));
+ fallthrough;
+ case 2:
+ onecmd |= (onecmd << (chip_mode * 8));
+ fallthrough;
+ case 1:
+ ;
+ }
+
+ /* And finally, for the multi-word case, replicate it
+ in all words in the structure */
+ for (i=0; i < words_per_bus; i++) {
+ val.x[i] = onecmd;
+ }
+
+ return val;
+}
+EXPORT_SYMBOL(cfi_build_cmd);
+
+unsigned long cfi_merge_status(map_word val, struct map_info *map,
+ struct cfi_private *cfi)
+{
+ int wordwidth, words_per_bus, chip_mode, chips_per_word;
+ unsigned long onestat, res = 0;
+ int i;
+
+ /* We do it this way to give the compiler a fighting chance
+ of optimising away all the crap for 'bankwidth' larger than
+ an unsigned long, in the common case where that support is
+ disabled */
+ if (map_bankwidth_is_large(map)) {
+ wordwidth = sizeof(unsigned long);
+ words_per_bus = (map_bankwidth(map)) / wordwidth; // i.e. normally 1
+ } else {
+ wordwidth = map_bankwidth(map);
+ words_per_bus = 1;
+ }
+
+ chip_mode = map_bankwidth(map) / cfi_interleave(cfi);
+ chips_per_word = wordwidth * cfi_interleave(cfi) / map_bankwidth(map);
+
+ onestat = val.x[0];
+ /* Or all status words together */
+ for (i=1; i < words_per_bus; i++) {
+ onestat |= val.x[i];
+ }
+
+ res = onestat;
+ switch(chips_per_word) {
+ default: BUG();
+#if BITS_PER_LONG >= 64
+ case 8:
+ res |= (onestat >> (chip_mode * 32));
+ fallthrough;
+#endif
+ case 4:
+ res |= (onestat >> (chip_mode * 16));
+ fallthrough;
+ case 2:
+ res |= (onestat >> (chip_mode * 8));
+ fallthrough;
+ case 1:
+ ;
+ }
+
+ /* Last, determine what the bit-pattern should be for a single
+ device, according to chip mode and endianness... */
+ switch (chip_mode) {
+ case 1:
+ break;
+ case 2:
+ res = cfi16_to_cpu(map, res);
+ break;
+ case 4:
+ res = cfi32_to_cpu(map, res);
+ break;
+ default: BUG();
+ }
+ return res;
+}
+EXPORT_SYMBOL(cfi_merge_status);
+
+/*
+ * Sends a CFI command to a bank of flash for the given geometry.
+ *
+ * Returns the offset in flash where the command was written.
+ * If prev_val is non-null, it will be set to the value at the command address,
+ * before the command was written.
+ */
+uint32_t cfi_send_gen_cmd(u_char cmd, uint32_t cmd_addr, uint32_t base,
+ struct map_info *map, struct cfi_private *cfi,
+ int type, map_word *prev_val)
+{
+ map_word val;
+ uint32_t addr = base + cfi_build_cmd_addr(cmd_addr, map, cfi);
+ val = cfi_build_cmd(cmd, map, cfi);
+
+ if (prev_val)
+ *prev_val = map_read(map, addr);
+
+ map_write(map, val, addr);
+
+ return addr - base;
+}
+EXPORT_SYMBOL(cfi_send_gen_cmd);
+
+int __xipram cfi_qry_present(struct map_info *map, __u32 base,
+ struct cfi_private *cfi)
+{
+ int osf = cfi->interleave * cfi->device_type; /* scale factor */
+ map_word val[3];
+ map_word qry[3];
+
+ qry[0] = cfi_build_cmd('Q', map, cfi);
+ qry[1] = cfi_build_cmd('R', map, cfi);
+ qry[2] = cfi_build_cmd('Y', map, cfi);
+
+ val[0] = map_read(map, base + osf*0x10);
+ val[1] = map_read(map, base + osf*0x11);
+ val[2] = map_read(map, base + osf*0x12);
+
+ if (!map_word_equal(map, qry[0], val[0]))
+ return 0;
+
+ if (!map_word_equal(map, qry[1], val[1]))
+ return 0;
+
+ if (!map_word_equal(map, qry[2], val[2]))
+ return 0;
+
+ return 1; /* "QRY" found */
+}
+EXPORT_SYMBOL_GPL(cfi_qry_present);
+
+int __xipram cfi_qry_mode_on(uint32_t base, struct map_info *map,
+ struct cfi_private *cfi)
+{
+ cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
+ cfi_send_gen_cmd(0x98, 0x55, base, map, cfi, cfi->device_type, NULL);
+ if (cfi_qry_present(map, base, cfi))
+ return 1;
+ /* QRY not found probably we deal with some odd CFI chips */
+ /* Some revisions of some old Intel chips? */
+ cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
+ cfi_send_gen_cmd(0xFF, 0, base, map, cfi, cfi->device_type, NULL);
+ cfi_send_gen_cmd(0x98, 0x55, base, map, cfi, cfi->device_type, NULL);
+ if (cfi_qry_present(map, base, cfi))
+ return 1;
+ /* ST M29DW chips */
+ cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
+ cfi_send_gen_cmd(0x98, 0x555, base, map, cfi, cfi->device_type, NULL);
+ if (cfi_qry_present(map, base, cfi))
+ return 1;
+ /* some old SST chips, e.g. 39VF160x/39VF320x */
+ cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
+ cfi_send_gen_cmd(0xAA, 0x5555, base, map, cfi, cfi->device_type, NULL);
+ cfi_send_gen_cmd(0x55, 0x2AAA, base, map, cfi, cfi->device_type, NULL);
+ cfi_send_gen_cmd(0x98, 0x5555, base, map, cfi, cfi->device_type, NULL);
+ if (cfi_qry_present(map, base, cfi))
+ return 1;
+ /* SST 39VF640xB */
+ cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
+ cfi_send_gen_cmd(0xAA, 0x555, base, map, cfi, cfi->device_type, NULL);
+ cfi_send_gen_cmd(0x55, 0x2AA, base, map, cfi, cfi->device_type, NULL);
+ cfi_send_gen_cmd(0x98, 0x555, base, map, cfi, cfi->device_type, NULL);
+ if (cfi_qry_present(map, base, cfi))
+ return 1;
+ /* QRY not found */
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cfi_qry_mode_on);
+
+void __xipram cfi_qry_mode_off(uint32_t base, struct map_info *map,
+ struct cfi_private *cfi)
+{
+ cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
+ cfi_send_gen_cmd(0xFF, 0, base, map, cfi, cfi->device_type, NULL);
+ /* M29W128G flashes require an additional reset command
+ when exit qry mode */
+ if ((cfi->mfr == CFI_MFR_ST) && (cfi->id == 0x227E || cfi->id == 0x7E))
+ cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
+}
+EXPORT_SYMBOL_GPL(cfi_qry_mode_off);
+
+struct cfi_extquery *
+__xipram cfi_read_pri(struct map_info *map, __u16 adr, __u16 size, const char* name)
+{
+ struct cfi_private *cfi = map->fldrv_priv;
+ __u32 base = 0; // cfi->chips[0].start;
+ int ofs_factor = cfi->interleave * cfi->device_type;
+ int i;
+ struct cfi_extquery *extp = NULL;
+
+ if (!adr)
+ goto out;
+
+ printk(KERN_INFO "%s Extended Query Table at 0x%4.4X\n", name, adr);
+
+ extp = kmalloc(size, GFP_KERNEL);
+ if (!extp)
+ goto out;
+
+#ifdef CONFIG_MTD_XIP
+ local_irq_disable();
+#endif
+
+ /* Switch it into Query Mode */
+ cfi_qry_mode_on(base, map, cfi);
+ /* Read in the Extended Query Table */
+ for (i=0; i<size; i++) {
+ ((unsigned char *)extp)[i] =
+ cfi_read_query(map, base+((adr+i)*ofs_factor));
+ }
+
+ /* Make sure it returns to read mode */
+ cfi_qry_mode_off(base, map, cfi);
+
+#ifdef CONFIG_MTD_XIP
+ (void) map_read(map, base);
+ xip_iprefetch();
+ local_irq_enable();
+#endif
+
+ out: return extp;
+}
+
+EXPORT_SYMBOL(cfi_read_pri);
+
+void cfi_fixup(struct mtd_info *mtd, struct cfi_fixup *fixups)
+{
+ struct map_info *map = mtd->priv;
+ struct cfi_private *cfi = map->fldrv_priv;
+ struct cfi_fixup *f;
+
+ for (f=fixups; f->fixup; f++) {
+ if (((f->mfr == CFI_MFR_ANY) || (f->mfr == cfi->mfr)) &&
+ ((f->id == CFI_ID_ANY) || (f->id == cfi->id))) {
+ f->fixup(mtd);
+ }
+ }
+}
+
+EXPORT_SYMBOL(cfi_fixup);
+
+int cfi_varsize_frob(struct mtd_info *mtd, varsize_frob_t frob,
+ loff_t ofs, size_t len, void *thunk)
+{
+ struct map_info *map = mtd->priv;
+ struct cfi_private *cfi = map->fldrv_priv;
+ unsigned long adr;
+ int chipnum, ret = 0;
+ int i, first;
+ struct mtd_erase_region_info *regions = mtd->eraseregions;
+
+ /* Check that both start and end of the requested erase are
+ * aligned with the erasesize at the appropriate addresses.
+ */
+
+ i = 0;
+
+ /* Skip all erase regions which are ended before the start of
+ the requested erase. Actually, to save on the calculations,
+ we skip to the first erase region which starts after the
+ start of the requested erase, and then go back one.
+ */
+
+ while (i < mtd->numeraseregions && ofs >= regions[i].offset)
+ i++;
+ i--;
+
+ /* OK, now i is pointing at the erase region in which this
+ erase request starts. Check the start of the requested
+ erase range is aligned with the erase size which is in
+ effect here.
+ */
+
+ if (ofs & (regions[i].erasesize-1))
+ return -EINVAL;
+
+ /* Remember the erase region we start on */
+ first = i;
+
+ /* Next, check that the end of the requested erase is aligned
+ * with the erase region at that address.
+ */
+
+ while (i<mtd->numeraseregions && (ofs + len) >= regions[i].offset)
+ i++;
+
+ /* As before, drop back one to point at the region in which
+ the address actually falls
+ */
+ i--;
+
+ if ((ofs + len) & (regions[i].erasesize-1))
+ return -EINVAL;
+
+ chipnum = ofs >> cfi->chipshift;
+ adr = ofs - (chipnum << cfi->chipshift);
+
+ i=first;
+
+ while(len) {
+ int size = regions[i].erasesize;
+
+ ret = (*frob)(map, &cfi->chips[chipnum], adr, size, thunk);
+
+ if (ret)
+ return ret;
+
+ adr += size;
+ ofs += size;
+ len -= size;
+
+ if (ofs == regions[i].offset + size * regions[i].numblocks)
+ i++;
+
+ if (adr >> cfi->chipshift) {
+ adr = 0;
+ chipnum++;
+
+ if (chipnum >= cfi->numchips)
+ break;
+ }
+ }
+
+ return 0;
+}
+
+EXPORT_SYMBOL(cfi_varsize_frob);
+
+MODULE_LICENSE("GPL");